US1789528A - Pump-priming mechanism - Google Patents

Description

Jan. 2o, 1931. C. s. LEWIS 1,789,528

A PUMP 'PRIMING MEQHANISM Filed May 7, 19.223V

E lu 'Q Q: l) LQ PJ N IU N O .1" lkq x z Q r @www Patented dan. 20, 193i` l insana I vlrarslrr OFFICE CHARLES s.V LEWIS, or sfr. Louis, mssounr Puur-rainure iuneiarnivrsiuv v Appnca'ion mea may?, 192s. seran Na. 275,631.v

l, This invention relates to al'pump vpriming mechanism, and is an improvement ton thepump lpriming mechanism. described in my vprior United States Patent No.A 1,080,917,

- 5 dated December 9,1913.v

The mechanism`r describedin my said patent comprises two chambers arranged at diffe'rentflevels and adapted to receive a liquid,

a supply pipe leading to the lower chamber l from a pool of liquid, or from a spacein which it is desired to create a vacuum, a dis'- charge pipe leading from the upper chamber,

a centrifugal or rotary pump arrangedwith vits intake communicating .with the lower y chamber and its outlet `communicating with the upper chamber and adapted to withdraw liquid from theilower chamber, so as'to produce a minus pressure in same and Ain the sup-- .u ply line, and a means for permitting a relatively vlesser volume of liquid to flow Ifrom the upper chamber into the lower chamber than the volume of liquid which the pump is.

' capable of withdrawing from the lower chamber during a given period, thus causing a partial vacuum or diminution of pressure in the-- lower chamber to whichhthe supply line leads. When the mechanism is to be used for pump-v ing liquid from a source of supply, it' is K rendered operative by introducing sufficient. liquid into the upper chamber, into the lower chamber, into the intake of the pump, into the impeller chamber of the pump, and into the discharge of the pump to completely lill said elements. The pumpis then set in operation, whereupon theliquid in the lower chamber will be drawn out of same and forced into `the upper chamber, thus causing an equal volume of liquid to be forced out ofthe upper chamber through -the discharge pipe leading from ythe same. The minus pressure that is `created in the lower chamber by,

the withdrawal of the liquid from said chamher will produce a zsuction in the supply line that causes liquid from the source of sup-.

ply to rise insaid supply line, or flow through said line a greater or less degree, according Ato the suction'that is'v exerted on thehsupply line by the withdrawal of the liquid from "the lower chamber.- After the charge of 5 liquid in the lower chamber has been with,

' which the i ump removes from said lower the mechanism.

drawn from same, as previously described, liquid starts to flow into said lower chamber from the, upper chamber, so as to provide the lowerchainber withl another charge of liquid chamber du ing the -second cycleof operations, so as to again create a mmus pressure in the lower chamber, andcause the liquid in the supply line to rise still higher in said line. These cycles are repeated until 'a conso tinuous column of liquid has been establishedl between the source of liquid supply and the impeller of the pump, after which liquid will be withdrawn continuously from the source of supply/and forced through the discharge pipe leading from the upper 'chamber of When the mechanism is in operation it is necessary that the pump remain air bound or inlsuchl a condition that it will not withdraw liquid from the" lower chamber during that portion of the first cycle in which liquid is passing from the upper chamber into the lower chamber, for if the pump should continue to withdraw liquid from thelower chamber during. the operaltion of filling said chamber, it would be impossible for enough liquid to collect in the lower chamber to form a charge that will produce the required minus pressure in the lower chamber when said charge is withdrawn from said chamber during, the' second cycle.

In the commercial use of the mechanism describedin my said prior patent it sometimes happened that the pump would not remain air bound at the completion ofthe operation of withdrawing liquid from' the lower chamber, with the result that the lower chamberl would not become filled with a full charge of liquid,.or with a charge of suiiicient -99 volume to insure the mechanism functioning properly. This was due to the. fact that 'liquid would become trapped in the lower end Vof the U-shaped arpipe which is attached' to the intake of the Apump and to the 95 lower chamber, which trapped liquid ywould prevent suiiicient .air from assing through said air pipe into the inta ecof the pump to cause the pump to remainlin anair bound.- condition, and thus entirely cease to with- *draw liquid from the lower chamber during the operation of filling said chamber.A

One object of my present invention is to remedy the above described defect of a pump priming mechanism of the general type described in my saidprior patent, and to this end I have provided the mechanism with a connection between the intake of the pump and the lower chamber which is of such con-4 cycle when the pump is drawing liquid from said lower chamber, the object being to prevent air or gas, which may at that moment be present in the upper. part of said lower chamber, from entering the pump and interrupting the flowA of liquid into the pump. However, the construction is such that said interposed body of liquid will drain into v the intake of the pump `after the liquid in the lower chamber has been withdrawn by the pump.

