US2741986A - Pumping system - Google Patents

Description

M. C. SMITH PUMPING SYSTEM April 17, 1956 2 Sheets-Sheet l Filed June 18, 1949 mLI 2 Sheets-Sheet 2 April 17, 1956 M. c. SMITH PUMPING SYSTEM Filed June 18, 1949 INVENTOR mbe-vvv ATTORNEY tive embodiment -rot' t'he. invention..

United States Patent O 2,141,9s PUMPING SYSTEM Industries, Inc.,;a corporationof` Rhode island Application time 1s, 1949, serial No. 99am 12Claimst (Cl. 103-..11)

, varying conditions.

The: invention .comprises provisions for bringing a pump into operation in response to withdrawal of iluid from a discharge. system: andfor bringing one or more other pumps into operationfin'response to increasedrates of withdrawalrof iluidfrom :said system; vand/ or stopping saidpumpor'pumps in response to decreased rates of withdrawal ofv iiuidfromfsaid. system. l

ihezinvent'ion alsoprovides a` pumping system wherein the kbringing of pumpsinto `opera-tion may .be placed under theAsole control ofiiow conditionsxin .the pump discharge system.

ima more specific aspecnone embodiment of .thelinventionillustrated'licrein .comprises a` pump brought into action by apressure switch in .response to a drop lin dis- Acharge systeml pressure below a predetermined amount; fin' combinationfwitlr means responsive `to flow of uid to ythe.discharge.system fortransferring to Vrate ofeiiow all `further" control over vthe lbringinginto .ac-tion',r maintaining in action, and: stopping, oftone'or` more y pumps or pump combinations;l

Inl another embodiment-herein illustrated, a` specific feature.' ofsthe inventionc'omprises 1a pump operatingcon- Atinnously, independently .of ypressure inthe discharge system, in'combination'withprovisions forbringing into t action `and:stopping one.. or .more additionall pumps under `controlof theIate-fofliowto said'discharge system.

A .further speciiicV feature, illustrated .in a-further em- -bodiment of the. invention, comprises provisions for bringing'fintofaction and stopping-'xone'or more pumps in re- .sp'onsetofrate of ilo-w andalso .for controlling .the operation of one: or more. of said pumps .in such amanner as to .maintain alpredetermined .pressure in the `.discharge system as desired, asxazfunctionfof ythe rate of flow `of 'fluid ein; said .discharge system.

Other .features and ladvantages of fthe invention will l'behereinaiter describedarid claimed.

inthe"accompanyingdrawingszfFi'g.' fl fis la diagrammatic viewxshowing :one .form of pumping system embodying the invention.

Fig. lzzliis'rawdi'agrammatic lView:show-ing a modifica` 1tionxof theembodimentillustratedinrlig.il.

Fig; 'isfa:diagrarnrrrtnticivilew;showing atfurtherialterna- Fig; '3 fis a5 fdiagramrnaticview'illustrating :still .another embodiment. ',Fig. 3a is ra' ldiagrammatic ,view showing :a modificaftio'ii ofthe embodiment' illustrated vin Fig. 3.

Referring torthe drawings, and vmore 'particularly-.to Fig. 1"thereof, .there aresshown'pumpslfand 11, ladapted to Areceive fluid'frorn` any su'itaiblesupplyv source and to ldischarge said ffluid' throughtheirvoutletsainto ya i discharge -conduit 12.

A'primerfnroveral, rfortconvenienceihereassumedtto y be fan elcctricimotor, "istprovidcl-wth a controller or starter Marsden CQxSmith', 'Richmond Va., assigner tol lli-LF f' 2,741,986 ce Patented Apr. 17., 1956 2 14, which is connected .to a source of electrical supply'by leads 15 and 16. A drive shaft ,17 actuated .by Prime mover 13 actuates. thepump 10, which may be of any suitable or conventional type'such as a centrifugal pump.

Another prime mover, for. convenience here assumed to bean electric. motor 18, is providedwith a controller `or starter 19, which is connected through leads 20 and 2,1 to the above-mentioned source of electrical supply. Adrive shaft 22 actuated by theprime mover 18 actuates the pump 1,1, which, like pump 10, may be of any suitable-or conventional type suchras a centrifugal'pump.

The discharge conduit 12 communicates Ythrough pipe 2,3 with a pressure switch 24 of conventional type for responding to the p ressurefiny said. conduit v12. `I n addition, the conduit 12` contains a Venturi tub@ 25 o r .other lqiown :means for creating changes in conditions as a function of the rateof flow. Said Vconduit 12 discharges into a system 26, which, if desired, may lead. to -a conventional'storage` tank in accordance with customary practice or may have various distribution lines connected thereto for conductring fluid to desired points, or both.

