CA1166733A - Slit nozzle and fast-acting shutoff valve - Google Patents
Slit nozzle and fast-acting shutoff valveInfo
- Publication number
- CA1166733A CA1166733A CA000373111A CA373111A CA1166733A CA 1166733 A CA1166733 A CA 1166733A CA 000373111 A CA000373111 A CA 000373111A CA 373111 A CA373111 A CA 373111A CA 1166733 A CA1166733 A CA 1166733A
- Authority
- CA
- Canada
- Prior art keywords
- nozzle
- slit
- adjusting element
- pulse
- fast
- 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
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D59/00—Separation of different isotopes of the same chemical element
- B01D59/34—Separation by photochemical methods
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05C—APPARATUS FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05C5/00—Apparatus in which liquid or other fluent material is projected, poured or allowed to flow on to the surface of the work
- B05C5/02—Apparatus in which liquid or other fluent material is projected, poured or allowed to flow on to the surface of the work the liquid or other fluent material being discharged through an outlet orifice by pressure, e.g. from an outlet device in contact or almost in contact, with the work
- B05C5/0254—Coating heads with slot-shaped outlet
- B05C5/0262—Coating heads with slot-shaped outlet adjustable in width, i.e. having lips movable relative to each other in order to modify the slot width, e.g. to close it
Abstract
Abstract of the Disclosure Slit nozzle and fast-acting shutoff valve for producing very brief gas flows accurately reproducible with respect to pulse width and spacing such as are required with pulse laser excitation for separation processes and photo-chemical processes including a first and a second nozzle part defining a nozzle slit therebetween, the first and the second nozzle parts forming the slit nozzle and, simultaneously the fast-acting shutoff valve, at least one of the nozzle parts being rapidly movable for varying the width of the nozzle slit practically between zero and a nominal size.
Description
~ ~ ~6733 The invention relates to a slit nozzle and fast-acting shutoff valve for generating very brief gas flows which are exactly reproducible with respect to pulse duratlon and spacing, such as are required for the excitation with pulse lasers for separating processes and photochemical processes. For purposes of uranium enrichment and other photochemical processes, a multipliclty of pro-cesses have already been proposed heretofore wherein the mixture of substances to be irradiated flows from a slit-shaped nozzle and is subsequently exposed, in the direction of the nozzle slit, to laser radiation of a given frequency.
' ~o ntin~oas/y ~' At present, however, Goa*i~ueus-by operating lasers of sufficient output are not available but only pulse lasers. This means that only a very small quantity of the gas jet leaving the nozzle can be excited. Because the pulse repetition frequency of such laser equipment i5 also too small for total irradiation of the continuous gas jet, it has been proposed heretofore (see German Published Non-Prosecuted Application (DE-OS) 28 10 7~1) to control the gas jet pulsewise by means of a fast-acting shu~off valve preceding the nozzle. Even if several sequentially fired laser devices are used, the opening time of such fast-acting shutoff valve is yet very short, so that the manufacture thereof is accompanied by very great mechanical difficulties. In these heretofore known constructions according to the state of the art, lt is necessary to make the dead space be-tween the valve proper and the nozzle as small as ever possible, but there are mechanical limits for meeting this requirement.
It is accordingly an object o~ the invention to provide a slit nozzle and fast-act~ng shutoff valve which not only solves the problem of the dead space bet~een the slit no~zle and the valve but also ensures the possibility of perfect adjustment of the required opening and closing times and therewith guarantees proper synchronization with the laser equipment and its technical potentials.
, -1- ~, - ~ . , , .
, .
~ 16B733 Ths invention provides a slit nozzle having a controllable fast-acting shut-off valve for producing pulse-like gas flows for selectively exciting gaseous mixtures with pu]se-like laser radiation, the nozzle being formed of a nozzle body having an upper and a lower nozzle part defining a nozzle slit therebetween having an opening for a gas flow openable and closable in pulse-like manner, comprising means for mounting the nozzle parts, and at least one adjusting element for moving the nozzle parts relative to one another in a direction opposing an elastic restoring force of said motmting means and varying the width of said nozzle slit between zero and a nominal size, the upper nozzle part having a space thereabove, and the lower nozzle part having a space therebelow, and adjusting element being disposed in one of said spaces.
The adjusting elements are preferably piezoelectrically acting elements ~ich also provide the elastic restoring force.
The adjusting elements may alternatively be magnetostrictively operating elements which undergo elastic deformation.
A gas chamber is disposed upstream of an inlet to the nozzle slit in the flow direction of gas through the nozzle, the adjusting elements being located in the gas chamber and having a positive locking connection with the elastic mounting means for the nozzle parts.
~' .
`: , i 7 3 3 Other ~eatures which are considered as characteristic Ror the in-vention are set forth in the appended claims.
