US2096226A - Exhausting method and apparatus - Google Patents

Description

Oct. 19, 1937. D. N. .cRosTHwAl-r. JR 2,096,225

EXHAUSTING METHOD AND APPARATUS Filed April 17, 1935 5 Sheets-Sheet l I u/en Jaw 11/ awzLZzw;

Oct. 19, 1937.

D. N. CROSTHWAIT, JR

EXHAUSTING METHOD AND APPARATUS Filed April 17, 1935 5 Sheets-Sheet 2 Ila I 3 illll I llll'll jl 01mg 5.-

r 1 14 /////////////I///// I/IIIy/A /lllllll llrlrzlll Oct..19, 1937. D. N. CROSTHWAIT, JR 5 EXHAUSTING METHOD vAND APPARATUS Filed April 17, 1955 5 Sheets-Sheet 3 937. D. N. c'os'rHwAn'. JR 2,096,226

EXHAUSTING METHOD AND APPARATUS 1937. D. N. CROSTHWAIT, JR 2,096,226

EXHAUSTING METHOD AND APPARATUS 5 sheets-Sheet 5 Filed April 17, 1935 Patented Oct. 19, I937 uNrrso STATES PATENT OFFICE EXHAUSTING METHOD AND APPARATUS Application April 17,1935, Serial No. 16,803 9 Claims. (01. 230-92) This invention relates to an improved method and apparatus for exhausting fluids, more particularly mixed gases and liquids, from one space and forcing them into-another space against a higher pressure. More particularly the invention relates to an improved form of jet exhauster using water as the actuating fluid, and more particularly designed for withdrawing condensate and non-condensable gases from'a heating systern.

In the well known kinetic exhauster of this general type, a jet of water is projected under pressure from a nozzle through a portion of the space containing the fluids to be exhausted and I5 thence into a restricted delivery tube, the fluid being entrained or drawn out with the liquid of the jet and carried into a separating tank from which the gases are vented. A portion of the water is then recirculated by means of a pump or similar apparatus through the jet to continue the exhausting process. According to the present invention a ring or lining of water-is continuously maintained within the entrance portion of the delivery tube so as to form an elastic lining for 5' the delivery tube or an enveloping wall of liquid through which the jet is projected. The fluids to be exhausted are entrained in the jet and between the jet and enveloping liquid wall, a portion of which is carried onward through the. delivery tube with the liquid of the jet. The advantages of this method and apparatus will be explained in more detail hereinafter.

The particular object of this invention is to provide an improved method'and apparatus for 3 exhausting fluids, as briefly described hereinabove and disclosed more in detail in the specifications which follow.

Another object is to provide an improved kinetic exhauster using water as the actuating fluid which attains a high efiiciency by obtaining a high ratio of air exhausted to the liquid streams furnishing the exhausting energy.

Another object isto provide an exhauster of this type in which the losses due to friction and changes of pressure are minimized by avoiding the inelastic impact of moving water particles on stationary surfaces by providing an enclosing wall of water which moves with the actuating jet.

Another object is to provide an elastic delivery tube into and through which the jet is projected.

Another object is to provide a method and apparatus which will cooperate with or compensate for changes in pressure caused by partial condensation of the vapor diffused through or between the water particles due to compression and also to the cooling action of the liquid streams.

Another object is to provide improved means for establishing and maintaining the wall of liquid which encloses the actuating jet.

Numerous other objects and advantages of this. invention will be more apparent from the follow ing detailed description of certain approved forms of apparatus designed and operating according to the principles of the invention. 7 10 In the accompanying drawings:

Fig. l is an elevation showing one form of the complete exhauster assembly, with parts broken away.

Fig. 2 is a partial side elevation and partial ver- 15 tical section taken substantially on the line 2--2 of Fig. 3, showing one form of the jet exhauster.

Fig. 3 is a vertical section taken substantially on the line 33 of Fig. 2.

Fig. 4 is'a diagrammatic vertical section illus- 2O trating the operation of one of the improved jetexhauster units.

Fig. 5 is a vertical section, similar to Fig. 2, showing a modified form of the jet exhauster.

Fig. 6 is a vertical section on a somewhat larger 2 scale taken substantially on the line 6-6 of Fig. 5.

- Fig. '7 is a horizontal section taken substantially on the line 11 of Fig. 5.