'25, and positioning a Ashaft 31-in correspondence ,with the rate of liuidliowthroughthe conduit 12; A switch larm 3.0,'whichmaybe st ecuredrto'theV shaft 3i, is thusrposi- 4tioned by` meter V29 in accordance .with the rate of ow of iluid through said conduit 12.

While thepartieular connections for controlling; the pumps may assume awide variety of formsone system whichmay be employed is `illustrated inFig. l andVma-ybe arrangediconvenicntly asVV follows: v

A conductor 32 yextends,frorrrone terminal of the controller ll-tokalconductor 3;3 which lleads to asource of electrical. energy .34. Another conductor 36 entends from the other'pterminal-ofthecontroller 14 ,and is connectedby .conductor 37 to a Contact 38 of a switch 40. .This-.conductor may, if desired, include a tmefdelay relay 36 for a purpose later` to be noted. A moi/,able contact 4140i said switch normally connects the Contact 3 8 with .another Contact .39, which, in turn, iseleetrically connected to a wire V42, yand thence, throughwiresf43 and 4 4, ,to a terminal of thepres'sure switch 24. Ihe opposite terminal of ysaid switch 24 is connected by a wire 3S withtheelectrical energy source 34;

The switch armrti, operable by theflowrmeter l2,94 in `accordance With-,the rate vofiiow in the conduit 12, `,is adapted to engage a plurality of stationary (either fixed V.or adjustable) arcuate contacts do,` 47, and 43 0f .Said

flow meter. The Icontact .4.6 :is connectedby a wire .49 with. the aforementioned wire l13. Contact 47 is connected by wire 50 with a 4coil S1 of the switch 4i), which,l coil-in turn is 4connectedby wire 52withthe aforementioned wire 33. Said coil 51, when energizedldisengages the movable .switch Contact 4 1 `from contacts 3.8 and 39, and. enga-ges saidvmovable .contact 41 with another pair of Vcontacts 53 and 54. The contact 53 `isconnected `through afwire 515 withonerterminalof controllerlQ, the other .terminal Y of, whichz'controller .is connected through wire 5,6 with wire 32 and thence with the supply wire .33; Contact Sis connectedto the aforementioned wire k42, and ,thus

jwith- ` wires 43 and 49. l Wire. s55 may, if desired, have 63 to the previously mentioned wire 36, while Contact 62 is connected to the aforementioned wire 42.

The supply wire 35 from the source of electrical energy 34 is connected by wire 65 with the movable switch arm 30 of the flow meter 29.

When there is no flow in the discharge line conduit 12, or a rate of flow below a predetermined value, the switch arm 30 of the flow meter is out of engagement with all of the arcuate contacts 46, 47, and 48, as shown in Fig. 1.

In the operation of the system above described, and assuming the How-meter switch arm 30 to be out of engagement with the aforementioned arcuate contacts, it may rst be noted that, so long as the pressure in the discharge line 12 is above a predetermined value, both of the pumps and 11 are out of action, since the pressure switch 24 is open. When, however, the pressure drops below said predetermined value, the pressure switch 24 responds and closes a circuit from supply wire 35, through wires 44 and 43, switch contacts 39 and 38, wires 37 and 36, controller 14, wire 32, and wire 33. The controller 14 is thereby energized, placing the prime mover 13 in service to operate the pump 1@ and supply iiuid to the discharge line 12.

The flow of fluid in said line 12 under the action of the pump 10 causes the flow meter to respond and its switch 3G to engage the arcuate contact 46. If desired, the pressure switch 24- may be of the well-known type embodying a conventional holding or time-delay means (such as a heater or a time clock) for maintaining said switch closed for a denite time, regardless of discharge pressure, in order to insure that the flow from said pump 10 will bring said flow meter switch arm 30 into engagement with contact 46.

Thereupon, the pump 1t! controller supply is shunted around the pressure switch 24, and the pump operation Vcontinues exclusively under the control of the rate of iiow in the line 12. Specifically, upon the engagement of switch arm and contact 46 current ows from the energy source 34 through wire 35, wire 65, arm 30, con- -tact 46, wires 49 and 43, contacts 39 and38, wires 37 and 36, controller 14 and thence through wires 32 and 33 to the energy source 34. The pump 10 thus continues l in operation independently of the condition of the pressure switch 24.

It', due to increased demand, the withdrawal of fluid from the main 26 increases, the rate of flow in the conduit 12 likewise increases, with consequent further clockwise movement of the arm 30 in Fig. 1. When said switch arm 30 engages the contact 47, the coil 51 of switch 40 is energized by way of wires 50 and 52. The r movable contact 41 of said switch 40 is thereupon disl engaged from contacts 38 and 39 and is engaged with contacts 53 and 54. As a result, the circuit through controller 14 is broken, and pump 10 is thrown out of action. Also, a circuit is established through controller 19 as follows: from source 34 through supply wire 35, wire 65, arm 3G, contact 46, wires 49 and 43, contacts 54 and 53, wire 55, controller 19, wire 56, and wires 32 and 33, back to said energy source 34. 1t will be noted that the contact 46 continues to be engaged by arm 30 when the latter is in engagement with contact 47.

