US3786835A

US3786835A - Pump control system

Info

Publication number: US3786835A
Application number: US00284364A
Authority: US
Inventors: J Finger
Original assignee: Sioux Steam Cleaner Corp
Current assignee: Sioux Steam Cleaner Corp
Priority date: 1972-08-28
Filing date: 1972-08-28
Publication date: 1974-01-22
Anticipated expiration: 1991-01-22
Also published as: CA961950A

Abstract

A fluid supply apparatus and control system, the apparatus including a plurality of independently operated fluid outlets and a plurality of fluid pumps each operative upon demand at the outlets to maintain a supply of liquid at least equal to the demand at the outlets. The control system includes control circuitry, fluid pressure operated switches, and relays for energizing only as many pumps as are required to maintain a given pressure under varying volume delivery requirements.

Description

6 1 1 1 11 :13 ilnite States atent 1 1 1111 3,766 Finger 1 Jan. 22, 197 1- 1 PUMP CONTROL SYSTEM 3,229,639 1/1966 Hignutt et al 417 7 x 5] n ento John F. Finger, Beresford S. Dak 1,304,529 5/1919 Arnold 137/567 X [73] Assignee: Sioux Steam Cleaner Corporation, P i E i -Willi R Cli Beresford, Attorney, Agent, or Firm-Merchant. Gould. Smith 221 Filed; Aug. 28, 1972 [21] Appl. No.: 284,364 [57] ABSTRACT A fluid supply apparatus and control system, the appai 137/566 5 1 ratus including a plurality of independently operated outlets and a of pumps ch op [58] Field of Search 137/566, 567, 417/5, 6, 7 five upon demand at the outlets to maintain a Supply of liquid at least equal to the demand at the outlets. [56] References Cited The control system includes control circuitry, fluid UNITED STATES PATENTS pressure operated switches, and relays for energizing 1,972,812 9/1934 Woolley 417/7 only as many pumps as are required to maintain a ,8 6 7/1957 Reed 417/7 X given pressure under varying volume delivery require- 2,sss,s7s 6/1959 BUCk.... 417/7 mam 3.135182 6/1964 Gray 137/567 X 2 Claims, 1 Drawing Figure 1 PUMP CONTROL SYSTEM The present invention relates to apparatus for supplying liquids under pressure to points of delivery such as jet nozzles used in automobile washing apparatus. In some types of car washing installations, the water or liquid is supplied to a plurality of washing machines or washing booths from a single storage tank or other source having delivery pressure less than required. In these, a single motor driven pump is usually used, the pump and its motor having a capacity sufficient to supply adequate pressure to all of the booths or machines when all of these are operating simultaneously. During off-peak periods, when only one or a small fraction of the total number of booths or washing machines are in operation, the single pump and its motor operate at a capacity far in excess of what is needed, resulting in a waste of electrical power consumed merely in recirculating the washing liquid within the system.

SUMMARY OF THE INVENTION An important object of this invention is the provision of apparatus for supplyingfluid or liquid under pressure to'a plurality of outlets, and of a control system which limits the use of power to that which is required to satisfy the demand at said outlets at any given time.

Another object of this invention is the provision of apparatus as set forth in which the power requirement for pumping varies with the demand for fluid at the outlets.

To these ends, I provide a header having a fluid inlet and a plurality of outlets for connection to fluid lines having valves controlling delivery of fluid from the header, a plurality of pumps having inlets operatively connected to a fluid supply source and outlets operatively connected to the header, and drive motors each drivingly connected to a different one of the pumps. The pumps are disposed in a parallel fluid circuit arrangement between the fluid supply source and the header, and the pumping motors are controlled by electrical control circuitry including fluid pressure operated switches in the fluid circuit arrangement. Each of the switches are operatively connected to a different one of the pump motors and are each operative responsive to predetermined pressures, different from the operating pressures of the other switches, to control operation of their respective pumps. In this manner, the number of pumps operating at any given time is dependent on the fluid pressure in the fluid circuit between the pumps and valves when one or more of the valves are open.

