Title:
Pumping system
United States Patent 2440981


Abstract:
This invention relates to pumping systems and in one of its more specific aspects to a pumping system wherein pumping apparatus is employed to transmit a fluid medium to a storage tank that is located at a point remote therefrom. The primary object of this invention is to provide a pumping...



Inventors:
Smith, Marsden C.
Application Number:
US57033044A
Publication Date:
05/04/1948
Filing Date:
12/29/1944
Assignee:
Builders, Iron Foundry
Primary Class:
Other Classes:
417/25, 417/31, 417/44.1, 417/44.2
International Classes:
F04D15/02
View Patent Images:
US Patent References:
2246940Pump control1941-06-24
2237574Control system1941-04-08
2223415Gas pressure booster system1940-12-03
1717814Lubricating system1929-06-18



Description:

This invention relates to pumping systems and in one of its more specific aspects to a pumping system wherein pumping apparatus is employed to transmit a fluid medium to a storage tank that is located at a point remote therefrom.

The primary object of this invention is to provide a pumping system having devices responsive to both pressure and rate of flow of fluid transmitted through the system for controlling the operation of the pumping apparatus.

Another object of the invention is to provide means for placing pumping equipment into and out of service depending upon the pressure at the discharge of the pumping equipment and the rate of withdrawal of fluid from the system.

The invention has for another object the provision of control means within a pumping system, which means is adapted to maintain a pumping equipment in operation in response to predetermined flow through the system within a predetermined pressure range developed downstream of the pumping equipment.

A further object of the invention resides in the provision of an automatic pumping system wherein the pumping unit or units are maintained in operation so long as conditions within the system justify such operation. In this manner the pumping equipment is operated at a relatively high efficiency and the effectiveness of storage facilities that form part of the system is increased.

A still further object of the invention is to provide a pumping system of the character indicated which is relatively simple in design and trouble-free in operation.

While the apparatus of the instant Invention may be advantageously employed in various types of systems, it is especially useful in systems for supplying water to a community. In city water systems it is customary to pump water from a reservoir to an elevated storage tank located at considerable distance from the reservoir. It has heretofore been the practice in city water systems to control the operation of the pumps either manually or automatically in response to the pressure head maintained in a storage tank.

The level of the water within the tank is generally maintained between predetermind upper and lower limits. When the water level drops to the lower limit within the tank, the corresponding low pressure head is utilized to start the pump at the pump station. Once it starts, the pump continues in operation until the level in the tank reaches the upper limit at which time 5 the pump is automatically cut off. Experience has demonstrated that there are a number of objections to the ordinary simple form of control. For one thing, it is usually customary in such systems to set the pump in operation when the level within the storage tank has dropped to say 40% of the maximum level. .For example, if the storage tank has an effective height of 25 feet, the pump is placed in operation when the level within the tank drops to 10 feet. The pump continues to supply water to the system until the level within the tank is raised to 25 feet at which time the pump is cut off. It will be noted that a rather substantial variation in pressure head occurs during the operation of the system. Also the effectiveness of the storage tank is materially reduced since necessary water is not supplied thereto until the level has receded a considerable distance, namely, 60% of the height of the tank. It will be apparent that if a sudden heavy demand is placed on the system due to a large fire or the like when the supply in the tank is at its lower limit, it may be difficult to supply the entire demand placed on the system under such circumstances.

Moreover, one of the important factors is that of friction loss. In many instances the pump is arranged to deliver water directly to outlets as well as to the storage tank. The friction loss through the conduit arrangement will vary considerably depending to a large extent upon the demand for water at various outlets. When the friction loss is high, the combined pressure which must be developed by the pump to overcome the head in the tank and the friction loss may exceed the pressure at which the tank is normally placed out of operation, even though the water within the tank may not have reached the predetermined upper level at which it is intended to stop the pump.