Fig. 8 is a vertical section corresponding to the central portion of Fig. 5 but showing a modifica- 30 tion.

Fig. 9 is partial vertical section showing still another modification. 1 i

Fig. 10 is a partial vertical section showing the 1 use of a multiple jet. 5

Figjll is a horizontal section illustrating the 3 means for separately delivering water to each 'of the chambers enveloping a group of separate delivery tubes.

Referring first to Figs. 1, 2 and 3, the exhaust- 40 ing apparatus comprises in general the separating tank A which contains the supply of actuating liquid, preferably Water, the pump B driven by the motor C, and the improved jet exhauster indicated generally at D. The rotary 45 pump B, preferably of the centrifugal type, is rotated by motor 0 through shaft l and connection 2. The pump withdraws water from tank A through pipe connection 3 and forces'this water through outlet 4 and manifold 5 intoand through 50 the nozzle or nozzles 6 of the jet exhauster. The

jets are projected into and through a portion of the exhausting chamber 1 and thence into and through the delivery tubes 8 which discharge into pipe 9 leading back into the upper portion of r- V V V 7 V! a arr open annular passage 32 connects the chammail-.1 ns fluids to be exhausted .(usually mixedliquids and gases) are delivered through pipe connection it? andstrainer H into and through the pipe connection" l2 provided with one-way valve l3 and thenceinto the exhausting chamber '1. Thefvalve l3 prevents the return of fiuidsfrom thehigher pressure spaces'into the low pressure space that has been exhausted when the exhausting apparatus is not .in'operation.

The exhausted fluids are carriedralong with the liquid of the actuating jet through the tubes 8 '7 and pipe}! into thetank A. Thenonecondensa Y ble gases are vented from tank A,;but the supply at intervals to permit the discharged the excess liquidi byfmeans'of a float-controlled mecha-'-' of water in tank A will be gradually augmented by thecondensate or other liquiddrawri into; the'tank. For the purposeofidischarging this excess liquid from'the tank, the pump manifold 5 is provided with a second discharge outlet 14 .throughlthe valve'casing l5 intov'a discharge-pipe I6- whichfleads' to the boiler of the heating sysi temor some'other place of discharge. The-valve":

l5 i's'normally close dbu t is automatically opened nismparts of which are": indicated at 11,18 and I9. The pressure gaugesin'dicated at '20 and 2| indicate the.. pressures fexisting atnthe high and,

low pressure sides or the exhauster respectively,

and the gauge 22 indicates thewater lever in tank A. The-combination taspthusi far briefly deL- scribed is substantially iold"and well knownyin 'this art,.the' presenti-invention relating? to im? provem'entsin the specific form "of jet exhauster assemblyjindicated generally at'D, several forms scribed as if onlyione uhit were included. Each c of which will now be described more in detail. a

I Referring'now more particularlytoFigs. 2 and 31 the form o'fxexhau ster assembly here shown comprises two similar exhausting units each comprising a nozzle and delivery tube." The assembly.

may comprise one oriseverat of these units, each of'which operates substantiallyindependently;

and for convenience theapparatus will be devertically positioned nozzler G is mounted in' the lower wall of-casingjz3 which encloses: the exhausting'chamber 1; so that the largeropen low- 7 er end of thernozzle memberwill be in open communication with the manifold 5. 'The' upper i discharge portion of the nozzleis restricted as at 24 so as togivei'added, velocity to thejet, the extreme upper portion of the nozzle passage be.- ing somewhat flared outwardly so" as to increase I the dispersionof the jet as, it is projected'upwardly throughthe' exhausting chamber T The delivery tube'assem'bly indicated generally ass is, as usual; proyided with'; a flared lowereinlet end 25 to receive the jet and iluids su cked or'entrained with the. jet liquid, an' intermediate portion 26 of smaller diameter, and a flared upper portion Zi of increased diameterto decrease the V vel'ocity of the: stream before it is -discharged,

intothe delivery pipe {I leading back into the tank A, The delivery tube 8 is made in two sepa- 7 rate portions, the *main' upper section being mounted atits lower end in the upper wall 28 of a casing ZBs'ec uredpntop of casing 23 and enclosin ra, liquid holding'orstorage chamber 30; 'The j shorter lowerfsec'tiontl of the delivery tube is mounted in the lower wall .of casing 29 sothat ber" 30 with the main vertical passage through the deliverytube The chamber 39 1's normally filled, with water, thesupplyj of lifquidt9 this chamber being maintained; under" low pressure; a

iniany one'o f several alternative ways'as will hereinafter described. I V i e The operation of one ofthese exhauster units will now be described referring more particularly f to the diagrammatic showing in Fig. 4. The