DESCRIPTION OF THE DRAWING The single view in the drawing is a mechanical and electrical diagram illustrating the invention, some parts being broken away.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT In the diagram, the numeral 1 indicates a liquid supply source, such as a tank or reservoir for holding water, preferably for the purpose of washing automotive vehicles. Although not shown, it may be assumed that the reservoir 1 is provided with an inlet for water from a city main, and with conventional means for heating the water to desired operating temperature. The apparatus of this invention involves pumping means for delivering water from the reservoir 1 to a plurality of car washing machines at substantially higher pressure than is available in most city mains, for effective cleaning. An elongated header 2 is provided with an inlet 3 and a plurality of outlets 4, each of the outlets 4 being connected to a different one of a plurality of fluid lines 5 having therein control valves 6. It may further be assumed that each of the control valves 6 is disposed remote from the header 2, each in a different washing booth or associated with a different car washing apparatus.

In the embodiment illustrated, the apparatus includes conduit means disposed to provide a parallel circuit arrangement including conduits or pipes 7 and 8 that are interconnected at spaced intervals by

branch conduits

9, 10, 11 and 12, the pipe 7 being connected at one end to the reservoir 1 to provide a discharge therefrom, and at its other end to the inlet 3 of the header 2. The pipe 8 has an end portion 13 that is connected to the pipe 7, as indicated at 14. A fluid pump 15 is interposed in the pipe 7, and is preferably of the centrifugal variety, having a relatively low pressure, high volume delivery capacity. Between the pump 15 and pipe connection 14, the pipe 7 has interposed therein a conventional flow switch 16, and a check valve 17, the check valve 17 being disposed between the flow switch 16 and pipe connection 14.

A plurality of relatively low volume, high pressure

positive displacement pumps

18, 19, 20, and 21, are each interposed in a respective one of the

branch pipes

9, 10, 11 and 12, each of the pumps 18-21 being operated by a respective one of a plurality of drive motors 22, 23, 24 and 25. Between their respective pumps 18-21 and their respective connections to the pipe 7, the branch pipes 9-12 are each provided with a respective one of a plurality of fluid flow operated

switches

26, 27, 28, and 29. Also interposed in the branch pipes 9-12, between their respective pumps 18-21 and their respective flow operated switches 26-29 are

respective check valves

30, 31, 32 and 33.

Return pipes

34, 35, 36 and 37 are each connected at one end to a respective one of the branch pipes 9-12, between their respective pumps 18-21 and the pipe 8, the return pipes 34-37 all being connected to a common return line 38 that extends to the reservoir 1. Each of the return pipes 34-37 has interposed therein a different one of a plurality of pressure relief or unloader valves 39.

The pump 15 is used to maintain a minimum charging pressure within the fluid system, including the header 2, fluid lines 5 to their respective valves 6, and pipes or conduits 7-12, including the pipe portion 13. Preferably, the charging pressure provided by the pump 15 is in the neighborhood of ten pounds per square inch. The pump 15 is operated by a motor 40 which, like the motors 22-25, is a three-phase motor controlled by a starting relay 41 including a relay coil 42 and switches 43 that are closed when the relay coil 42 is energized. The relay 41 further includes a switch 44. The switches 43 are interposed in leads 44a that are connected to a fused three-wire power line 45. The relay 42 is interposed in a grounded lead 46, in series with a manually operated control switch 47, the lead 46 extending from the secondary winding of a transformer 48, the primary winding of which is connected to a pair of conductors of the power line 45 by means of leads 49 and 50.

