US2897764A - Pump priming arrangement - Google Patents

Description

1959 H. E. TRACY 2,897,764

PUMP PRIMING ARRANGEMENT Filed Feb. 3, 1956 3 Sheets-Sheet 1 w \9 x \9 Q T R I I 6 T #525597 E. 7fi6 Y IN V EN TOR.

H. E. TRACY PUMP PRIMING ARRANGEMENT 3 Sheets-Sheet 2 Filed Feb. 3, 1956 y 2N N R m 5m r J k N\ a m -Qw. m I G R m6 mm wv mm mw WW NM QM Q 3 mm {1| mm QM n Q0 Q Q NN) m wm. -Q a A Q h wv w m Nm. mm Q Aug. 4, 1959 I H. E. TRACY 2,897,754

PUMP PRIMING ARRANGEMENT Filed Feb. 5, 1956 3 Sheets-Sheet 5 z/e-eaeer 5. reac Y IN VEN TOR.

prrog/vgy United States Patent 2,897,764 Patented Aug. 4, 1959 nice PUIVIP PRIIVIING ARRANGEMENT Herbert E. Tracy, Alhambra, Califi, assignor to 'Borg- Warner Corporation, Chicago, 11]., a corporation of Illinois Application February 3, 1956, Serial No. 563,327

16 Claims. (Cl. 103-113) One problem encountered in the operation of most centrifugal pumps is that of air binding. If a pump has just been placed on stream, or if it had been in operation but has been shut down for some time, there will not normally be any, or very much liquid remaining in the pump casing. If the pump is started, and normal flow is to be established, the impeller must create a low pressure area adjacent the intake passage so that liquid will flow into the pump. Since the impeller is designed to pump liquid rather than gas, the lack of liquid in the pump usually makes it impossible for the impeller to sufiiciently exhaust the pump casing of air or other gases which cause the binding. A suitable priming arrangement is there fore necessary on the first use of a pump and at intervals thereafter when the pump may have been shut down for a period of time.

The present invention provides a priming arrangement that is effective upon the first use of a pump, and also one that is automatic upon subsequent start-ups if there is still liquid remaining within the casing. It also incldes a valving arrangement which is operable to cut oif liquid through the priming circuit, once normal flow of liquid is established.

The invention includes a casing having an inlet chamber, a pump chamber, and an outlet chamber. A multiple valve member governs flow into and out of the outlet chamber. Movement of the multiple valve member is eflected by a pressure piston. Actuation of the pressure piston is automatically controlled by a float valve responsive to the liquid level in the inlet chamber.

A gas flow passage is provided from the inlet chamber to a Venturi section within the multiple valve member. A check valve within the gas flow passage prevents back flow.

The pump casing is arranged so that the impeller is within the pump chamber and at the lowest level within it. Consequently, if there is any liquid at all in the pump, as for example after being shut down for a time, it will be available for pumping and priming. If there is not enough liquid in the casing, some will have to be added, as through a suitable fitting in the outlet passage, which is on top of the pump.

A flow path is provided so that priming liquid is forced by the impeller through a nozzle carried within the Venturi. The liquid jets out from the nozzle, and through the Venturi section. This creates a low pressure zone and gas is driven from the inlet chamber through the gas flow passage, into the priming liquid. The liquid is circulated out of the multiple valve member, around a turbulence producing plate, and back to the impeller. As the liquid passes around the plate and fills the outlet chamber, the entrained gas separates from the liquid and passes through the pump outlet passage. As more and more gas is evacuated from the inlet chamber, the pressure therein drops, and more liquid enters. Soon the liquid level rises to a point where it may open a one way swinging plate valve. Liquid pours into the pump chamber and the impeller drives it toward the outlet chamber.