The instant invention overcomes the foregoing objections to pressure control pump systems by controlling the operation of the pump in response to a combination of conditions. I utilize both the pressure developed within the system and the rate of flow of fluid therethrough for controlling the pump or pumps. The pump is initially placed in operation in response to the pressure head within the storage tank. Howi0 ever, when the pump is once started it will not be cut out as soon as the pressure builds up to the maximum head provided by the tank, but will continue in operation so long as there is a substantial draft from the system. In other 5 words, the system is so arranged that the pump 2,440,981 3 is automatically operated so long as the conditions within the system justify the supplying of water thereto. By virtue of the practice of this invention, the pumps may be operated at a relatively high efficiency and at the same time conserve the water that is stored in the tank for emergency use.

The above enumerated objects; as:well' as otherobjects, together with- the advantages attainable by the practice of this invention, will be readily understood by reference to the following detaileddescription taken in conjunction with the, an--nexed drawings, wherein Figure 1 is a somewhat diagrammatical rep, resentation of a system embodyinrigapparatus f6r- 1 practicing the invention; and Figure 2 is a diagrammaticalIillustration of-a:modified embodiment of the invention.

Referring now to the drawings wherein- like reference numerals designate corresponding parts throughout ..the several.:figures;. and -more. particularly.toTFigure 1 thereof, .a .prime mover 10. which is'preferably an electric motor is providedwith a controller oristarter.1 IIwhich. is connected: to a isource of :electrical supply (not shown) by leads; 12 and;13.' A drive shaft 14 actuated. by prime mover I Vimparts rotation to a suitable pump.15:such as acentrifugalpump Water from a reservoir (not, shoWrin: is, supplied in the inlet of; pump 15 -by' a conduit. 16 and is discharged 3 through the pump outlet -into a flow or; main line 17 that cmniunitcates with- an elevated starage tank 8I'gerierally-located ,at a:distance fromn the pump. An altitude valve- generally designated-by numeral 19 automatically cuts off: thesupply of water- to- the-:storage tank when -the water reaches a-predetermined maximum levelL.

A-Venturi tube- or -other -khown type, of- differential pressure-producer-is placed- in-series in line, 17 One or more branch-or distribution lines 2 P-having a-control'valve-221-is conneeted-to lineI7 intermediate the-Ventiri tube and the- storage tank. Pressure pipes 23 and 24',communicate with the upstream side and throat of the Venturi tube and the interior of -aflow meter-25-which is preferably- of the recording type.- The differential7 pressure -aeross-the Venituri tube serves as' a -measure; as indicated and recorded- by meter 25-of rate of fluidlow through-line 17. A switch arm 26-pivoted at 2 -t Ispositioned by-the meter -60256in acebrdancea withthe rate-of-flow through line:17;' Atonductor 28 1ormingaa-leg of an electric circuit is- connected-to controller I l'and-toswitch 26T It:will be' observed that switch 26 -isrotatable- abbut'P pivot 21" and is so -constructed 5and.arrangedas -to successvely-form: -electricalcontact with- arcuate conductormembers-29, 30 and:'31: The individUal-arcuate member contacted'by switch- 2"'at'any particular time will depend upon the rate of fluid flow through the line. Ir. As.illustrated, switch, 26 i1sin. contct of a'- circuit -inoluding contiroltbr II' andd:- con- with arcuate member.30D, The meter is.of atypa that switch.26 -contacts arcuate member 29 when. the rate of.fluidaiflow-is within- a predetermined range such, as r., Switch. 26 ;contacts arcuate member 30 when the rate of fluid flow is increased to,.a; higher range -Ra. and-correspondingly :con-. tactsamember, 3 :when the rate of fluid flow is: within an upper range of rate -of flow. R. Con-ductors 32,:33 and'34, respectively; establish electrical connectionibetween'members 29, 130 and 3 1 and< corresponding- pressurreresponsive switches generally denoted-by reference numerals 35, 36-and 317 conduietor:34s':connected-with each'75-pres of the pressure responsive switches and controller II.

Pressure responsive switches 35, 36 and 37 communicate with flow line 17 by way of conduits 39,40 and 41, respectively. Each of these switches is subject to the pressure in line 17 on the discharge side of pump 15 and each switch is adapted to be actuated into circuit breaking positionirr response to different maximum pressures.

10. For example, switch 35 remains closed until the pressure of the fluid in conduit 39 exceeds a predetermined value such as P1 at which time the switch opens. Correspondingly, switches 36 and 37: remain closed-until the pressure in lines 40 aird: ,41i exceeds, corresponding predetermined nmaximaumvalues-P`-and P3, respectively.

