US1995812A

US1995812A - Pump priming means

Info

Publication number: US1995812A
Application number: US665854A
Authority: US
Inventors: William H Noble
Original assignee: Pennsylvania Pump & Compressor
Current assignee: Pennsylvania Pump & Compressor; Pennsylvania Pump & Compressor Co
Priority date: 1933-04-13
Filing date: 1933-04-13
Publication date: 1935-03-26
Anticipated expiration: 1952-03-26

Description

March 26, 1935. w, H NOBLE 1,995,812

PUMP PRIMING MEANS Filed April 15, 1935 INVENTOB W11. H/VuZz/e B) Z V M ATTORNEY Patented Mar. 26, 1935 1.995.812 r rnnmno MEANS Application April 13, 1933, Serial No. 665,854

1 Claim. (Cl. 103-113) This invention relates to pump priming means, particularly electrically controlled priming means for an electric motor driven centrifugal pump.

An object of the invention is to provide a sim- 5 ple, easily operated and maintained pumping installation started by a manual or gravity switch to first flood the pump with water and then start the pump in normal operation.

One feature that enables me to accomplish the above named object is that a main starting switch, preferably operated by a solenoid, is closed for starting the main motor only after the main pump is flooded, a valve in the connection between the main and priming pump closed, and a high 'is developed.

Another object of the invention is to provide a pressure operated switch in the discharge of the main pump to break the circuit for the priming pump so that as soon as the main pump is operating normally the priming pump will be stopped but'may again be started to prime the main pump if pressure within the discharge becomes unduly low.

With the above and other objects in view my invention includes the features of construction and operation set forth in the following specification and illustrated in the accompanying drawing.

In the accompanying drawing annexed hereto and forming a part of this specification, I have shown my invention embodied in a centrifugal pump installation but it will be understood that the invention can be otherwise embodied and that the drawing is not to be construed as defining or limiting the scope of the invention, the claims appended to this specification being relied upon for that purpose.

In the drawing the figure is a side elevation vof 40 a complete pumping installation embodying the invention, parts being shown diagrammatically to more clearly indicate their operation.

In the above mentioned drawing I have shown but one embodiment of the invention which is now deemed preferable, but it is to be understood that changes and modifications may be made within the scope of the appended claims without I departing from the spirit of the invention.

Briefly and in its broadest aspect the present 50 inventionmay include the following principal parts: First, a main pump and driving motor preferably directly connected; second, a vacuum pump having 9. directly connected driving motor, the intake of the vacuum pump being connected with the interior of the main pump; third, a

vacuum in the suction pipe of the priming pump float in the connection between the pumps to open and close the connection; fourth, a vacuum controlled switch in said connection; fifth, a pressure operated switch in the discharge of the main pump moved to an open position when pres- 5 sure within the discharge reaches a predetermined pressure; sixth, a circuit for thepriming pump including the pressure operated switch in the discharge line of the main pump; seventh, a relay energized by a circuit including the pres- 10 sure operated switch in the discharge line; and eighth, circuits including a solenoid coil for moving the starting switch for the mainpump into and maintaining the switch in closed position.

Referring more in detail to the figures of the 15 drawing, there is provided a main pump 10 having an electric motor 11 directly connected thereto. As the particular types of motor 11 and pump 10 are immaterial they will not be described more in detail. A suction pipe 12 extends downward .20"

from the pump 10 into a sump or well from which the water is to be pumped and a discharge pipe 13 is provided in which is disposed a suitable check valve 14. All of the above elements are or may be well-known or standard equipment usually found in installations of the described type. The pump 10 is mounted above the surface of the water being pumped, the distance being suilicient to require priming for eflicient starting.

Mounted conveniently adjacent the main 30 pump 10 is a priming pump 15 of any standard type such as a dry vacuum pump of the centrifugal type. This smaller pump 15 may be directly connected to its driving motor 16 as shown. The main pump 10 and priming pump 15 are 35 connected by a passage 17 from the intake of the priming pump 15 to the main pump casing 10 preferably immediately adjacent the intake eye of the impeller (not shown).

' Within the above-mentioned connection 17 is 40 ;a float 18 vertically movable within a casing 19.

With the casing of the main pump 10 filled with air, and until priming is completed by the casing becoming filled with water, the float 18 is in its lowermost position and the connection 17 is open. The priming pump 15 when operating exhausts the air from the main pump casing 10 and intake -12 through theconnection 17, water entering these parts from the well being pumped. As soon as the casing of pump 10 becomes flooded and water enters the float casing 19, the float 18 rises and closes, a. valve 20 formed by the conical end of the float which enters and is forced against a seat formed in the outlet of the float chamber 19. Continued operation of the priming pump 15 56 after this valve 20 closes serves to materially increase the vacuum in the passage 1'7.

Adjacent the connection 1'7 between the pumps and is a switch 21 opened and closed by variations of pressure within the connection 17. This switch 21 is adjusted to close only under the maximum vacuum within the connection 1'7. So long as the float 18 is in its lower position during priming the switch 21 remains open. As soon, however, as the float 18 rises and closes the valve 20 in the connection 17 the vacuum in the intake of the priming pump 15 immediately rises rapidly whereupon the switch 21 closes. The switch 21 shown in the drawing is diagrammatic, only the minimum pressure or degree of vacuum at which the switch 21 is closed being regulated by the spring normally holding the switch 21 toward its open position. The function of this switch 21 will presently be described in connection with the operation of the priming pump 15 and starting of the main pump 10.

