US 1608691 A
Description (OCR text may contain errors)
ov, 30 #92a Los,
R. w. BAILEY TREATMENT 0F STEAM T0 REDUCEv OR REVENT CORROSION Filed Dec. 1'?. 1921 2 Smets-sheet 2 ATTORNEY Patented Non.r 39, i926.,
naiss RCI-ARD-WILLAM BALEY, OF ALTRZ'GHAM, EEGLAND, ASSGNGR T0 WESTNG- HOUSE ELECTRIC 35 MANUFACTURENG COMPANY, A CQRPRATEON OF PENNSYL- VANEA.
TREATMENT 0F STEAM T0 REDUCE 0R PREVENT CGRRGSION.
Application filed December 17, 1921, Serial No.
Ihis invention relates to means for treating steam to reducel or prevent corrosion of apparatus or plants in which it isutilized and while it is applicable generally to steam plants of various kinds, it is directed principally to the reduction or prevention of corrosion of the blading in steamfturbines. f
With this object in view it has already been suggested to provide in connection with steam turbines and other engin-es a corredible strainer through which steam'is caused to pass before entering the turbine or other engine, the steam in passing; lthrough the strainer coming into 4contact with metals which so far as corrosion is concerned are similar to or not less acted upon than those of the turbine or engine parts in which the steam is to be'afterwards employed. It does not, however, appear to have been appreciated that corrosion of the metals in question only proceeds in the presence of moisture and the passing 4of dry steam through such a strainer as has been heretofore suggested would not necessarily attain the result desired. I
- According to the present invention a device such as the corrodible strainer heretofore suggested is arranged to be located in the path of the steam from the boiler to the lturbine or other appliance at a point where the steaml contains a sufficient amount of moisture to enable the device to be effective. Consequently, when the steam is superheated before being used, the device or strainer will, according to the present invention, be located between the boiler and the superheater. Where the steam at no part of its path is in a sufficiently vwet or saturated condition to obtain the most effective neutralization or lremoval of the active corrosive elements contained in the steam, water may be injected into the corrodible strainer in the form of a fine spray or may be caused to trickle over the surface of the material provided in said device or the steam may be partly condensed by passing it through a device somewhat similar for example to a feed water heater lof the surface type so that its moisture content is raised to the necessary amount. Preferably, a steam drieror `separator is incorporated for the purpose of removing excess moisture from the steam after 528,055, and in Great Britain December 20, 192i).
Yit has been treated before its admission to the turbine or other apparatus in which it is to be used.
To enable the invention tc be clearly understood it will now be described with referenceto the accompanying drawings in which F ig. l is a diagrammatic sectional elevationof steam treating apparatus in accordance with the invention, applied by way of example to a. water tube steam boiler; 2 is a sectional elevation of one form of the steam treating apparatus sho-wing the parts thereof in greater detail and Fig. 3 is a section on the line lll-HI of Fig. 2; Fig. i is a ysectional elevation of another form of the steamk treating apparatus and Fig. 5 is a section on. the line VV of F ig. e. F 6 is a sectional elevation of. a further form of the steam treating apparatus in accordance with the invention. Fig. 7 is a sectional elevation lof a still further form of the steam heating apparatus, and Fig. 8 is a section on the line VIIIe-VH1 of Fig 7.
Referring to Fig. l of the drawings, l is the upper 4.drum forming' partrof a common form of water-tube boiler, 2 and 3 indicate respectively the front and back water tubes connecting thev said drum to a lower drum not shown, and 4: indicates a superheater which. is connected to an off-take header 5 and an intake header V6.l rllhe latter is connected with a pipe which in the ordinary way terminates in a portion 8 shown in dotted lines within the upper portion of the shell of the boiler above the water level therein. The steam treating apparatus in accordance with-the present invention is indicated at 10 and comprises a drum or casing ll ofcylindrical, rectangular or other shape having its ends closed, kfor example, by caps l2 and 13. rlhe treatment material indicated at le consisting of iron plates e2:- panded sheet, turnings or the like for eX- ample, is arranged substantially in the central portion of the casing 11. The casing 1l is conveniently supported on the top ofthe upper drum l of the boiler and is connected with the latter through a pipe 15 through which the steam passes from the drum l into the casing' ll thence passing upwards through the treatment material lli and leaves the said casing by means of an outlet pipe' 16 sar which is connected directly to the pipe 7, the portion 8 being dispensed with. In the case, however, of a new boiler Ahaving'. t-he treater apparatus lin accordance with the'invention usedV therewith, the pipe 16 may be connected to theinlet header 6 or' the .superheater 4 in any'V convenient manner.