Letriusassume-that.valve 22 is closed and that storage tank 18 is filled to its maximum level L.

Ufder-these conditions, switch 26 will be in the position indicated in dotted lines and switch 35 will be-open since the pressure within: the system will'exceed-Pi.- Prime- mover 10 arnd -therefore: pump .15 will be-placed but of service. If the level intank -8l'drops below-Li and there is stillno flow25g through line: 21,, switch 26 will:remain in the dotted position but switch 35 will be closed since the pressure -within: the- system at this time is below- value PPi. Tkhe circuit to controller: II is completed' under:; these circumstances through 6conductor- 2 8, switch 76 nmember 29, conductor 32, pressure switchl35 and' conductor 38 with the result that 'the p-rime-mover is placed in service and 'water is -supplifed to tank-. I18-until the pressure int the system exeeedsPi at-which time pres3s surb-eswitch 35is oP~eiL'et-us next':assume-that there-is:a substantial demand. on '-the :system'through distribution line 21 Faid-thatthe levelbof thebwater- within tank- 18 is at-osemeýintermediate-poiiit between -Lanid 1. 4 -Urider -these-conditibns; swithles 35 'and. 36 will both:b -closed since' the-pressure acting thereon is-assumed -as-being -below -either -Pi or -P2, The pump will be initially -set:tin-.-operation-through the circuit cortainiing switch-:35ahn i member 29. 45-:If-the-rate-of ifluid fl6wothrough line :I'lis-withinthe-range- R,,t theen switch 26-is rotated to-:theposition illustrated fi fill liies -in -the-drawing; therebycomnpleting thecircuit to- controller II through imember-30 arid,switchl-36d- The pump is.--aintained n' operatibnr through thelast mentibned,-circuit -until changes -in either the rate of fluid flow or the pressure cause this circuit to-beopened.The-enibodiient of the .inventiorn- illustrated 5in-Figurei 2 amounti - a' modification .-opf that illustrated in Figure 1. T-is,-embbdiinFent'-of-the-i invention-4includes- a-pressurec6ndriti, 45 :establi7hing comnaiction bWetwee'fldw-lie I and- apressuare-respsivesP-olith ·:ts abe--sihi0laigitothe-Prssured reftsic4e*isw rit eso"shben i Fi acir. Pressincidisg contcrIcomrises:on' i a :eg duictofrs ~4tsaidi48. - A seonrd: pre'ssure--condlit 4testablishues comiiriicatinn'- between- flw line 6- ('aid -~ a secod- pressure sswitch 50? Pressureswith'50 'is -cnnected :aerosscbhndctirs 47 and* 48 :Itrbugh' a-condiUct or:5 , a tiltiig switch 552 in a flow- meter-53i aidconduetors l'5and 55 With the-- arrangement- shbwn'r in' Figure- 2, 70·-switch'46'is-'so'ceistriutedd-and arranged as-to bei closed wh&bni the-pressu~rebin thbisystem-is"-withina predetermined-ranigei suchas between Pi and-P5.

P-essure switch-50:-is adapted tob-remain'closeduntil 'thIe pressure-withii'the system -exeeeds: a electedipressure&thhtiShighterthan the maximiimr pressure P at which switch 46 is set to open.

Switch 46 will be closed so long as the pressure in the system is within the range P4 and Ps.

Should the pressure within the system drop below P4 or rise above P5, switch 46 will open.

Tilting switch 52 is of a character and is so selected as to be opened by meter 53 when the rate of fluid flow through line 17 is below a predetermined value such as R4 but to be closed when such rate of flow is the same as or greater than R4. When the rate of fluid flow through conduit 17 is the same as or greater than the value R4 and pressure switch 50 is closed, the pump will continue to supply water to the system so long as conditions permit. Should the pressure increase to a value greater than that at which switch 50 is set, that switch will be opened, placing the pump out of service; or should the rate of fluid flow through line 17 decrease to a value below R4, tilting switch 52 will be opened, similarly placing the pump out of service.