Although the invention is illustrated and described herein as em-bodied in a slit nozzle and fast-acting shuto~ valve, it ls nevertheless not intended to ~e limited to the details sho~n, since various modi~ications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation o the invention, however, together with additional objects and advantages ~hereof will be 'aest understood from the following description of specific embodiments when read in connection ~th the accompanying drawings, in which:
Pigure 1 is a longitudinal sectlonal view of a sli~ nozzle and fast-acting shutoff valve in accordance with the invention;
Figure 2 is a cross-sectional v~ew of Figure 1 taken along the line ~I-II;
Figure 3 is a cross-sect~onal view o~ another embodiment of the in-vention;
Figure 4 is an enlarged fragmentary ~iew o Figure 3;
Figure 5 is a longitudinal sectional view of Figure 3 taken along 20the line V-V; and Figure 6 is a simplified diagrammatic view of the system according to the invention in conjunction with laser equipment as well as an optical de-lay line for extendlng the effective act~on o a laser pulse.
Since the pulses of the gas leavIng ~he nozzle, which ~s exp~nded there~n ~n a conventional manner, for example adiahatically, and is ~hereby undercooled, are very short, for example 10 5 sec, the system valve/nozzle must have very high resonance frequencies and a very small dead valume. Both re-_3_ :, , , :- ' .
: ;,' ' , I 3 ~6733 quirements are met by the fact that the nozzle lips themselves i.e. ~he upper part and the lower part of the slit nozzle, assume the shutoff function. The dead space is thereby completely avoided and the high resonance frequency is achieved by using moving elements with a high resonance frequency.
Because the pulse width of a laser is in the order of magnitude of a m;crosecond or less, it is advisable, however, to prolong the radiation time by letting this laser pulse traverse the gas beam several times and thereby simultaneously improve the effect of the irradiation. This purpose is then served by the previously mentioned optical delay line. Such delay lines are alread~ known in the art and the principle of such a line is described by R.H.
~lerriott and J.J. Schulte ln Applied Optics, August 65, Volume ~, Page 8B3.
Further details of this invention can be seen in Figures 1, 2 or 3 to 5 which show embodiment possibilities by way of examples. The last Figure 6 shows the possible application of this system in conjunction with a laser e~uipment as well as an optical delay line for extending the effec~ive action of a laser pulse.
Referring now to ~he drawing, and first particularly to Figure 1 thereof, there is shown a feed canal 16 through which the gas to be irradiated is transported to the slit-shaped nozzle 15, the breadth of which may be in the order of magnitude of meters. It is defined by an upper no~zle part 1 and a lower nozzle par~ 2, which are connected integrally to the nozzle body 20, The width of the nozzle gap is several hundredths o~ a millimeter. By means of screws 22, piezoelectric control elements 41 and ~2 are fastened in the nozzle body 20 between the nozzle parts 1 and 2, respectively, on the one hand, and a respective abutment 21, on the other hand. This purpose is also served by mounting feet or paws 23 which are connected to the nozzle body 20 by screws 2~.
Pigure 2 is a cross-sectional view taken along the line II-II of I 1 66~33 Figure 1, showing the elongated shape or breadth o~ the nozzle gap 15 as well as the arrangemen~ of the piezoelectric bodies 41. The latter are made up of a number of small plates 43, 44 (Figure 1~ which are provlded with metalllzed surfaces and are connected via a line 46 to a non-illustrated controlled voltage source. If the nozzle slit 15 is very long, several such stacks of individual elongated piezoelectric plates 43 or 44 are arranged. Between these and toward the outer or marginal zones, there are spaces 47 to receive the feed lines 46.
The slit nozzle 15 is closed off laterally by plates 19 fastened to the nozzle aody, and a permanently elastic sealing body 25 is provided in the region of the upper and the lower part 1 and 2, respectively, of the nozzle.
~he manner of operation of this device ls that, upon application of a voltage to the piezoelectrlc plates 43 and 44, the entire stack 45 expands and thereby compresses the nozzle parts 1 and 2 untll the nozzle gap 15 is closed. After the voltage is removed, the nozzle parts 1 and 2, which were elastically deformed thereby, spring back and, thereby, again free the path for the gas flow 16. By switching-on the current, the nozzle gap is thus closed in this case and, by shutting off the current, it is opened again.
By~programming the wave shape of the current rise as well as the expansion data, the motion of the upper and the lower nozzle parts 1 and 2 can be con-trolled so that a uniform and bounce-free closing of the entire nozzle gap 15 is achieved.
It $hould additionall~ be menti~oned that the opening and closing times can be shor~ened further by making the external shape of the plezoplate stack 45 conical. The plates w~th less width are then always at the moving end which further reduces the mass of the nozzle parts in its entirety in-cluding the piezoelectric elements. It is further possible to influence these opening and closing times through mechanical construction of the connection of .
. . .
, ' '. - ' ' ' ' ~
.
- ' . , ,~ . ~ .
7 ~ 6~;~33 the upper and lower nozzle parts 1 and 2 to the rest of the nozzle body 20, because in this manner, the modulus of elasticity ~s also adjustable.
rn thls embodiment, the variation o~ the piezoelectric control elements 41 and ~2 has a direct influence llpon the variation of the nozzle gap of the slit nozzle 15.
In the next embodiment shown in Figures 3, 4 and 5, the piezoelectric control elements 4 are arranged so that any change there~n is transmitted to the nozzle gap 15 according to the lever law i.e. a smaller leng~h change of the control elements 4 is sufficient to open or close the slit nozzle. Whereas, ~n the first em~odiment discussed herelnbefore, the application of the voltage to the control elements leads to a closing o~ the slit nozzle~ exactly the re-verse is the case in the embodiment described hereinafter.