Steam in a comparatively wet condition enters the treater .10 through Vthe pipe and coming` into contact with the treatment material 14 corrodes the latter and its corrosive constituents are thereby reduced.
`case the steam doesy not possess sufficient moisture content for proper corrosive action with the treatmenty material 14,. the incoming steam may be artificially wetted byfmeans of a spray device 17 arranged immediately above the treatment material 14Y and :supplied with water through a pipe 18 from any conve-nient so-urce. TWater from `the spraying device-17 will trickle over the surface loi the treatmentl material 14 and drip into the bottom ot the-'casing 11. A pipe connection 19v with a submerged discharge is provided* between the lower part of' the casing 11 and the drum 1 of the boiler by Cil which water collecting in thebottom ol' the vcasing" is passed into the boiler. Said pipe has an inlet 20, which is at a lowerlevel than'the inlet ofthe pipe 15 into the casing I 11, but some distance from the bottom'thereof,so thatv the latter can serve as a receptacle for anyfdepositl or debris which may fall fromV the treater. Vilitliin 'the upper Vpart ofthe casingis preferably arranged a separator 21 oil any we-lllrno-wntype through which thev steam passes before leaving by the outlet pipe 16. This separator- 2.1 serves to remove the excess moisture 'from the steam and may advantageously ltake the same form as thetreaterA andV comprise similar'materialso that inl addition to the steam being-i drred'theiebv, further or more complete removal of the corrosive constituents oil the steam some'o'f which may havebeen added to the steam by thewater supplied for moistening it, takes place in the drying or separating'process.
Rer'erringl to the detailed and preferred construction of the `treater illustrated in Figs. 2 `and 3, the treatment material 14 is in ther form oif'a plurality' of rectangular .plates ar angedparallel'with one another in Fig. 3) then passes dmvmvards beneath the lower edges oi the walls of the `iframe and therceupwzerds as show-ahy the arrow 2G through the plates oi .the treatment material 14. The .steam drier or separator 2l is preferably ol similar construction to the treater 14 and is provided with an openended rectangular trame 27 having'v a flange 28 at its lower edges resting upon an internal flange 29 within the drinn or easing 11. The steam passes upwards through the treate-r` 14 and the drier 2land thence passes as shown by the arrows 30 over the top edge of' theV frame 27 and leave` the casing 11l by vhe outletV pipe 16. rlhe actionzofthisfform of thetreating"apparatus is the-saune as that of the apparatus otlligl 1. The steamenters by the inlet pipe lfandis .deflected by the vertical sides of the frame 22, its speed being greatly decreased owing to the largetcrosssectional area of its path; rllhe velocity of t'he'steam after enteringthe outlet pipeli is increased owingto the reduction ofthe sectional *area` of thel passages through which it passes. luthis manner a relatively low steam -speed through the -apparatus is 0btained and the tendency to disturbance at the entrance of thetreatment materiali Ais reduced. rlhe .method of supporting the ii'raines22 and 27 uponiianges as described, permit: the treatment material to be readily renewedvor cleaned. lt will be understood that instead o 'f rectangular platesthe said frames may carryV expanded or" perforated plates arranged 'horizontally or vertically or iron turnings may be used.v Furthermore,-
the plates or the like may be arranged in groups or sections or horizontal layers. Or 1 ne plates may be inclined and so arrangedl Vthat steam 1s caused to take a`z1gzag path through the apparatus.k