Water jet a projected upwardly with considerable velocity from nozzle 6 passes rather freely through the small lower sectional of the'delivery tube but I tends to dispersesoas tor-more completely fill f the upper section 8 ofthejdelivery tube.' -'-The 7 fluids b in the exhausting chamber 1 are sucked; *upwardly by .ithe jet wand partiallytentrained therewith." The body of :water c in chamber-30 7 tends to flow inwardly through annular 'passage 32 into thee-deliverytubejand the upwardly flowthrough this passage.

flow of water through passage. 32, and at times 'ing' jet 'aralso tends to .draw .water inwardly Ontthe other hand, the: 5 higher pressure in the delivery tube against which t the jet is projected tends to resist this inward actually 'forces thewater outwardly'as the outward lateralipressure atr this point rises. the vresult of these opposing and substantiallylbalanced forces a ringr o r elastic throat of "water is; Y e

velope of water within the-zlowerportion of de-V maintained withinthegdeliverytube adjacent the passage ,32 and serves to 'furnish a lining or enliverytubet which mergeslwiththe wateriof the jet as the combinedfluids pass upwardly through the delivery tube and are discharged into the" While there will, normally be' a withpipe 9.

drawalrofr liquid from chamber 3D to maintain;

this' ringor throatof'water and the water lining or envelope within tube 8,'this discharge of water will be quite smallas compared with the volume of water furnished to the upwardly flowing stream i by the jet a. The fiuids b sucked upwardly from chamber 1 are not only entrained between the dispersed water particles-of the jet a but are also ejntrainedbetween the jet and the liquidenvelope furnished by ring dand the enclosing twatere'n} velope that moves upwardly with the jet. Asa V consequencegviolent frictional engagement with t t '7 the stationary walls of the delive y tube is mini V Inized. This feature of thei-operation maybe better explained by referring to the ifamiliar for-t water in an open rain barrel." These bubbles form due to the entrainment of 'air by water fio wing into the barrel, the; drops of water striking the surface of the water in the barrel andren- 'mation of bubbles of water upon the surface: of

trapping air'particles due to the action of cohesion resulting frornrtheviscosity of the water. These j bubbles-float uponthesurface'of the barrel with e the air securely entrapped in the film of water sur rounding them until the bubbles .strike' the 'sides of the barrel whereupon they break andthe fentrappedair is lost In this exhauster this principle is used to entrap air particles in the dispersedj wav 7 t er of -the upwardlyflowing jet,jand instead of;

:striking the :wa llsof thedelivery tube and thus releasing the air, the gas-carrying water particles are surrounded" by1an envelope of water at d which is elastic and .moves upwardly "with the liquid streamjthus minimizing the release of the V v r entrained gas until thevstream has passed up- J wardly-into the area (if-higher pressure; The

surroundingwater throat (1 will automaticallyadjust its diameter in accordance with pressure t changes in this portion of the delivery-tube thus providing a more steady and continuous. sucking action on the fluids'bin chamber 'l and minimizingthe effectpf pressure variations inthe jet and in the space into which the fluids are projected. V Tlr is apparatus is" adapted to handle a gas-vapor mixture of fluids b which may consist in varying proportions of air or non-condensable gases, condensable vapor, and dispersed liquid particles. The variation in the proportion of these materials, as well as the pressurechange caused by condensation of a portion of the vapor all tends to create pressurefluctuations in the delivery tube and these are compensated for by the elastic liquid ring or throat at so as to provide a more steady and efiicient operation.

In the forms of apparatus shown in Figs. 2, 3, 5, 6, '7 and 8 the water supply in chamberw which furnishes liquid for the elastic ring 11 is replen-' ished from the condensate which flows into exhausting chamber 1 and then collects in the bottom portion 33 of this chamber. A passage 34 leads upwardly from chamber 33 through strainer 35 into chamber 36 which is connected. through restricted passage 31 with chamber 38 communicating at 39 with the water supply chamber 30.