`Another thing that sometimes occurs under some operating conditions with a mechanism of the kind described in my saidprior pat-v ent, is that air becomes trapped between the impeller of the pump and the level of the liquid in the intake of the pump during the operation of filling the lower chamber, thus causing the pump to lag or falter before starting to withdraw liquid from the lower chamber, due, of course, to the fact that the slug of air in the intake prevents the liquid in the intake from freely entering the impeller chamber of the pump. Accordingly, I propose to connect the intake of the pump withthe upper chamber of the mechanism in such a manner that air which becomes trapped in the pump intake between the surface of the liquid in the intake and the impeller chamber of the pump, during the operation of fllin the lower chamber, will be positively expe led from the intake of thev pump at the completion of theI operation of filling the lower chamber, thereby effectively 'eliminating the pump remaining in an'air bound condition vat a time when the .pump is expected to withdraw a charge of liquid from the lower chamber, to create a minus pres'- sure in said chamber. .f

Another object of my present invention is to provide a pump priming mechanism of the general type referred to, with a means for preventing air from collecting in the intake of the pump and interfering with the operation of the pump after a continuous column of liquid has been established between the source of supply and the impeller of the pump. l

And still another object of my present invention is to provide an improved means for permitting air to passl from the lower chambe-r into the upper chamber during the y it comprises two chambers A and B of un-v equal capacity adapted to hold a liquid and arranged so that the large chamber A is located at a higher level than the small chamber B, a centrifugal or rotary pump D,

an inlet C for said pump communicating at oneend with the impeller chamber of the pump and at its opposite end with the lower portion of the chamber B, an outlet E lead-v ing from the pump D to the chamber A, preferably to the upper portion of said chamber A, a discharge pipe F leading from the upper end of the chamber A, a supply line or vacuum line I that leadsto the Ilower chambervB, and meansl for permitting liquid to pass from the upper chamber A into the lower chamber B, so as to `1ill said lower chamber, after the pump has withdrawn a charge of liquid from said lower chamber to create a minus pressure in same.

My improved apparatus herein described is distinguished, however, in numerous respects from the apparatus describedA in my said` prior patent. For example, it is equipped with a regulator or timer of novel `construction for maintaining' the pump D in an air bound condition after a charge of liquid has been withdrawn from the lower chamber, and for preventing said pump from y resuming the delivery of liquid to the chamber A until after the lower chamber'B has been purged Vof air or gas and lilled with another` charge of liquid ,it is provided with a conduit or other suitable passageway leading from the intake of the pump to the upper chamber A through which any air that vhas become trapped in the pump intake will be expelled from same at the completion of the operation of filling the lower chamber with liquid; it is provided with a conduit or other suitable passageway leading from thesupply line to the intake of the pump, so as to cause liquid to be supplied continuously to the pump intake after a column of liquid has been established between the source of supply and the impeller of the pump, thereby preventing air from collecting in'the intake of the pump and interfering with the operation of the pump, and it is provided with a means of novelconstruction for permitting air to pass fromrthe lower chamber into the upper chamber during the operation of filling the lower chamber, and for admitting air to the supply line, thus preventing the liquid in the apparatus being'siphoned out of same, in the event air leaks into the apparatus at a time when the pump is idle or not in operation. Moreover, my improved apparatus herein described is of such design that no check valves are required between the supply line or vacuum line and the lower Chamber l As illustrated in the drawing, the discharge pipe F leading from' the upper end of the chamber A is provided with a check valve G that permits liquid, gas or air to escape.

from the chamber A through the discharge pipe F, but effectively prevents liquid or air from returning to said chamber through said sure differential.

