CA1216479A - Process for cleaning a steam generator - Google Patents
Process for cleaning a steam generatorInfo
- Publication number
- CA1216479A CA1216479A CA000458461A CA458461A CA1216479A CA 1216479 A CA1216479 A CA 1216479A CA 000458461 A CA000458461 A CA 000458461A CA 458461 A CA458461 A CA 458461A CA 1216479 A CA1216479 A CA 1216479A
- Authority
- CA
- Canada
- Prior art keywords
- spray
- supporting plate
- pipe bundle
- lances
- openings
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F28—HEAT EXCHANGE IN GENERAL
- F28G—CLEANING OF INTERNAL OR EXTERNAL SURFACES OF HEAT-EXCHANGE OR HEAT-TRANSFER CONDUITS, e.g. WATER TUBES OR BOILERS
- F28G15/00—Details
- F28G15/04—Feeding and driving arrangements, e.g. power operation
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B08—CLEANING
- B08B—CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
- B08B3/00—Cleaning by methods involving the use or presence of liquid or steam
- B08B3/02—Cleaning by the force of jets or sprays
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F22—STEAM GENERATION
- F22B—METHODS OF STEAM GENERATION; STEAM BOILERS
- F22B37/00—Component parts or details of steam boilers
- F22B37/02—Component parts or details of steam boilers applicable to more than one kind or type of steam boiler
- F22B37/48—Devices for removing water, salt, or sludge from boilers; Arrangements of cleaning apparatus in boilers; Combinations thereof with boilers
- F22B37/483—Devices for removing water, salt, or sludge from boilers; Arrangements of cleaning apparatus in boilers; Combinations thereof with boilers specially adapted for nuclear steam generators
Abstract
ABSTRACT
A method of cleaning a steam generator having spaced upwardly and downwardly spaced pipe bundles in a casing, which includes introducing through two accesses into a space between the pipe bundle portions an elongate, rigid, rotatable high pressure lance having at least one pair of radially directed spray openings for fluid jets, introducing through each access a suction line provided with a suction opening adjacent the bottom, shifting the lances with the spray head directed between the rows of pipes of the pipe bundle portions, oscillating the lances, spraying a cleaning liquid through the spray heads under a pressure higher than 200 bars and with a mean flow rate for both spray heads together of more than 200 liters per minute and sucking the sprayed liquid away from the bottom through the suction lines during the cleaning with a -total suction capacity which is markedly higher than the mean flow rate of the spray heads together.
A method of cleaning a steam generator having spaced upwardly and downwardly spaced pipe bundles in a casing, which includes introducing through two accesses into a space between the pipe bundle portions an elongate, rigid, rotatable high pressure lance having at least one pair of radially directed spray openings for fluid jets, introducing through each access a suction line provided with a suction opening adjacent the bottom, shifting the lances with the spray head directed between the rows of pipes of the pipe bundle portions, oscillating the lances, spraying a cleaning liquid through the spray heads under a pressure higher than 200 bars and with a mean flow rate for both spray heads together of more than 200 liters per minute and sucking the sprayed liquid away from the bottom through the suction lines during the cleaning with a -total suction capacity which is markedly higher than the mean flow rate of the spray heads together.
Description
This invention relates to a method of cleaning a steam generator of the so-called U type which includes an upstanding outer casing, a pipe bundle in the shape of a U
mounted in the casing, the pipe bundle having an upward-extending bundle portion and a downward extending bundleportion with a space between the two portions~ each bundle portion comprising a number of spaced rows of pipes, a bottom at the foot of the pipe bundle which closes the openings between -the pipes and between the pipes and the outer casing, at least two accesses through the outer casing at substantially opposite sides thereof, the accesses lying above the bottom and providing access to the space between the two bundle portions.
~team generators of the above~defined kind are used in nuclear power stations. The heating fluid which is heated inside the nuclear reactor is led through the pipe bundle and abandons heat to the fluid, generally water, which lies in the space about the pipes, whereby steam is generated. Said steam is used for driving turbines and after cooling, is returned back to said space.
Due to various chemical reactions, there if formed about the pipe bundle an iron oxide, namely magnetite. Said ~,q~
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iron oxide settles on the pipe bundle, the bearing plates ~ox said pipe bundle, and mostly the bottom. At each main-tenance procedure, generally yearly, of the nuclear power s-tation, the iron oxide has to be removed. In connection 5 with the difficult reachability of the steam generator and mostly due to the prevailing radio-activity, the steam generator cannot be dismantled for such cleaning, so that the removal of the sludge and thus more particularly the iron oxide, requires special methods. There is always 10 made use -therefore of accesses which are provided in the lower portion of the steam generator, above the bottom and which during the normal operation of said steam generator, open on lines or are closed by metering apparatus or covers.
Through releasing one or a plurality of said accesses, 15 it is possible to spray loose with a high-pressure lance having a spray head, the sludge from the bottom and possibly from other portions of the inner volume of the steam genera-tor. The main problem does however lie in removing said sludge from the generator.
In known methods for cleaning a steam generator of the above-defined type, with the purpose of such removing, an additional amount of li~uid is fed to the bo-ttom during the spraying of pressurized liquid through the spray heads.
In the known me-thod of the kind defined in this 25 application, which is disclosed in Belgian Pa-tent No.
8~9,706, said additional liquid amount is fed by means of a sprinkling head which is brought above the bottom center.
When the steam generator is provided between 30 the bottom and the lowermost pipe supporting plate, with four accesses, spraying is effected under a pressure of about 250 bars by means of four high-pressure lances with spray heads, which are introduced through said four accesses.
Said high-pressure lances are moved simultaneously s-tepwise 35 from the center to the outer cas.ing, and the lances are always rota-ted in the same direction over a plurality of revolutions about the axis the.reof between the succeeding displacements.
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The four spray heads have an outer diameter of only 8 mm and cannot spray enough liquid to insure good removal of the sludge from the bottom. Consequently there is caused during the spraying, a flowing over -the bo-ttom, from the center to the outer casing, by means of the sprink-ling head which sprinkles low-pressure liquid on the bottom.
The cleaning liquid and -the sludge are sucked in two mutually opposite locations lying next to the outer casing.
When the steam generator also has two accesses openin~ above -the lowermost supporting plate and lying opposite one another, cleaning is firstly effected above the lowermost supporting plate with a high-pressure lance.
Use is made therefore of but one high-pressure lance with a spray head, which is in-troduced in succession thro~gh both accesses, each time being moved stepwise from the center to the outer casing, and being rotated always in the same direction over a plurality of revolutions about the lance axis between the steps. In spite of said spray head having a larger diameter than the above-mentioned heads, it cannot spray enough liquid on the suppor-ting plate to insure good removal of the sludge thererom, so that also during the cleaning of the supporting plate and those portions of the steam genera-tor lying thereabove, additional liquid is sprinkled with the sprinkling head on the supporting p]ate.
~o remove all the sludge from the bottom, it is necessary with this known method at the end of the clean-ing to spray li~uid with spray guns under a pressure of 300 bars on the bottom, at least against the outer casing.
Thè use of a sprinkling head during the clean-ing and of spray guns at the endl makes the method intricate and time-consuming. Said additional liquid feeding devices naturally also increase the volume and costs of the appara-tus re~uired for the application of the method.
Moreover it has been noted that in spite of sprink-ling with the sprinkling head, sludge could still remain on the bottom. In certain locations on the bottom, a driving~
back of liquid and consequently a limi-ted liquid 1OW did in fact occur, because the liquid sprayed by the spray head or heads did oppose the Elow of that liquid being sprin~led by the sprinkling head.
The invention seeks to obviate said drawbacks and to provide a method for cleaning a steam generator of the above-defined type which allows a useful removal of the sludge from the bottom in a simple and fast way, tha~
is without the need for an additional supply of liquid to cause a Elowing over the bottom and possibly a spraying with spray guns at the end.
The method according to the present invention comprises the step of:- introducing through each of the two accesses and into the space between the pipe bundle portions an elongated, rigid high pressure lance which is rotatable about its longitudinal axis and is shiftable in the direction of its longitudinal a~is, each lance including a spray head at the end thereoE introduced into said space, the spray head having at least one pair of radially directed spray openings for directing fluid jets radially outwardly from the longitudinal a~is of the lance on substantially opposite sides of the spray head, introducing through each oE the two accesses at least one suction line provided with at least one suction opening sîtuated adjacent the bottom within ~he outer casing, shifting simultaneously stepwise both lances such that between each shifting step the jets fro~ the spray head are directed between the rows of pipes of the pipe bundle portions, oscillating both of the lances at least between the shifting steps, spraying a cleaning liquid through the spray heads at least during the oscillating of the lances under a pressure higher than 200 bars and with a mean flow rate for both spray heads together of more than 200 liters per minute, and sucking -the sprayed liquid away from the bottom through ~he suction lines during the cleaning with a total suction capacity which is markedly higher than the mean Elow rate of the spray heads together.
It is mostly the combination of the above mention-ed hlgh spraying pressure, the above mentioned simul-taneous spraying with at least two high~pressure lances wi-th spray heads, and the conditions of revolving and Elow rates men-tioned herebefore, which allows complete removal of thesludge from the whole bo-ttom without using an additional liquid feed or additional operations.
The use of an oscillating high-pressure lance with spray head when cleaning a steam generator oE the above-defined type, is known per se from UOS~ Pa-tent ~,079,701, but wi-th the method as disclosed in said paten-t specification, the cleaning is performed with bu-t one single high-pressure lance with a spray head, which is brought into the steam genera-tor through two opposite access-es in succession, and which is moved s-tepwise from nex-t to the ou-ter casing to the center. Said known me-thod ls thus not of the type as defined in this patent application, whereby spraying is effected with at least two spray heads at -the same time. Besides, the single spray head in this known method has a flow rate of but abou-t llO liters per minute. rrhe spraying pressure is not given. In any case also wi-th -this known method an addl-tional Eeed of liquid causing a s-tream and actually a circumEerential s-tream over the bottom, appears to be necessary to ob-tain a good removal of sludye from the bo-ttom. Even with such addit1On-al liquid feed, the removing of sludge Erom the bottom is still quite difficult, probably because the flow caused by said additional liguid does not cover the complete bottom area. The single spray head does not only have to be in--troduced in succesion through -two accesses, but also has to be moved to-and-fro several times along the leng-thwise direc-tion, in such a way that said me-thod is quite time-consuming.
In a particular embodiment of the invention, the high-pressure lances bearing spray heads at the ends thereof are swung to-and-fro over an angle which is smaller than 360 and preferably between two end posi-tions which make an angle of about 180 to one another.