Figure 3 is a cross-sectional vlew and Pigure 5 a longitudinal sectional view of a nozzle, an enlarged ~ragmentary cross-sectlonal view of which is illustrated in Figure 4. The nozzle itself ls formed of two nearly symmetrical parts 1 and 2 which close of~ a distributor space 3 for the gas flowing out through the nozzle. This space 3 contains a number of piezo-control elements 4 whlch are built up in a conventional manner from circular plates metallized at the end faces thereof. These are provided alternatingly with contacts for the current so that each plate can be connected to a voltage via leads 7 and 8. As shown in Figure 3, each control element 4 is insulatedly built ~nto a corrosion-resistant envelope with an electric ~eedthrough at one-half the height, because this location is not subjected to motion. Several such elements are arranged so that they make pressure contact with the nozzle parts 1 and 2 and are held in the posit~on thereof by a spacer 6 (see Figure 5).
They are electrically insulated, o~ course, in a suitable manner -from the nozzle parts 1 and 2 as well as from the nozzle body 20, ' : ' '. . '~
~ 3 ~6733 As mentioned hereinbefore, the current is fed to the piezoelectric elements 4 via the leads 7 and 8. If voltage is applied to the latter, these piezoelements 4 expand accord~ng tothe value of the voltage, and the nozzle parts 1 and 2 are forced apart~ With 200 volts and 20 plates of 1 millimeter thickness each, excursions of several hundredths of a millimeter are attainable.
Depending upon the position of the piezoelements 4 between the nozzle gap and the clamplng of the nozzle parts 1 and 2 in this body 20, the stroke of the elements is transformed according to the lever law. When the voltage is re-moved, the nozzle returns tothe original closed position because of the elast-icity of the nozzle parts 1 and 2. To laterally seal the nozzle parts 1 and 2, the latter are clamped between the plates 9, which are connected to one another by screws 91. The plates 9 contain a sealing ring 10. An additional sealing member 11 is furthermore provided at ~he ends of the slit nozzle, and is held in the position thereof by clamps 12.
The plates 9 are part of the wall of a treatment chamber into which the gases expanded in the nozzle 15 flow. For access of the laser radiation to this otherwise non-illustrated housing, windows 13 and 14 are disposed in the lateral plates 9. The laser beam in front of the nozzle 15 then has maxi-mall~ the cross section represented by the circle 38 in Figure 3.
Since piezoelectric elements have very brief rise or increase times, very short opening times for the slit nozzle 15 are also possible. Since they also generate relatively large forces, the moment of inertia of the nozzle parts 1 and 2 and, therefore, the restoring force thereof can be made large.
~f, in addition, as shown in Figure 3, the mass of the moving parts 1 and 2 is kept small, this also results in correspondingly short closing tlmes.
The characteristic of the piezoelements 4 that they develop the greatest force at the beginning of the movement also has an advantageous effect .
- .
.
` ' ' .~
I ~ ~6733 on sho~t opening times. These times can be shortened ~urther l the length of the piezoelements 4 and the shape of the no~le parts 1 and 2 are matched to one another in such a manner that the nozzle ~s closed under pretenslon. Then~
the opening begins only if the moved masses, with the exception of the nozzle lips l.e. the region of the nozzle constriction, have themselves already reached a certain velocity. On closing of the nozzle gap 15, possible deformlng shocks are prevented by appropriate electrical voltage control of the pieZoelectric elements.
Instead of the piezoelectric control elements used ln these embodl-ments, elements based on magnekostriction can, of course, also be used in an equivalent manner.
This device of a controllable slit nozzle is suitable particularly for application in conventional laser isotope separation. It is of partîcular interest to perform, in this manner, the enrichment of uranium with its uranium 235 isotope, wherein generally the gaseous compound UF6 is used.
Figure 6 shows diagrammatically the interrelation and arrangement of the laser beam relative to a gas jet 17 which has left the nozzle 15 and has substantially the cross section 3g ~see Figures 3 and 1). This laser beam enters and leaves the gas jet 17 via the windows 13 and 14 shown in Figure 5.
In Figure 6, the laser equipment is identified by reference numeral 31 and the laser beam leaving the latter by reference numeral 30. The laser beam 30 pen-etrates the gas jet 17, over the entire width thereof and arrives at the delay line 32~ The latter ls formed of two nearly confocal mirrors 39 and 40, between which the beam is reflected back and forth several times outside the axis. After the desired delay tlme, this baam then strikes the auxlliary mirror 36, is re-flected by the latter to the auxiliary mirror 35 and by the latter again through the gas jet 17 to the auxiliary mirror 37. The beam reflected by the mirror 37 -8~
.. ~ .
' ~ ~''. '. ', follows a diferent path than the lncoming path thereof.
If the laser pulse ~idth is equal to the delay time, then the irradiation time for uninterrupted irradiation is increased multiplicatively by the number of passages, If the pulse width is shorter, gaps in tlme are produced with a corresponding extension of the overall duration. If the laser pulse width is longer than the delay time, then the pulses overlap and the power densit~ is higher during the overlap time. All three cases are of practical interest and can be realized by suitable adjustment of the control elements 4, 41 and 42 as well as of the delay line in conjunctlon with ~he laser equipment.