discharge pipe. The supply line I leads from a vessel, chamber, well, pool or sump L that may either be above the level or below the level ofthel chambers A and B, said supply line being herein illustrated as arranged with its lower end submerged in a pool of liquid L located at a lower level than the bottom of the chamber B and leading upwardly from said pool to a horizontal portion I of the supply line that is arranged at a higher level than the top of the chamber A. This horizontal portion I of the supply line communicates with an upright portion I2 of the supply line that leads downwardly to the chamber B,it being essential that the f, portion I be located at the same or at a higher level than the chamber A, in order to prevent back flowof the liquidlto the pool L by gravity. Said uprightportion I? may either be disposed vertically or at an"angl,

l but when the large chamber A is superim- Y posed upon the small chamber. B, as herein illustrated, it is preferable to have the por-I tion I2 of the supply line extend downwardly through `the chamber `A, as shown in the drawing. 1

, The regulator or timer, previously referred' to, that constitutes one of the novel featuresof my present invention, is positive in its action, as it operates by both gravity and pres- It comprises a small receptacle K arranged entirely or partly with` in the upper portion of the 'lower chamber B, or arranged outside of said chamber and connected by a pipe with the interior of the upper portion of said chamber. Said receptacle K, when arranged within the chamber B, is open at its upper side and is connected by a downwardly inclined pipe or small duct M with the intake C of the pump. This duct M is used tointroduce liquid into the intake C of the pump from the receptacle K during the operation of fillinglthe lower chamber B with liquid, and i`s so proportioned in cross sectional area that the receptacle K is not emptied of liquid until after the liquid in the lower chamber B has been withdrawnby the .pump D, thereby eliminating the possibility of the flow of liquid from the chamber B ceasing or being interrupted by air or gas which may be present in the upper'part of the chamber B passing into the pump intake C until yafter the entire charge of liquid has been withdrawn from said chamber.-

Said duct is also used to permit the liquid to pass from the intake C of the pump into the receptacle K during the operation of filling the chamber B. 'Ihe duct Mais also used in conjunction with the receptacle K to form a connection between the intake of the pump and the upper portion of the chamber B through which air will pass into the intake of the pump, and thus insure th'e pump remaining air bound during the operation of filling the lower chamber B with liquid.

Communication is established between the chamber A' and the chamber B by a by-pass or connection N through which ,liquid passes y the pipe O is provided with a valve or other suitable means O for regulating or entirely stopping the flow of liquid through said pipe O. In order that the various chambers, pipes, ducts and connections of the apparatus may be filled conveniently with a priming liquid, a filling, pipe P equipped with a .stop valve P is attached to the upper end of the. portion I2 of the su ply line.

The con uit or passageway previously referred to that is used to permit theescape of air that becomes trapped in the pump intake between the impeller chamber of the pump and the level of the liquid inl the intakeis herein illustrated as being formed by a pi e R that leads from theipump intake C to t e ^chamber A preferably `below the point of the expelled from said chambers,

the lower chamber B, the pump intake C and .pump D, the pipe M and receptacle K, the

upper chamber A, the intake portion of the discharge pipe F ylocated below the check valve G, the outlet E of the pump, the pipes R and S, and the connection C between the outlet of the pump and the vertical portion I2 of the supply line. The air or gas that is ducts and pipes .by the entrance of the priming liquid into the same escapes through the portion of the discharge pipe F located above said check valve. The apparatus is now in readiness to commence the first cycle which is started by setting the pump D in operation', at the proper rate of rotation, so as to cause the charge of liquid in the chamber B to be withdrawn from said chamber through the inlet C of the pump, and forced upwardly through the outlet E into the chamber A, thereby causing ban approximately equal quantity of liquid to be forced out of the chamber A into the discharge pipe F. vDuring this period of the first cycle a relatively lesser quantity of liquid is returned to the chamber B through the by-pass N and through the pipe O, some liquid also passing into the inlet C of the pump, through the pipe R. The combined quantity of liquid that is returned to the chamber B in a given time is less than the quantity of liquid that the pump simultaneously withdraws from said chamber B through the inlet C. .Consequently, the operation of withdrawing the charge of liquid from the chamber B pro.