In an embodiment of the invention, the high-pressure lances bearing spray heads at the ends thereof are only revolved between the shiftings thereof.
In an advantageous embodiment of the invention, a total flow rate which is larger than 250 liter per minute is sprayed.
In a useful embodiment of the invention, use is made, for sucking the liquid from the bot-tom, of a pump with a suction capacity of at least 1000 li-ter per minu-te.
In a preferred embodiment oE the invention, use is made, for sucking -the liquid from the bottom, of a line which comprises a flexible suction hose, and a metal shoe provided with a suction opening, which shoe connects through a connection opening to one end of the hose, which shoe is located on the bottom with the suction opening thereof directed along the bottom circumference.
In another embodiment of the invention, use is ~0 made for spraying of a spray head which comprises a hollow round body and which is provided with at leas-t one pair spray openings directed cross-wise to the lengthwise axis and lying opposite one another.
Tlle invention will be more readily apparent from the following description of a method for cleaning a steam generator, which is given as an example only and with refer-ence to the accompanying drawings, in which:
Figure 1 is a front view, partly broken away, oE a portion o~ a s-team generator wherein a me-thod embodying the invention is applied;
Figure 2 shows a vertical ~ection of the lowermost part of the steam generator of figure 1, during khe applica-tion of the method, but wherein for the sake of clarity, the pipe bundle has not been shown;
Figure 3 shows a horizontal section of the lower-most part of the steam generator from figure 2, during -the application of the method;
Figure 4 is a side view, in t.he uppermost half, and shows, in the lowermost half, a lengthwise section of a spray head used for the present method drawn on a larger scale;
Figure 5 is a side view of a detail of -the suction line used for the present method, also on a larger scale than figures 1 to 3;
Figure 6 shows a vertical section similar to the one in figure 2, of part of a steam generator during the application of the present method but pertaining to another embodimen-t of said steam generator and also another embodiment of the method according to the inven-tion; and Figure 7 shows a hori~ontal section of that part shown in figure 6 of the steam generator, taken along line VII-~II of Eigure 6.
In the various figures, the same reference numerals pertain to the same elements.
The steam generator to which the method is applied and a portion of which is shown in detail in figure 1, is of the U-pipe type which is particularly used in nuclear power stations. Such steam generators are known per se and an embodiment thereof is described in the above-mention-ed U.S. Patent No. ~,079,701~ The steam generator will only be described hereinafter as ~ar as required to make clear the method of cleaning.
As apparent mos-tly from figure 1, -the steam genera-tor comprises a verti.cally-arra~ged round vessel 1 which is divided by a bottom 2 into two spaces, narnely a lowermost space 3 for the primary medi.um heated by the nuclear reactor, and an uppermost space 4 for the secondary medium, which is the water to be converted into s-team.
Inside the space 4 which opens at the upper side thereof to turbines lnot shown), a pipe bundle 5 is arranged, which bundle extends in the shape of a reversed U. Both the pipes of the upwardly-running portion of the bundle and those of the downwardly-running portion thereof pass at -the ends thereof through the bottom 2 and thus communicate respectively with an outlet portion and an inlet portion of the space 3, which space is divided by a partition 14 into said two portions, Through the pipes of pipe bundle 5 -thus flows the primary medium. The medium abandons heat to the water which is fed at the top to space 4, between the outer casing 6 which bounds the space 4 on the outer side and which is thus formed by the outer wall of vessel 1, and an inner casing 7 which surrounds the pipe bundle 5 and reaches down to a distance from bottom 2. The bottom
mounted in the casing, the pipe bundle having an upward-extending bundle portion and a downward extending bundleportion with a space between the two portions~ each bundle portion comprising a number of spaced rows of pipes, a bottom at the foot of the pipe bundle which closes the openings between -the pipes and between the pipes and the outer casing, at least two accesses through the outer casing at substantially opposite sides thereof, the accesses lying above the bottom and providing access to the space between the two bundle portions.
~team generators of the above~defined kind are used in nuclear power stations. The heating fluid which is heated inside the nuclear reactor is led through the pipe bundle and abandons heat to the fluid, generally water, which lies in the space about the pipes, whereby steam is generated. Said steam is used for driving turbines and after cooling, is returned back to said space.
Due to various chemical reactions, there if formed about the pipe bundle an iron oxide, namely magnetite. Said ~,q~
'7 B
iron oxide settles on the pipe bundle, the bearing plates ~ox said pipe bundle, and mostly the bottom. At each main-tenance procedure, generally yearly, of the nuclear power s-tation, the iron oxide has to be removed. In connection 5 with the difficult reachability of the steam generator and mostly due to the prevailing radio-activity, the steam generator cannot be dismantled for such cleaning, so that the removal of the sludge and thus more particularly the iron oxide, requires special methods. There is always 10 made use -therefore of accesses which are provided in the lower portion of the steam generator, above the bottom and which during the normal operation of said steam generator, open on lines or are closed by metering apparatus or covers.
Through releasing one or a plurality of said accesses, 15 it is possible to spray loose with a high-pressure lance having a spray head, the sludge from the bottom and possibly from other portions of the inner volume of the steam genera-tor. The main problem does however lie in removing said sludge from the generator.
In known methods for cleaning a steam generator of the above-defined type, with the purpose of such removing, an additional amount of li~uid is fed to the bo-ttom during the spraying of pressurized liquid through the spray heads.
In the known me-thod of the kind defined in this 25 application, which is disclosed in Belgian Pa-tent No.
8~9,706, said additional liquid amount is fed by means of a sprinkling head which is brought above the bottom center.
When the steam generator is provided between 30 the bottom and the lowermost pipe supporting plate, with four accesses, spraying is effected under a pressure of about 250 bars by means of four high-pressure lances with spray heads, which are introduced through said four accesses.
Said high-pressure lances are moved simultaneously s-tepwise 35 from the center to the outer cas.ing, and the lances are always rota-ted in the same direction over a plurality of revolutions about the axis the.reof between the succeeding displacements.
$ ~
-- 3 ~
The four spray heads have an outer diameter of only 8 mm and cannot spray enough liquid to insure good removal of the sludge from the bottom. Consequently there is caused during the spraying, a flowing over -the bo-ttom, from the center to the outer casing, by means of the sprink-ling head which sprinkles low-pressure liquid on the bottom.
The cleaning liquid and -the sludge are sucked in two mutually opposite locations lying next to the outer casing.
When the steam generator also has two accesses openin~ above -the lowermost supporting plate and lying opposite one another, cleaning is firstly effected above the lowermost supporting plate with a high-pressure lance.
Use is made therefore of but one high-pressure lance with a spray head, which is in-troduced in succession thro~gh both accesses, each time being moved stepwise from the center to the outer casing, and being rotated always in the same direction over a plurality of revolutions about the lance axis between the steps. In spite of said spray head having a larger diameter than the above-mentioned heads, it cannot spray enough liquid on the suppor-ting plate to insure good removal of the sludge thererom, so that also during the cleaning of the supporting plate and those portions of the steam genera-tor lying thereabove, additional liquid is sprinkled with the sprinkling head on the supporting p]ate.
~o remove all the sludge from the bottom, it is necessary with this known method at the end of the clean-ing to spray li~uid with spray guns under a pressure of 300 bars on the bottom, at least against the outer casing.
Thè use of a sprinkling head during the clean-ing and of spray guns at the endl makes the method intricate and time-consuming. Said additional liquid feeding devices naturally also increase the volume and costs of the appara-tus re~uired for the application of the method.
Moreover it has been noted that in spite of sprink-ling with the sprinkling head, sludge could still remain on the bottom. In certain locations on the bottom, a driving~
back of liquid and consequently a limi-ted liquid 1OW did in fact occur, because the liquid sprayed by the spray head or heads did oppose the Elow of that liquid being sprin~led by the sprinkling head.
The invention seeks to obviate said drawbacks and to provide a method for cleaning a steam generator of the above-defined type which allows a useful removal of the sludge from the bottom in a simple and fast way, tha~
is without the need for an additional supply of liquid to cause a Elowing over the bottom and possibly a spraying with spray guns at the end.
The method according to the present invention comprises the step of:- introducing through each of the two accesses and into the space between the pipe bundle portions an elongated, rigid high pressure lance which is rotatable about its longitudinal axis and is shiftable in the direction of its longitudinal a~is, each lance including a spray head at the end thereoE introduced into said space, the spray head having at least one pair of radially directed spray openings for directing fluid jets radially outwardly from the longitudinal a~is of the lance on substantially opposite sides of the spray head, introducing through each oE the two accesses at least one suction line provided with at least one suction opening sîtuated adjacent the bottom within ~he outer casing, shifting simultaneously stepwise both lances such that between each shifting step the jets fro~ the spray head are directed between the rows of pipes of the pipe bundle portions, oscillating both of the lances at least between the shifting steps, spraying a cleaning liquid through the spray heads at least during the oscillating of the lances under a pressure higher than 200 bars and with a mean flow rate for both spray heads together of more than 200 liters per minute, and sucking -the sprayed liquid away from the bottom through ~he suction lines during the cleaning with a total suction capacity which is markedly higher than the mean Elow rate of the spray heads together.
It is mostly the combination of the above mention-ed hlgh spraying pressure, the above mentioned simul-taneous spraying with at least two high~pressure lances wi-th spray heads, and the conditions of revolving and Elow rates men-tioned herebefore, which allows complete removal of thesludge from the whole bo-ttom without using an additional liquid feed or additional operations.
The use of an oscillating high-pressure lance with spray head when cleaning a steam generator oE the above-defined type, is known per se from UOS~ Pa-tent ~,079,701, but wi-th the method as disclosed in said paten-t specification, the cleaning is performed with bu-t one single high-pressure lance with a spray head, which is brought into the steam genera-tor through two opposite access-es in succession, and which is moved s-tepwise from nex-t to the ou-ter casing to the center. Said known me-thod ls thus not of the type as defined in this patent application, whereby spraying is effected with at least two spray heads at -the same time. Besides, the single spray head in this known method has a flow rate of but abou-t llO liters per minute. rrhe spraying pressure is not given. In any case also wi-th -this known method an addl-tional Eeed of liquid causing a s-tream and actually a circumEerential s-tream over the bottom, appears to be necessary to ob-tain a good removal of sludye from the bo-ttom. Even with such addit1On-al liquid feed, the removing of sludge Erom the bottom is still quite difficult, probably because the flow caused by said additional liguid does not cover the complete bottom area. The single spray head does not only have to be in--troduced in succesion through -two accesses, but also has to be moved to-and-fro several times along the leng-thwise direc-tion, in such a way that said me-thod is quite time-consuming.