Thus, the first and second case i.e. the pulse width is equal to or greater than the delay time, can be of inteTest for processes wi~h a relatively long life of the excited states, for example, for selective condensation ~German Published Non-Prosecuted Application (DE-OS~ 28 49 162). The last-mentioned case, where the pulse width is shorter than the delay time, can be used in pro-cesses, for example, for which time-shaping of the laser pulse is of advantage such as, for example, in multistage excitation.
The residual energy contained in the laser beam can be returned to the laser by a conventional type of beam arrangement or can also be fed to a second laser to trigger thereby a further light pulse.
_9_ ,,
' ~o ntin~oas/y ~' At present, however, Goa*i~ueus-by operating lasers of sufficient output are not available but only pulse lasers. This means that only a very small quantity of the gas jet leaving the nozzle can be excited. Because the pulse repetition frequency of such laser equipment i5 also too small for total irradiation of the continuous gas jet, it has been proposed heretofore (see German Published Non-Prosecuted Application (DE-OS) 28 10 7~1) to control the gas jet pulsewise by means of a fast-acting shu~off valve preceding the nozzle. Even if several sequentially fired laser devices are used, the opening time of such fast-acting shutoff valve is yet very short, so that the manufacture thereof is accompanied by very great mechanical difficulties. In these heretofore known constructions according to the state of the art, lt is necessary to make the dead space be-tween the valve proper and the nozzle as small as ever possible, but there are mechanical limits for meeting this requirement.
It is accordingly an object o~ the invention to provide a slit nozzle and fast-act~ng shutoff valve which not only solves the problem of the dead space bet~een the slit no~zle and the valve but also ensures the possibility of perfect adjustment of the required opening and closing times and therewith guarantees proper synchronization with the laser equipment and its technical potentials.
, -1- ~, - ~ . , , .
, .
~ 16B733 Ths invention provides a slit nozzle having a controllable fast-acting shut-off valve for producing pulse-like gas flows for selectively exciting gaseous mixtures with pu]se-like laser radiation, the nozzle being formed of a nozzle body having an upper and a lower nozzle part defining a nozzle slit therebetween having an opening for a gas flow openable and closable in pulse-like manner, comprising means for mounting the nozzle parts, and at least one adjusting element for moving the nozzle parts relative to one another in a direction opposing an elastic restoring force of said motmting means and varying the width of said nozzle slit between zero and a nominal size, the upper nozzle part having a space thereabove, and the lower nozzle part having a space therebelow, and adjusting element being disposed in one of said spaces.
The adjusting elements are preferably piezoelectrically acting elements ~ich also provide the elastic restoring force.
The adjusting elements may alternatively be magnetostrictively operating elements which undergo elastic deformation.
A gas chamber is disposed upstream of an inlet to the nozzle slit in the flow direction of gas through the nozzle, the adjusting elements being located in the gas chamber and having a positive locking connection with the elastic mounting means for the nozzle parts.
~' .
`: , i 7 3 3 Other ~eatures which are considered as characteristic Ror the in-vention are set forth in the appended claims.
Although the invention is illustrated and described herein as em-bodied in a slit nozzle and fast-acting shuto~ valve, it ls nevertheless not intended to ~e limited to the details sho~n, since various modi~ications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation o the invention, however, together with additional objects and advantages ~hereof will be 'aest understood from the following description of specific embodiments when read in connection ~th the accompanying drawings, in which:
Pigure 1 is a longitudinal sectlonal view of a sli~ nozzle and fast-acting shutoff valve in accordance with the invention;
Figure 2 is a cross-sectional v~ew of Figure 1 taken along the line ~I-II;
Figure 3 is a cross-sect~onal view o~ another embodiment of the in-vention;
Figure 4 is an enlarged fragmentary ~iew o Figure 3;
Figure 5 is a longitudinal sectional view of Figure 3 taken along 20the line V-V; and Figure 6 is a simplified diagrammatic view of the system according to the invention in conjunction with laser equipment as well as an optical de-lay line for extendlng the effective act~on o a laser pulse.
Since the pulses of the gas leavIng ~he nozzle, which ~s exp~nded there~n ~n a conventional manner, for example adiahatically, and is ~hereby undercooled, are very short, for example 10 5 sec, the system valve/nozzle must have very high resonance frequencies and a very small dead valume. Both re-_3_ :, , , :- ' .
: ;,' ' , I 3 ~6733 quirements are met by the fact that the nozzle lips themselves i.e. ~he upper part and the lower part of the slit nozzle, assume the shutoff function. The dead space is thereby completely avoided and the high resonance frequency is achieved by using moving elements with a high resonance frequency.
Because the pulse width of a laser is in the order of magnitude of a m;crosecond or less, it is advisable, however, to prolong the radiation time by letting this laser pulse traverse the gas beam several times and thereby simultaneously improve the effect of the irradiation. This purpose is then served by the previously mentioned optical delay line. Such delay lines are alread~ known in the art and the principle of such a line is described by R.H.
~lerriott and J.J. Schulte ln Applied Optics, August 65, Volume ~, Page 8B3.