ducesa minus pressure in said chamber and i'n the, supply l1ne I, with the result that the liquid in the pool L will rise inthe supply line I to a height depending upon the pressure differential in the chamber B, in the intake portion of the supply line I2 and at the surface of the pool L Liquid continues to flow into the lower chamber B and pump intake C through the various ducts, ipes or passageways provided for this purpose, and during this period in the cycle liquid is draining vout of the receptacle K into thc pump intake vthrough the downwardly inclined ductM. After the receptacle K has been emptied v of liquid, any air or gas contained in the upper part of the chamber B will escape from said chamber through the receptacle K and pipe M into the upper part of the inlet C of the pump, thus unifying the pressure in the chamber B and pump inlet valve G intothe B, thus insuring said chamber being lilled with a charge of liquid of the proper volume. At this period in the cycle, i. e., after the flow of liquid from the pump C has ceased, the air or vapor pressure in the chambers A and B, in the receptacle K, in the pump inlet C and outlet E, in the supply line I and in the ducts R and O becomes uniform or equalized through the pipe O, because the end of y said pipe O which discharge E of the pump 1s no longer submerged and sealed with liquid, and the liquid previously contained in said pipe O has drained out of same into the vertical portion I2 of the supply line. Moreover, at this period of the cycle the chamber B is partly iilled with air or gas which has passed into it from the space in the vertical portion I2 of the supply line between the surface of the liquid in the pool L, and the chamber-B, and said chambervB is partly filled with liquid which returned to it through the various devices provided for this' purpose. As the impeller chamber of the pump D is partly filled with air or gas at this period of the cycle, said pump cannot withdraw liquid from the chamber B, and as the air or gas pressure in the chambers A, and B is uniform, the liquid in the chamber A will descend by gravity into the chamber B and pump' intake through the by-pass N and pipeR, thus gradually filling the chamber B, the receptaclel K, the pum the supply line.

- As the/liquid descends Afrom the chamber A to the chamber B and V'g'gi'adually fills said chamber B, the air or gas which at this time is in the chamber B, receptacle K and pump inlet C, escapes through the pipes 'M, S, vertical portion I2 O, said air entering the upper portion of the chamber A above the level of the liquid in the same` When the level of the liquid in the chamber B and the pump inlet C rises to the point where the pipe M is attached to the inlet C, the remaining air or gas in the chamber B e capes'through the vertical portion I2 of the supply line, and thence through the lpipe O and outlet E of the pump, into the chamber A,-and when the chamber B and receptacle K are completely filled with liquid, the air or gas in the upper part of the pum inlet C escapes upwardly through the pipe into the chamber A. At this moment there is a 'continuous body of liquid p extending from the chambers A and B into terminates inside of the` P inlet C and part of the vertical portion I2 of of the supply line, and pipe Y Eand the portion of the discharge line it prevents the liquid in the apparatus beingf siphoned out of same back to the source of supply. In the event of air entering the apparatus, due to leakage of the valve G or from any other cause, while the .pump is not in motion, said air would rise or ascend into the upper part of the chamber A, and thence pass into .the pump outlet E and a small quantity of the liquid inthe supply line I would flow by gravity to the pool or well L.

i But when a quantity of air or gas sucient to fill thepump outlet E to the point where the pipe O is connected to the same has entered,`

then the return iow of liquid from the chambers A and Y B back to the source of supply will be eifectively prevented and the incoming air flowing directly through the pipe O nto the horizontal portion I of the supply Second and subsequent cycles At the beginning of the second cycle, the chamber B, receptacle K, pump inlet pipe C, part of the vertical portion I? of the sup-` ply line, the pipes R and M and a part of the pipe S are filled with liquid, and the upper portion of the chamber A, pump outlet pipe beldw the check valve G contain the gas or air which had previously been expelled from the chamber B, receptacle K, pipe M, pump inlet pipe C,-vertical portion I2 of the supply line andthe pipe S during the operation of filling the lower chamber B with liquid. At

ythis time the chamber A contains suflicient the pipe It,

liquid to seal the upper end of During thls where it enters said chamber.

second cycle the pump D draws the charge p of liquid from the-chamber B throughl the pump inlet C and delivers said charge through the pump outlet E into the upper part of the chamber A, gradually compressing the air or gas in the upper part of the chamber A to a pressure sufficient to overcome the pressure in the portion of the discharge pipe-F beyond the check valve G,