In a particular embodiment of the invention, the high-pressure lances bearing spray heads at the ends thereof are swung to-and-fro over an angle which is smaller than 360 and preferably between two end posi-tions which make an angle of about 180 to one another.
In an embodiment of the invention, the high-pressure lances bearing spray heads at the ends thereof are only revolved between the shiftings thereof.
In an advantageous embodiment of the invention, a total flow rate which is larger than 250 liter per minute is sprayed.
In a useful embodiment of the invention, use is made, for sucking the liquid from the bot-tom, of a pump with a suction capacity of at least 1000 li-ter per minu-te.
In a preferred embodiment oE the invention, use is made, for sucking -the liquid from the bottom, of a line which comprises a flexible suction hose, and a metal shoe provided with a suction opening, which shoe connects through a connection opening to one end of the hose, which shoe is located on the bottom with the suction opening thereof directed along the bottom circumference.
In another embodiment of the invention, use is ~0 made for spraying of a spray head which comprises a hollow round body and which is provided with at leas-t one pair spray openings directed cross-wise to the lengthwise axis and lying opposite one another.
Tlle invention will be more readily apparent from the following description of a method for cleaning a steam generator, which is given as an example only and with refer-ence to the accompanying drawings, in which:
Figure 1 is a front view, partly broken away, oE a portion o~ a s-team generator wherein a me-thod embodying the invention is applied;
Figure 2 shows a vertical ~ection of the lowermost part of the steam generator of figure 1, during khe applica-tion of the method, but wherein for the sake of clarity, the pipe bundle has not been shown;
Figure 3 shows a horizontal section of the lower-most part of the steam generator from figure 2, during -the application of the method;
Figure 4 is a side view, in t.he uppermost half, and shows, in the lowermost half, a lengthwise section of a spray head used for the present method drawn on a larger scale;
Figure 5 is a side view of a detail of -the suction line used for the present method, also on a larger scale than figures 1 to 3;
Figure 6 shows a vertical section similar to the one in figure 2, of part of a steam generator during the application of the present method but pertaining to another embodimen-t of said steam generator and also another embodiment of the method according to the inven-tion; and Figure 7 shows a hori~ontal section of that part shown in figure 6 of the steam generator, taken along line VII-~II of Eigure 6.
In the various figures, the same reference numerals pertain to the same elements.
The steam generator to which the method is applied and a portion of which is shown in detail in figure 1, is of the U-pipe type which is particularly used in nuclear power stations. Such steam generators are known per se and an embodiment thereof is described in the above-mention-ed U.S. Patent No. ~,079,701~ The steam generator will only be described hereinafter as ~ar as required to make clear the method of cleaning.
As apparent mos-tly from figure 1, -the steam genera-tor comprises a verti.cally-arra~ged round vessel 1 which is divided by a bottom 2 into two spaces, narnely a lowermost space 3 for the primary medi.um heated by the nuclear reactor, and an uppermost space 4 for the secondary medium, which is the water to be converted into s-team.
Inside the space 4 which opens at the upper side thereof to turbines lnot shown), a pipe bundle 5 is arranged, which bundle extends in the shape of a reversed U. Both the pipes of the upwardly-running portion of the bundle and those of the downwardly-running portion thereof pass at -the ends thereof through the bottom 2 and thus communicate respectively with an outlet portion and an inlet portion of the space 3, which space is divided by a partition 14 into said two portions, Through the pipes of pipe bundle 5 -thus flows the primary medium. The medium abandons heat to the water which is fed at the top to space 4, between the outer casing 6 which bounds the space 4 on the outer side and which is thus formed by the outer wall of vessel 1, and an inner casing 7 which surrounds the pipe bundle 5 and reaches down to a distance from bottom 2. The bottom
2 sealingly closes the openings between the pipes of pipe bundle 5, and between the pipes and the outer casing 6, so that said water cannot enter space 3. Said wa-ter rises inside the inner casing 7 and is converted in-to steam by contacting the pipe bundle 5, and is discharged at the top of space 4 through the s-team turbines.
To retain the pipes of pipe bundle 5 in position, a plurality of supporting plates 8 lying above one another are arranged above bottom 2 and inside inner casing 7.
The outer circumference of said supporting plates 8 lies
To retain the pipes of pipe bundle 5 in position, a plurality of supporting plates 8 lying above one another are arranged above bottom 2 and inside inner casing 7.
The outer circumference of said supporting plates 8 lies
3~ some small distance away from the inner side of inner casing 7, so that a ring-like sli-t 9 remains open between the edge of each supporting plate 8 and the inner casing 7.
Each supporting plate 8 is moreover further provided in the center thereof, between the ascending and descending portions of pipe bundle 5, with an opening 10.
During the operation of the steam generator, the sludge, mainly magneti-te, settles down on the lower ~l2~ '7~
part of the steam generator, in such a way that the sludge to be removed lies mainly on bottom 2, the lowermos-t support-ing plate 8, and the lowermost portion of pipe bundle 5.
The steam generator is provided above bot-tom 2 and adjacent thereto, with a plurality of accesses to said pipe bundle 5. Said accesses are either closed by covers, or communicate through a line with apparatus such as for example meters, duxing the normal use of the steam generator. The cleaning of the steam generator differs somewhat according to the number and location of said access-es.
In one embodiment of the above-defined known steam generator, said generator is provided hetween bot-tom 2 and the lowermost supporting plate 8, with two diametri-cally-opposted openings 11 with a diameter of about 15 cm, in the outer casing 6.
Said openings open on the space 12 between the ascending portion and the descending portion of the U-shaped pipe bundle 5. Opposite each opening 11 -the inner ~ casing 7, which reaches in this embodiment quite close to the bottom 2 and down to below -the openings 11, is provided with an equally-sized opening 13 which Eorms together wi-th said opening 11, an access to the pipe bundle 5. Figures 1 to 5 relate to this embodiment of the steam genera-tor~
For clearness' sake, the pipe bundle 5 is not shown in figure 2, and but partly in figure 3O
For cleanin~ the s-team generator, both openings 11 in outer casing 6 are released by removing the cover mounted thereon, naturally after stopping the steam generator and emptying the uppermost space 4.
On each one of both openings 11 is mounted a spraying device of that type which comprises mainly a frame 15, a high-pressure lance 16 which is slidable along its lengthwise axis and rotatable to-and-fro abou~ said axis relative to said frame and which bears on the :Eront end thereof a spray head 17, and two suction lines 20-23 support-ed by said frame.
~ spraying device which is particul~rly suitable Eor -the application of the method is disclosed in Belgian Patent 897,6~3 in the name of the Applicant. Said spraying device comprises means to automatically shift and revolve the high-pr~ssure lance 16. It is clear that the shifting and revolving of the high-pressure lance does not necessari-ly ha~e to occur with the means as disclosed in Belgian Patent 897,603, but may also be performed in other ways and even by hand.
The frame 15, which is shown in the simplest form thereof in figures 2 and 3, namely as a mounting flange, is fixed instead on -the cover which did close the opening 11, on the outer side of outer casing 6. Said mounting flange closes thereby sealing the opening 11 about the high-pressure lance 16 and both suction lines 20-23.
For each spraying device, use is made of a high-pxessure lance 16 with an outer diameter of 21 mm and an inner diameter of 12.5 mm. The high-pressure lance 16 is naturally so arranged as to ha~e the spray head 17 lie inside vessel 1. That end lying outside said vessel 1 o~ both high-pressure lances 16 is connec-ted by means of supply hoses to the same high-pressure pump which can pump water under a pressure higher than 200 bars, preferably about 250 bars or more, and with a flow rate of more than 200 liters per minute and preferably of more -than 250 liters per minute, for example between 250 and 360 liters per minute. For clearness' sake, neither the supply hoses nor the pump are shown in the figures.
The spray head 17 which is fixedly secured to each one of the high-pressure lances 16, is shown in detail in figure 4. Said spray head 17 comprises a hollow round body 18 which is screwed wich a cone-shaped end on the corresponding high-pressure lance 16. The inner side o~
the hollow body 18 opens on the outer side by means of two pairs of round openings 19, directed radially relative to the lance axis and with a diameter of 2 mm. ~oth openings 19 of the same pair are directed diametrically opposite ~$~
one another. The openings 19 from one pair are direc-ted at right angle to the openings of the other pair. The spacing between both pairs is equal to the center-to-center spacing be-tween the adjacen-t rows of the pipe bundle 5~
as m~asured in parallel relationship with the lance axis.
Both spray heads 17 are so brought in the space 12 between the ascending and the descending par-t of the pipe bundle 5 -that said openings 19 lie in the center between two adjacent rows of pipes of the bundle 5. The high-pressure lances 16 pass through an opening 11 in the outer casing 6 and the opposite opening 13 in the inner casing 7, and they are directed with the lengthwise direction thereof radially, in parallel relationship with the bottom 2.
While spraying with the above-defined pressure and with a total flow rate, i.eO a flow rate for both spray heads 17 together, equal to the above defined flow ra~e, i.e. with a pressure higher than 200 bars and preferably about 250 bars or more and with a flow rate larger than 200 liters per minute and preferably larger than 250 l/min e.g. between 250 and 3~0 l~min, both high-pressure lances 16 are moved simultaneously stepwise along the lengthwise direction thereof, that is the radial direction of the vessel 1, in parallel relationship with bottom 2~ ~t each step -the spray heads 17 are moved over a distance which is equal to the center-to-cen-ter spacing be-tween the adjacent pipe rows, as considered in parallel rela-tionship with space 12, or as many times this center-to-center spacing as the spray head 17 is provided with pairs of spray openings 19, i.e. in the present case twice said center-to-center spacing. The spray heads are there~y moved once or a plu-rality of times between substantially the center o~ vessel 1 and the outer side thereof, that is approximately nex-t to the outer casing 6 and actually up to against the inner casing 7. The first stepwise shifting while spraying may occur as well towards the center or away from the center.
Between the succeeding small movements of the ~z~
spray heads 17, i.e. in those moments at which -the spray heads ~ie with the spray openings 19 thereof between ad~acent rows of pipe bundle 5, said spray heads 17 are revolved once and prefera~ly a plurality of times around the lance axis, to-and-fro over an angle which is sma~ler than 360 and preferably over a total angle of about 180. In the last case each spray head 17 is swung from its neu-tral position which it takes during the linear shifting thereof, first over 90 in the one direction, then over 180 in -the opposite direction, and finally again towards its neutral position, after which this cycle may possibly be repeated anew.