The pump 11, which is of greater capacity than pump 10, now comes into action and supplies iluid to the conduit 12 and main 26. Should the flow rate in the line or conduit 12 increase further, bringing the arm 311 into engagement with contact 48, the pump 11 remains in action (since the arm 30 remains in engagement with contacts 46 and 47) but the pump 1@ is additionally brought into action so that both pumps discharge into the conduit 12. When the arm 30 engages contact 48 the r' coil 58 of switch 59 is energized by way of wire 57. Thereupon the movable contact 60 of switch 59 engages contacts 61 and 62. Current can then llow from source 34 through wires 35 and 65, arm 30, contact 46, wires 49, 43 and 42, contacts 62 and 61, wires 63 and 36,

controller 14, and thence through wires 32 and 33 back to the source 34.

Should the demand now be met so that the flow rate increases no further the arm 3i) moves no further clockwise. It will, of course, be apparent that, if desired, additional pumps and ow meter contacts may be provided so as to throw one or more additional pumps into action in case of further flow rate increase in the line 12. If the ow rate should now decrease sufficiently for the arm 30 to move counter-clockwise out of engagement with Contact 48, the coil 58 of switch 59 is deenergized, in consequence of which the circuit through the controller 14 is broken at the contacts 61 and 62, and the pump 10 is thrown out of action.

The pump 11 remains in action until, upon decrease in flow rate suiicient to disengage arm 30 from contact 47, the coil 51 of switch 40 is de-energized, breaking the circuit through controller 19 at contacts 53 and 54, and establishing a circuit through controller 14 at contacts 33 and 39. Pump 11 is thus now out of action and pump 1i), of lesser capacity, is in action. Should the flow rate now decrease suiciently to disengage arm 30 from contact 46, current cannot flow to the controller 14 by way of arm 30, but said controller will remain energized if at the time the pressure in the line 12 has dropped suiciently low for the pressure switch 24 to be closed. If said pressure in line 12 is above the value for closing switch 24, at the time arm 30 disengages contact 46, no current can flow through controller 14 and the pump 10 is thrown out of action until the pressure in line 12 drops below the value at which the pressure switch 24 closes.

The time delay relay 36', which, as above noted, may be inserted in the wire 36, is of a well-known standard type, and has a terminal continuouslyvconnected by wire 36 to the supply wire 35. Its purpose is to maintain the controller 14 energized for an appreciable period of time atter engagement of flow-meter switch arm 30 with contactV segment 47, so as to continue pump 10 in operation until pump 11 comes up to speed. Thus, when, in its clockwise movement pursuant to increased ow in conduit 12, the switch arm 30 comes into engagement with contact 47, the resultant breaking ofthe circuit through contacts 38 and 39 of switch 40 will not immediately terminate the `operation of pump 10; but the latter will continue in operation, through a ow of current from supply wire 35, wire 36", time-delay relay 36', controller 14, and wire 32 to supply wire 33. This operation continues for a period suiiicient for pump 11 (which is thrown into operation upon engagement of contact arm 30 with contact 47) to come up to speed, whereupon the time-delay relay 36' breaks the circuit through the controller 14 and pump 10 is thrown out of action. Said relay 36 does not delay the bringing of the pump 10 into operation through the engagement of contacts 38 and 39 by contact 41, or the engagement of contacts 61 and 62 by contact 60. Relays of this type, which do not delay establishment of a circuit upon engagement of control contacts, but which delay disestablishment of the circuit upon opening of said contacts, are well-known in the art and need not be specifically described.

The time-delay relay which, is previously noted. may be included in the wire 55, is of the same type as relay 36', and has a terminal connected through wires 55 and 36" to supply wire 35. Its purpose is to maintain the controller 19 energized for an appreciable period of time after disengagement of How-meter switch arm 30 from contact segment 47, so as to continue pump 11 in operation until pump 10 comes up to speed. Thus, when. in its counter-clockwise movement pursuant to decreased ow in conduit 12, the switch arm 30 leaves contact 47. the resultant breaking of the circuit through contacts 53 and 54 of switch 40 will not immediately terminate the operation of pump 11; but the latter will continue in operation, through a ow of current from supply wire 35, wire 36", wire..55", time-delay relay 55', controller 19,

Should the demand for iluid increase and the sum of the flow rates in conduits 71, 71 thereby increase further, so that the arm engages contact 97, the coil 101 of switch 101 is energized by way of arm 30', contact 97, and wire 109. Thereby the movable contact 103 is disengaged from contacts 100 and 102 and is cngaged with contacts 105 and 106. As a result of the disengagement of contact 103 from contacts 100 and 102, pump 82 is thrown out of action. However, current now flows from source 93 through supply wire 95, arm 30', Contact 96 (which remains engaged by arm 30') wire 99, contacts 105 and 106, wire 107, controller 91, and thence through wire 92 back to the source 93. Controller 91 is thus now energized and renders motor 90 effective to operate pump 83. The latter, which is of greater capacity than, pump 82, thus pumps iluid into the discharge conduit 71.

