US2440981A - Pumping system - Google Patents

Description

M. C. SMITH PUMPING SYSTEM May 4, 1948;

Filed Dec. 29, 1944 @Wk MSSS l atented May 4, 194' UNITED STATES PATENT oEEicE PUMPING SYSTEM Marsden C. Smith, Richmond, Va., assgnor to Builders Iron Foundry, Providence, R. I., a corl lporation of Rhode Island f Application December 29, 1944, Serial No. 570,330

l 11 Claims.

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

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 uponthe pressure at the discharge of the-pumpi ng equipment and the rate of Withdrawal of fluid from the system.

TheV 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 iiow through the system within a predetermined pressure range developed downstream of the pumping equipment. i

A- further object o f the invention resides in the provision of an automatic pumping system whereinvthe pumping unit or units are maintained in operation so long as conditions within f 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.- Y I 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. v

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 maintainedin 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. VOnce it starts, the pump continues in operation until the level in the tank reaches theupper limit at which time v v ,2 Y the pump is automatically cut oif. Experience has demonstrated that therev 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 hasan effective height of 25 feet, the pump is placed in operationl when the level within the tank drops to-lO feet. The pump continues tovsupply water-"to the system until the level within the tank isvraisedto 25 feet at which time the pump is out olf. It will be noted that a ratherI substantial variation in pressure head loccurs ,during the operation of the system. Also the eiectiveness of thestorage tank is materially reduced since necessary water is not supplied thereto until the level has receded a considerable distance, namely, of the height of the'tank. It will be apparent that if a sudden heavy, demand is placed on thesystem due to a large iireor the rlike when the supply in the tank is atqits lower limit, it may be dicult 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 frictiony loss through the conduit arrangement will vary considerably dependingto a large extent upon the demand for Water vat various outlets'. When the friction loss is high, the'combined pressure which must be developed by the pumpto overcome the head in the tank and the friction los's may exceed the pressure atwhich ,they tank is normally placed out of operation, even though the water Within the tank may.. not have reached the predetermined upper level atwhich it 'is Yintended to stop the pump.. i n i 'e The instant invention overcomes the foregoing objections to pressure -control'pump systems by controlling the operation of the Vpump in response to a combination ofconditions. I utilize both the pressure developed withinthe system and the rate of now of iiuid therethrough for controlling the pumpor pumps. The pump is initially placed in operation in response to the pressure head within the storagetank. I-IoW- ever, when the pump is 'once started it Ywill not be cut out asv soon -as the pressure builds up to the maximum head provided by thetank, but will continue in operation so long as there isa substantial draft from the system. In other words, the system is so-arranged that the pump 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 relativeli7 high eiiiciency and at the same time conserve the water that is stored in the tank for emergency use.

The abovelenume'rated object'sf ase-well as other. obj ects, togetherx withthe advantagesattainable by the practice of this invention, will be readily 10 understood by reference to the following detailedE description taken in conjunction with the-ananeXed drawings, wherein Figure 1 is a somewhat diagrammatical representation of a system embodyiri'gfappara'tusifor"' 15.1 practicing the invention; and

Figure 2 is a diagrammaticalillustrationiofaf. modied embodiment of the invention. y