During the spraying, i.e. during the alternating shifting and revol~ing of the high-pressure lances 16 with the spray heads 17, the cleaning water which falls on bottom 2, is continuously sucked off. Therehy use is made of one or a pluralit~ of suction pumps for example diaphragm pumps, with a to-tal suction capacity which is markedly larger than the supply capacity for water through the spray heads 17, and -thus markedly larger than the above-defined water flow ra-te. This is re~uired to avoid water remaining on bot-tom 2. A water layer on bo-ttom 2 would break the streams directed to said bottom 2 from the spray heads 17 and prevent the spraying loose of sludge from bottom 2. Preferably, the total suction capacity of the suction pump or pumps is larger than 1000 liters per minute and for example 1200 liters per minute.
~ oth suction lines 20-23 of each spray device are naturally connected to the suction pump or pumps, not shown for clearness' sake in the fig~res. Each suction line 20-23 is comprised of a small tube 20 which is mounted in a seal in said mounting flange of frame 15, a hose 21 connecting theretQ on the inner side of vessel 1, a stain less steel shoe 22 connecting to hose 21, and a suc-tion hose 23 which connects the small tube 20 -to the suction pump or pumps.
The shoe 22 is shown in detail in figure 5. The Ele~ible hose 21 connec-ts -to the uppermost open end of the shoe. The shoe foot is also open at the top. ~he shoe 22 fits between the outer casing 6 and the inner casing 7. When arranging each spray device, both shoes 22 of both suc-tion lines 20-23 of this device are let down between outer casing 6 and inner casing 7, until the foot bears on bottom 2, so that bo-th shoes 22 are di~ected with the open to~ thereof away from one another along the circumferen-ce of bottom 2.
The water which is sucked off by means of the suction pump or pumps/ is fed to a filter unit which may be of known structure and will not be shown in the figures for clearness' sake. Said filter unit comprises three filter housings which are succeedingly provided with filter cartridges with a fineness of respectively 10, 5 and 0.5 microns. The filtered water is fed to a supply tank from which it is anew sucked, notably for feeding the high-pressure lances 16.
The above-described operations, namely -the alter-nating shifting and revolving while spraying oE the high-pressure lances 16 with spxay heads 17, and the simultaneous sucking and filtering of the cleaning water, are conducted until no sludge can be seen any more in the sucked water through the sight glasses which are mounted in the hoses 23. The feed and discharge pumps are stopped and the spray-ing devices are removed. Finally the openings 11 are closed back by a cover.
In another embodiment of a steam generator, the lowermost supporting plate 8 lies somewhat nearer the bottom 2 and actually level with both said openings 11 lying op-posite one another in the outer casing 6, which openings 11 lie in turn higher. Such other embodiment of the steam generator further differs from the above-described embodi-ment in the inner casing 7 ending at a longer distance from bottom 2 and, underneath said inner casing 7, four smaller openings 24 are arranged in ou-ter casing 6.
Said openings have a diame~er of bu-t 50 mm. The four openings are staggered by approximately 90 relative to one another 7 but they are not located on the symmetry planes of -the pipe bundle. No single opening 24 thus opens on space 12, but all of the openings 24 open directly on -the pipe bundle 5. The openings 24 are direc-ted with the lengthwise direction thereo~ approximately in the radial direction.
Figures 6 and 7 per-tain to such a steam generator.
The cleaning oE such a steam generator is per-formed in two steps.
During a first step, the upper side of -the lower-most supporting plate 8 together with the steam generator part lying directly above, is cleaned, a-t leas-t partly.
One proceeds thereb~ exactly in the same way as when cleaning bottom ~ in the above-described embodiment of the method. Over each opening 11 is thus mounted as described above, a sprayiny device with a high-pressure lance 16 and a spray head 17 mounted thereon. Said high-pre~sure lance 16 extellds through the opening 13 in inner casing 7 and above the lowermost supporting plate 8. While spraying with the above-defined pressure and flow rate, both spray heads 17 are simultaneously shifted s-tepwise, while between two succeeding steps, said spray heads are revolved one or a plurali-ty of times to-and-fro preferably over an angle of about 180. Ater having determined visual-ly by means of sight glasses which are mounted in the suc-tion hoses ~3~ that substantially no sludge is carried along with the sucked water, the spraying is stopped, but both spraying devices are left on the steam generator.
The second step is now performed, whereby the bo-ttom 2 and that por-tion of the steam yenera-tor lying between bot-tom 2 and the lowermost supporting plate 8 are cleaned, while further cleaning that portion of the steam generator lying above the supporting plate 3.
The covers which close the four openings 24 are first removed. Instead of each cover, there is mounted a spraying device which is similar to the above-described '7~
spraying device but which differs s-tructurally mainly due to said devices comprising no suction hoses, the high-pressure lances 25 having ~ut an outer diameter of 8 mm and an inner diameter o~ 3mm, the spray head 26 mounted on each su~h high-pressure lance 25 also having a smaller diameter than said spray heads 17 and moreover being provid-ed with but one pair spraying openings 19 lyin~ opposite one another which openings have moreover but a diameter of 1.8 mm.
The smaller size of the high-pressure lances 25 with the pertaining spray heads 26 resul-ts from the fact -that said components are not brought in a space 12 but on the contrary cross-wise through the pipe bundle 5.
The lengthwise direc-tion of the high-pressure lances is so selected as to let said latter ones pass between the pipes, and said leng~hwise direction may differ thereby from -the lengthwise direction of.the openings 2~. The mounting flange of the frame 15 of each of said latter spray devices is then also specially fitted to impart after securing against the edges of an opening 24, the required direction to the shiftable and revolvable high-pressure lance 25.
The four high-pressure lances 25 are connected to the same high-pressure pump to which both high-pressure lances 16 are also connected, and water under said pressure higher than 200 bars and preferably higher than 250 bars is sprayed at the same time through the four spray heads 2~ and the two spray heads 17. There is sprayed thereby throu~h -the six spray heads together a total mean flow rate which is larger than 200 liters per minute and lies preferably between 250 and 360 liters per minu-te. During the spraying, the water is sucked from the bottom 2 with a suction capacity which is markedly larger than said latter flow rate and which is preferably higher than 1000 liters per minute, and lies for example in the range of 1200 liters per minute, by means of the four suction lines 20-23 which are part of the two devices which are mounted on the openings 11 .
During the spraying and sucking, as well the four high-pressure lances 25 with spray heads 26 as the two high-pressure lances 16 with spray heads 17 are moved simultaneously and stepwise between approximately ~he center 5 of vessel 1 and the outer side thereof, whereby between each two steps, the high-pressure lances 25 and 16 respective-ly with the pertaining spray heads 26 and 17 respectively, are swung to-and-fro, preferably over 180 in the above-described way.
The intermittent shi~ting of said high-pressure lances 16 does not have necessarily to occur synchroneously with the intermittent shifting of the four lower high-pressure lances, but said shiftings are actually preferably performed synchroneously. In said latter case, the high-pressure lances 16 and 25 are moved at each step over a distance which is equal to the center-to-center spacing between the pipes, as the spray heads have but one pair spraying openings 19 and between the succeeding shiftings and thus during the to-and-fro swinging, said spraying openings have to lie opposite the following intermedia-te spaces between the pipe rows of bundle 5.
Part of the water supply is sprayed through the spray heads 17, but said heads are not means for causing a well-determined directed stream over bottom 2.
Not only do these spray heads spray with the same pressure as the spray heads 26, but during the spray-ing said spray heads 17 are shifted and revolved alterna-tive-ly. The spray heads 17 take consequently actually part in the cleaning process. When the spray heads 17 lie above the center opening 10 in the lowermost supporting plate 8, which opening is quite large and has a diamter in the range of 80 cm, said spray heads spray directly on the bottom 2. When -the spray heads 17 lie next to the opening 10, they further clean the supporting plate 8 and that portion lying thereabove of the steam generator. The water sprayed through the spray heads 17 can fall as well through the opening 10 as through the slit 9 Oll bottom 2 and the .. . ... .. . . ., .,, . _ . ... ..
'7~
path selec-ted by the water is dependent on the location of the spray heads 17 and thus is not always the same.
All of the above-described embodimen-ts of -the method are quite simple and allow a fast and very good cleaning of the steam generator.
The invention is in no way limited to the above-described embodiments and within the scope of the patent application, many changes may be brought to the described embodiments, notably as regards the shape, the composition, -the arrangement and the number of the components which are being used for embodying the invention.
It is particularly not necessary to spray cons-tant-ly during the cleaning. It may be enough to spray exclusive-ly when the spray heads are being swung -to-and-fro. In this case the above mentioned conditions of flow rate have to be met during each spraying. Moreover one might also spray in a pulsa-ted way instead of spraying continuously, in which case, the mean flow rate has to fulfil the above-defined conditions.
The liquid which is sprayed does not necessarily have to be water. Other cleaning liquids may be sprayed.
More than ~ne pump can be used to supply liquid to the spray heads.
Each supporting plate 8 is moreover further provided in the center thereof, between the ascending and descending portions of pipe bundle 5, with an opening 10.
During the operation of the steam generator, the sludge, mainly magneti-te, settles down on the lower ~l2~ '7~
part of the steam generator, in such a way that the sludge to be removed lies mainly on bottom 2, the lowermos-t support-ing plate 8, and the lowermost portion of pipe bundle 5.
The steam generator is provided above bot-tom 2 and adjacent thereto, with a plurality of accesses to said pipe bundle 5. Said accesses are either closed by covers, or communicate through a line with apparatus such as for example meters, duxing the normal use of the steam generator. The cleaning of the steam generator differs somewhat according to the number and location of said access-es.
In one embodiment of the above-defined known steam generator, said generator is provided hetween bot-tom 2 and the lowermost supporting plate 8, with two diametri-cally-opposted openings 11 with a diameter of about 15 cm, in the outer casing 6.
Said openings open on the space 12 between the ascending portion and the descending portion of the U-shaped pipe bundle 5. Opposite each opening 11 -the inner ~ casing 7, which reaches in this embodiment quite close to the bottom 2 and down to below -the openings 11, is provided with an equally-sized opening 13 which Eorms together wi-th said opening 11, an access to the pipe bundle 5. Figures 1 to 5 relate to this embodiment of the steam genera-tor~
For clearness' sake, the pipe bundle 5 is not shown in figure 2, and but partly in figure 3O
For cleanin~ the s-team generator, both openings 11 in outer casing 6 are released by removing the cover mounted thereon, naturally after stopping the steam generator and emptying the uppermost space 4.
On each one of both openings 11 is mounted a spraying device of that type which comprises mainly a frame 15, a high-pressure lance 16 which is slidable along its lengthwise axis and rotatable to-and-fro abou~ said axis relative to said frame and which bears on the :Eront end thereof a spray head 17, and two suction lines 20-23 support-ed by said frame.