Should the sum of the rates of ow in conduits 71 and 71' increase further, until arm 30 engages Contact 98, a circuit is closed through said arm 30', contact 9%,

wire 111, and coil 110 of switch 110. The movable contact 112 is thus engaged with contacts 113 and 114. At the same time the switch arm 30', in moving into engagement with Contact 911, moved o-ut ot engagement with contact 97, thus de-energizing coil 101' ot switch 101, with resultant engagement of movable contact 103 with contacts 100 and 102.

Through the contacts 100 and 102 the controller 85 is energized, while through the contacts 113 and 114 the controller 91 is energized. Thus both pumps 82 and 88 are now actuated to supply tluid to the discharge line 71.

Upon decrease of the sum of the rates of ow of fluid in conduits 71 and 71', sufficient to cause arm 30' to move counter-clockwise out of engagement with contact 98 and into engagement with contact 97, the coil 110 of switch 110 is deenergized, and movabie contact 112 is disengaged from contacts 113 and 114i. Hoy ever, coil 101' is now energized, bringing movable contact 103 out of engagement with contacts 100 and 1112 and into engagement with contacts 105 and 106, so that controller 91 remains energized and pump 18 remains in action. 1n consequence of the disengagement of contact 103 from contacts 100 and 102, controller S5 is deenergized and pump 82 is thrown out of action. Upon decrease in thc sum of the flow rates in conduits 71 and 71 suicient for arm 30' to become disengaged from contact 97, the coil 10.1' is deenergized, and movable contact 103 is disengaged from contacts 105 and 106 and is engaged with contacts 100 and 102. 1n consequence of the disengagement of contact 103 from contacts 105 and 106, the controller 91 is deenergized and pump SS thrown out of action; but due to the engagement of said contact 103 with contacts 100 and 102, the controller 85 is energized and the lower capacity pump 82 is placed in operation. lf the sum of the ow rates now decreases further so that arm 30' is disengaged from Contact 96, the controller 85 is deenergized and pump 82 thrown out of action, so that the only pump remaining in operation is the pump 70.

It will, of course, be apparent that, if desired, the tlow meter 29 may, like flow meter 29 in Fig. l, respond only to the ow rate in one conduit; in which event tl. summation apparatus in Fig. 2 may be omitted and said flow meter 29 be connected directly to the pipes Si) and 81 to respond only to the rate of tlow in the conduit 71.

The time delay relays 104 and 107' may be of the same type as the relays 36 and 55' previously referred to in connection with Fig. l. Relay 104 has a terminal connected by a wire 104 to the supply wire 95, while relay 107' also has a terminal connected to said supply wire by a wire 107".

The purpose of relay 104' is to maintain controller 85 energized for an appreciable period of time after engagement of the flow meter switch 30 with contact 97 so as to continue pump 82 in operation until pump 8S comes up to speed. Thus, when, in its clockwise movement the switch arm 30 comes into engagement with said contact 97, the resultant breaking of the circuit through contacts 100 and 102 of switch 101 will not immediately terminate the operation of pump 82; but the latter will continue in operation, through a tlow of current from supply Wire 95, wire 104, time-delay relay 104', controller 85, and wire 94 to supply wire 92. This operation continues for a time su'icient for pump S3 (which is thrown into operation upon engagement of contact arm 30 with Contact 97) to come up to speed` whereupon the time-delay relay 10ft' breaks the circuit through the controller 85 and pump 82 is thrown out of action. Said relay 104' does not delay the bringing of the pump S2 into operation through the engagement of contacts and 102 by contact 103.

The time-delay relay 107' has for its purpose the maintaining of the controller 91 energized for an appreciable period after disengagement of flow-meter switch arm 30 from contact 97, in the counter-clockwise movement of said switch arm, so as to continue pump d3 in operation until pump 82 comes into operation. Thus, when, in its counter-clockwise movement, said arm 30' leaves contact 97, the resultant breaking of the circuit through contacts 105 and 106 will not immediately terminate the operation of pump 88; but the latter will continue in operation, through a flow of current from supply wire 95, wire 107", time-delay relay 107', controller 91, and back to supply wire 92. This operation continues for a time suicient for pump 32 (which was thrown into operation upon said disengagement of arm 30' from contact 97) to come up to speed, whereupon the time-delay relay 107' breaks the circuit through controller 91 and throws pump 88 out of action. Said relay 107 does not delay the bringing of pump 88 into actie-11 through the engagement of contact 103 with contacts 105 and 106, or the engagement or" contact 112 with contacts 113 and 114.