Further details of this invention can be seen in Figures 1, 2 or 3 to 5 which show embodiment possibilities by way of examples. The last Figure 6 shows the possible application of this system in conjunction with a laser e~uipment as well as an optical delay line for extending the effec~ive action of a laser pulse.
Referring now to ~he drawing, and first particularly to Figure 1 thereof, there is shown a feed canal 16 through which the gas to be irradiated is transported to the slit-shaped nozzle 15, the breadth of which may be in the order of magnitude of meters. It is defined by an upper no~zle part 1 and a lower nozzle par~ 2, which are connected integrally to the nozzle body 20, The width of the nozzle gap is several hundredths o~ a millimeter. By means of screws 22, piezoelectric control elements 41 and ~2 are fastened in the nozzle body 20 between the nozzle parts 1 and 2, respectively, on the one hand, and a respective abutment 21, on the other hand. This purpose is also served by mounting feet or paws 23 which are connected to the nozzle body 20 by screws 2~.
Pigure 2 is a cross-sectional view taken along the line II-II of I 1 66~33 Figure 1, showing the elongated shape or breadth o~ the nozzle gap 15 as well as the arrangemen~ of the piezoelectric bodies 41. The latter are made up of a number of small plates 43, 44 (Figure 1~ which are provlded with metalllzed surfaces and are connected via a line 46 to a non-illustrated controlled voltage source. If the nozzle slit 15 is very long, several such stacks of individual elongated piezoelectric plates 43 or 44 are arranged. Between these and toward the outer or marginal zones, there are spaces 47 to receive the feed lines 46.
The slit nozzle 15 is closed off laterally by plates 19 fastened to the nozzle aody, and a permanently elastic sealing body 25 is provided in the region of the upper and the lower part 1 and 2, respectively, of the nozzle.
~he manner of operation of this device ls that, upon application of a voltage to the piezoelectrlc plates 43 and 44, the entire stack 45 expands and thereby compresses the nozzle parts 1 and 2 untll the nozzle gap 15 is closed. After the voltage is removed, the nozzle parts 1 and 2, which were elastically deformed thereby, spring back and, thereby, again free the path for the gas flow 16. By switching-on the current, the nozzle gap is thus closed in this case and, by shutting off the current, it is opened again.
By~programming the wave shape of the current rise as well as the expansion data, the motion of the upper and the lower nozzle parts 1 and 2 can be con-trolled so that a uniform and bounce-free closing of the entire nozzle gap 15 is achieved.
It $hould additionall~ be menti~oned that the opening and closing times can be shor~ened further by making the external shape of the plezoplate stack 45 conical. The plates w~th less width are then always at the moving end which further reduces the mass of the nozzle parts in its entirety in-cluding the piezoelectric elements. It is further possible to influence these opening and closing times through mechanical construction of the connection of .
. . .
, ' '. - ' ' ' ' ~
.
- ' . , ,~ . ~ .
7 ~ 6~;~33 the upper and lower nozzle parts 1 and 2 to the rest of the nozzle body 20, because in this manner, the modulus of elasticity ~s also adjustable.
rn thls embodiment, the variation o~ the piezoelectric control elements 41 and ~2 has a direct influence llpon the variation of the nozzle gap of the slit nozzle 15.
In the next embodiment shown in Figures 3, 4 and 5, the piezoelectric control elements 4 are arranged so that any change there~n is transmitted to the nozzle gap 15 according to the lever law i.e. a smaller leng~h change of the control elements 4 is sufficient to open or close the slit nozzle. Whereas, ~n the first em~odiment discussed herelnbefore, the application of the voltage to the control elements leads to a closing o~ the slit nozzle~ exactly the re-verse is the case in the embodiment described hereinafter.
Figure 3 is a cross-sectional vlew and Pigure 5 a longitudinal sectional view of a nozzle, an enlarged ~ragmentary cross-sectlonal view of which is illustrated in Figure 4. The nozzle itself ls formed of two nearly symmetrical parts 1 and 2 which close of~ a distributor space 3 for the gas flowing out through the nozzle. This space 3 contains a number of piezo-control elements 4 whlch are built up in a conventional manner from circular plates metallized at the end faces thereof. These are provided alternatingly with contacts for the current so that each plate can be connected to a voltage via leads 7 and 8. As shown in Figure 3, each control element 4 is insulatedly built ~nto a corrosion-resistant envelope with an electric ~eedthrough at one-half the height, because this location is not subjected to motion. Several such elements are arranged so that they make pressure contact with the nozzle parts 1 and 2 and are held in the posit~on thereof by a spacer 6 (see Figure 5).
They are electrically insulated, o~ course, in a suitable manner -from the nozzle parts 1 and 2 as well as from the nozzle body 20, ' : ' '. . '~
~ 3 ~6733 As mentioned hereinbefore, the current is fed to the piezoelectric elements 4 via the leads 7 and 8. If voltage is applied to the latter, these piezoelements 4 expand accord~ng tothe value of the voltage, and the nozzle parts 1 and 2 are forced apart~ With 200 volts and 20 plates of 1 millimeter thickness each, excursions of several hundredths of a millimeter are attainable.