~ spraying device which is particul~rly suitable Eor -the application of the method is disclosed in Belgian Patent 897,6~3 in the name of the Applicant. Said spraying device comprises means to automatically shift and revolve the high-pr~ssure lance 16. It is clear that the shifting and revolving of the high-pressure lance does not necessari-ly ha~e to occur with the means as disclosed in Belgian Patent 897,603, but may also be performed in other ways and even by hand.
The frame 15, which is shown in the simplest form thereof in figures 2 and 3, namely as a mounting flange, is fixed instead on -the cover which did close the opening 11, on the outer side of outer casing 6. Said mounting flange closes thereby sealing the opening 11 about the high-pressure lance 16 and both suction lines 20-23.
For each spraying device, use is made of a high-pxessure lance 16 with an outer diameter of 21 mm and an inner diameter of 12.5 mm. The high-pressure lance 16 is naturally so arranged as to ha~e the spray head 17 lie inside vessel 1. That end lying outside said vessel 1 o~ both high-pressure lances 16 is connec-ted by means of supply hoses to the same high-pressure pump which can pump water under a pressure higher than 200 bars, preferably about 250 bars or more, and with a flow rate of more than 200 liters per minute and preferably of more -than 250 liters per minute, for example between 250 and 360 liters per minute. For clearness' sake, neither the supply hoses nor the pump are shown in the figures.
The spray head 17 which is fixedly secured to each one of the high-pressure lances 16, is shown in detail in figure 4. Said spray head 17 comprises a hollow round body 18 which is screwed wich a cone-shaped end on the corresponding high-pressure lance 16. The inner side o~
the hollow body 18 opens on the outer side by means of two pairs of round openings 19, directed radially relative to the lance axis and with a diameter of 2 mm. ~oth openings 19 of the same pair are directed diametrically opposite ~$~
one another. The openings 19 from one pair are direc-ted at right angle to the openings of the other pair. The spacing between both pairs is equal to the center-to-center spacing be-tween the adjacen-t rows of the pipe bundle 5~
as m~asured in parallel relationship with the lance axis.
Both spray heads 17 are so brought in the space 12 between the ascending and the descending par-t of the pipe bundle 5 -that said openings 19 lie in the center between two adjacent rows of pipes of the bundle 5. The high-pressure lances 16 pass through an opening 11 in the outer casing 6 and the opposite opening 13 in the inner casing 7, and they are directed with the lengthwise direction thereof radially, in parallel relationship with the bottom 2.
While spraying with the above-defined pressure and with a total flow rate, i.eO a flow rate for both spray heads 17 together, equal to the above defined flow ra~e, i.e. with a pressure higher than 200 bars and preferably about 250 bars or more and with a flow rate larger than 200 liters per minute and preferably larger than 250 l/min e.g. between 250 and 3~0 l~min, both high-pressure lances 16 are moved simultaneously stepwise along the lengthwise direction thereof, that is the radial direction of the vessel 1, in parallel relationship with bottom 2~ ~t each step -the spray heads 17 are moved over a distance which is equal to the center-to-cen-ter spacing be-tween the adjacent pipe rows, as considered in parallel rela-tionship with space 12, or as many times this center-to-center spacing as the spray head 17 is provided with pairs of spray openings 19, i.e. in the present case twice said center-to-center spacing. The spray heads are there~y moved once or a plu-rality of times between substantially the center o~ vessel 1 and the outer side thereof, that is approximately nex-t to the outer casing 6 and actually up to against the inner casing 7. The first stepwise shifting while spraying may occur as well towards the center or away from the center.
Between the succeeding small movements of the ~z~
spray heads 17, i.e. in those moments at which -the spray heads ~ie with the spray openings 19 thereof between ad~acent rows of pipe bundle 5, said spray heads 17 are revolved once and prefera~ly a plurality of times around the lance axis, to-and-fro over an angle which is sma~ler than 360 and preferably over a total angle of about 180. In the last case each spray head 17 is swung from its neu-tral position which it takes during the linear shifting thereof, first over 90 in the one direction, then over 180 in -the opposite direction, and finally again towards its neutral position, after which this cycle may possibly be repeated anew.
During the spraying, i.e. during the alternating shifting and revol~ing of the high-pressure lances 16 with the spray heads 17, the cleaning water which falls on bottom 2, is continuously sucked off. Therehy use is made of one or a pluralit~ of suction pumps for example diaphragm pumps, with a to-tal suction capacity which is markedly larger than the supply capacity for water through the spray heads 17, and -thus markedly larger than the above-defined water flow ra-te. This is re~uired to avoid water remaining on bot-tom 2. A water layer on bo-ttom 2 would break the streams directed to said bottom 2 from the spray heads 17 and prevent the spraying loose of sludge from bottom 2. Preferably, the total suction capacity of the suction pump or pumps is larger than 1000 liters per minute and for example 1200 liters per minute.
~ oth suction lines 20-23 of each spray device are naturally connected to the suction pump or pumps, not shown for clearness' sake in the fig~res. Each suction line 20-23 is comprised of a small tube 20 which is mounted in a seal in said mounting flange of frame 15, a hose 21 connecting theretQ on the inner side of vessel 1, a stain less steel shoe 22 connecting to hose 21, and a suc-tion hose 23 which connects the small tube 20 -to the suction pump or pumps.
The shoe 22 is shown in detail in figure 5. The Ele~ible hose 21 connec-ts -to the uppermost open end of the shoe. The shoe foot is also open at the top. ~he shoe 22 fits between the outer casing 6 and the inner casing 7. When arranging each spray device, both shoes 22 of both suc-tion lines 20-23 of this device are let down between outer casing 6 and inner casing 7, until the foot bears on bottom 2, so that bo-th shoes 22 are di~ected with the open to~ thereof away from one another along the circumferen-ce of bottom 2.
The water which is sucked off by means of the suction pump or pumps/ is fed to a filter unit which may be of known structure and will not be shown in the figures for clearness' sake. Said filter unit comprises three filter housings which are succeedingly provided with filter cartridges with a fineness of respectively 10, 5 and 0.5 microns. The filtered water is fed to a supply tank from which it is anew sucked, notably for feeding the high-pressure lances 16.
The above-described operations, namely -the alter-nating shifting and revolving while spraying oE the high-pressure lances 16 with spxay heads 17, and the simultaneous sucking and filtering of the cleaning water, are conducted until no sludge can be seen any more in the sucked water through the sight glasses which are mounted in the hoses 23. The feed and discharge pumps are stopped and the spray-ing devices are removed. Finally the openings 11 are closed back by a cover.
In another embodiment of a steam generator, the lowermost supporting plate 8 lies somewhat nearer the bottom 2 and actually level with both said openings 11 lying op-posite one another in the outer casing 6, which openings 11 lie in turn higher. Such other embodiment of the steam generator further differs from the above-described embodi-ment in the inner casing 7 ending at a longer distance from bottom 2 and, underneath said inner casing 7, four smaller openings 24 are arranged in ou-ter casing 6.
Said openings have a diame~er of bu-t 50 mm. The four openings are staggered by approximately 90 relative to one another 7 but they are not located on the symmetry planes of -the pipe bundle. No single opening 24 thus opens on space 12, but all of the openings 24 open directly on -the pipe bundle 5. The openings 24 are direc-ted with the lengthwise direction thereo~ approximately in the radial direction.
Figures 6 and 7 per-tain to such a steam generator.
The cleaning oE such a steam generator is per-formed in two steps.
During a first step, the upper side of -the lower-most supporting plate 8 together with the steam generator part lying directly above, is cleaned, a-t leas-t partly.
One proceeds thereb~ exactly in the same way as when cleaning bottom ~ in the above-described embodiment of the method. Over each opening 11 is thus mounted as described above, a sprayiny device with a high-pressure lance 16 and a spray head 17 mounted thereon. Said high-pre~sure lance 16 extellds through the opening 13 in inner casing 7 and above the lowermost supporting plate 8. While spraying with the above-defined pressure and flow rate, both spray heads 17 are simultaneously shifted s-tepwise, while between two succeeding steps, said spray heads are revolved one or a plurali-ty of times to-and-fro preferably over an angle of about 180. Ater having determined visual-ly by means of sight glasses which are mounted in the suc-tion hoses ~3~ that substantially no sludge is carried along with the sucked water, the spraying is stopped, but both spraying devices are left on the steam generator.
The second step is now performed, whereby the bo-ttom 2 and that por-tion of the steam yenera-tor lying between bot-tom 2 and the lowermost supporting plate 8 are cleaned, while further cleaning that portion of the steam generator lying above the supporting plate 3.
The covers which close the four openings 24 are first removed. Instead of each cover, there is mounted a spraying device which is similar to the above-described '7~
spraying device but which differs s-tructurally mainly due to said devices comprising no suction hoses, the high-pressure lances 25 having ~ut an outer diameter of 8 mm and an inner diameter o~ 3mm, the spray head 26 mounted on each su~h high-pressure lance 25 also having a smaller diameter than said spray heads 17 and moreover being provid-ed with but one pair spraying openings 19 lyin~ opposite one another which openings have moreover but a diameter of 1.8 mm.
The smaller size of the high-pressure lances 25 with the pertaining spray heads 26 resul-ts from the fact -that said components are not brought in a space 12 but on the contrary cross-wise through the pipe bundle 5.
The lengthwise direc-tion of the high-pressure lances is so selected as to let said latter ones pass between the pipes, and said leng~hwise direction may differ thereby from -the lengthwise direction of.the openings 2~. The mounting flange of the frame 15 of each of said latter spray devices is then also specially fitted to impart after securing against the edges of an opening 24, the required direction to the shiftable and revolvable high-pressure lance 25.
The four high-pressure lances 25 are connected to the same high-pressure pump to which both high-pressure lances 16 are also connected, and water under said pressure higher than 200 bars and preferably higher than 250 bars is sprayed at the same time through the four spray heads 2~ and the two spray heads 17. There is sprayed thereby throu~h -the six spray heads together a total mean flow rate which is larger than 200 liters per minute and lies preferably between 250 and 360 liters per minu-te. During the spraying, the water is sucked from the bottom 2 with a suction capacity which is markedly larger than said latter flow rate and which is preferably higher than 1000 liters per minute, and lies for example in the range of 1200 liters per minute, by means of the four suction lines 20-23 which are part of the two devices which are mounted on the openings 11 .