As the liquid level in the inlet chamber rises, a float moves up. This opens a control valve, and priming liquid may then work behind one side of the pressure piston. The piston is actuated and moves the multiple valve against the force of a balance spring so that when liquid communication is established between the inlet chamber and the impeller, the liquid priming circuit will be closed oil, the gas flow passage will be blocked, and ports opened so that liquid will be pumped from the impeller directly through the outlet chamber and out of the pump. It is to be emphasized that when normal flow is established, there is no circulation through the priming circuit. The pump acts as if there were no priming arrangement present, and there is no needless friction loss.

Accordingly it is a primary object of the invention to provide a self-priming arrangement for a pump.

It is a further object of the invention to provide a self priming arrangement for a pump in which the priming circuit is deactivated when full flow is established through the pump.

It is a further object of the invention to provide a pump priming arrangement which is controlled by a multiple valve member actuable in response to change in liquid level within the inlet chamber for the pump.

It is a still further object of the invention to provide a self priming arrangement for a pump in which a multiple valve controls flow through the pump, a piston is eifective to shift the valve between a priming and a full flow position, and a float valve responsive to level of liquid in the pump inlet chamber governs movement of the piston.

These and other objects of the invention will become apparent fromthe following detailed description when read in conjunction with the accompanying drawings.

Figure 1 is a cross-sectional view of a pump and pump priming apparatus made in accordance with the invention, with the apparatus set so that the priming operation may take place.

Figure 2 is similar to Figure 1 except that the priming control valve has been moved to cut off priming flow.

Figure 3 is a cross-sectional view of the apparatus taken along the line 33 of Figure 1.

Figure 4 is a perspective view of the multiple control valve and piston operator therefor.

Figure 5 is an enlarged view of the nozzle and Venturi section illustrated in Figure 1.

Figure 6 is a sectional view taken along the line 66 in Figure 5.

Turning now to the drawings:

In Figures 1 and 2, there is illustrated a pump casing 12 having an inlet fitting 13 and an outlet fitting 14. Inlet fitting 13 is in liquid communication with inlet chamber 16, and outlet fitting 14 provides an exit pas sage from outlet chamber 17. Pump chamber 20 is located between the inlet and outlet chambers. When the level of liquid in the inlet chamber is high enough, the one way flap or plate valve head 18 will open and allow liquid to enter the pump chamber. The valve head 18 prevents back flow from the pump chamber if inlet pres-' sure should suddenly drop.

Within inlet chamber 16 there is mounted float 19. Rise or fall of float 19 is effective to elevate or depress float valve rod 22. Rod 22 has a pair of longitudinally spaced limit stops 24 and 25 on its periphery. In addition, the rod 22 has an annular reduced section as at 27 intermediate the stops 24 and 25. When the float 19 is in its lowermost position, portion 27 is out of liquid communication with passages 29 and 30. When float 19 is elevated, the reduced portion 27 enables liquid to flow from passage 29 through passage 30. When this occurs, piston 32 will be forced to the right for a purpose which will be explained below. A

The upper portion of inlet chamber 16 opens to a gas flow pipe 34. Gas may pass in one direction through pipe 34 as indicated by the arrow, but back flow of gas or liquid is prevented by the one way check valve 35.

At the bottom of pump chamber 20, there is mounted ir'npeller 37. Impeller 37 provides the motivating force for both priming and normal flow through the pump. Liquid passes from the impeller through a fitting 39 Fitting 39 contains outlet ports 40 adjacent one end of it. other end of the fitting 39 is shaped to form a nozzle 42'. Liquid passing through the nozzle 42 exits through the holes 44 and into the Venturi section 46 of multiple valve control member 48. This is best illustrated in Figures and 6.