Depending upon the position of the piezoelements 4 between the nozzle gap and the clamplng of the nozzle parts 1 and 2 in this body 20, the stroke of the elements is transformed according to the lever law. When the voltage is re-moved, the nozzle returns tothe original closed position because of the elast-icity of the nozzle parts 1 and 2. To laterally seal the nozzle parts 1 and 2, the latter are clamped between the plates 9, which are connected to one another by screws 91. The plates 9 contain a sealing ring 10. An additional sealing member 11 is furthermore provided at ~he ends of the slit nozzle, and is held in the position thereof by clamps 12.
The plates 9 are part of the wall of a treatment chamber into which the gases expanded in the nozzle 15 flow. For access of the laser radiation to this otherwise non-illustrated housing, windows 13 and 14 are disposed in the lateral plates 9. The laser beam in front of the nozzle 15 then has maxi-mall~ the cross section represented by the circle 38 in Figure 3.
Since piezoelectric elements have very brief rise or increase times, very short opening times for the slit nozzle 15 are also possible. Since they also generate relatively large forces, the moment of inertia of the nozzle parts 1 and 2 and, therefore, the restoring force thereof can be made large.
~f, in addition, as shown in Figure 3, the mass of the moving parts 1 and 2 is kept small, this also results in correspondingly short closing tlmes.
The characteristic of the piezoelements 4 that they develop the greatest force at the beginning of the movement also has an advantageous effect .
- .
.
` ' ' .~
I ~ ~6733 on sho~t opening times. These times can be shortened ~urther l the length of the piezoelements 4 and the shape of the no~le parts 1 and 2 are matched to one another in such a manner that the nozzle ~s closed under pretenslon. Then~
the opening begins only if the moved masses, with the exception of the nozzle lips l.e. the region of the nozzle constriction, have themselves already reached a certain velocity. On closing of the nozzle gap 15, possible deformlng shocks are prevented by appropriate electrical voltage control of the pieZoelectric elements.
Instead of the piezoelectric control elements used ln these embodl-ments, elements based on magnekostriction can, of course, also be used in an equivalent manner.
This device of a controllable slit nozzle is suitable particularly for application in conventional laser isotope separation. It is of partîcular interest to perform, in this manner, the enrichment of uranium with its uranium 235 isotope, wherein generally the gaseous compound UF6 is used.
Figure 6 shows diagrammatically the interrelation and arrangement of the laser beam relative to a gas jet 17 which has left the nozzle 15 and has substantially the cross section 3g ~see Figures 3 and 1). This laser beam enters and leaves the gas jet 17 via the windows 13 and 14 shown in Figure 5.
In Figure 6, the laser equipment is identified by reference numeral 31 and the laser beam leaving the latter by reference numeral 30. The laser beam 30 pen-etrates the gas jet 17, over the entire width thereof and arrives at the delay line 32~ The latter ls formed of two nearly confocal mirrors 39 and 40, between which the beam is reflected back and forth several times outside the axis. After the desired delay tlme, this baam then strikes the auxlliary mirror 36, is re-flected by the latter to the auxiliary mirror 35 and by the latter again through the gas jet 17 to the auxiliary mirror 37. The beam reflected by the mirror 37 -8~
.. ~ .
' ~ ~''. '. ', follows a diferent path than the lncoming path thereof.
If the laser pulse ~idth is equal to the delay time, then the irradiation time for uninterrupted irradiation is increased multiplicatively by the number of passages, If the pulse width is shorter, gaps in tlme are produced with a corresponding extension of the overall duration. If the laser pulse width is longer than the delay time, then the pulses overlap and the power densit~ is higher during the overlap time. All three cases are of practical interest and can be realized by suitable adjustment of the control elements 4, 41 and 42 as well as of the delay line in conjunctlon with ~he laser equipment.
Thus, the first and second case i.e. the pulse width is equal to or greater than the delay time, can be of inteTest for processes wi~h a relatively long life of the excited states, for example, for selective condensation ~German Published Non-Prosecuted Application (DE-OS~ 28 49 162). The last-mentioned case, where the pulse width is shorter than the delay time, can be used in pro-cesses, for example, for which time-shaping of the laser pulse is of advantage such as, for example, in multistage excitation.
The residual energy contained in the laser beam can be returned to the laser by a conventional type of beam arrangement or can also be fed to a second laser to trigger thereby a further light pulse.
_9_ ,,
Claims (4)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A slit nozzle having a controllable fast-acting shut-off valve for producing pulse-like gas flows for selectively exciting gaseous mixtures with pulse-like laser radiation, the nozzle being formed of a nozzle body having an upper and a lower nozzle part defining a nozzle slit therebetween having an opening for a gas flow openable and closable in pulse-like manner, comprising means for mounting the nozzle parts, and at least one adjusting element for moving the nozzle parts relative to one another in a direction opposing an elastic restoring force of said mounting means and varying the width of said nozzle slit between zero and a nominal size, the upper nozzle part having a space thereabove, and the lower nozzle part having a space therebelow, said adjusting element being disposed in one of said spaces.
2. A slit nozzle according to claim 1 wherein said at least one adjusting element comprises a piezoelectric control element.
3. A slit nozzle according to claim 1 wherein said at least one adjusting element comprises a magnetostrictive control element.