Referring now to the drawings wherein'like* reference numerals designate corresponding parts thronghoutthel severaligures .and --.moret par.- ticularlyitofFigure- 1 thereof; Aa prime mover I3 which isrpreferablyian electric motor is provided withl ai controllerorstarter l.I I 'which is connected; to; a sourcesor fgelectrical supply.. (not shown) by: leads. IZand i |33 A drivessh'aft I4Ia`ctuated. by prim'ezm'over Iffimpartstrotation to a suitable pump Ifsuchas acentriiugalpump: Water fromv a ireservoirf (noti-shown) iis'. supplied 5 in the inlet Otfpump-'IS byfa conduitl and` is discharged we throng-h1` the DU-,I'Il"0utlet'tintol-a` wgor'fmain line I1 that`-communicateswth-an elevated sterN age'ta'nk I Sfgenerally locatedfatia: distance fromthe pum-p9 Arxaltitude val-ve` generally-desig-V natedby numeral I @automatically fcuts olif 'the 35 f. supplyf off watrft'cr the-storage tank whenthe waterreaches al predetermined maximum level Li VAli/'erfituridirmelor Lother typeJ ofdiffer ential pressureproducervf-is placed/ inf-series inline-I I5V One-or more brancherv distribution lines 40 f 2 I'lh'av'irig alcontrollvalveenis connectedstoline-` I 'I 'intermediate theventuriftube and thel storage tankj@ g lressure--pi`pes`- 231i' and 24'# communicate with the upstreamsid'eand throat of--the Venturi'. tube and the interiorjofaiiiow`meter 25which is 45L preferably* -of *the -recordin`gj type.` The diiler entiai;pressureacrossjhe-venturi tube serves^asfa -xneasuref as indicatd'jand recordedJ byK mete`r- 25,-ofrateoifluidlowthrough-line I1.` Aswitchn l arnr; 26ppivotedfat I"1.'Ifisfpositioned b'y 'the 'meter '50 25Min accordancelwithQ-the'trate lofriiow( through-"r linexl'l;` Aj1v:oridiictf'ir2Ilriezirmin'gral:legtorarreleci tricipcircuitisj connectdto controller I If-'andj-toH switch 2B: It' iwlllbe observed ,that switch 2 6 rotatable" aboutpivot 21 Tand 'is `so constructed L andarr'anged "as -t "successively j' form `electricalt contact withj-arcuatefconductor members.29; 3o'VV and:"3 Iii The individual larcuate memberV con tacted`b`y switch ZGat'a'ny particular time 'will' dependgupon therate of uidlflwfthroughjthe linejl 1.1 Asfillustrated; switch. 261ls1in., Contact. with Varcuate `member.0. The meterA .is-of; atype that.switcnpzgcontacts arcuate-lmeniberm when. the Trate foi; iiuid.flow.is. ewithlnxa predetermined. 1 65. l. range fsuch; as Rr. Switchf26 @contacts arcuate member YSII when the -rate of uidffiowgis increased` toca; higherffrange :Ramandzcorrespondingly;.con= tactsgmembcr,l 3I'gzwhen .the rateeof .-iluid iiowis.:v

withiman upperrangeiof rate foiiiiow; R3. Con-70e` ductors'3233and34, respectively; establish electric'al .connectiolbtweenfmembers A29, `30 "andv y3 I` andL correspondirigA .pressure #responsive vswitches genera-ilyA denoted-:by reference numerals =35,'f 3Irl andf31'. A' conductor?38 iisilconnectedfwith eachh'l of the pressure responsive switches and controller II.

Pressureresponsive switches 35, 36 and 31 communicate with ow line I1 by way ofconduits 39, 40 and 4 I, respectively. Each of these switches is subject to the pressure in line I1 on the discharge side* of pump I5 and each switch is adapted -to be actuated into circuit breaking position"l in response"todifferentmaximunr pressures. For example, switch remains closed until the pressure of the fluid inconduit 39 exceeds a predetermined value such as P1 at which time the switchcpens. Correspondingly, switches 3B and 31 remain closduntil the pressure in lines 4U aird'i ,41? exceeds?" vcorresponding predetermined maximimiivaluesfP-and P3, respectively.

Letxusfassumethattvalve 22 is closed and that storagetank I8 is filled to its maximum level L. Uderthese conditions, switch 26 will be in the position indicated in dotted lines and switch 35 willi be-fopen; since-.the pressurev` within'.A the system wiilieXceediPit. l Prime`move'r I @fand l thereforc' pump .I 5 willbaplace'dhutoi service.'A If 'thelevelz intim pressure P at whichswitch 46 is set to open. Switch 46 willbe closed so long-as the pressure inthe 'system islwithin the range P4 and Ps. Should the pressure Withinthe system drop below P4 or rise above Ps, switch 46 will open.

Tilting switch' 5-2 is of a character and is so selected as to be opened by meter 53 when the rate of uid flow through line Il isbelow a predetermined value such as R4 but to be closed when such rate of iiow is the same as or greater than R4. When the rate of fluid flow through conduit I1 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 iluidflow through line Il decrease to a value belowR4. tilting switch 52 will be opened, similarly placing the pump out of service.

As above described, Ithe various controls are discussed in connectionwth 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 beused 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 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 resortedfto without departing from the spirit of the invention or the scope 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 conduit connected to the pump outlet, and means responsive to the pressurenof the fluid in the conduit and to therate of fluid flow through the conduit for controlling the operation of the pump.

2. 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 means responsive to the pressure of the :duid in the conduit and to the rate of fluid flow through the conduit 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 uid.

3. A pumping system comprising a pump including an inlet and an outlet, means for delivering uid 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 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 responseto rates of iluid ow 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 positon in response to rates of iluid iiow through the conduit outside a predetermined.