The exit end of passage 3'! is closed by a swinging valve 40 carried by lever 4| pivoted at 42. This valve permits the upward fiow' of water from collection chamber 33 into supply chamber 30 (this upward flow being created by the suction of the jet) but prevents the return flow of water from the upper chamber 30. Some of the condensate which drains into chamber 1 will be drawn through this outside valve passage to supply the liquid for the enveloping throat D, while the remainder of this condensate will be drawn up by the jet and discharged through the .delivery tube along with the entrained gases. It will be noted that the water is drawn into the storage space 30 by the suction produced by the jet and is, therefore, under low pressure and there is never any substantial pressure tending to force the water inwardly through the annular passage 32. The one way valve 40, as well as the back-pressure set up by the restricted passage 31, tend to prevent the return ilow of liquid from chamber 30 under the influence of gravity or an abnormal increase of the pressure of the jet. In this manner a supply of water under quite low pressure is maintained in and about the annular passage 32, and the lateral pressures at the inner and outer sides of this passage are normally. substantially balanced.

In the modification shown in Fig. 9, condensate delivered into exhausting chamber 1 drains into the chamber 43 having a port 44 leading into passage 45 through which liquid is drawn upwardly into chamber 30. A valve 46 which closes the inlet end of port 44 is carried by one arm of a bellcrank 41 pivoted at 48, the other arm of this bellcrank carrying a float 49. When the liquid level in chamber 43 is low, the valve 46 will be moved to closed position to cut off the flow of liquid through passage 45. When sufficient liquid has accumulated in chamber 43, the float 49 will open the valve and permit liquid to be drawn up through passage 45 into chamber 30. With this float arrangement it is possible to make the opening for the flow of water proportional to the rate at which the water accumulates in chamber 43. Also when no water is accumulating the valve isclosed to store the the water supply'within tank A. Pipe 56 is pref erablyv provided at some intermediate point with a restricted orifice to control the flow of water to chamber 38. Since the storage chamber 30 is positioned at a height near. thev normal water level in tank A, and the restricting orifice in pipe 50 limits the rate of flow therethrough, the supply of water in chamber 30 will be replenished'as requiredlbut will remain under 'the desired low pressure. This form of the invention is preferable where the apparatus is to operate under a high vacuum with little or no condensate returning from the heating system, that is. the fluids to be exhausted are mostly gaseous.

In the forms of apparatus shown in Figs. 5 to 9 inclusive, a second auxiliary delivery tube section 5!, quite similar in form to the auxiliary section 3! previously described, is interposed be-' tween section. 3| and the: main section 8 of the delivery tube. This second tube section 5! is mounted in a -web 52 which divides a portion of chamber 30 into the lower chamber 34) and the upper chamber 30". Passages 32' and 32" communicate with the'delivery tube between the auxiliary sections 3| and 5!, and the sections and 8 respectively so as to provide two separate rings or throats of liquid within the entrance portion of the delivery tube. The advantage of this two-stage system. is that it increases the area of the portion which has liquid Walls or substantially elastic walls, and provides two rings of water instead of a single one so that a better enveloping action is obtained. It has been found that this two-stage construction increases the i efficiency of the apparatus, and it should be understood that two or more such sections may be used if found desirable.

In the modification shown in Fig. 8 the intermediate tube section 5l', instead of being fixed in the web 52 is vertically slidable therethrough between the limits determined by the collars 53 and 54 so that the section 5| can automatically adjust itself vertically in response to the pressures acting thereon so as to properly proportion the liquid flow through the annular passages 32' and 32". The parts will be so designed with relation. to the weight of member 5! and thepressure of the upwardly flowing liquid stream that this movable tube section will float between the opposing forces and properly distribute the flow of water to the two liquid rings. Preferably the web 52 will be provided with an orifice 52' for restricting the flow of Water into chamber 39" thus providing a time interval to elapse before,

the equalizing of the pressures in the two chambers 3B and 30 so that the sliding portion of the delivery tube will be permitted to react to V the difference in pressure.

It Will be understood that this two-stage form of delivery tube can be used with either a single jet exhauster element or with each of a multiplicity of jets as shown in any of the Various modifications.

In the modification shown in Fig. 10, the nozzle 6' is provided witha plurality of separate outlets 55 soas to project a plurality of separatejets upwardly into a single delivery tube (which may be provided with either one or a plurality of auxiliary sections as hereinabove described.) The operation of this form of the invention is the same as already described except that additional suction space and entrainmentsurface is provided between the several separate streams or jets. All of these jets are surrounded by the envelope of water within the delivery tube.