4. A slit nozzle according to claim 1 wherein said one adjusting element is located in said space above the upper nozzle, and another adjusting element is located in said space below the lower nozzle.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP3010178.1 | 1980-03-17 | ||
| DE3010178A DE3010178C2 (en) | 1980-03-17 | 1980-03-17 | Slotted nozzle equipped with a quick-acting valve to induce pulsed gas flows |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1166733A true CA1166733A (en) | 1984-05-01 |
Family
ID=6097436
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000373111A Expired CA1166733A (en) | 1980-03-17 | 1981-03-16 | Slit nozzle and fast-acting shutoff valve |
Country Status (6)
| Country | Link |
|---|---|
| US (1) | US4431136A (en) |
| EP (1) | EP0036164B1 (en) |
| JP (1) | JPS56141823A (en) |
| AU (1) | AU539723B2 (en) |
| CA (1) | CA1166733A (en) |
| DE (1) | DE3010178C2 (en) |
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|---|---|---|---|---|
| US5322568A (en) * | 1985-12-28 | 1994-06-21 | Canon Kabushiki Kaisha | Apparatus for forming deposited film |
| DE3833093A1 (en) * | 1988-09-29 | 1990-04-12 | Siemens Ag | FUEL INJECTOR PROVIDED FOR INTERNAL COMBUSTION ENGINE WITH CONTROLLABLE CHARACTERISTICS OF THE FUEL JET |
| US5152456A (en) * | 1989-12-12 | 1992-10-06 | Bespak, Plc | Dispensing apparatus having a perforate outlet member and a vibrating device |
| US5938117A (en) | 1991-04-24 | 1999-08-17 | Aerogen, Inc. | Methods and apparatus for dispensing liquids as an atomized spray |
| US7628339B2 (en) | 1991-04-24 | 2009-12-08 | Novartis Pharma Ag | Systems and methods for controlling fluid feed to an aerosol generator |
| US6629646B1 (en) * | 1991-04-24 | 2003-10-07 | Aerogen, Inc. | Droplet ejector with oscillating tapered aperture |
| US6540154B1 (en) * | 1991-04-24 | 2003-04-01 | Aerogen, Inc. | Systems and methods for controlling fluid feed to an aerosol generator |
| US5271226A (en) * | 1992-04-24 | 1993-12-21 | The United States Of America, As Represented By The Secretary Of Commerce | High speed, amplitude variable thrust control |
| DE4331267A1 (en) * | 1993-09-15 | 1995-03-16 | Uranit Gmbh | Multiple-orifice nozzle arrangement |
| DE4411569C1 (en) * | 1994-04-02 | 1995-07-20 | Itw Dynatec Gmbh Klebetechnik | Application head metering flowing medium |
| US6085740A (en) | 1996-02-21 | 2000-07-11 | Aerogen, Inc. | Liquid dispensing apparatus and methods |
| US5758637A (en) | 1995-08-31 | 1998-06-02 | Aerogen, Inc. | Liquid dispensing apparatus and methods |
| US6205999B1 (en) | 1995-04-05 | 2001-03-27 | Aerogen, Inc. | Methods and apparatus for storing chemical compounds in a portable inhaler |
| US6014970A (en) * | 1998-06-11 | 2000-01-18 | Aerogen, Inc. | Methods and apparatus for storing chemical compounds in a portable inhaler |
| US6782886B2 (en) | 1995-04-05 | 2004-08-31 | Aerogen, Inc. | Metering pumps for an aerosolizer |
| FR2772646B1 (en) * | 1997-12-19 | 2000-02-25 | Kuhn Nodet Sa | IMPROVED SPRAY NOZZLE |
| US6235177B1 (en) * | 1999-09-09 | 2001-05-22 | Aerogen, Inc. | Method for the construction of an aperture plate for dispensing liquid droplets |
| MXPA02010884A (en) * | 2000-05-05 | 2003-03-27 | Aerogen Ireland Ltd | Apparatus and methods for the delivery of medicaments to the respiratory system. |
| US6948491B2 (en) | 2001-03-20 | 2005-09-27 | Aerogen, Inc. | Convertible fluid feed system with comformable reservoir and methods |
| US7100600B2 (en) * | 2001-03-20 | 2006-09-05 | Aerogen, Inc. | Fluid filled ampoules and methods for their use in aerosolizers |
| US7971588B2 (en) * | 2000-05-05 | 2011-07-05 | Novartis Ag | Methods and systems for operating an aerosol generator |
| US8336545B2 (en) * | 2000-05-05 | 2012-12-25 | Novartis Pharma Ag | Methods and systems for operating an aerosol generator |
| US7600511B2 (en) * | 2001-11-01 | 2009-10-13 | Novartis Pharma Ag | Apparatus and methods for delivery of medicament to a respiratory system |
| US6543443B1 (en) | 2000-07-12 | 2003-04-08 | Aerogen, Inc. | Methods and devices for nebulizing fluids |
| US6546927B2 (en) | 2001-03-13 | 2003-04-15 | Aerogen, Inc. | Methods and apparatus for controlling piezoelectric vibration |
| US6550472B2 (en) | 2001-03-16 | 2003-04-22 | Aerogen, Inc. | Devices and methods for nebulizing fluids using flow directors |