-only one thereof may be closed at a time.

5. A pumping system lcorrnprising a pump in cluding 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 thev conduit above a predetermined pressure and a serially connected switch that is actuated to circuit opening position in response to rates of uid 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 seco-nd predetermined range, said circuits being so arranged that only one thereof may be closed at a time, depending on the rate of fluid iiow through the conduit.

6. A pumping system .comprising a pump including an inlet and an outlet, means for delivering iluid to the pump inlet, a discharge conduit connected to the pump outlet, and at least a pair oi electric circuits for automatically controlling.

the operation of the pump, one of said circuits including a serially connected pressure responsive switch that is maintained in circuit closing position so long as the fluid pressure in the conduit is within a predetermined range and that is actuated to and maintained in circuit opening Y ends-"st netted pressure respons-iveswitch that isV actuated spense te rates of fluid flow through the conduit outside a-seeond predetermined range, said circuitsbe'ing so arranged that only one thereof may beclosed at a'time-depending on the* rate of 4fluid iiow through thecondui't. Y I

7. A pumping system comprising a pump including an in-let and an outlet, means for delivering fluid to the pump inlet,ra discharge conduit connected to the pum-p outlet, and a plurality o f electric lcircuits for automatically controlling the operation of the pump, a switch serially connected -in each of said circuits, each of said switches being actuated to circuitfopening positionin response to a rise in iuidpressure in the conduit :above a coresponding predetermined pressure, vserially connected switch means common to all-oisaid circuits, and means responsive tovariations in the rate of fluid flow through the conduit for actuating said switch means to selectively place the same in circuit closing position inone of said circuit-s at atirnei 8; A pumping system comprising a pump in-V cluding an inlet and an outlet, means for deli-ver-v ing iiuidto the pump inlet, a discharge conduit connected to the pump outlet, a plurality of electric circuits for automatically 1 controlling the operation of the pump, one of said circuits including `a serially connected switch that is constructed and arrangedto be maintained in circuit closing position so long as the fluidpressurc 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 position so long as the fluid pressure in the conduit is withinV a second predetermined range and to he actuated to circuit opening position in response to `iluid pressure in the conduit outside said'second range and a serially connected switch that is'mai'ntained in circuit closing position in response to'rates of lluid flow through the conduit at leastas great as a preselected rate andthat is maintained in circuit opening position in respense to rates of fluid flow through the conduit below said preselected rate.

9. A pumping system comprising a pump including an inlet andan outlet, means for deliv-- lli- A Y' Number Bring ntic to the @imp inlet, a dischargeY eos-` duit connected to"A the pump outlet, meansres'ponsive to 'thestatic "pressure of fluid vin said conduit; means'responsive to the differential pressure of fluid Aflowing between certain points in said '-conduit, and means responsive to both said pressure responsivemeans for controlling the operationlof said pump. Y Y

"10 .V`A pumping system comprising a pump includingan inlet and an outlet, means'forfdel-ivering iluidtothepump 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 olosedfuntil said pressure 4exceeds -a certain value, and the other of saidfswitches-being adapted to be closed until saidlpressure exceeds a higher value, means for controlling operation of said pump, connections between` said switches and-said controllingmean's, dinerential pressurel means Y responsive to flowlof fluid insaid conduit for cooperating with the last mentioned 'switch "to maintain said -pump in operation `when said uid now exceeds a certain value despite -op'enirig of the rst mentioned switch. f

1l. A pumping -system-comprising a conduit and pumpinglmeans for discharging fluid into saidwcondut-a plurality Vof means responsive to the staticY pressure or"Y fluid in said conduit, means connected to both said l pressurelresponsive means for controllingoperation of said pumping means, one'ofvsaid` pressure responsive means being arranged'tolmaintain said pumping means in action until said static Vdischarge pressure increases to `a. predetermined value, andditerential pressure means responsive vto thev flow of fluid in said conduit-,tor cooperating with the `other pressure responsive Vmeans tol maintain said pumping means in operation when said fluid flow exceeds a vgiven rate'despite increase in said static pressure above said predetermined value.

MARSDEN C. SMITH.

murnnnucss CITED The following references arev of record in the tile of this patent: l

UNITED s'rATEsPATEN'rs 4Name 'Date 1,717,814 f Strong et al. June 18,1929 2,223,415 Groves Dec-3, 1940 2,237,574' Persons Apr. 8, 1941 Hood June 24, 1941

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