As above described, the various controls are discussed in connection with the operation of a single pump. It will be apparent that the operation of a plurality of pumps may be properly controlled by similar arrangements of apparatus.

While the present invention has been discussed in detail in connection with storage tanks, it will be apparent to those skilled in the art that it may be used with various other systems; for example, the arrangements herein described may be used advantageously in supplying water to a tall building that does not have a storage tank.

Also, the invention is adapted to be used with beneficial results in a booster arrangement, such as the type employed in transmitting oil or the like considerable distances.

From the foregoing, it is believed that the construction, operation and advantages obtainable by the practice of my instant invention will be 4 readily understood by persons skilled in the art.

It is to be borne in mind, however, that various changes in the apparatus herein illustrated and described may be resorted to without departing from the spirit of the invention or the scope 4 of the subjoined claims.

I claim: 1. A pumping system comprising a pump including an inlet and an outlet, means for delivering fluid to the pump inlet, a discharge con- 6 duit connected to the pump outlet, and means responsive to the pressure of the fluid in the conduit and to the rate of fluid flow through the conduit for controlling the operation of the pump.

2. A pumping system comprising a pump in- 6i cluding an inlet and an outlet, means for delivering fluid to the pump inlet, a discharge conduit connected to the pump outlet, and means responsive to the pressure of the fluid in the conduit and to the rate of fluid flow through the con- 6 duit for controlling the operation of the pump, said means comprising a plurality of electric circuits each including a pressure actuated switch and a switch actuated in response to the rate of flow of the fluid. 3. A pumping system comprising a pump including an inlet and an outlet, means for delivering fluid to the pump inlet, a discharge conduit connected to the pump outlet, and at least a pair of electric circuits for controlling the operation of the pump, one of said circuits including a pressure responsive switch that is actuated to circuit opening position upon a rise in fluid pressure in the conduit above a predetermined pressure and a switch that is actuated to circuit opening position in response to rates of fluid flow through the conduit outside a predetermined range, the other of said circuits including a pressure responsive switch that is actuated to circuit opening position upon a rise in fluid pressure in the conduit above a second predetermined pressure and a switch that is actuated to circuit opening position in response to rates of fluid flow through the conduit outside a second predetermined range, -said circuits being so arranged that only one thereof may be closed at a time.

4. A pumping system comprising a pump including an inlet and an outlet, means for delivering fluid to the pump inlet, a discharge conduit connected to the pump outlet, and at least a pair of electric circuits for automatically controlling the operation of the pump, one of said circuits including a serially connected pressure responsive switch that is actuated to circuit opening position upon a rise in fluid pressure in the conduit above a predetermined pressure and a serially connected switch that is actuated to circuit opening position in response to rates of fluid flow through the conduit outside a predetermined range, the other of said circuits including a serially connected pressure responsive switch that is actuated to circuit opening position upon a rise in fluid pressure in the conduit above a second predetermined pressure and a serially connected switch that is actuated to circuit opening position in response to rates of fluid flow through the conduit outside a second predetermined range, said circuits being so arranged that only one thereof may be closed at a time. 5. A pumping system comprising a pump including an inlet and an outlet, means for delivering fluid to the pump inlet, a discharge conduit connected to the pump outlet, and at least a pair of electric circuits for automatically cono0 trolling the operation of the pump, one of said circuits including a serially connected pressure responsive switch that is actuated to circuit opening position upon a rise in fluid pressure in the conduit above a predetermined pressure and a 5 serially connected switch that is actuated to circuit opening position in response to rates of fluid flow through the conduit outside a predetermined range, the other of said circuits including a serially connected pressure responsive switch that 0 is actuated to circuit opening position upon a rise in fluid pressure in the conduit above a second predetermined pressure and a serially connected switch that is actuated to circuit opening position in response to rates of fluid flow through 5 the conduit outside a second predetermined range, said circuits being so arranged that only one thereof may be closed at a time, depending on the rate of fluid flow through the conduit.