Within the discharge line 13 of the main pump 10 immediately adjacent the pump casing is a pressure operated switch 22, this switch being closed while there is no appreciable pressure within the discharge l2 and being moved to its open position when the water in the discharge pipe 12 exceeds a predetermined pressure preferably slightly less than normal operating pressure. The function of this switch 22 will appear in connection with the description of the operation of the complete mechanism.

The motor 11 for the main pump 10 is started and stopped by movement of a main switch 23 having a solenoid 24 which when energized will move the switch 23 to closed position, the switch being normally open. Any standard form of switch 23 for this purpose is satisfactory, the one shown being of the three-bar type, also having a handle for manual operation, all of which are shown diagrammatically in the drawing.

To hold the main switch closed after priming has been completed, the main pump started operating normally, and the priming pump stopped, a relay coil 26 is provided operating a switch 27 in the circuit for the solenoid 24. When the starting switch 25; shown conventionally as a push button, is first closed, the relay coil 26 is energized by a circuit from L2 through the manual switch 25, and the discharge pressure operated switch 22 which at this time is closed back to L1. The relay operated switch 27 is therefore held open, the holding solenoid 24 being energized at this time by another circuit, that is by the parallel circuit including the vacuum operated switch 21. As soon, however, as the discharge pressure operated switch 22 opens to stop the priming pump 15 the relay 26 is de-energized closing the switch 27 and thus completing a circuit to energize the solenoid 24 and maintain the main switch 23 closed. During normal operation of the pump 10 after the priming pump 15 has stopped the main switch 23 is held closed by the circuit from L2 to the relay switch 27, through the holding coil 24 to L3.

The priming operation is started before the main switch 23 is closed to start the main motor 11 and pump 10. To initiate the priming operation starting switch 25 is closed either manually or by gravity, as by elevation of a float attached to the switch and resting on the surface of the water within the well or sump. Closing ofthis switch 25 by any desired means, as manually, completes a circuit including the priming pump motor 16 so that this pump 15 starts exhausting the intake 12 and casing of the main pump 10 of air and allows water to fill the casing and finally lift the float 18 within the connection 17 between the main pump 10 and priming pump 15. This circuit as above described includes the switch 22 which is closed as there is no appreciable pressure within the discharge pipe 13 until the pump 10 starts. With the float 18 lifted and the connection 17 closed the vacuum within the intake of the priming pump 15 suddenly increases, that is, the absolute pressure drops. This change of pressure causes switch 21 to close and complete a circuit including the operating coil 24 for the switch 23 for the main motor 10. This circuit extends from L2 to the switch 21 thence to the solenoid 24 and to L3. With the switch 23 closed the main pump 10 then begins its operation which builds up pressure within the discharge 13 as soon as water is delivered. When pressure in the discharge pipe 13 reaches a predetermined amount the switch 22 is opened thusswitch 21 which in turn is closed by increased vacuum in the connection 17 between the pumps immediately following the lifting of float 18. As

,soon, however, as the priming pump 15 stops this switch 21 again opens as the vacuum in the connection 1'7 begins to drop so that another circuit must be provided for energizing the switch solenoid during normal operation. For that purpose a circuit is closed including the switch solenoid 24 as soon as the switch 22 operated by discharge pressure opens. This circuit includes the relay switch 27 which is allowed to close upon opening of the circuit for its coil 26 by opening of the switch 22 operated by discharge pressure. The main switch 23 is thus held in its closed position during normal operation of the pump 10.

In order to prevent air entering the main pump 10 during operation after the priming pump 15 has stopped, a check valve 28 preferably in the form of a ball is provided in the connection 17 between the pumps. This valve 28 is, as shown, held to its seat by ravity.

Normal operation of the main pump 10 will continue so long as pressure continues in the discharge pipe 13 suflicient to maintain the switch 22 open. Should the pressure in the discharge pipe 13 drop for any reason the switch 22 will be allow to close and energize the circuit for the relay 26 and open this relay switch 27 in the circuit for the main switch holding solenoid 24. The main switch 23 is therefore moved to its open position thus stopping the main pump 10.

vWith the admission of air to the main pump casing 10 for any reason float casing 19 will be emptied of water so that float 18 will fall and open the connection 17 between the pumps 10 and 15. This movement of the float 18 will occur prior to the pressure dropping within the pump discharge l3 suiiicient to cause closing of the switch 22. As.soon as the switch 22 in the discharge line 13 closes the priming pump again starts and the priming cycle again takes place as desired above. These successive primings and operations will take place as conditions call for them so long as the starting switch 25 remains closed. If, however, this starting switch 25 is moved to its open position after the initial primmaily open vacuum operated switch whereby said ing operation is completed and the priming pump 15 isstoppedthemainpump lowilinotbeagain started after stopping for lack of pressm'e within the discharge line 18. This is for the reason that the starting switch 25 and switch 22 in the discharge line13 are in the circuit for the priming pump 15.

What I claim is:

A priming device for pumps comprising in combination, a. main pump, a priming pump therefor,

driving motors. for said pumps, e main switch controlling the circuit for said main pump motor, e. solenoid ior moving said switch to closed position, a circuit for said solenoid including 8. normain switch is eiosed only after seid min pump is-iuliy primed, a circuit for said priming pump, a pressure operated switch therein whereby said priming pump circuit is opened end the priming pump stopped when discharge of the main pump reaches a predetermined pressure, a holding circuit for said solenoid, and a relay energized while said priming pump is operating to maintain open said solenoid holding circuit, said reluy being deenergized to close said solenoid holding circuit when the pressure operated switch opens the priming motor circuit.