Referring now to the construction' of the apparatusillustrated in Figs. 4 and 5, the casing'll is here arranged vwith Aits aXiSsUbstantially horizon-tal and supported on .the top of thefdrum 1 of the-boiler in any convenient manner. The treatment mat'erial'14 consisting of iron plates, for example, isI arranged within a Aframe 31 which is rectanvguiar in horizontal cross sectionand as before, is open atthe top `and bottom. The said" frame is cut away, as'clearly shown, in a Aslanting direction towards the ends so as vto er1-pose the vertical edges of the plates and is provided with flanges substantially in the centre of the two sides thereof' which are parallel-with the axis of the casing. The iianges 32 rest upon horizontal webs 33' arranged within the casing 11 as clearly shown in Fig. 5. The casing is provided with a partition which lits around the right hand end of the upper partoii the frame 31 to provide 'a substantially steam-tight joint there with as shown at 34 in Fig.. 4. A similar partition 35is arranged in they lower part' of the other end of the casing 11 and tits around the-lower part of the :trame 31 also providing a substantially steam-tight joint therewith. These partitions along with the ianges 32 and 33 cause the steam entering by the inlet pipe 15 and leaving by the outlet pipe 16 to assume the -path indicated by the arrows, that is, the steam passes upwards through the space in the left hand end ot the casing 11 and thence passes downwards and laterally into the treatment material 14. The steam then leaves the plates of treatment material 14 in a 'downward and lateral direction and passes upwards through the space at the right hand end of the casing 11 leaving by the pipe 16. The spraying device 17 is provided above the treatment material and the outlet pipe 19 is arranged in the manner described with reference to Fig. 2, a valve 36 being provided in said pipe it desired. The
end covers 12 and 13 being removable, en-l able the interior oi. the casing 11 to be inspected and permit the withdrawalofthe frame 31 containing the treatment material.
In the arrangement illustrated in Figs. 4 and 5, no drier or separator is shown but a separate drier may be employed it desired, In the apparatus of 6, however, a steam drier yor separator is provided in the following manner. The frame 37 containing the treatment material 14 is somewhat similar to the frame 31, described in connection with Figs. 4 and 5 excepty that the side walls abo-ve the flanges 32 are not cut away, the side walls below the flanges 32 being cut away at 38 and 39 at eachend as shown. rlChe drum or casing 11 is provided with two partitions 40 and 41 fitting around the upper portion of the two ends of the casing 37 and with a third partition 42 fitting around the lower part of the casing 39 and located a suitable distance along the said casing from the inlet end. lVith the above described disposition of the partitions 40, 41 and 42, the steam entering by the inlet pipe 15 is caused to pass upwards and laterally into the treatment material 14 into a space 43 in the upper portion of the drum 11 between the partitions and 41 and thence downwards through the treatment material21 separated from the treatment material 14 by the lower partition 42 and constituting the steam drier or separator. The steam leaves the plates of the treatment material 21 downwards and laterally and passes in the space into the right hand endof the drum 11 and thence outwards through the pipe 1 6. It will be understood that by suitably disposing the partitions 40, 41 and 42, the steam may be made to pass downwards through the treater 14 and upwards through the drier or separator or upwards through both of these devices. This arrangement possesses the advantage that any corrosive constituents liberated by the spray are carried over the surface of the treatment material by the steam and are neutralized later, and since the steam passes upwards through the drier 21, a more complete separation of the water from the steam may be obtained.,
it will be understood that the outlet pipe 19 instead or" being connected to the end covers 13 may be connected with the lower surtace of the drum as shown in Figs. 1 and 7. In this way the end covers are left free from any connections and can thus be readily removed.