| US6732944B2 (en) * | 2001-05-02 | 2004-05-11 | Aerogen, Inc. | Base isolated nebulizing device and methods |
| US6554201B2 (en) | 2001-05-02 | 2003-04-29 | Aerogen, Inc. | Insert molded aerosol generator and methods |
| US20030168057A1 (en) * | 2001-12-14 | 2003-09-11 | Inhale Therapeutic Systems, Inc. | Electronically controllable aerosol delivery |
| US20050205089A1 (en) * | 2002-01-07 | 2005-09-22 | Aerogen, Inc. | Methods and devices for aerosolizing medicament |
| US7677467B2 (en) * | 2002-01-07 | 2010-03-16 | Novartis Pharma Ag | Methods and devices for aerosolizing medicament |
| CA2472644C (en) | 2002-01-07 | 2013-11-05 | Aerogen, Inc. | Devices and methods for nebulizing fluids for inhalation |
| ES2603067T3 (en) | 2002-01-15 | 2017-02-23 | Novartis Ag | Methods and systems for operating an aerosol generator |
| EP1509259B1 (en) * | 2002-05-20 | 2016-04-20 | Novartis AG | Apparatus for providing aerosol for medical treatment and methods |
| US20070044792A1 (en) * | 2005-08-30 | 2007-03-01 | Aerogen, Inc. | Aerosol generators with enhanced corrosion resistance |
| US8616195B2 (en) * | 2003-07-18 | 2013-12-31 | Novartis Ag | Nebuliser for the production of aerosolized medication |
| US7267121B2 (en) | 2004-04-20 | 2007-09-11 | Aerogen, Inc. | Aerosol delivery apparatus and method for pressure-assisted breathing systems |
| US7946291B2 (en) | 2004-04-20 | 2011-05-24 | Novartis Ag | Ventilation systems and methods employing aerosol generators |
| BRPI0509991A (en) * | 2004-04-20 | 2007-10-16 | Aerogen Inc | aerosol delivery apparatus, methods and compositions for pressure-assisted breathing systems |
| US7290541B2 (en) * | 2004-04-20 | 2007-11-06 | Aerogen, Inc. | Aerosol delivery apparatus and method for pressure-assisted breathing systems |
| JP5064383B2 (en) * | 2005-05-25 | 2012-10-31 | エアロジェン，インコーポレイテッド | Vibration system and method |
| US8348177B2 (en) * | 2008-06-17 | 2013-01-08 | Davicon Corporation | Liquid dispensing apparatus using a passive liquid metering method |
| DE102012109124A1 (en) | 2012-09-27 | 2014-03-27 | Vermes Microdispensing GmbH | Dosing system, dosing process and manufacturing process |
| DE102012109123A1 (en) | 2012-09-27 | 2014-03-27 | Vermes Microdispensing GmbH | Dosing system, dosing process and manufacturing process |
| DE102013224453A1 (en) * | 2013-11-28 | 2015-05-28 | Marco Systemanalyse Und Entwicklung Gmbh | Valve for dosing media in the smallest quantity range |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3055631A (en) * | 1960-11-25 | 1962-09-25 | Dean O Kippenhan | Electrostriction valve |
| GB1217225A (en) * | 1968-05-23 | 1970-12-31 | Automotive Prod Co Ltd | Improvements in or relating to electrically operated valves and fluid-flow directing devices |
| US4334883A (en) * | 1972-07-07 | 1982-06-15 | The United States Of America As Represented By The United States Department Of Energy | Isotope separation by laser means |
| US3981480A (en) * | 1974-12-19 | 1976-09-21 | The United States Of America As Represented By The United States Energy Research And Development Administration | Variable gas leak rate valve |
| DE2745900C3 (en) * | 1977-10-12 | 1981-01-15 | Brueckner-Apparatebau Gmbh, 6120 Erbach | Slot nozzle |
| DE2810791C3 (en) * | 1978-03-13 | 1985-06-05 | Kraftwerk Union AG, 4330 Mülheim | Method and device for separating a gaseous mixture of isotope compounds |
-
1980
- 1980-03-17 DE DE3010178A patent/DE3010178C2/en not_active Expired
-
1981
- 1981-03-09 EP EP81101724A patent/EP0036164B1/en not_active Expired
- 1981-03-12 US US06/242,920 patent/US4431136A/en not_active Expired - Fee Related
- 1981-03-16 JP JP3773081A patent/JPS56141823A/en active Granted
- 1981-03-16 AU AU68396/81A patent/AU539723B2/en not_active Ceased
- 1981-03-16 CA CA000373111A patent/CA1166733A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| AU539723B2 (en) | 1984-10-11 |
| AU6839681A (en) | 1981-09-24 |
| EP0036164A3 (en) | 1982-01-27 |
| JPS6345245B2 (en) | 1988-09-08 |
| DE3010178C2 (en) | 1985-10-03 |
| EP0036164B1 (en) | 1984-03-07 |
| JPS56141823A (en) | 1981-11-05 |
| DE3010178A1 (en) | 1981-09-24 |
| US4431136A (en) | 1984-02-14 |
| EP0036164A2 (en) | 1981-09-23 |
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| MKEX | Expiry |