It will be understood that, if desired, the conduit 71' may be supplied with iluid from one or more pumps under the control of the flow meter 29. For instance, the pumps 70 and 82 might discharge into conduit 71' instead of into conduit 71; and the conduit 71 might be arranged to receive iluid from the pump 83 only.

In the embodiment shown in Fig. 3, conventional pumps and 131 deliver fluid to a discharge conduit 132, having a Venturi section 133 or other how-responsive means as previously noted. Pipes 134 and 135 are connected to the upstream and throat portions respectively of Venturi section 133 `and also to the interior of a ilowmeter 136, which may be the same as flow meters 29 in its response to the rate of flow of fluid in conduit 132.

The switch arm 137, which may be secured to shaft 137' of said flow-meter moves clockwise in response to increased rate of flow and assumes a position corresponding to the rate of i'low and assumes a position corresponding to the rate of flow in the discharge conduit 132. The latter communicates with a system 138, which, in turn, may be connected to distribution lines, or, if desired, to a storage tank in accordance with customary practice, or both.

The pump 130, which may be of the centrifugal or any other desired type, is driven through shaft 139 by a prime mover 140, which may be an electric motor. The latter is thrown into and out of operation by a conventional controller or starter 141 adapted to establish and disestablish connection between the pump motor 140 and a suitable power source, such as a source of electrical power supply, connected to said controller by wires 142, 142 and 143, 143. The control of said starter or controller 141 may be elected from another energy source, such as source of electric energy; for which purpose a terminal of said controller is connected through wires 142, 143", and 144 to one side of said source, and another terminal ot' said controller is connected through wire 149,

pressure-switch 14S, wire 147, andrwire 146 to the opposite side of said. source 145.

The embodiment illustrated in Fig. 3 includes provisions for controlling the operation of the pumps in such manner (as, for example, by varying their speed) as to maintain a predetermined pressure in the dis-charge system, as a function of the rate of ow ofy fluid in saiddischarge system. For that purpose, the speed of the prime mover 140 may bevaried by a speed-controller 150 of conventional construction. The latter, as sho-wn, has three` terminals. One of said termina-ls Iis connected through awire 151 to conventional pressure switches 152 and'153l These switches, like the switch 148, are connected to the discharge conduit 132 for response tothe pressure therein, but the pipe connections between, said switches and said conduit are omitted to avoid unnecessary complication in the drawing. Another terminal of said speed controller 150 is connected to said switches` 152`and 153 by a wire 154. The third', or common terminal, of the said speed controller `is connected to the aforementioned wire 144.V

The pump 131, of centrifugal or other desired type, is operated through shaft 156 by a prime mover, such as a wound-rotor, electric motor 157. The latter is thrown into and out of operation by a conventional controller or starter 15S, adapted to establish and dises-tablish connection between the pump motor 157 and an electrical power source connected to said controller through' wires 142,142', and 143, 143. The control of said's-tar-ter or controller 158 may be eiected from the electrical energy source 145, through connectionspresently to be described. A wire 159 conne-cts a terminal of controller 158 to one of a .set of either xed or adjustable arcuaite contacts engageable bythe switch arm 137 of vtheiiow-meter 136, while another terminal of said controller is connected through wires 143 and `1441tosaid source 145.

The connections for controllingthe pumps and associated parts in accordance withy the-rate of How of fluid infthe. discharge system may take any of a variety of forms. 4One convenient system of c-onnections ,which may be employed for the purpose is illustrated in Fig. 3 and may conveniently be arranged as follows:

The arcuate contacts of the flow-meter aredesignated 161),y l161, 162,163, 164, and 1.65,.respectively. 'Contact 161)y is,.conneoted by a wire 16'6to the. aforementioned wire.149. Contact 161 is, connected through a wire 167 to. the pressure switcht 152', while, `contactY 162- Vis .con-

nested through wiref168A to the-pressure .switch 153.

Contact 163 isy connected: mathe-previously mentioned wire159 whichrunsto'controller 158.Y

The.v flow-meter contacts 164 andl ,are-connected" respectively, .by wires 170 and. 171 to pressure: switches 172 and 173. These switches, like. thosenumbered 148-, 15.2,; and 153, are connected. by suitable piping:` (not shown) to the conduit 132,.,so as. to respond. to Athe pressure therein.

Thespeed of- `the motor 157 may be varied by a speed`v controller 175 of conventional type. t, One. of the-three terminals of said controller is connected through awirel 1.7.6.1With. the pressure switch 172, andthroughcwires 176 and..17,7`with pressure switch. 173..A Another terminal 'of` said speed controller-175 isconnectedthrough wire-.178

with pressure switch 1.72 and` throughy Wires-11173 and L79: with pressureswitch 173. The commomorfreturn terminal ofcontroller. 1.75 is connected` through the previously mentioned wires 143" and 144-tofoneg-side. of theelectricalt energy source.1 45.