During the spraying and sucking, as well the four high-pressure lances 25 with spray heads 26 as the two high-pressure lances 16 with spray heads 17 are moved simultaneously and stepwise between approximately ~he center 5 of vessel 1 and the outer side thereof, whereby between each two steps, the high-pressure lances 25 and 16 respective-ly with the pertaining spray heads 26 and 17 respectively, are swung to-and-fro, preferably over 180 in the above-described way.
The intermittent shi~ting of said high-pressure lances 16 does not have necessarily to occur synchroneously with the intermittent shifting of the four lower high-pressure lances, but said shiftings are actually preferably performed synchroneously. In said latter case, the high-pressure lances 16 and 25 are moved at each step over a distance which is equal to the center-to-center spacing between the pipes, as the spray heads have but one pair spraying openings 19 and between the succeeding shiftings and thus during the to-and-fro swinging, said spraying openings have to lie opposite the following intermedia-te spaces between the pipe rows of bundle 5.
Part of the water supply is sprayed through the spray heads 17, but said heads are not means for causing a well-determined directed stream over bottom 2.
Not only do these spray heads spray with the same pressure as the spray heads 26, but during the spray-ing said spray heads 17 are shifted and revolved alterna-tive-ly. The spray heads 17 take consequently actually part in the cleaning process. When the spray heads 17 lie above the center opening 10 in the lowermost supporting plate 8, which opening is quite large and has a diamter in the range of 80 cm, said spray heads spray directly on the bottom 2. When -the spray heads 17 lie next to the opening 10, they further clean the supporting plate 8 and that portion lying thereabove of the steam generator. The water sprayed through the spray heads 17 can fall as well through the opening 10 as through the slit 9 Oll bottom 2 and the .. . ... .. . . ., .,, . _ . ... ..
'7~
path selec-ted by the water is dependent on the location of the spray heads 17 and thus is not always the same.
All of the above-described embodimen-ts of -the method are quite simple and allow a fast and very good cleaning of the steam generator.
The invention is in no way limited to the above-described embodiments and within the scope of the patent application, many changes may be brought to the described embodiments, notably as regards the shape, the composition, -the arrangement and the number of the components which are being used for embodying the invention.
It is particularly not necessary to spray cons-tant-ly during the cleaning. It may be enough to spray exclusive-ly when the spray heads are being swung -to-and-fro. In this case the above mentioned conditions of flow rate have to be met during each spraying. Moreover one might also spray in a pulsa-ted way instead of spraying continuously, in which case, the mean flow rate has to fulfil the above-defined conditions.
The liquid which is sprayed does not necessarily have to be water. Other cleaning liquids may be sprayed.
More than ~ne pump can be used to supply liquid to the spray heads.
Claims (17)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A method of cleaning a steam generator of the so-called U type which includes an upstanding outer casing, a pipe bundle in the shape of a U mounted in the casing the pipe bundle having an upward-extending bundle portion and a downward extending bundle portion with a space between the two portions, each bundle portion comprising a number of spaced rows of pipes, a bottom at the foot of the pipe bundle which closes the openings between the pipes and between the pipes and the outer casing; at least two accesses through the outer casing at substantially opposite sides thereof, the accesses lying above the bottom and providing access to the space between the two bundle portions; the method comprising the steps of:
(a) introducing through each of the two accesses and into the space between the pipe bundle portions an elongated, rigid high pressure lance which is rotatable about its longitudinal axis and is shiftable in the direction of its longitudinal axis, each lance including a spray head at the end thereof introduced into said space, the spray head having at least one pair of radially directed spray openings for directing fluid jets radially outwardly from the longitudinal axis of the lance on substantially opposite sides of the spray head;
(b) introducing through each of the two accesses at least one suction line provided with at least one suction opening situated adjacent the bottom within the outer casing;
(c) shifting simultaneously stepwise both lances such that between each shifting step the jets from the spray head are directed between the rows of pipes of the pipe bundle portions, (d) oscillating both of the lances at least between the shifting steps;
(e) spraying a cleaning liquid through the spray heads at least during the oscillating of the lances under a pressure higher than 200 bars and with a mean flow rate for both spray heads together of more than 200 liters per minute and (f) sucking the sprayed liquid away from the bottom through the suction lines during the cleaning with a total suction capacity which is markedly higher then the mean flow rate of the spray heads together.
(a) introducing through each of the two accesses and into the space between the pipe bundle portions an elongated, rigid high pressure lance which is rotatable about its longitudinal axis and is shiftable in the direction of its longitudinal axis, each lance including a spray head at the end thereof introduced into said space, the spray head having at least one pair of radially directed spray openings for directing fluid jets radially outwardly from the longitudinal axis of the lance on substantially opposite sides of the spray head;
(b) introducing through each of the two accesses at least one suction line provided with at least one suction opening situated adjacent the bottom within the outer casing;
(c) shifting simultaneously stepwise both lances such that between each shifting step the jets from the spray head are directed between the rows of pipes of the pipe bundle portions, (d) oscillating both of the lances at least between the shifting steps;
(e) spraying a cleaning liquid through the spray heads at least during the oscillating of the lances under a pressure higher than 200 bars and with a mean flow rate for both spray heads together of more than 200 liters per minute and (f) sucking the sprayed liquid away from the bottom through the suction lines during the cleaning with a total suction capacity which is markedly higher then the mean flow rate of the spray heads together.
2. The method of Claim 1 wherein each of said spray heads includes a second pair of radially directed spray openings for directing fluid jets radially outwardly from the longitudinal axis of the lance on substantially opposite sides of the spray heady the second pair of spray openings being longitudinally spaced from said at least one pair by a distance substantially equal to the center-to-center distance between adjacent rows of pipes in said bundle portions, the directions of fluid jets from said at least one and said second pair of spray openings being substantially perpendicular.
3. The method of Claim 1 wherein both of the lances are oscillated over an angle of about 180 degrees.
4. The method of Claim 1 wherein the high-pressure lances bearing a spray head at the end thereof are oscillated at least once to-and-from a neutral position succeedingly over the 90 degree in the one direction and back, and over about 90 degrees in the other direction and back.
5. The method of Claim 1 wherein liquid is sprayed through the spray heads with a pressure of at least about 250 bars.
6. The method of Claim 1 wherein a total mean flow rate which lies between 250 and 360 liters per minute is sprayed.
7. The method of Claim 1 wherein a suction capacity of at least 1000 liters per minute is used to suck the sprayed liquid from the bottom.
8. The method of Claim 1 wherein a line which comprises a flexible suction hose and a metal shoe as an end portion is used for sucking the sprayed liquid from the bottom.
9. The method of Claim 1 wherein two suction lines are arranged in each one of said two openings lying opposite one another and through which a high-pressure lance is introduced, the suction openings of both lines being directed along the circumference of the outer casing but in opposite directions.
10. The method of Claim 1 wherein there is cleaned a steam generator which comprises moreover an inner casing which is mounted inside the outer casing and around the pipe bundle and reaches down to some distance away from the bottom, and a supporting plate for the pipe bundle which is mounted above the bottom in the inner casing with at least a major portion of the outer circumference thereof loose from the inner casing, so that liquid can fall over the edge thereof on the bottom, which steam generator is provided, in the outer casing thereof, between the bottom and said supporting plate, with at least two openings lying approximately opposite one another, and is provided in the inner casing thereof, opposite each opening in the outer casing, also with an opening in which method said two high-pressure lances are each introduced through an opening in the outer casing and an opening in the inner casing.
11. A method for cleaning a steam generator of the so-called U -type which includes an upstanding outer casing; a pipe bundle in the shape of a V mounted in the casing, the pipe bundle having an upward-extending bundle portion and a downward extending bundle portion with a space between the two portions, each bundle portion comprising a number of spaced rows of pipes; a bottom at the foot of the pipe bundle which closes the openings between the pipes and between the pipes and the outer casing; at least two accesses through the outer casing at substantially opposite sides thereof, the accesses lying above the bottom and providing access to the space between the two bundle portions; the method comprising the steps of:
(a) introducing through each of the two accesses and into the space between the pipe bundle portions an elongated, rigid high pressure lance which is rotatable about its longitudinal axis and is shiftable in the direction of its longitudinal axis, each lance including a spray head at the end thereof introduced into said space, the spray head having two pairs of radially directed, longitudinally spaced spray openings, each pair being disposed to direct fluid jets radially outwardly from the longitudinal axis of the lance on substantially opposite sides of the spray head, the pairs being longitudinally spaced by a distance substantially equal to the center-to-center spacing between adjacent rows of pipes of the pipe bundle portions and the fluid jets directed outwardly therefrom being approximately perpendicular to each other;
(b) introducing through each of the two accesses at least one suction line provided with at least one suction opening situated adjacent the bottom within the outer casing;
(c) shifting simultaneously stepwise both lances such that between each shifting step the jets from the spray head are directed between the rows of pipes of the pipe bundle portions;
(d) oscillating both of the lances through an angle of about 90 degrees on each side of a neutral position at least between the shifting steps;
(e) spraying a cleaning liquid through the spray heads at least during the oscillating of the lances under a pressure higher than 200 bars and with a mean flow rate for both spray heads together of more than 200 liters per minute, whereby the jets from the two pairs of openings in the spray heads of each lance move across the entire area of the bottom between two adjacent rows of pipes of the pipe bundle portions; and (f) sucking the sprayed liquid away from the bottom through the suction lines during the cleaning with a total suction capacity which is markedly higher than the mean flow rate of the spray heads together.
(a) introducing through each of the two accesses and into the space between the pipe bundle portions an elongated, rigid high pressure lance which is rotatable about its longitudinal axis and is shiftable in the direction of its longitudinal axis, each lance including a spray head at the end thereof introduced into said space, the spray head having two pairs of radially directed, longitudinally spaced spray openings, each pair being disposed to direct fluid jets radially outwardly from the longitudinal axis of the lance on substantially opposite sides of the spray head, the pairs being longitudinally spaced by a distance substantially equal to the center-to-center spacing between adjacent rows of pipes of the pipe bundle portions and the fluid jets directed outwardly therefrom being approximately perpendicular to each other;
(b) introducing through each of the two accesses at least one suction line provided with at least one suction opening situated adjacent the bottom within the outer casing;
(c) shifting simultaneously stepwise both lances such that between each shifting step the jets from the spray head are directed between the rows of pipes of the pipe bundle portions;
(d) oscillating both of the lances through an angle of about 90 degrees on each side of a neutral position at least between the shifting steps;
(e) spraying a cleaning liquid through the spray heads at least during the oscillating of the lances under a pressure higher than 200 bars and with a mean flow rate for both spray heads together of more than 200 liters per minute, whereby the jets from the two pairs of openings in the spray heads of each lance move across the entire area of the bottom between two adjacent rows of pipes of the pipe bundle portions; and (f) sucking the sprayed liquid away from the bottom through the suction lines during the cleaning with a total suction capacity which is markedly higher than the mean flow rate of the spray heads together.