In the form of apparatus shown in Fig. 11, four separate similar exhausting units are grouped in close proximity as indicated by the four sepa rate auxiliary delivery tube sections 31 SIP,

31, and 314;" Instead-of having each ofthese units supplied with water from. a single chamber 30,:the casing is provided withinterior webs 'so V as to divide the chamber into four separate supplychambers 30 30, 30, and 30 one for each of the units. These'fchambers are separately supplied with. water through manifold 56. and

Z elastic rings has its own source of water supply have no direct effect upon. the pressuresin an' .adjacentunit as mightbethecase if all drew ,their water supply from asingle chamber.

In any of the forms of construction herein;

prevent thereturn of air particles from the re gion .of higher pressure intol which the fluids at? pressure fluctuations in one of the units will above disclosed, instead of supplying additional water continuously or intermittently through the other Words; the supply of Waterin this'chamber' would be furnished from' the stream-flowing through the delivery tube. "Such anapparatus scribed but it is more eflicient than the' ordinary type of jetexhauster.

chamber by any of the methods already described, this chamber 30 might be made closed 'or dead"end'so that Water would be stored therein upon a rise in pressure in the delivery tube andreleasedwhen the pressure falls. In

is not as "efficientas the forms hereinabove de- It is also possible in 'a system such as disclosedin Fig. 2' toomit the one- Way 'v alVe 40 '(or the control valve 46 as shown 'in Fig; 9) withasmall sacrifice in the amount of vacuum obtainable with the apparatus.

It will be noted that inall forms of'the invention a storage space fora supply of water is provided around the annular .opening leading into thefthroat of the delivery tube, this supply be ing, however, under quite low pressure. The

flow of water, one way or the other, through the annular opening 32 will'depend upon variations inthe suction ;or pressure of the jet, a substan 5 '45 tial balance of pressures being normally main tained in the throat portion of the 'deli'verytube.

:Normally there 'will be a rather small flow of 7 Water through'passage 32 and into' the throat of the delivery tube to' maintain the liquid lining.

It is most convenient to attain these 'results'byprojecting the jet upwardly,'as in the-forms of apparatus herein disclosed. so thatfthe action of gravity on the water supply maybe more easily jcontrolled. It is possible,-h'owever,, to' operate the jets downwardly, or in any direction, in which case the supply of waterforz thethroat-must be r V restrictedfand controlled so as' to' maintain thef n'ecessary balance of pressures;

f An exhausting apparatus of thisg'eneralty'pe fluids (gases'and liquids) for example inexhaustkinetic'principle', that is the mechanical witha drawing orthe fluids irom the space to be exhausted. Such condensationasdoes occur enprojected.

the deliverytubejoinswith the'water' of the jet I to insurea proper sealing of. the .tube'and-pre f ventsla breaking'down of the suction-as, well as.-

'hances the exhaustingactio'n, and this condensing action may be increased by supplying'the ac-" tuatingrwater at :colder temperatures; In this manner azcombined condenser and provided.

proved type of 'exhauster;

Y'Ihis improved exhauster insures reliable startej hing 'ofxthe exhausting .actionaftjera periodbf; disuse, and this is important since an exhausting V apparatus of ithis type is used. intermittently.

air. pump is.

With the ordinary type of'jetxexhauster there is r "altendency-when startingforjthe actuating 'jet" water togsho'ot .throughthede'livery tube Without adhering to .the walls and sealing them so as to 20" The elastic liquid throat provi'ded in making more effective the'zentrainmentfof the gasparticles. The. water. envelope, provided Within" the delivery tube from 'a source'separate from the jet-acts in effect as an elastic. delivery 1.'A' jet exhauster comprising a chamber into;

which fluids to beexhausted are delivered, a nozzle projecting into thechamber, meansfor forcing ajet of liquidundelf pressure through the nozzle, a delivery tube leading. from the V chamber into whichtube the jet is'projected,ua'

' liquid-holding chamber surrounding the entrance portion of the delivery tube, means for supplying liquid to this chambe grtherebeing avpair. of spaced apart annular ,openings'in; the delivery 7 tube :surrounding the passage. therethrough and,

communicating with this. chamber theportion of the; tube between thelannularyopenings.being' relative sizes; oi thev anmovable to'adjust the nular openings.