` thereby causing said check valve to open and permit the `compressed air or gas to escape through the discharge pipe F. The passage of 'any gas or air from the upper part of the chamber A or from the pump outlet E into the chamber B through the pipe O is-effectively prevented by reason of the fact that the end of the pipe O which communicates with the pump outlet E is then iiooded or sealed bythe liquid that is escaping through the pump outlet E into the chamber A dur- F established between the pool L ing this period, i. e., whilethe pump D is withdrawing chamber B andl delivering said charge to the chamber A. The discharge of liquid from the-.pump D intol the chamber A continues until the receptacle K has been completely emptied of liquid, whereupon the discharge of theliquid from the pump will be interrupted by reason of the air or gas which entered the chamber B during the pumping interval, escaping from said chamber through the receptacle K and. pipe M into the pump inlet pipe C The iiow of liquid through the pump outlet'E having ceased, the pipe O now beingopen or unsealed and the check valve G now being closed, the air or gas pressure in the chambers A and B and in the connecting ducts becomes equal-- ized, thus completing the second cycle. Upon the completion of this second cycle the liquid in the supply lineI will have ascended to a greater height than it had attained at the end of the first cycle, the level at which the liquid'now stands in the supply line being dependent upon the difference in the pressures in the chamber B and at the surface of the inlet end the pool or well L, in which of the supplyv line L is submerged.

the charge of liquid from the After practically all of the air or gas originally contained in the supply line I has been exhausted vl`by repeated cycles of 4pumpl ing and refilling, as above described, or after the'pressure'diiierence between the chamber B and pool L has reached such a degree as to cause a continuous column of liquid-to be and the impeller chamber of the spump, a quantity of liquid will flow continuously from the h orizontal portion I of the supply line, through the pipe S, into the pipe M, thereby keeping said pipe M illed with liquid,v and thus preventing air or gas, which may be in the upper part of the chamber from escaping from said chamber and passing into the pump inlet pipe CV through the receptacle K and ipe M. f

If the level of the liquid in the pool L recedes, during the operation of drawing liquid out of said pool, or if the vertical distance between the horizontal portion I of the supply line and thelevel of the liquid in the pool L is increased, or if air or gas enters the upper portion of the supply line or the upper portion of the chamber B, to such an extent or degree as to cause the flow of the liquid from the pool vL through the supply-.line I into the chamber B to be interrupted, or considerably diminished, then Ithe liquid in the downwardly-inclined pipes M and S will drain out of said pipes into the pump inlet pipe C, due 4to gravity, and any air or gas in the chamber B will then pass from the upper part of said chamber through the receptacle,

K and pipe Said pump will immediately cease delivering liquid to the outlet pipe E, and upon the cessation of` the flow of liquid ,through the outlet pipe E, the check valve G will close and the pipe O will become unsealed, thereby causing the pressures in the chambers A and B to become cqualized through the pipe C, as previously described. Thereafter, liquid will return to the chamber B and refill the same through the connection N and pipe R, and the gas or air which had accumulated in the chamber B and receptacle K will pass into the chamber A, as previously described. Subsequently, when the chamber B is emptied or exhausted of liquid, a minus pressure will be again created in said chamber and in the supply line I. Thus cycles will continue until the pressure Vdifference between the chamber B and the surface of the pool L is sufiicient to cause a continuity of flow of liquid from the pool L to the chamber B, the-number of cycles that the apparatus makes depending upon the length and diameter of the supply line I and upon the vertical distance from the chamber B to the source from which the supply of 1i uid is drawn;

en thisapparatus is used solely as a means of diminishing pressure in a vessel, piping system, or other device, the apparatus will operate in the'manner previously described, except that there will be no ow olf- A liquid into the chamber B from the line. In such cases the cycles will conti-nue so long as the pumpl) continues to operate at the proper rate of rotation and the diminution ofi-pressure will continue until the great- Iest diminuion of'pressure obtainable with the character and temperature of the .liquid contained in the appa-ratus will have been attained. 2

The proper functioning `ofthis apparatus is dependent upon the interrupted withdrawal of a predetermined quantity of liquid from thevchamber B by the pump D, followed by a period of time during which the pump D remains air or gas bound and does not withdraw liquid, and during this period the lower chamber B is replenished with a charge of liquid preparatory to the subsequent pumping operation of the cycles.