The'. switch arm.137. ot'theflow meter'is connected toiv the previously `mentioned. wire 146.- When.` there is. no iowl in. the. conduit 132, ora .flowv rate. below apredetermined, amount, the switch arm-137is in` the positiony shown inFig. 3, .out of engagement withall of -thevarcuate contacts. 16u- 1.65.

When, -thefswitclr arm` 137 is in the position.,,sh` |owrr.and..` theY pressure. in thetconduit` 1321s,. above a :predetermined-4 amount, yboth ofthe pumps and 131 areoutofactien, since the pressure. switch 148 isopen and. no current can flow to either of the pump-operating motors 140,- 157. When, however, the pressure in. the conduit 132: drops lbelow said predetermined amount, the pressure switch143 responds and closes a circuit from one side of the source. 145, through supply wirev 146, `vvire.147, pressure lswitch 14S, wire 149, controller orl starter 141, wires 14 and 143, and wire 144 to the other side of saidsource1'45.v The starter 141 is therebyenergized, placing the motor in service to operate the pump. 130i and supply fluid to the discharge system. y p n The iiow of uid in the line 132 under` the action of the pump 130 causes the flow meter 136 to respond and its switch arm 137 to engagethearcuate contacts .160 and 161. Engagement of said arm 137 withcontact. 161') shunts the pump 13) controllersupply around the pressure switch 148, so that the pump operation continues. even though` ythe pressure-fin the conduit 132 rises suliiciently for said switch 143 to open., Specifically, upon engagement of flow-meter switch arm 137 withv contact 160, current ows from energy source 145through supply wire 146, arm 137, contact 160,.,wire 166,. wire 149, controller or star-ter 141, and Wires 142V, 143, and 144 back to said source 145. The pump 130 thus continuesv in operation independently of the condition of the pressure switch 148-.

The pressure switch 148,1ike the previously described pressure switch 24, may, if.vdesired,.be of the Well-known type, embodying a conventional holding or ptime-delay means for maintaining said switch closed for a definite time regardless lof. discharge pressure, .in:order :to insure that the ilow from the pump 13d-will bringfthe How-meter switch arm 137 into engagementA with contacts 160 and 161.

Asfpreviously observed', the How-meter switch arm 1-37 engages the contact 161 concurrently with the Contact 16).` Upon engagement of said-arm 137 and contact 161 con'- nection is established between the supplywire 146 and the wire 167 which extendsV to the pressure switch 152. If the pressure in the conduit i1321s below a predetermined amount y(as, for example, 80 pounds 4per square inch) the pressure switch. 152 closes and. thereby establishes. aconnection between Wires167 and 151i. Currentthus. now ilows. from supply wire 146, arm 137, contact 161, wire167,`pressure switch 152, and wire 1515 to one of the terminals., of thespeed controller 150, and thence from the return terminalrof said speed controller to the return supply wire144. The iiowfof currentfrom wire 151.through the speed controller towire 144 operates the controller in conventional manner to ncrease the speedof. the prime mover or motor 140. The pump 1301s thereby caused to run.` faster, thus increasing the., pressure in the discharge conduit 1-32.` if this pressure isv raisedi abover a. .predetermined amountv (such las 84 pounds per. square inch)` thepressure switch 152 establishes a connection between wire 167 and wire 154 so that current now. flows through the speed-controller 15 from wire154 tov the. common. or. return supply wire 144. Thereby. the controller'. 150 iscaused` in' conventional' manner-to reduce thespeed of the prime moveror motor 140, thus causing .the-pump 130: to runslower and-reduce the pressurein. the discharge conduit 132.

IfY the iiow`` rateA in the dischargeconduit increases suf-` 137110 longer engages contact` 161... The' engagement of arm-137`With Contact 162establishesfa connection-between the supply wire 146 and-wire 168,"thusbringing pressure switch 153intoaction. If thepressure in the discharge Y conduit. 132.is below an lincreased.predetermined -value (85 pounds per square inch, for exampletheswitch.153

establishes. aconnection betweenewires 168r and .1=51 so that current flows from supply wire 146 through arm 137, contact 162, wire 16S, wire 151, speed-controller 150, and return Wire 144. As previously noted, the flow of current through said speed controller from wire 151 to wire 144 increases the speed of operation of the pump 130; and this speed increase is maintained so long as the pressure in the discharge conduit 132 is below a predetermined increased value (such as 89 pounds per square inch). lf the pressure in said conduit rises above said value, the switch responds by connecting said wire 163 to wire 154, so that current flows through the speed controller 1511 from wire 154 to wire 144, with consequent reduction of the pump operating speed. Through the pressure switch 153 the pressure in the discharge line is maintained at a higher Value to overcome the higher pipefriction at the increased flow rate, thereby maintaining the pressures at down-stream points within desired limits.