6. A pumping system comprising a pump in) eluding an inlet and an outlet, means for delivering fluid to the pump inlet, a discharge conduit connected to the pump outlet, and at least a pair of electric circuits for automatically controlling the operation of the pump, one of said circuits Sincluding a serially connected pressure responsive switch that is maintained in circuit closing position so long as the fluid pressure in the condult is within a predetermined range and that is actuated to and maintained in circuit opening position in response to fluid pressure in the conduit outside said range and a serially connected switch that is actuated to circuit opening position in response to rates of fluid flow through the conduit outside a predetermined range, the other of said circuits including a serially conniected pressure responsive switch that is actuated to circuit opening position upon 'a rise in fluid pressure in the conduit above a second predeterminied pressure and a serially connected switch that is actuated to circuit opening position in response to rates of fluid flow through the conduit outside a second predetermined range, said circuits-being so arranged that only one thereof may be closed at a time depending on the rate of fluid flow through the conduit.

7. A pumping system comprising a pump including an inlet and an outlet, means for delivering fluid to the pump inlet, a discharge conduit connected to the pump outlet, and a plurality of electric circuits for automatically controlling the operation of the pump, a switch serially connected in each of said circuits, each of said switches being actuated to circuit opening position in response to a rise in fluid pressure in the conduit :above a coresponding predetermined pressure, serially connected switch means common to all of said circuits, and means responsive to variations in the rate of fluid flow through the conduit for actuating said switch means to selectively place the same in circuit closing position in one of said circuits at a time.

8. A pumping system comprising a pump including an inlet and an outlet, means for delivering fluid to the pump inlet, a discharge conduit connected to the pump outlet, a plurality of electric circuits for automatically controlling the operation of the pump, one of said circuits including a serially connected switch that is constructed and arranged to be maintained in circuit closing position so long as the fluid pressure in the conduit is within a predetermined range and to be actuated to circuit opening position in response to fluid pressure in the conduit outside said range, another of said circuits including a serially connected switch that is constructed and arranged to be maintained in circuit closing posi tion so long as the fluid pressure in the conduil is within a second predetermined range and tc be actuated to circuit opening position in respons( to fluid pressure in the conduit outside said second range and a serially connected switch thai is maintained in circuit closing position in re. sponse to rates of fluid flow through the condui at least as great as a preselected rate and tha is maintained in circuit opening position in re. sponse to rates of fluid flow through the condui below said preselected rate.

9. A pumping system comprising a pump in cluding an inlet and an outlet, means for deliv ering fluid to the pump inlet, a discharge Conduitc connected to the pump outlet, means responsive to the statio pressure of fluid in said conduit, means responsive to the differential pressure of fluid flowing between certain points in said conduit, and means responsive to both said pressure responsive means for controlling the operation-of said pump.

10. A pumping system comprising a pump including an inlet and an outlet, means for delivering fluid to the pump inlet, a discharge conduit connected to the pump outlet, a plurality of circuit-controlling switches responsive to the static pressure of fluid in said conduit, one of said switches being adapted to be closed until said pressure exceeds a certain value, and the other of said switches being adapted to be closed until said pressure exceeds a higher value, means for controlling operation of said pump, connections between said switches and said controlling-means, differential pressure means responsive to flow of fluid in said conduit for cooperating with the last mentioned switch to maintain said pump in operation when said fluid flow -exceeds a certain value despite opening of the first mentioned switch.

11. A pumping system-comprising a conduit and pumping means for discharging fluid into said conduit, a plurality of means responsive to the static pressure of fluid in said conduit, means connected to both said pressure responsive means for controlling operation of said pumping means, one of said pressure responsive means being arranged to maintain said pumping means in action until said static discharge pressure increases to a predetermined value, and differential pressure means responsive to the flow of fluid in said conduit -for cooperating with the other pressure * responsive means to maintain said pumping - 40 means in operation when said fluid flow exceeds S a given rate despite increase in said static presS sure above said predetermined value.

MARSDEN C. SMITH.

S-REFERENCES CITED t The following references are of record in the S file of this patent: t UNITED STATES PATENTS 50 Number 1,717,814 2,223,415 2,237,574 2,246,940 Name Date Strong et al. -----. June 18, 1929 Groves ----------- Dec. 3, 1940 Persons ----------- Apr. 8, 1941 Hood ------------ June 24, 1941