This-sequence off functioning and the perifodicity are accomplished through receptacle K and pipe M which interpose a measured or specific quantity of liquid between the gas or alr in the upper part of the chamber B and the pump intake C for the purpose of preyenting said gas or air fiowing into pump intake C during the pumping periodA of the cycles. Thecross-sectional area of the outlet of pipe M is so proportioned that the chamber B will be emptied ofl liquid to the point where the pump inlet pipe C is attached to said chamber before all of the liquid in the receptacle K has escaped from same through the pipe M into the pump inlet' pipe C. yDur- Supply tion N and pipes R and O passes through the pump and the pump continues to deliver the liquid so returning into the chamber A through the pump outlet E. But when the receptacle K has been emptied of liquid, the

air or gas in the upper part ofthe chamber B,A passes through the pipe M into the pump inlet C, and thence into the pump D, thus causing the pump to cease delivering liquid and remain in an air bound condition. Said pump will not resume the delivery of liquid through the outlet pipe E until after the chamber B has been again entirely filled with liquid and the receptacle K and pipe M flooded with liquid. When the chamber B, receptacle K and pipe M are filled with liquid,

the pump D is again in readiness toresume the delivery of liquid through the pump outlet.

The action of the pipe R which is used to permit a slug of entrapped air to escape from the intake C of the pump is as follows: When the chamber B and receptacle/K are entirely filled with liquid,the pump D is still main- -tained in an air bound condition by a small amount of air or gas being entrapped in the pump inlet C betweenthe rotating element of the pump and thev point where the pipe M enters the inlet C, thereby preventing the liquid in the pump inlet C from entering the impeller chamber of. the pump. This small slug ofair or gas remains entrapped in the upper partof the pump inlet C after the i chamber B is entirely filled with liquid, and untilthe static pressure from the chambers A and B is communicated by reason of the continuity of the body of liquid through the connection N and pump inlet C. When this,

condition of hydro-static pressure has been established, then'the pressure in the pipe R at the point Where said pipe is attached to the chamber A rises to a pressure in excess of the static pressure in the chamber A at the point Where the pipe R is connected to same. At thismoment the hydro-static pressure in the chamber A at the point where the pipe R is connected to same isovercome and the slug of the entrapped airin the upper` partof thepump inlet C is suddenly forced upwardly through the pipe R into the chamber A, thereby permitting the liquid in the intake C to enter the'impeller chamber of the pump, and thus put said -pump in condition to withdraw liquid from the chamber B.

As previously stated, the function of the pipe S is to keep the pipe M Hooded vwith liquid after a continuous column ofliquid has been established between the source of` supply and the impeller chamber of the pump. The` object inflooding the pipe M under this conditionis to prevent air or-gas, which may at this timebe contained in the y upper part of the chamber B, fro-1n entering the pump D or the inlet C of said pump,

portion I2 of the supply line, even though said chamberB is partly iilled with air or gas, and will continue to so deliver liquid under this condition .until the chamber B contains air or gasto a point where the pump inlet C is attached to same.

' dition arises and chamber B is exhausted of liquid to the point where the inlet C terminates in said chamber, then a quantity of air will enter the pump Dthrough the inlet C,

" causingr said pump to.n become air or gas 'which had become entrapped within the bound. Consequently, Vthe pump'D will not deliver liquid, and as the` delivery of liquid from said pump ceases, the flow=of liquid ythrough the supply line l ceases, and as the flow; of' liquid -in said supply. line ceases, the liquid in the pipe S will drain out of same. 1When said pipe S is drained, the pipe M will likewise drain into the pump inlet C, and at this moment air or gas will pass through the pipe M -into the inlet C and pump D, causing the liquid in ,the inlet'C to descend to the level of the liquid in the chamber B.

yWhile the pump D is in operation and is delivering liquid, there is a constant and continuous return of` liquid from the. chamber A to the chamber B through the connection N and' through the pipeQ, and there is also a return of liquid through the pipe R from the chamber A into rthe pump inlet C. After the supply line l has been entirely exhausted'of air or gas, and thereisal continuous flow of liquid being delivered bythe pump D and dis- 'charged through the discharge pipe F leading from the chamber A, no purpose is served by the return ofliquid through the pipes C)t and R and connection N, and therefore, this return flow can be prevented by' closing the valves C', R1 and N. i

'The pump described in my said prior patentis required to begin discharging liquid against a pressure greater than the pressure of the liquid at its intake, and the greater this pressure diference', the longer isthe time interval required to expel any air orga-s pumps impeller orimpeller chamber, the eX- pulsion of this air or gas being a pre-requisite to the proper functioning of the pump. ln

Y' my present pump there existsno pressure difference between that at the pumps intake and that at which the pump is required to begin discharging liquid, and therefore, the period of time required for expelling any entrapped-air or gas from the `pumps impeller or chamber is materially reduced. r

i Having thus described my invention, what When this con-- I claim as new and desire lto secure by Letters Patent is i l. A pump priming mechanism, compris-l ing a chamber that is adapted to hold a charge of liquid, a supply line or suction line v leading to said chamber, a pump f or withdrawing thecharge of liquid from sald chamber so as to create a minus pressure in same,l

means for supplying another charge of liquid to said chamber, and` a connection between the intake ofthe pump and said chamber that is adapted to hold liquid which is supplied to the pump intake by gravity simultaneously withl the operation of withdrawing a charge of liquid from said chamber.