Assume now that the demand for iuid from the conduit 132 and main 138 increases still further, with consequent increase in ow rate sufficient for the arm 137 to engage the contacts 163 and 164. Through the engagement of arm 137 with contact 163, current iiows from suppiy wire 146, arm 137, contact 163, and wire 159 to the coutroller S for the pump 131, and thence from said controller to wire 143 and the return wire 144. The controller or starter 15S now places the prime mover or motor 157 in service to actuate the pump 131, which may be of greater capacity than pump 131).

The engagement of the arm 137 with contact 164 connects supply wire 146 with wire 170 which runs to the pressure switch 172. The latter connects the wire 17d to wire 176 so long as the pressure in the discharge conduit 132 is below a still higher predetermined value (90 pounds per square inch, for example) so as to insure overcoming increased pipe-friction incident to the higher rate of ow. So long as said discharge pressure is below said increased amount, current ows from wire 176 through the speed controller 175 and thence through the return Wires 143 and 144. Such flow of current through said controller 175 operates the latter to increase the speed of operation of the prime mover or motor 157, and thus of the pump 131. When a predetermined pressure value in the discharge line 132 is exceeded (94 pounds per square inch, for example), the pressure switch 172 connccts said wire 176 to wire 178, so that current now ows through the speed controller 175 from wire 178 to wire 143, with resultant operation of said controller to reduce the speed of the motor 157 and pump 131.

Upon still further increase in rate of flow of fluid in the discharge conduit 132, the How-meter switch arm 137 comes into engagement with contact 165. Pumps 130 and 131 remain in operation, since said arm 137 continues to engage the contacts 161B and 163. Since, however, arm 137 is no longer in engagement With the contact 164, the pressure switch 172 is no longer in action. At the same time, the engagement of arm 137 with contact 165 establishes connection between wires 146 and 171, and thus to pressure switch 173, which responds to a discharge pressure at a predetermined value still higher than any of the previously mentioned pressure switches.

So long as the pressure in the discharge conduit 132 is below a predetermined higher value (95 pounds per square inch, for example), the pressure switch maintains a connection between wire 171 and wire 177, so that current ows by wire 176 through the speed controller 175 to the return wires 143 and 144. The controller 175 thus causes the motor 157 and pump 131 to operate at increased speed. When a predetermined pressure value is exceeded (99 pounds per square inch, for example), the pressure switch 173 connects said wire 171 to wire 179, so that current flows by wire 178 through speed controller 175 and thence to the return wires 143 and 144. Thereby the controller 175 reduces the speed of the motor 157 and pump 131.

While, upon engagement of the flow-meter switch arm 137 with contacts 163 and 164, the pump 130 may be cut out if desired, 1 have shown the contact segment 160 as of sufficient extent to be engaged by said arm 137 throughout its engagement with the other Contact segments, so that the pump 13? is continuously in operation from the time when arm 137 comes into engagement with segment 16) in the clockwise movement of said arm until said arm 137 is disengaged from said segment 161) in the counterclocl-:wise movement of said arm. Thus, in this arrangement the pump 131i is in operation continuousiy as tong as the ilow rate in conduit 132 equals or exceeds that at which arm 137 is brought into engagement with contact segment 160. While neither of the pressure switches 152, 153 is in action when the switch arm 137 engages contacts 163 and 164, the pump 130 continues in operation at the speed corresponding to the setting of the controller 1511 when arm 137 left engagement with segment 162. Of course, by shortening the length of the segment 16), the pump 130 could be thrown out of operation at any desired point in the clockwise movement of the switch arm 137.

Upon decrease in ow rate in the discharge conduit 132, the arm 137 moves counter-clockwise, disengaging the contact and engaging the contact 164. Pressure switch 173 is thus thrown out of action and pressure switch 172 returned to operation. Upon suticient further decrease in flow rate, the arm 137 moves out of engagement with contacts 163 and 164, and comes into engagement with contact 162. Pressure switch 172 is now thrown out of action, as is also pump 131. However, the smaller-capacity pump 130 remains in operation, due to the continued engagement of arm 130 with segment 169, and the pressure switch 153 which controls the speed of operation of said pump is restored to action by engagement of said arm with segment 162.

Still further decrease in ow rate causes said arm 137 to move out of engagement with contact 162 and to engage the contact 161, with the result that pump 130 is brought under control of the pressure switch 152 to maintain a reduced pressure in the discharge conduit. Upon -suicient further decrease in ow rate in said conduit, the arm 137 moves out of engagement with both contacts 160 and 161, so that pressure switch 152 is thrown out of operation, and current can no longer flow through the controller 141 by way of said arm 137. Pump 130 will thus be thrown out of action, unless the pressure in the discharge line 132 is below that at which the pressure switch 148 responds to establish current ow through said controller 141 by way of wires 147 and 149. Upon such response of the switch 148 to discharge line pressure the pump 130 will operate to maintain a minimum pressure in conduit 132, or to return the now-meter switch arm 137 into engagement with contacts 160 and 161.

