US2235973A - Primer for centrifugal pumps - Google Patents

Description

March 25, 1941. A. P.1 2,235,973

PRIMER FOR CENTRI FUGAL PUMPS Filed Feb. 25, 1939 VZ/f.

I INVENTOR. 40/"/0fl 46/76 ATToRNEYs Patented Mar. 25, 1941 UNITED STATES PATENT OFFICE Adrian I. Adney, Battle (lreek l licln, asalgnor to American-March Pumps, Inc., Battle Creek, Mlclh, a corporation oi! Michigan Application February 25, 1939, Serial No. 258,381

7 Claims.

This invention relates to improvements in primers for centrifugal pumps.

The main objects oi! this invention are:

First, to provide an improved priming mecha- 5 nism for centrifugal pumps, which is highly eiii cient and effective Ior priming pumps where there is a very considerable percentage of vacuum required for effective priming.

Second, to provide a priming assembly for cenm triiugal pumps, which is entirely automatic in operation. v

Third, to provide a priming apparatus for internal combustion engine driven centrifugal pumps in which the exhaust of the engine is effectively utilized. a

Fourth, to provide a priming apparatus for internal combustion engine driven centrifugal pumps in which theengine is effectively protected irom the entrance of water thereinto.

Filth, to provide a priming apparatus for centrifugal pumps in which the priming means is automatically cut out when the pump is completely primed and cut in when the pump loses its prime.-

5 Sixth, to provide a priming apparatus having the above advantages, which may be very easily installed or embodied in internal combustion engine centrifugal pumps now quite extensively used.

30 Further objects relating to details and economies oi the invention will appear from the description to follow. The invention is defined and pointed out in theclaims.

35 Preferred embodiments of'the invention are 11- lustrated in. the accompanying drawing, in which:

Fig. 1 is a fragmentary side elevation oi. an internalcombustion engine driven centrifugal parts being broken away to better show structural details, and other parts being shown conventionally. I

Fig. 2 is a fragmentary section online '.'-2 of Fig. 1.

The embodiment illustrated is especially designed as a pump for ditch or excavation draining, irrigation, or the purposes and I have shown it as a portable unit mounted on a skidlike base I. It will be understood, of course,

pump embodying the features of the invention,

vided with a babe disposed across the same.- the purpose of the bai'lle being to prevent swirling or rotary movement being set up or induced in the intake 'as a result of the action of the rotor of the pump, and this bailie is of consid- 5 erable advantage in relation to the priming connection which will later be described.

The pump is provided with a discharge 6 having a return check valve I this check valve being provided with a guide stem at which is threaded at I so that the stem may be adjusted to control the opening of the check valve.

The engine exhaust pipe or conduit III is provided with an exhaust pressure tank or chamber ll having a discharge valve I! which is actuated by a diaphragm pressure means designated generally by the numeral I; to open the valve when there is sulilcient water pressure in the discharge 8 and to close the valve when the pump pressure has dropped due tothe pump losing its prime, this valve opening means being connected by the pipe II to the discharge of the pump in advance of its check valve I.

The ejector I5 is connected to the exha conduit Ill to communicate therewith in parallel with the pressure chamber by the connection I6 and is provided with a nozzle indicated at H properly positioned in relation to the suction housing of the ejector and to the delivery memher I alined with the nozzle as is indicated by dotted lines in Fig. 1. Ejectors of this general 'carbon about the ejector is thereby prevented.

Such accumulation inevitably takes place in the 49 case of an ejector out 01f part of the time and open part of the time, with resultant changes in the operating characteristic of the ejector.

The ejector is connected to the intake of the pump by the pipe or conduit I! having the return check valve 2} therein, this valve being preferably of the flap type and also having a float actuated valve 2| between the check valve and pump intake and preferably directly on top of the latter, the float 2: of the valve being housed in the valve chamber 23 which serves as a float chamber. It will be noted that this valve is shown by dotted lines in open position. When the pump has been fully primed, water rising or passing through the valve chamber 23 will seat the valve and cut of! the connection. However, the float of valve 2| is designed so that it will not be closed by the flow of air through the chamber 23 and conduit is even when there .is a substantial amount of water mixed with the air. when the pumpis stationary and the suctioniine has pressure or a head of water in the same, the valve 2| will close and prevent water entering the engine. Likewise, with the pump stopped and a loop elevated in the suction orintake hose, the water would tend to flow into the engine, but valve 2| prevents this.

It should be noted that the priming connection of the ejector is to the intake or suctionside of the pump, a feature of substantial importance in apparatus which is primed while the pump is running, for a centrifugal pump cannot be efiectively voided of air on the discharge or pressure side thereof while running, inasmuch 25 nect the intake with as the air is forced inwardly oi the impeller and gathers as a globule at the center thereof, being verydiflicult or impossible to remove.

With the parts arranged as illustrated in Fig. l, the pump is automatically primed on the startingof the engine, it only being necessary to conthe source of water supply. In the event the apparatus is not eq ipped with an automatically opening exhaust valve If, it is necessary on starting the apparatus to close the exhaustvalve l2 and proceed-as before and as soon as the pump has been primed, open the exhaust valve l2, which permits the engine to develop its maximum horse exhaust for a wer and speed. It will be understood that in rder to secure the desired pressure and velocity of discharge, the ejector nozzle I'I constitutes a restriction in the discharge of exhaust.

The exhaust pressure tank is a highly desirable feature in securing a uniform pressure and adds materially to the speed of priming, as it results in a substantially-uniform pressure in the ejector nozzle as distinguished from' pulsing or varying pressures such as might result from an internal combustion engine having only one or few cylinders.