2. -Ai pump priming mechanism, comprising a chamber that is ladapted to hold a charge of liquid, a supply line or suction line leading to said chamber, a lpump for withdrawing 'the charge of liquid from said chamber so as to create a minus pressure in same, means for supplying another charge of liquid to saidf chamber` and aconnection between the in-4 take of the pump and said chamber that is adapted to hold liquid which is supplied to the pump intake by gravity simultaneously with the operation of withdrawing a charge of liquid from said chamber, said connection being so constructed and arranged that it will supply suliicient air to the intake of the pum-p -to insure the pump remaining in an air bound condition during the operation of filling said chamberwith liquid.

3. pump priming me chanism,'compris ing a chamber that is adapted to hold a charge of liquid, a supply' line or suction line leading to said chamber, a pump for withdrawing the charge of liquidl from said chamber so as to create a minus pressure in same,

means for supplying another charge of liquid to said chamber, and a lconnection between the intake ofthe. pump and the upper vportion of said chamber that comprises a receptacle adapted to hold a liquid and arranged so that the liquid in said receptacle will pass into the pump intake by gravity simultaneously with the opera-tionl of withdrawing'the charge of liquid from said chamber.

'4. A pump priming mechanism, compris'- ing a chamber that is adapted'to hold a charge'of liquid, a suction line or vacuum line.

leadingto said chamber@ a pump for withdrawing the charge ofliquid from said chamloer so as to create a minus pressure in same` means for replenishing the charge of liquid in said chamber, and means connected to the top side of the intake of the pump for permitting air that becomes trapped in said intake duringthe operation ofy filling said chamber with liquid to escape from said intake, thereby insuring the. liquid in the intake passing into the chamber ofthe pump.

5: A pump priming mechanism, comprisl ing two chambers arranged atdilferent levels y l Il) rio i communicating with the lower chamber andv and adapted to hold a liquid, a suction line or vacuum line leadingto'th'e lowei chamber, apump of the rotary type having its intake its outlet coii'imunicating with .the upper chamber for withdrawing a charge of liquid vchamber at a point below the level of the liquid in said chamber for permitting a .slug of entrapped-air in the intake of the pump to escape from same in the operation of filling the lower chamber.

6.' A pump prin'iing mechanism, comprising two chambers arranged at different levels and adapted to hold a liquid, a' suction line o ivacuum line leading to the lower chamber; a

pump of the rotary type arranged with its inlet communicating with the lower chamber and its outlet communicating with the upper Achamber for withdrawing a chargeof liquid vfrom the lower chamber and forcing said charge into the upper chamber, means for permitting the liquid to pass from the upper chamber into the lower chamber, a connection between the intake of the pump and the-up perportion of said lower chamber arranged so as to supply liquid to said intake during 'the opera-tion of withdrawing the charge from the lower chamber and to supply air to.

said intake during the operation oftilling the lower chamber, and a passageway leading from the pump intake to theupper chamber for permitting entrappe'd air to escape i'lomfsaid intake under certain conditions.

Apump priming mechanism, 'comprising a chamber that is adapt-@dto hold liquid, a` pump of the-rotary type communicating with said chamber, a suction line leading to said chamber from a sou-ree of liquid supply, and a passageway oi' conduit leading from ,Y the suction line and attached tothe pump inouslv supplying liquid to said intake after a.

r ul

take at a point between said chamber and the imneller chamber of the pump for continucontinuous column of liquid has been established between the source of supply and the i mueller chamber of the,punip.

D 8. A pump priming mechanism, comprising two chambers arranged at different levels and adapted to hold a liquid, a suction line that leads to said lower chamber, a pump of the rotaiytype arranged withits intake communicating withthe lower chamber and its outlet communicating with the upper chamber for drawing a charge oit' liquid from said lower chamber and forcing said charge into the upper chamber, means for permitting `liquid to pass 4from the upper chamber .into

the lower chamber to form a charge in said lower chamber, a discharge pipe leading from the upper chamber and equipped with a'clieck valve, and a connection between the outlet of the pump and said suction line arranged at a higher elevation than the liquid level in the upper chamber and constructed so as to permit air to pass from the-lower chamber into the upper chamber and also to admit air to the suction line to prevent siphoning.