Control means for the several pump motors 22-25 includes respective ones of a plurality of motor starting relays 51, 52, 53 and 54,

time delay relays

55, 56, and 57, and a plurality of pressure operated switches 58, 59, 60 and 61. The pressure operated switches 58-61 are preferably of the type produced by Honeywell Inc. under their trademark PRESSURETROL, and operate to open the control switches thereof responsive to increase in fluid pressure over a predetermined amount within a fluid line. The switches 58-61 are operatively coupled to the pipe 8, the switch 58 being connected to the pipe 8 between the

branch pipes

9 and 10, the switch 59 being connected to the pipe 8 between the branch pipes and 11, the switch 60 being connected to the pipe 8 between the

branch pipes

11 and 12, and the switch 61 being connected to the pipe 8 between the branch pipe 12 and end portion 13 of the pipe 8.

The relay 51 comprises a coil 62, a plurality of motor control switches 63, and indicator light switch 64 and a relay control switch 65. The switches 63-65 are closed responsive to energization of the relay coil 62. The switches 63 are each interposed in one of the leads of a triple-wire conductor 66 connected to the power line 45 and to the motor 22. In a similar manner, the relays 52, 53 and 54 include respective relay coils 67, 68 and 69, the relay 52 including motor starting switches 70 interposed in triple line 71 extending from the power leads 45 to the motor 23, a light switch 72 and a relay control switch 73, the

switches

70, 72 and 73 being closed responsive to energization of the relay coil 67. The relay 53 includes motor control switches 74, a light switch 75, and a relay control switch 76, the switches 74-76 being closed responsive to energization of the relay coil 68, the switches 74 being interposed in motor leads 77 connected to the power leads 45 and to the motor 24. The relay 54 includes motor control switches 78 and a light switch 78a, these switches being closed responsive to energization of the relay coil 69, the switches 78 being interposed in motor leads 80 connected to the power leads 45 and to the motor 25.

Preferably, and as shown, the control circuitry for the several motors 22-25 and 40 is of lower voltage than that of the pump motors 22-25 and 40, the lower voltage circuitry including a lead 79 that is connected at one end to the lead 46, and which extends through the light switch 44 of the relay 41, and through a lamp 79a to ground. A branch lead 81 extends from the lead 79 through the light switch 64 of the relay 51 and a lamp 810 to ground. A second branch lead 82 extends from the lead 79 through the light switch 72 of the relay 52, and through a lamp 83 to ground. Another branch lead 84 extends from the lead 79 through the light switch 75 of the relay 53, and through a lamp 85 to ground. Likewise, a branch lead 86, connected to the branch lead 84, extends to the light switch 78a of the relay 54, and from thence through a lamp 87 to ground.

The coil 62 of relay 51 is interposed in series arrangement with the flow operated switch 26 and pressure operated switch 58 in a lead 88 that is connected to the low voltage lead 79. A manually operated switch 89 is disposed in the lead 88. The flow operated switch 16 is connected in parallel circuit arrangement with the flow operated switch 26 by a pair of leads 90. The relay 52 is dependent upon operation of the relay 51 for energization of its relay coil 67, the coil 67 being interposed in a lead 91 that is grounded at one end, and which is connected at its opposite end to the lead 79, the switch 65 of the relay 51 being interposed in the lead 91. Also interposed in the lead 91 is a manually operated switch 92. As shown, the time delay relay 55 is disposed in the circuit comprising the lead 91. The pressure operated switch 59 includes a pair of

switch sections

92a and 93, the former of which is interposed in the lead 91 in series with the switch 65 of the relay 5] and the flow operated switch 27. A shunt lead 94, having interposed therein the switch 93, is connected at one end to the lead 91 between the switch 27 and switch section 92, and at its other end to the lead 91 between the switch 27 and the time delay 55, to shunt out the flow operated switch 27. The time delay relay 55 is also connected in a grounded lead 95 connected to the lead 91 between the

switches

65 and 92.