12. The method of Claim 11 wherein the lances are introduced through the accesses such that the spray heads are positioned adjacent the center of the generator and the lances are stepwise shifted simultaneously toward the outer casing.
13. A method for cleaning a steam generator of so-called U type, which steam generator consequently comprises:
an upstanding outer casing a pipe bundle mounted therein, which extends in the shape of a reversed U and comprises an upwards-extending bundle portion and a downwards-extending bundle portion with a space between both portions, each portion comprising a number of rows spaced from each other and extending crosswise to said space;
a bottom which closes at the foot of the pipe bundle the openings between the bundle pipes and between said pipes and the outer casing;
an inner casing which is mounted inside the outer casing and around the pipe bundle and reaches down to a distance from the bottom; and a supporting plate for the pipe bundle, which supporting plate is mounted above the bottom inside the inner casing, with at least a major portion of the circumference thereof loose from the inner casing, so that liquid can fall over tile edge thereof on the bottom, which supporting plate is provided in the center thereof with an opening, which steam generator is provided between the bottom and supporting plate with a plurality of accesses giving access to the pipe bundle, and is provided directly above the supporting plate with two accesses lying opposite one another and giving access to the space between said two bundle portions inside the inner casing, which method comprises:
cleaning the space above the supporting plate by, (a) introducing through each of said two accesses above the supporting plate an elongated high pressure lance which is rotatable about its longitudinal axis, is shiftable in the direction of its longitudinal axis and carries, fixedly mounted on the end introduced through the access, a spray head provided with at least one pair of radially directed spray openings;
(b) introducing through each of said two accesses above the supporting plate at least one suction line comprising an end portion provided with at least one suction opening, said end portion being situated against the bottom and against the outer casing;
(c) shifting simultaneously stepwise both lances, in such a way that between each shifting step the spray heads spray between rows of the pipe bundle;
(d) oscillating said lances over an angle of about 180 degrees at least between shifting steps;
(e) spraying cleaning liquid through said spray heads, at least during said oscillating, under a pressure higher than 200 bars and with a flow rate for both spray heads together of more than 200 liters per minute; and (f) sucking the used cleaning liquid away from the bottom through the suction line during the cleaning with a total sucking capacity which is markedly higher than said latter flow rate; and cleaning the space between the bottom and the supporting plate by:
(a) introducing through each of said plurality of accesses to the space between the bottom and the supporting plate a rigid high pressure lance which is rotatable about its longitudinal axis is shiftable in the direction of said longitudinal axis and carries fixedly mounted on its end a spray head provided with at least one pair of radially directed spray openings;
(b) shifting stepwise said lances in such a way that between each shifting step the spray heads may spray between rows of the pipe bundle;
(c) oscillating said lances over an angle of about 180 degrees at least between shifting steps;
(d) spraying cleaning liquid through said spray heads, at least during said oscillating under a pressure higher than 200 bars; and (e) sucking the used cleaning liquid away from the bottom through said suction line introduced for cleaning the space above the supporting plate with a total sucking capacity which is markedly higher than the total flow rate of liquid sprayed.
an upstanding outer casing a pipe bundle mounted therein, which extends in the shape of a reversed U and comprises an upwards-extending bundle portion and a downwards-extending bundle portion with a space between both portions, each portion comprising a number of rows spaced from each other and extending crosswise to said space;
a bottom which closes at the foot of the pipe bundle the openings between the bundle pipes and between said pipes and the outer casing;
an inner casing which is mounted inside the outer casing and around the pipe bundle and reaches down to a distance from the bottom; and a supporting plate for the pipe bundle, which supporting plate is mounted above the bottom inside the inner casing, with at least a major portion of the circumference thereof loose from the inner casing, so that liquid can fall over tile edge thereof on the bottom, which supporting plate is provided in the center thereof with an opening, which steam generator is provided between the bottom and supporting plate with a plurality of accesses giving access to the pipe bundle, and is provided directly above the supporting plate with two accesses lying opposite one another and giving access to the space between said two bundle portions inside the inner casing, which method comprises:
cleaning the space above the supporting plate by, (a) introducing through each of said two accesses above the supporting plate an elongated high pressure lance which is rotatable about its longitudinal axis, is shiftable in the direction of its longitudinal axis and carries, fixedly mounted on the end introduced through the access, a spray head provided with at least one pair of radially directed spray openings;
(b) introducing through each of said two accesses above the supporting plate at least one suction line comprising an end portion provided with at least one suction opening, said end portion being situated against the bottom and against the outer casing;
(c) shifting simultaneously stepwise both lances, in such a way that between each shifting step the spray heads spray between rows of the pipe bundle;
(d) oscillating said lances over an angle of about 180 degrees at least between shifting steps;
(e) spraying cleaning liquid through said spray heads, at least during said oscillating, under a pressure higher than 200 bars and with a flow rate for both spray heads together of more than 200 liters per minute; and (f) sucking the used cleaning liquid away from the bottom through the suction line during the cleaning with a total sucking capacity which is markedly higher than said latter flow rate; and cleaning the space between the bottom and the supporting plate by:
(a) introducing through each of said plurality of accesses to the space between the bottom and the supporting plate a rigid high pressure lance which is rotatable about its longitudinal axis is shiftable in the direction of said longitudinal axis and carries fixedly mounted on its end a spray head provided with at least one pair of radially directed spray openings;
(b) shifting stepwise said lances in such a way that between each shifting step the spray heads may spray between rows of the pipe bundle;
(c) oscillating said lances over an angle of about 180 degrees at least between shifting steps;
(d) spraying cleaning liquid through said spray heads, at least during said oscillating under a pressure higher than 200 bars; and (e) sucking the used cleaning liquid away from the bottom through said suction line introduced for cleaning the space above the supporting plate with a total sucking capacity which is markedly higher than the total flow rate of liquid sprayed.
14. The method of Claim 13 which further comprises during the cleaning of the space between the bottom and supporting plate, shifting simultaneously stepwise both lances introduced above the supporting plate;
oscillating said both lances over an angle of about 180 degrees at least between shifting steps, and spraying cleaning liquid through said two spray heads, at least during said oscillating, under a pressure higher than 200 bars and with a mean flow rate for both spray heads together, that together with the total flow rate of the four spray heads together in the space between the bottom and the supporting plate, is more than 200 liters per minute.
oscillating said both lances over an angle of about 180 degrees at least between shifting steps, and spraying cleaning liquid through said two spray heads, at least during said oscillating, under a pressure higher than 200 bars and with a mean flow rate for both spray heads together, that together with the total flow rate of the four spray heads together in the space between the bottom and the supporting plate, is more than 200 liters per minute.
15. The method of Claim 13 wherein each of the spray heads introduced above the supporting plate includes two pairs of radially directed spray openings, the openings of one pair being directed at right angle to the openings of the other pair, and both pairs lying at a distance from one another which corresponds to the center-to-center spacing, between the rows of the pipe bundle as measured in the direction of the longitudinal axis of the lance.
16. The method of Claim 13 wherein four accesses are provided between the bottom and the supporting plate and wherein a rigid high pressure lance is introduced through each of said four accesses.
17. A method for cleaning a steam generator of so-called U type, which steam generator consequently comprises:
an upstanding outer casing;
a pipe bundle mounted therein, which extends in the shape of a reversed U and comprises an upwards-extending bundle portion and a downwards-extending bundle portion with a space between both portions, each portion comprising a number of rows spaced from each other and extending crosswise to said space;
a bottom which closes at the foot of the pipe bundle the openings between the bundle pipes and between said pipes and the outer casing;
an inner casing which is mounted inside the outer casing and around the pipe bundle and reaches down to a distance from the bottom; and a supporting plate for the pipe bundle, which supporting plate is mounted above the bottom inside the inner casing, with at least a major portion of the circumference thereof loose from the inner casing, so that liquid can fall over the edge thereof on the bottom, which supporting plate is provided in the center thereof with an opening, which steam generator is provided between the bottom and supporting plate with four accesses giving access to the pipe bundle, and is provided directly above the supporting plate with two accesses lying opposite one another and giving access to the space between said two bundle portions inside the inner casing, which method comprises:
cleaning the space above the supporting plate by;
(a) introducing through each of said two accesses above the supporting plate a right high pressure lance which is oscillating around its longitudinal axis, is shiftable in the direction of its longitudinal axis and carries fixedly mounted on its end a spray head provided with two pairs of radially directed spray openings, the openings of one pair being directed at right angle to the openings of the other pair, and both pairs lying at a distance from one another which corresponds to the center-to-center spacing, between the rows of the pipe bundle as measured in the direction of the longitudinal axis of the lance;
(b) introducing through each of said two accesses above the supporting plate at least one suction line comprising an end portion provided with at least one suction opening, said end portion being situated against the bottom and against the outer casing and being directed with the suction opening along the circumference of the bottom;
(c) shifting simultaneously stepwise both lances, in such a way that between each shifting step the spray heads may spray between rows of the pipe bundle;
(d) oscillating said lances over an angle of about 180 degrees at least between two succeeding shifting steps;
(e) spraying cleaning liquid through said spray heads, at least during said oscillating, under a pressure higher than 200 bars and with a flow rate for both spray heads together of more than 200 liters per minute; and (f) sucking the used cleaning liquid away from the bottom through the suction line during the cleaning with a total sucking capacity which is markedly higher than said latter flow rate; and cleaning the space between the bottom and the supporting plate by:
(a) introducing through each of said four accesses to the space between the bottom and the supporting plate a rigid high pressure lance which is oscillating around its longitudinal axis, is shiftable in the direction of said longitudinal axis and carries fixedly mounted on its end a spray head provided with at least one pair of radially directed spray openings;
(b) shifting stepwise said lances in such a way that between each shifting step the spray heads may spray between rows of the pipe bundle;
(c) oscillating said lances over an angle of about 180 degrees at least between shifting steps;
(d) spraying cleaning liquid through said spray heads, at least during said oscillating under a pressure higher than 200 bars; and (e) sucking the used cleaning liquid away from the bottom through said suction line introduced for cleaning the space above the supporting plate with a total sucking capacity which is markedly higher than the total flow rate of liquid sprayed.