9; A pump priming mechanism, comprising two chambers arranged at different levels and adapted to hold a liquid,;a suction line that leads to said lower chamber, a pump of the rotary type arranged with its intake c'ommunicating with the lower chamber and its out-let communicating with the upper chamber for drawing a charge of liquid from said lower vchamber andy forcing said charge into the upper chamber, means for permitting liquid to pass from the upper chamber into the lower chamber to form a charge in said lowerv chamber, a discharge pipe leading'fiom the -upper chamber and equipped with a check valve, and a vconnection betweenthe pump outlet and saidsuction line constructed and arranged so that said connection will be water sealed when liquid is beingdelivered by the pump to the upper chamberand will be iinsealed at all other times.

lower ,chamber and introducing said liquid into the upper chamber, means for permitting a charge'nof liquid to pass from the upper chamber into theglower cli'a'inber and into the intakel ofthe pump, means for permitting the air displaced from the lower chamber and the pump intake .during the operation of filling the same to enter the upper chamber, and a connection betweenthe pump intake andfthe upper portion of the lower chamber arranged so as to form a self-draining passageway through which air can pass from t-he lower chamber into the pump intake and thus maintain the pump in an air bound condition during the operation of supplying a charge of liquid to the lower chamll. A pump priming mechanism, comprising two chambers arranged at different levels 'and adapted to hold a liquid, a suction line 10. A pump priming mechanism, compris-, ing two chambers arranged at diil'erent levelsv leading to said lower chamber, a discharge line leading. from the upper chamber and equipped with a check valvea pump of the ting a charge of li uid to pass from the upper chamber into theflower chamber and into the intake of the pump, means for permitting 3 y the same to enter-theaipper chamber, and a the air displaced from thev lower chamber and the pump intake during the operation of illing the same to enter the upper chamber, a

ations of the mec anism.

equipped w1th connection between the pump intake and the upper portion of the lower chamber .arranged so as to form a self-draining passageway through. which air can pass from the lower .chamber intothe pump intake and thus maintain the pump 1n an air bound condition durlo' ing the operation of supplying a charge of liquid to the lower chamber, a conduit leading from the pump intake and attached to said upper chamberat a point below the liq-` uid level in said chamberfor permitting a slug of trapped air to escape from the pump intake, and a conduit leading from the suction line and attached to the pump intake for continuously supplying liquid to thevsame after a continuouscolumn of liquid has been established between. the pump `and the source of y liquid supply.

passageway between the intake of the pump yper chamber.

the'lower chamber and into the ing from the pump intake and attached to said upper chamber at a point below the liquid level in said chamber for 'permitting a slug of trapped air to escape from the pump intake, a conduit leading from the suction line and attached to the pump intake for continuously supplying liquid to the same after a continuous column of liquid has been established between the pump and the source of liquid supply, a conduit attached to the suction line at va point above the level of the liquid in the upper chamber and having an inlet end which terminates at such a point in the outlet of the pump that said inlet end will be` sealed against the passageway of air when liquid is flowing from the pump into the uphamber and introducing said liquid'` `'CHARLES s. LEWIS.

and said chamber having provision for maintaining avbody of liquid between the air in said chamber and the liquid in said intake during a certain ortion of the' .cycle of oper- 13. AA pum priming mechanism, cmprising two cham ers arran d atdierent levels and'adapted to hold a 'quid, a suction line leading to said lower chamber, a discharge vline leading from the upper chamberand equipped with a check valve, aI-pump of the chamber into the pump intake and thus mainrotary type for withdrawing liquidfrom'the lower chamber and introducing vsaid liquid into the upper chamber, means for permitting a charge of liquid to pass from the upper chamber into .the lower chamber and into the intake of the pump, means for permitting the air displaced from the lower chamber and the pump intake during theoperation of filling the same to enter the upper-chamber, a con' nection between the pump intake and. the. upi per portion of the llower` chamber arranged so as to form aj self-draining passageway through which air can pass from the lower tain the pump in an airbound condition dur- -ing the operation of sup lying a charge of 1 liquid to the lower chamlier a conduit lead-

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