The relays 53 and 54 are controlled in the same manner as the relay 52, the coil 68 of the relay 53 being interposed in a grounded lead 96 in series with the time delay relay 56, the flow operated switch 28, the former of a pair of switch sections 97 and 98 of the pressure operated switch 60, the switch 73 of the relay 52, and a manually operated switch 99. Like the circuit for the coil 67, the circuit for the coil 68 includes a shunt lead 100 in which the switch section 98 is interposed, and which is operative to shunt out the flow operated switch 28. The time delay relay 56 is also disposed in a circuit comprising a grounded lead 101 connected at one end to the lead 96 between the

switches

73 and 99. As shown, the lead 96 is connected to the low voltage control lead 79.

The coil 69 of the relay 54 is interposed in a grounded lead 102 in series with the time delay relay 57, flow operated switch 29, the fomier of a pair of switch sections 103 and 104, the switch 76 and a manually operated switch 105, the lead 102 being connected to the lead 79 by means ofa portion of lead 84. A shunt lead 106 connects the switch section 104 in series with the switch section 103, and is disposed to shunt out the flow operated switch 29. The time delay relay 57 is disposed in a circuit comprising a grounded lead 107 that is connected to the lead 102 between the switches 76 and 105.

The flow operated switches 16 and 26-29 are of wellknown conventional types, these switches being open when no liquid flow is present in their respective pipes 7 and 9-12. The pressure operated switches 58-61 are set to be closed when pressure in the system downstream from the pumps 18-21 reaches predetermined lower limits, and are opened by predetermined rise of pressure in the system downstream from the pumps 18-21. Each of the controls or switches 58-61 are set to open and close at pressures different from those of the others of the switches 58-61. As an example, the switch 58 may be set to open at a line pressure of 700 pounds per square inch, and close when the pressure drops to a point slightly thereunder. The others of the switches 59, 60 and 61 are set to open at progressively lower pressures. For example, the switch 59 may be set to open at a line pressure of 650 pounds per square inch, the switch 60 to be opened at 600 pounds per square inch, and the switch 61 to open at 550 pounds per square inch. Like the switch 58, the switches 59-61 are adapted to close when the line pressure drops to points slightly below their respective opening pressures. The arrangement of the switches 59, 60 and 61 is such that, when pressure is being built up in the pipe 8, header 2 and fluid lines 5, the switch sections 93, 98 and 104 open before their respective cooperating

switch sections

92a, 97 and 103, as will hereinafter become apparent. It will here be noted that the time delay relays 55, 56 and 57 are of a type well known to those familiar with electrical controls and, in and of themselves, do not comprise the instant invention. Hence, further detailed showing and'description of the time delay relays is omitted in the interest of brevity.

OPERATION To initiate operation of the supply apparatus, the manually operated switch 47 is closed to energize the coil 42 of the relay 41. Energization of the coil 42 causes closing of the several switches 43 and the switch 44 to respectively energize the pump motor 40 and light the lamp 79a to indicate that the pump is in operation. The pump 15 supplies fluid to the entire system up to the several valves 6. The several manually operated switches 89, 92, 99 and 105 are then closed and the apparatus is ready for use. Opening of any one of the valves 6 causes an immediate pressure drop within the header 2 and pipes 7 and 8. Water flowing through the pipes 7 or 8 will cause either switch 16 or 26 to close, thus energizing the coil 62 of relay 51, initiating operation of the high pressure pump 18 which not only replenishes the supply of water in the pipe 8, header 2 and the opened one of the valves 6, but rapidly builds up pressure within the pipe 8, header 2 and fluid lines 5. During operation of the pump 18, the switch 65 is closed to provide an energizing circuit for the relay coil 67 through the lead 91 and shunt lead 94. However, the time delay relay 55 is arranged to delay energization of the coil 67 of relay 52 until such time as pressure builds up to a point where switch 59 opens. Thus, the circuit to the coil 67 is broken before the coil 67 becomes energized. However, should a second valve 6 be opened while the first is still open, pressure in the pipe 8 and header 2 will be reduced to a point where the switch 59 is closed. After a predetermined time interval, the circuit will be completed through the time delay relay 55 to energize the coil 67 of relay 52, initiating operation of the motor 23 and pump 19. It will be noted that, once the pump 19 is put into operation, the flow operated switch 27 will close so that, after the switch section 93 is open, the circuit will still be complete through the relay coil 67 until the switch section 92a is opened by pressure in the pipe 8 rising to the set 650 pounds per square inch.