I desire to point out that the mechanism is adapted for use on turbine driven pumps, for example, and in that case the exhaust pressure tank is not so important, as thedischarge of turbine engine is substantially uniform.

In an installation such as shown in m. 1, it

is desirable that theexhaust pressure chamber ll be correctly positioned; that is; my investigations indicate that if it is too remote from the ejector the fullest advantage is not obtained and if it is too close the full advantage of steady flow of exhaust is not secured, and I have found that in an embodiment such as I have illustrated when the pressure tank is ten or twelve inches from the ejector connection to the exhaust, verywater (which has a swirling movement) rotatably approaches the connection, the water tending to swirl'in the direction indicated by-the arrow in Fig.- 2. The baflle thereby shields the vacuum line aperture or connection from the direct flow of water, and creates a small pocket which permits the air to be drawn up off from the water,-i..e., separated from the same in priming.

Structures embodying my invention are highly emcient and I have illustrated my improvements as embodied with internal combustion engine driven pumps. The exhaust gases of such engines are, I have found, highly efficient. The elector soon becomes heated and this adds to its eillciency, but I am not just certain to what to ascribe this emciency.

I have illustrated and described my improvements in comparatively simple and very practical embodiments thereof. I have not attempted to illustrate or describe various other embodiments or adaptations as it is believed that this disclosure will enable those skilled in the art to embody or adapt my improvements as may be. desired.

5 Having thus described my invention, what I claim as new and desire to secure by Letters Patent is: I

1. In an pparatus of 'the"'class described, the

combination with a centrifugal pump, of 'an engine for driving said pump, an exhaust conduit-for said engine having an exhaust pressure chamber therein, said pressure chamber bein provided with a, discharge valve, 9. pressure actuated means for opening said exhaust pressure chamber discharge valve and having control connections with the discharge of the pump,

and an ejector connected to said exhaust con- 'duit in parallel with said exhaust pressure chamfor said ejector to the pump. l

2. In an apparatus of the class described, the combination with a centrifugal pump and an internal combustion engine for driving the pump.

of an exhaust conduit for said en i e provided with an exhaust pressure chamber, an ejector connected to saidconduit in parallel with the said exhaust pressure chamber, whereby the fluid pressure in said chamber smooths the flow of gas fnpm said conduit through the ejector, a discharge valve for controlling the pressure in said pressure chamber, and means for automatically opening said valve associated with the discharge of the pump.

3. In an apparatus of the class described, the

. combination with a centrifugal pump and an engine for driving said pump, of an exhaust conduit for said engine having an exhaust pressure chamber therein, said pressure chamber being provided with a discharge valve, a pres-. sure actuated means for opening said pressure chamber discharge valve operatively associated with thedischarge of the pump, and an exhaust actuated ejector connected to said exhaust con-'- duit in parallel'with said pressure chamber, said ejector having a priming connection with said' P m 4. In an apparatus of the class described, the combination with a pump and an engine for driving said pump, of an exhaust line for said engine having an exhaust pressure chamber therein provided with a discharge valve, pressure actuated means operativelv connectedi to and controlled by said pump for actuating said discharge valve, and an exhaust-actuated ejector mitting having a priming connection to the pump and in fluid pressure transmitting communication with said pressure chamber whereby the fluid pressure in said chamber smooths the flow of gases through said ejector when said pressure chamber discharge valve is closed, the operation of said ejector being governed in accordance with the actuation of said valve.

5. In an apparatus of the class described, the combination with a pump and an engine for driving said pump, of an exhaust line for said engine having an exhaust pressure chamber therein provided with a discharge valve, means for actuating said discharge valve, and an exhaust-actuated ejectorhaving a priming connection to the pump and in fluid pressure transcommunication with said pressure chamber whereby the fluid pressure in said chamber smooths the flow of gases through said ejector when said pressure chamber discharge valve is closed, the operation of said ejector being governed in accordance with the actuation of said valve.

6. In an apparatus of the type described, the combination with a rotary pump and an engine connected thereto for driving the same and provided with' an exhaust line having a valve opening therein, of means for priming said pump while the latter is actuated by the engine, comprising a discharge valve to control the opening and the pressure in the line, pressure actuated means connected to the valve and operatively connected to and controlled by said pump for actuating said valve, and an exhaust actuated ejector having a priming connection to the pump on the suction side thereof, means associated with and in communication with said vent filling of the connection with liquid, said last named means being actuated by liquid flowing through said connection, said ejector bein 'connected to said exhaust line in parallel with the discharge opening whereby when the latter is open flow of exhaust from the line through the ejector is substantially reduced, said ejector being continuously open for the flow of exhaust therethrough during priming or non-priming operation whereby to minimize accumulationo exhaust-carried deposits thereon.

7. In an apparatus of the type described, th combination with a rotary centrifugal pump and an engine connected thereto for driving the same and provided with an exhaust line having a valve opening therein, of means for priming said pump while the latter is actuated by the engine, comprising a discharge valve to control the opening and the pressure in the line, pressure actuated means connected to the valve and operativelyconnected to and controlled by said pump for actuating said valve, and an exhaust actuated ejector having a priming connection to the pump on the suction side thereof, said ejector being connected to said exhaust line in parallel with the discharge opening whereby when the latter is open flow of exhaust from the line through the ejector is substantially reduced, said ejector being continuously open for the flow of exhaust therethrough durim priming or non-priming operation whereby mp minimize accumulation of exhaust-carried deposits thereon.

ADRIAN P. ADNEY.

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