2. A jet exhauster.comprisingfa.chamberinto i 50 Whichfluidsto be'exhausted are delivered, a.

nozzle projectinginto the chamber, means. for

forcing a jet-of liquid under pressure'throughthe Y nozzle, a delivery tube-leadingfrom the'chambe'r intowhich tube the jet is' 'projected,j a liquid V holding chamber surrounding the entrance por'- tionof the delivery tube, means for supplying liquid: to this chamber, there being agpair of:

communicating with thischambenthe porti'on'of spaced apart annular openingsxinfthe delivery 7 tube surrounding the passage the'rethrough'and has been found to be especially effective and ad: Pv Y vantageous, when used for withdrawing mixed' the tube' between the. annular openings floating openings.

3. The method of exhausting a mixture of under substantially balanced lateral pressures I etween the'adjacen't liquidstreains to automati- Z .cally adjustfthe' relative; sizes of the annular around the exit from thespace and through and" in contact with which the'jetuisyprojected, the

by thesuction of the jet against the .action of gravity from liquids delivered into the space.

liquidjsupplying the annular body being drawn,

4. The method of exhausting a mixture of gases and liquids from an enclosed space which consists in entraining this mixture between liquids furnished by a jet projected through the space and an annular body of liquid maintained around the exit from the space and through and in contact with which the jet is projected, the pressure of the annular body of liquid being socontrolled that the inward pressure of the annular body of liquid and the opposing lateral pressure of the jet are substantially balanced so as to provide an elastic liquid throat about the jet.

5. The method of exhausting a mixture of gases and liquids from an enclosed space which consists in entraining this mixture between liquids furnished by a jet projected upwardly through the space and an annular body of liquid maintained above the space and around the exit therefrom, and through and in contact with which annular body of liquid the jet is projected, the pressure or" the annular body of liquid being so controlled that the opposed lateral pressures of the jet and annular body of liquid are substantially balanced.

6. The method of exhausting a mixture of gases and liquids from an enclosed space which consists in entraining this mixture between liquids furnished by a jet projected upwardly through the space and an annular body of liquid maintained above the space by the suction of the jet and through and in contact with which the jet is projected.

'7. A jet exhauster comprising a chamber into which mixed fluids to be exhausted are delivered, a nozzle projecting upwardly into the chamber, a delivery tube leading upwardly from the chamber in line with the nozzle, means for forcing a jet of liquid upwardly through the nozzle and chamber and into and through the delivery tube, a liquid storage chamber above the first-mentioned chamber and surrounding the lower portion of the delivery tube, there being an annular opening surrounding the passage through the tube and leading from the storage chamber into the entrance portion of the tube so that liquid may pass through this opening to form a liquid lining! for the tube, fluids from the first-memtioned chamber being entrained between the liquids of the jet and lining, and means for maintaining a supply of liquid under low pressure in the storage chamber.

8. A jet exhauster comprising a chamber into which mixed fluids to be exhausted are delivered, a nozzle projecting upwardly into the chamber, a delivery tube leading upwardly from the chamber in line with the nozzle, means for forcing a jet of liquid upwardly through the nozzle and chamber into and through the delivery tube, a liquid storage chamber above the first-mentioned chamber and surrounding the lower portion of the delivery tube, there being an annular opening surrounding the passage through the tube and leading from the storage chamber into the entrance portion of the tube so that liquid may pass through this opening to form a liquid lining for the tube, fluids from the first-mentioned chamber being entrained between the liquids of the jet and lining, and a restricted passage leading from the first-mentioned chamber to the storage chamber through which passage liquid is drawn upwardly by the suction of the jet to maintain the supply in the storage chamber. 7

9. A jet exhauster comprising a chamber into which mixed fluids to be exhausted are delivered, a nozzle projecting upwardly into the chamber, a delivery tube leading upwardly from the chamber in line with the nozzle, means for forcing a jet of liquid upwardly through the nozzle and chamber into and through the delivery tube, a liquid storage chamber above the first-mentioned chamber and surrounding the lower portion of the delivery tube, there being an annular opening surrounding the passage through the tube and leading from the storage chamber into the entrance portion of the tube so that liquid may pass through this opening to form a liquid lining for the tube, fluids from the first-mentioned chamber being entrained between the liquids of the jet and lining, a restricted passage leading from the first-mentioned chamber to the storage chamber through which passage liquid is- DAVID N. CROSTHWAIT, JR.

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