If, during the time that two of the valves 6 are open, a third valve 6 is opened, pressure in the pipe 8 and header 2 will drop to a point where the switch sections 97 and 98 of the pressure operated switch 68 will close to cause a circuit to be completed through the time delay relay 56 which, after a predetermined time interval will close the circuit through the relay coil 68 to energize the motor 24 and initiate operation of the pump 20 while the pumps 18 and 19 are still operating. While the pumps 18-20 are operating, opening of another valve 6 will cause initiation of operation of the pump 21 in the same manner as above described with respect to the pumps 19 and 20.

As long as a sufficient number of valves 6 are open to cause a pressure drop in the pipe 8 and header 2 to a point below 550 pounds per square inch, or whatever pressure the final pressure operated switch 61 is set at, all of the pumps 18-21 will remain in operation. As soon as any one or more of the valves 6 are closed, pressure will begin to build up in the pipe 8 and header 2 until the lowest switch operating pressure, or 550 pounds per square inch, is reached. At this time, the switch 61 will open, thus cutting the circuit to the relay coil 69. Preferably, the time delay relay 57 will operate to keep the relay coil 69 energized for a predetermined time interval so that the pump 21 will remain in operation in the event that a closed one of the valves 6 is reopened. If the closed one of the valves remains closed or the number of valves 6 in open condition is decreased, pressure of liquid in the pipe 8 and header 2 will increase to cause deenergization of the motor 24 and its pump 20, motor 23 and its pump 19 in succession, until all of the valves 6 are again closed, after which the pump 18, alone of the high pressure pumps, will remain in operation until pressure in the pipe 8 and header 2 again reaches the predetermined maximum of 700 pounds, after which the motor 22 will be deenergized and the pump 15 will continue to operate to maintain the minimum charging pressure within the system.

From the above, it will be seen that only a sufficient number of the pumps 18-21 are put into operation to supply the demand ofliquid as determined by the number of valves 6 in open condition. When any one of the valves 6 are opened, the pump 18 is always the first to be actuated, opening of other valves 6 causing the

pumps

19, 20 and 21 to be actuated in succession. Upon closing of the different valves 6, the high pressure pumps 18-21 are deenergized in the reverse order. Although not shown, it may be assumed that the relay 51 controlling the motor 22 for the pump 18, may be provided with a timing device which will maintain the motor 22 in an operating condition for a predetermined time interval after the maximum pressure is reached in the pipe 8 and header 2, so that reopening of a single valve 6, after the same has been closed for a short time, will permit the pump 18 to remain in operation, and thus decrease the number of times of starting and stopping of the motor 22. The pressure relief valves 39 operate to prevent the various pumps 18-21 from becoming overloaded during any stage of the water supply operation.

This invention has been thoroughly tested and found to be completely satisfactory for the accomplishment of the objectives set forth; and, while I have shown and described a commercial embodiment of the fluid supply apparatus and control therefor, it will be understood that the same is capable of modification without departure from the spirit and scope of the invention, as defined in the claims.

What is claimed is:

1. In a fluid supply apparatus:

a. a fluid reservoir;

b. a header having fluid inlet means, and outlet means adapted to be connected to a plurality of fluid lines each have a valve controlling fluid flow from said header;

c. a plurality of fluid pumps each having a fluid inlet and a fluid outlet;

d. conduit means connecting said pump inlets to said reservoir and said pump outlets to the fluid inlet means of said header and disposing said pumps in 7 8 succession in a parallel fluid circuit arrangement 3. each of said control relays except the last in the between said reservoir and header; succession thereof including a relay operated e. a plurality of drive motors each drivingly conswitch connected in series with the pressure opnected to a different one of said pumps; erated control switch and coil of the next sucf. and control means for said drive motors, comprisceeding relay in said succession, so that operaing circuitry including: tion of each relay and its respective drive motor 1. a plurality of control relays arranged in succesfollowing the first relay in the succession thereof sion, one for each of said drive motors, each is dependent upon energization of each precedrelay including a relay coil, ing relay in said succession thereof.