an upstanding outer casing;
a pipe bundle mounted therein, which extends in the shape of a reversed U and comprises an upwards-extending bundle portion and a downwards-extending bundle portion with a space between both portions, each portion comprising a number of rows spaced from each other and extending crosswise to said space;
a bottom which closes at the foot of the pipe bundle the openings between the bundle pipes and between said pipes and the outer casing;
an inner casing which is mounted inside the outer casing and around the pipe bundle and reaches down to a distance from the bottom; and a supporting plate for the pipe bundle, which supporting plate is mounted above the bottom inside the inner casing, with at least a major portion of the circumference thereof loose from the inner casing, so that liquid can fall over the edge thereof on the bottom, which supporting plate is provided in the center thereof with an opening, which steam generator is provided between the bottom and supporting plate with four accesses giving access to the pipe bundle, and is provided directly above the supporting plate with two accesses lying opposite one another and giving access to the space between said two bundle portions inside the inner casing, which method comprises:
cleaning the space above the supporting plate by;
(a) introducing through each of said two accesses above the supporting plate a right high pressure lance which is oscillating around its longitudinal axis, is shiftable in the direction of its longitudinal axis and carries fixedly mounted on its end a spray head provided with two pairs of radially directed spray openings, the openings of one pair being directed at right angle to the openings of the other pair, and both pairs lying at a distance from one another which corresponds to the center-to-center spacing, between the rows of the pipe bundle as measured in the direction of the longitudinal axis of the lance;
(b) introducing through each of said two accesses above the supporting plate at least one suction line comprising an end portion provided with at least one suction opening, said end portion being situated against the bottom and against the outer casing and being directed with the suction opening along the circumference of the bottom;
(c) shifting simultaneously stepwise both lances, in such a way that between each shifting step the spray heads may spray between rows of the pipe bundle;
(d) oscillating said lances over an angle of about 180 degrees at least between two succeeding shifting steps;
(e) spraying cleaning liquid through said spray heads, at least during said oscillating, under a pressure higher than 200 bars and with a flow rate for both spray heads together of more than 200 liters per minute; and (f) sucking the used cleaning liquid away from the bottom through the suction line during the cleaning with a total sucking capacity which is markedly higher than said latter flow rate; and cleaning the space between the bottom and the supporting plate by:
(a) introducing through each of said four accesses to the space between the bottom and the supporting plate a rigid high pressure lance which is oscillating around its longitudinal axis, is shiftable in the direction of said longitudinal axis and carries fixedly mounted on its end a spray head provided with at least one pair of radially directed spray openings;
(b) shifting stepwise said lances in such a way that between each shifting step the spray heads may spray between rows of the pipe bundle;
(c) oscillating said lances over an angle of about 180 degrees at least between shifting steps;
(d) spraying cleaning liquid through said spray heads, at least during said oscillating under a pressure higher than 200 bars; and (e) sucking the used cleaning liquid away from the bottom through said suction line introduced for cleaning the space above the supporting plate with a total sucking capacity which is markedly higher than the total flow rate of liquid sprayed.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| BE2/60192A BE897603A (en) | 1983-08-26 | 1983-08-26 | Apparatus for cleaning a steam generator by means of a high-pressure lance |
| BE2/60192 | 1983-08-26 | ||
| BE2/60384 | 1984-04-05 | ||
| BE2/60384A BE899330A (en) | 1984-04-05 | 1984-04-05 | METHOD FOR CLEANING A STEAM GENERATOR |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1216479A true CA1216479A (en) | 1987-01-13 |
Family
ID=25661788
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000458461A Expired CA1216479A (en) | 1983-08-26 | 1984-07-09 | Process for cleaning a steam generator |
Country Status (3)
| Country | Link |
|---|---|
| US (1) | US4620881A (en) |
| CA (1) | CA1216479A (en) |
| FR (1) | FR2550967B1 (en) |
Families Citing this family (17)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4769085A (en) * | 1983-08-26 | 1988-09-06 | Innus Industrial Nuclear Services S.A. | Method for cleaning a steam generator |
| US4676201A (en) * | 1984-07-25 | 1987-06-30 | Westinghouse Electric Corp. | Method and apparatus for removal of residual sludge from a nuclear steam generator |
| US4848278A (en) * | 1985-11-26 | 1989-07-18 | Apex Technologies, Inc. | Nuclear steam generator sludge lancing method and apparatus |
| BE1000357A4 (en) * | 1987-02-26 | 1988-11-08 | Innus Ind Nuclear Service | An apparatus for cleaning of a heat exchanger. |
| US4859249A (en) * | 1988-03-14 | 1989-08-22 | E. I. Du Pont De Nemours And Company | Process for cleaning enclosed vessels |
| US4972804A (en) * | 1989-04-25 | 1990-11-27 | Alexander T. Kindling | Method and apparatus for organizing the flow of fluid in a vertical steam generator |
| US5019329A (en) * | 1989-12-26 | 1991-05-28 | Westinghouse Electric Corp. | System and method for vertically flushing a steam generator during a shock wave cleaning operation |
| US5241723A (en) * | 1991-10-21 | 1993-09-07 | The Babcock & Wilcox Company | Nozzle structure with improved stream coherence |
| CA2115109C (en) * | 1994-02-01 | 2000-04-25 | James P. Vanderberg | Automated sludge lance |
| US5782209A (en) * | 1995-09-20 | 1998-07-21 | The Babcock & Wilcox Company | Segmented automated sludge lance |
| FR2742858B1 (en) * | 1995-12-22 | 1998-03-06 | Framatome Sa | METHOD AND DEVICE FOR CLEANING A TUBULAR PLATE OF A HEAT EXCHANGER FROM THE INSIDE OF THE HEAT EXCHANGER BEAM |
| FR2754331B1 (en) * | 1996-10-07 | 1998-12-18 | Sra Savac | TOOL FOR HIGH-PRESSURE WATER JET CLEANING, IN PARTICULAR CLEANING OF A TUBULAR PLATE OF STEAM GENERATOR |
| KR101103820B1 (en) * | 2009-09-18 | 2012-01-06 | 한전케이피에스 주식회사 | Dual type equipment for water jet cleaning on the top of the tube sheet of steam generator in nuclear power plant |
| US9400145B2 (en) | 2014-07-25 | 2016-07-26 | Stoneage, Inc. | Flexible multi-tube cleaning lance positioner guide apparatus |
| CN106944444B (en) * | 2017-05-09 | 2024-03-29 | 湖州浩森科技股份有限公司 | Electric heating steam cleaning device for glassware |
| CN112139157B (en) * | 2020-08-24 | 2022-03-25 | 神华铁路装备有限责任公司 | Pipe outer wall cleaning equipment and method |
| CN114653694B (en) * | 2020-12-22 | 2023-03-17 | 核动力运行研究所 | Opposite-swing nozzle structure for washing sludge of tube plate of steam generator |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3254448A (en) * | 1964-03-23 | 1966-06-07 | Ruthner Othmar | Installation for the artificial cultivation of plants, bacteria and other organisms |
| US3985572A (en) * | 1974-11-04 | 1976-10-12 | Georgia-Pacific Corporation | Automatic spray cleaning apparatus and method |
| US4068405A (en) * | 1975-09-11 | 1978-01-17 | Joseph W. Campbell | Automatic food plant production |
| US4018213A (en) * | 1976-04-05 | 1977-04-19 | Mann Jr Harold J | Solar heating structure |
| US4079701A (en) * | 1976-05-17 | 1978-03-21 | Westinghouse Electric Corporation | Steam generator sludge removal system |
| AT350832B (en) * | 1977-05-12 | 1979-06-25 | Ruthner Othmar | PLANT FOR IMPROVING THE STORAGE OF BIOCHEMICAL ENERGY THROUGH THE USE OF SOLAR ENERGY AND / OR OTHER ELECTRO-MAGNETIC RADIATION ENERGY IN PLANTS |
| US4195441A (en) * | 1977-05-23 | 1980-04-01 | Baldwin Richard E | Solar greenhouse |
| US4173212A (en) * | 1977-10-17 | 1979-11-06 | The Board of Regents for the Oklahoma Agricultural and Mechanical Colleges | Self-contained solar greenhouse |
| US4141498A (en) * | 1977-10-31 | 1979-02-27 | Walter Marschner | Combination structure and greenhouse utilizing indirect solar energy |
| US4198953A (en) * | 1978-03-28 | 1980-04-22 | Terra Tek, Inc. | Solar illuminated energy conserving greenhouse |
| US4249340A (en) * | 1978-12-07 | 1981-02-10 | Environmental Research Institute Of Michigan | Solar energy collector |
| US4276856A (en) * | 1978-12-28 | 1981-07-07 | Westinghouse Electric Corp. | Steam generator sludge lancing method |
| US4273076A (en) * | 1978-12-28 | 1981-06-16 | Westinghouse Electric Corp. | Steam generator sludge lancing apparatus |
| US4262656A (en) * | 1979-02-28 | 1981-04-21 | Chris Esposito | Solar climate control for greenhouses |
| US4289116A (en) * | 1979-10-16 | 1981-09-15 | Meadowbrook Resort, Inc. | Solar heating system for a greenhouse or other building |
| US4393859A (en) * | 1980-02-19 | 1983-07-19 | Armco Inc. | Solar collector roof |
| US4356664A (en) * | 1980-12-01 | 1982-11-02 | Othmar Ruthner | Plant for the continuous production of green forage |
| FR2506428A1 (en) * | 1981-05-22 | 1982-11-26 | Framatome Sa | METHOD AND DEVICE FOR DECOLMATING THE UPPER FACE OF THE TUBULAR PLATE OF A STEAM GENERATOR |
| BE889706A (en) * | 1981-07-23 | 1982-01-25 | Booy Support Bv | METHOD FOR REMOVING SLUDGE FROM A STEAM GENERATOR |
| US4407236A (en) * | 1981-09-21 | 1983-10-04 | Combustion Engineering, Inc. | Sludge lance for nuclear steam generator |
| BE890490A (en) * | 1981-09-24 | 1982-01-18 | Natdevco Nv | METHOD FOR CLEANING A STEAM GENERATOR WITH WATER AND MEASURING METHOD |
| FR2514108B1 (en) * | 1981-10-06 | 1986-06-13 | Framatome Sa | PROCESS AND DEVICE FOR REMOVING SLUDGE FROM THE TUBULAR PLATE OF STEAM GENERATORS |
-
1984
- 1984-05-14 US US06/609,802 patent/US4620881A/en not_active Expired - Fee Related
- 1984-07-04 FR FR8410635A patent/FR2550967B1/en not_active Expired
- 1984-07-09 CA CA000458461A patent/CA1216479A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| FR2550967A1 (en) | 1985-03-01 |
| US4620881A (en) | 1986-11-04 |
| FR2550967B1 (en) | 1986-08-01 |
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| Date | Code | Title | Description |
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| MKEX | Expiry |