The multiple valve control member 48 is hollowed out and open' at one end, as at ports 50. Liquid can flow out of ports 50 and around turbulence producing plate 52 into the outlet chamber 17. When the valve control member 48 is in the position shown in Figure 1, ports 54' on casing web 56 are in alignment with an annularly milled out section 58. Consequently, priming liquid may flow in through ports 54 around section 58, out through port 55, and back to the impeller 37. (See Figures r and 3:

In addition to there being holes 44 in nozzle 42, there is also a flow path from the nozzle 42 through the hollow rod 60. (See Figure 5.) Rod 60 extends between nozzle 42 and base piece 61. As will be seen in Figure 2, when float valve rod 22 is elevated, liquid will flow through rod 60, passage 29, annulus 27, and passage to the back side 63 of piston 32. Piston 63 fits loosely within bore 73. Pressure on the back side 63 will force piston 32 to the right as shown in Figure 2. Piston 63 is connected to push tube 65 which is co-axially slideably mounted upon rod 60. Push tube 65 is fastened to the end of valve member 48 as at 66. Motion of the piston 32 to the right is therefore effective to move the valve control member 48 to the right against the action of bala'ncing spring. 67. When multiple valve member 48 is in the position shown in Figure 2, ports 69 are in alignment with the ports of fitting 39, and flow takes place directly to the outlet chamber 17.

The operation of the structure is as follows:

If the pump is being installed, and contains no liquid, or, if the pump has been standing idle for some time and contains very' little liquid, priming liquid must be poured into the outlet chamber 17. This is preferably done before connecting inlet 13 and outlet 14 to their respective lines in a new installation, but could be done by opening a suitable fitting installed in the outlet line (not shown), or by disconnecting the outlet line and then pouring priming liquid into the pump. Such liquid would flow to the bottom of pump chamber 20, adjacent impeller 37. The pump would then be put into operation and impeller 37 would commence to drive liquid through the fitting 39. The multiple valve control member 48 would be in the position shown in Figure 1 so that ports 40' are closed off. The priming liquid would be driven through holes 44 in nozzle 42. As this liquid passes through Venturi section 46, a low pressure area would be created. Since the ports 71 of valve member 48 allow communication between the gas flow passage 34. and theinterior of the Venturi section 46, gas will be driven through the passage 34 from the inlet chamber 16. The gas will be absorbed by the priming liquid which is driven out through the ports 50 and around the turbulence producing plate 52. The turbulence will cause the gas to come out of solution and pass through the outlet fitting 14. The priming liquid will complete its circuit by passing through ports 54, around reduced annular portion 58, out through port 55 and back to impeller 37. This circulation will continue until the pressure is very greatly reduced within inlet chamber 16. This will cause the inlet chamber to fill with liquid. The level will rise until valve plate 18 opens and liquid will pour into pump chamber 20.

At the same time float 19 be elevated to the position shown in Figure 2, inasmuch as the liquid level in chamber 16 has risen. This will elevate valve rod 22 so that pressure will be applied through hollow rod 60, passage 29,- annular portion 27; passage 30', to the back face 63 of the piston 32. This will move the piston and multiple valve control member 48 to the position in Figure 2. In this position ports 71 are cut ofll, as are ports 54 and 55: Ports 69 are alignment with ports 40, and so normal flow is established from the inlet chamber 16 through the pump chamber 20, outlet chamber 17, and outlet fitting 14. No unnecessary fn'ction losses through the priming circuit are obtained at this time, since the priming circuit is closed off. I I

At such time as the pumpis shut down, andthe level of liquid in inlet chamber 16 diminishes, float 19 will drop toward the position of Figure 1. This will cut off the application of pressure to the back face 63 of piston 32. Spring 67 will then be elfective to shift multiple valve member 48 back to the position in Figure 1. Liquid trapped on the back side 63 of piston 32 will gradually leak past piston 32 since piston 32 fits loosely within the bore 73. When piston 32 has moved back to the position of Figure l, the arrangement would then be set for the next priming operation.

While the invention has been described in what is now considered to be a preferred form, it is to be understood that the invention is not limited to the specific details of such form but instead covers all changes, modifications, and adaptations within the scope of the appended claims.