2. andaplurality of fluid pressure operated control 0 2. The apparatus defined in claim 1 in which the switches disposed in said fluid circuit arrangepumps of said plurality thereof are of relatively high ment in a succession between said pumps and pressure delivery type, and in further combination with said header, and each connected in series with alow pressure system-charging pump interposed in said the relay coil of a respective one of said relays, conduit means between said reservoir and said plurality the first control switch in the succession thereof of pumps, and a drive motor for said system-charging being disposed to control the first pump in the pump, said control means including a circuit for said succession of pumps to deliver fluid at a predelast-mentioned driving motor for energizing said motor termined high maximum pressure, the others of independently of the drive motors for said relatively said control switches in the succession thereof high pressure pumps, to maintain a given low pressure being disposed to control their respective pumps fluid charge in said conduit means between said reserto deliver fluid at predetermined progressively voir and said high pressure pumps. lower maximum pressures,

Claims

1. In a fluid supply apparatus: a. a fluid reservoir; b. a header having fluid inlet means, and outlet means adapted to be connected to a plurality of fluid lines each have a valve controlling fluid flow from said header; c. a plurality of fluid pumps each having a fluid inlet and a fluid outlet; d. conduit means connecting said pump inlets to said reservoir and said pump outlets to the fluid inlet means of said header and disposing said pumps in succession in a parallel fluid circuit arrangement between said reservoir and header; e. a plurality of drive motors each drivingly connected to a different one of said pumps; f. and control means for said drive motors, comprising circuitry including: 1. a plurality of control relays arranged in succession, one for each of said drive motors, each relay including a relay coil, 2. and a plurality of fluid pressure operated control switches disposed in said fluid circuit arrangement in a succession between said pumps and said header, and each connected in series with the relay coil of a respective one of said relays, the first control switch in the succession thereof being disposed to control the first pump in the succession of pumps to deliver fluid at a predetermined high maximum pressure, the others of said control switches in the succession thereof being disposed to control their respective pumps to deliver fluid at predetermined progressively lower maximum pressures, 3. each of said control relays except the last in the succession thereof including a relay operated switch connected in series with the pressure operated control switch and coil of the next succeeding relay in said succession, so that operation of each relay and its respective drive motor following the first relay in the succession thereof is dependent upon energization of each preceding relay in said succession thereof.

2. and a plurality of fluid pressure operated control switches disposed in said fluid circuit arrangement in a succession between said pumps and said header, and each connected in series with the relay coil of a respective one of said relays, the first control switch in the succession thereof being disposed to control the first pump in the succession of pumps to deliver fluid at a predetermined high maximum pressure, the others of said control switches in the succession thereof being disposed to control their respective pumps to deliver fluid at predetermined progressively lower maximum pressures,

2. The apparatus defined in claim 1 in which the pumps of said plurality thereof are of relatively high pressure delivery type, and in further combination with a low pressure system-charging pump interposed in said conduit means between said reservoir and said plurality of pumps, and a drive motor for said system-charging pump, said control means including a circuit for said last-mentioned driving motor for energizing said motor independently of the drive motors for said relatively high pressure pumps, to maintain a given low pressure fluid charge in said conduit means between said reservoir and said high pressure pumps.

3. each of said control relays except the last in the succession thereof including a relay operated switch connected in series with the pressure operated control switch and coil of the next succeeding relay in said succession, so that operation of each relay and its respective drive motor following the first relay in the succession thereof is dependent upon energization of each preceding relay in said succession thereof.