Referring to the arrangement illustrated in Figs. 7 and 8, the drum or casing 11 is provided with a horizontal web 44 extending completely around its inner walls. A vertical partition r45 extends upwards from the lower part ot the drum or casing 11 as tar as the said web 44 and divides the lower part of the casing into two compartments 46 and 47, one of which is larger than the other as shown.` The larger compartment 46 contains the treater 14carried in a rectangular frame 48 and provided `with a tiange 49 which is adapted to rest upon the web 44 and at one end upon the upper end of the partition 45. The smaller compartment 47 contains a drier or separator 21 carried in a rectangular frame 50 provided with flanges 51 resting upon. the web 44 and at one end also upon the upper end ot' the partition 45. The treatment compartment 46 is provided with lateral inlet openings 52 connected with the inlet pipe 15 by means ot passages 53. The openings 52 are arranged below the web 44 so that the steam entering the pipe 15 passes beneath the lower edges of the trame 4S and thence upwards through the treatment material 14 in said trame. On leaving the treater-the steam passes over the upper edges of the trames 48 and 50 and ot' the partition 45V and thence downwards through the drier or separator 21 into the space beneath the web 44 in the compartment 47. The steam leaves the latter compartment through lateral openings 54 communicating by passages 55 with the outlet pipe 16. The spraying device 17 is provided over the treater 14 in the manner already described. The water outlet pipe 19 is provided as before to drain the water from the treatment compartment 46 into the boiler or elsewhere and a pipe 56 is provided for draining away any water that may accumulate in the separator compartment 47.
It will be understood that various valves such as indicated at 57 and 58 in Fig. 4 may be provided for isolating the treating apparatus and suitable by-passes, not shown, sov as to'permit the boiler to supply steam direct in the event of the said apparatus being out of order and also to permit it being opened up for inspection or other purposes. ln carrying out the invention the material employed in the anti-corrosive device or Y steain, and means for injecting a spray orl strainer inay be ot various kinds andY the invention is not li-niited; to a specicinaterial o-rtliis purpose. ln' the case oi* steam turbines having steel bla-des,-l oneniaterial which is very suitable 'for the purpose is sheet iron or expanded sheet steel or a light network of steelor steel tui'iiings offering anr extend ed surface inay'be employed as already described. ylllliere water-is injected into the apparatus for the purpose of' increasing the moisture content oi'tl'ie steam, a portion of the boiler t'eed may be employed at the tenr.
peratnre at 'which it enters the boiler, the
quantity being arrangedv to be definite fraction of the total lfeed.
Having non'V particularly desfribed and ascertained the nature ofA inyk said'invention andf in What inaiiner the saine is to be performed, I declare that what I claiin is :m
l. .Inra Vsteani generating plant, the coinloination oi a steam conduit, a corrodible strainer interposed in the steani conduit for separating the corrosive contents froml the Water into 'tlie corrodible strainer.
2. n afsteani generating plant, the coin-A bination et VaV steam conduit, a corrodible strainer interposed in the steain conduit for Vseparating the corrosive contents ironi the steain, 'means for injecting a spray or' Water into tlie'corrodible strainer, andA a separator for drying the stearn after Dassin@ through .l to b o tli e1 corrodible strainer.
in a stearn` generating plant, the coinbination oit a steam conduit, a corrodible Y strainer comprised of a plurality of elenients of corrodible materialV arranged parallel and in closely spaced relation for separating the corrosive contents from vthe steain, means for effecting a flow of steamiiiV onedirection throughtl'ie corrodilile,v strainer,
andlineans for introducing a sprayot Water into tlie vstrainer insiich al manner that it trieldes over tlie elements in av direction opposite the 'steani flow, and a separator for drying the steam Vaiter passing through the corrodible strainer;
In combination, a conduitl'for conveyj ing steani, a corrodible strainer interposed in the conduit and coniprised of a'plurality of plates oi'i norrodible nia-terial arranged in parallel-and inclosely spaced relation, means eliectiiig a ii'ow oi' steani in one direotionbetween they plates, nieaiis or'injecting Water tien, between the plates, ineansi'oi" inject ing water into the strainer and eif'lectingfa :Flow thereof between the plates in a direction opposite tothe steain flow, means vfor.
.draining the Water injected into the strainer including nieans for collecting foreign vInater introduced with' the Water, and a separator -lfer drying the steani after passage through the strainer. i
ln testimony whereof, I Vhave hereunto subscribed niy naine this 24th day of No- Aveniber 1921.
RICHARD ll/YILLIAM BLEY