What is claimed is:

l. A self priming arrangement for a pump, comprising a casing having an inlet and outlet chamber, an impeller within the casing to circulate fluid, a valve member to control flow within the casing, a first set of control ports within said valve member, means providing a gas bleed on passage from the inlet chamber to a point adjacent the said first set of control ports, a Venturi section within said valve member adjacent to said control ports, a nozzle within the valve member, flow from said impeller through the nozzle and into the Venturi section being effective to create a low pressure area in the Venturi whereby gas will be driven from the inlet chamber through the gas flow passage, a piston connected to said valve member to shift it from a position where said first control ports are open to a position where they are closed, means defining a liquid connection between the nozzle and one side of the piston, and float valve means in one of said chambers to open or close off the said liquid connection responsive to said one of the chambers containing liquid at a predetermined level.

2. An arrangement as in claim 1 wherein a reaction spring bears against one end of the said valve member and the said piston is connected to the valve member at its other end.

3. An arrangement as in claim 2 wherein a second set of control ports are provided within the valve member between the outlet chamber and the pump chamber, the said second set' of ports being opened when the said first set are closed.

4'. A self priming arrangement for a pump comprising a casing having an inlet chamber and an outlet chamber, an impeller within the casing, a gas bleed off passage from the inlet chamber, three-way valve means including a relatively stationary valve member and a shiftable hollow three way valve member having a first set of ports to control flow of gas from said bleed off passage to said outlet chamber, a second set of ports to control direct flow from the impeller to the outlet chamber, said stationary valve member having a third set of ports for enabling the flow of fluid from said outlet chamber to said impeller, means including an annular milled out peripheral portion on said shiftable three way valve member for controlling the flow through the third set of ports of fluid from the outlet chamber back to the impeller during the priming operations, means for normally retaining said shiftable three way valve member in a first set position wherein gas flow through said bleed oil passage and said first set of ports and fluid flow from the outlet chamber back to the impeller through said third set of ports and said annular milled out portion occurs, and means for shifting said shiftable three-way valve member to a second position wherein the last mentioned flows are cut off and flow from the impeller through the said second set of ports is opened.

5. A structure as in claim 4 wherein said means for shifting said valve member includes a pressure piston attached to the said three way valve member to effect movement between its said first and second positions, means providing a pressure flow path from within said three way valve member to one side of said piston, a second valve means to control flow in said last named pressure flow path, and operating means for said second valve means responsive to fluid in one of said chambers.

6. A structure as in claim 5 wherein the operating means for said second valve means includes a float disposed in said inlet chamber.

7. In a pump having a casing, inlet and outlet chambers in said casing, a pump chamber in said casing at a level below said inlet chamber, a pump element operatively disposed in said pump chamber, and priming means for selectively controlling the flow of fluid from said pump chamber to said outlet chamber, said priming means including a valve housing interposed between said outlet and pump chambers, and a multiple valve assembly in said valve housing, said valve assembly including a hollow barrel reciprocably mounted in said valve housing, said barrel having a Venturi section and a port adjacent to said Venturi section, means establishing com munication between said port and said inlet chamber, said valve housing and said barrel having means for establishing fluid communication between said outlet chamber and said pump chamber when said barrel is in one position, nozzle means cooperative with said barrel for directing the flow of fluid through said barrel while precluding the direct flow of fluid from said pump chamber to said outlet chamber when said barrel is in said one position, and operating means for shifting said barrel to a second position to interrupt the flow of fluid from said pump chamber to said outlet chamber, said nozzle having means for closing said port when said barrel is in said second position.

8. A pump as defined in claim 7 wherein said nozzle means comprises a hollow body carried by said casing, said barrel having a skirt telescopically engaged with said body, said body and skirt having ports registering with one another upon movement of said barrel to said second position, whereby fluid will flow from said pump chamber to said outlet chamber through said nozzle body.

9. A pump as defined in claim 7, wherein said operating means includes means defining a piston chamber communicating with said pump chamber, a piston slideably disposed in said piston chamber for movement in one direction responsive to pump pressure, means connecting said piston to said barrel, means normally biasing said piston in the other direction, and means including a float valve having a float disposed in said inlet chamber for selectively admitting or precluding the admission of fluid to said piston chamber behind said piston.

10. In a pump having a casing, inlet and outlet chambers in said casing, a pump chamber in said casing, flow controlling means including a multiple valve housing in said casing, a barrel shiftably disposed in said valve housing for movements between first and second position, and means defining an evacuation passage extending from said inlet chamber to said valve housing, means for directing the flow of pump fluid through said barrel into said outlet chamber, means normally maintaining said barrel in said first position when the fluid is below a given level in said chamber, said barrel having means for etfecting the suction of gas from said inlet chamber through said evacuation passage responsive to the flow of pump fluid through the barrel, said barrel and said valve housing having means forming a passage for the flow of fluid from said outlet chamber back to said pump chamber when said barrel is in said first position, means for shifting said barrel to the second position responsive to the fluid level in one of said chambers, and said barrel and said flow directing means having ports registered when said barrel is in said second position for establishing fluid communication between said pump chamber and said outlet chamber.

11. In a pump priming device, a multiple valve assembly including a housing having a longitudinally extended bore, an open-ended hollow barrel reciprocally disposed in said bore for movement to and from first and second positions relative to the housing, said housing having a pair of ports, said barrel having a passage for establishing communication between said ports when said barrel is in said first position, said barrel having a port intermediate its ends, said housing having means communicating with said barrel port when the barrel is in said first position, a hollow nozzle projecting into an end of said barrel and fixed with relation to said barrel, said barrel and nozzle having overlapping portions respectively provided with ports, said latter ports being in registry when said barrel is in said second position, and means for shifting said barrel to said first and second positions.

12. A device as defined in claim 11, wherein the means for shifting said barrel to said second position comprises a fluid pressure operated device, and including means for directing fluid from said nozzle to said fluid pressure operated device, and means operatively connected between said fluid pressure operated device and said valve for shifting the latter in one direction to said second position.

13. A device as defined in claim 11, wherein the means for shifting said barrel to said second position comprises a fluid pressure operated device, and including means for directing fluid from said nozzle to said fluid pressure operated device, and means operatively connected between said fluid pressure operated device and said valve for shifting the latter in one direction to said second position, and the means for shifting said barrel to said first position includes a spring engaged with said barrel.

14. A device as defined in claim 11, wherein said barrel is provided with a Venturi section adjacent the port therethrough.

15. A device as defined in claim 14, wherein said nozzle is provided with an axial extension constituting a valve for closing said port in the barrel adjacent to said Venturi section upon movement of the barrel to said second position.

16. A priming arrangement comprising a pump casing having an inlet chamber, a pump chamber, and an outlet chamber, an impeller within the pump chamber, a multiple valve assembly between the pump chamber and the outlet chamber, a Venturi section within the multiple valve assembly, means defining a gas bleed ofl passage from the inlet chamber to the said Venturi section whereby passage of fluid through the Venturi is effective to cause a pressure reduction for causing the flow of gas through the bleed off passage, and operating means to shift the multiple valve assembly from a first position where gas is allowed to flow through the said bleed ofl passage to a second position Where gas How in said bleed off passage is out 01?, said operating means including a piston chamber having a pistonreciprbcably mounted therein, means for directing fluid from said multiple valve assembly to said piston chamber, and means operatively connected between said piston and said multiple valve member for shifting the latter With said piston, a float valve dispos'ed in said inlet chamber; and said float valve including valve means for interrupting the flow of fluid to said piston chamber upon descent of said float valve.

References (lifted in the file of this patent UNITED STATES PATENTS Hentscbel Aug. 28, 1928 Jauch et al. July 2 6, 1938 Mueller Feb. 12, 1946 Antes Oct. 26, 1948 Bennett May 17, 1949 Nicolette June 6, 1950 Harris Mar. 3, 1953

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