Preferably, the segments 161 and 162 are spaced from each other by a slight angular gap, so that the switch arm 130 will not engage both segments simultaneously. Likewise, the segments 162 and 164, also 164 and 165 are preferably separated by a slight angular gap for the same reason.

In Fig. 3a I have shown a modification of that portion of the Fig. 3 arrangement that involves the pressure switch control circuits. More specifically in Fig. 3a, the switch 172 maintains control of both pump 130 and 131 when the flow meter arm 137 is on the segment 164, while switch 173 maintains control of both of said pumps when said arm 137 is on segment 165. This is effected by connecting lines 151 and 154 of speed-controller 150 to the lines 177 and 179, respectively, as shown in Fig. 3a.

1n order to prevent pressure switches 152 and 153 from attempting to control pump 131 when it is not running (i. e., when switch arm 137 is on segment 161 or 162), a relay 180 `is shown in Fig. 3a, said relay having a coil 181 connected between the wire 159 and wire 143". A movable contact 182 of said relay 180 is adapted to be moved into and out of engagement with a pair of stationcatanese @ry-,contests i183 and i18n-ion-.separatt .d:.Parts` ofttheportion of .wirefl :that lleads to` tthe speed controller 1-'l5. .As ylong asstheallowmeter Aswitchzarm '51357 fis out :of engage- :mentfwthasegment 16.3, currenacannotfow:throughwire 159 and the coil 181 of relay E180fis fdeenergized; under 3 which :condition jthe. movable contact 182 fof tsaid `relay is Vout of engagement with contacts `l-Srand 184. Thus, while pressuresswitch .152 will-.control the action .fof the :Speed-controller' 1:50 .as long as :switch varm .13j-engages :segment 16;1,.and pressure-switch 153 will fcontroltheac- :tionfof saidsspeed-controllerias dong ars-said arm 137 engagesisegment 1.62., neither of .said pressure-switches can icontrol the;` pump e131, .since `contact -182 is `outof engage- .tuent with .contacts $18.3 :and .184 :under-those conditions. When, however, switch arm 137 engages segment 16.3 and .16!!,tpressu're-.switch-172risithrownlinto. action v throughengagementf Saidrarmiwith segmentfli) and the coil180 of relay .,181 is energized (throngh engagement of .said arm f1.3.7 with-segment 1.65). vThereupon, -the movable i contact-1820isaidfnelay engagesthestationary contacts 18S-and 184, so .that the'speed-,controller 175 for pump .1311 istconnected `to ;the Ywires 143" :and 14.4, vand l thus be- `cornes subject .to control 4,by pressure-switches :17,2 and 17;'3. ipreviouslynoted, .said pressureswitches-.1-72 .and 173 :are :also reonnected for :the -cont-rol of :the vspeed ofthe pump 130, since the Wires 151 and 154 of the speed-controller 15.0 `are Anonnected ftowires"177 and 17.9 and thus to said pressure-switches.

lf desired, in Fig. 3 or Fig. 3a, there may be placed in the supply 5oline 1146, "between -the supply'source "145 and the :point 'of'connection of wire 1i46to wire 147., a convent-ion-l pressure-"switch, responsive to pressure .in the suction orsupplyl side V'of-thepumps 130, 1131, Whichswitch is normally `closed ybut lopens when the ysuction `Apressure falls outside certain limits, 'as-Whenn'o fluid supply, or insutlicient iiuid supply,isa:vailable forthe pumps. A simi- 'larpressureswitch 1responsive to supply line suction may beprovided in either of the systems shown in -Figs. 1 and?.

It will be app-arent thatthe number of pumps vthrown into and out'oftaction `may 'bervaried as desired `from the number showtnby way-ofexarnplefin each of Figs. l, la, 2, 3, and 3a. Also, if desired, various combinations oftixed and variable speed pumps maybe employed. .For instance, `in"Fig. 3, the pump '130 might, if desired, be operated at "fixed speed'by simply omitting the variablespeed controller 150, while retaining the variable-speed operation of pump 131. It will also be apparent that, if desired, the flow-meter 29 in Fig. l or Fig. la, or the owmeter 136 in Fig. 3, may respond to the sum of flow rates in different conduits as illustrated in connection with flowmeter 29 in Fig. 2. Numerous other variations will be apparent, within the scope of the appended claims.

The terms and expressions which I have employed are used as terms of description and not of limitation, and I have no intention, in the use of such terms and expressions, of excluding anyequivalents of the features shown and described or portions thereof, but recognize that various modifications are possible within the scope of the invention claimed.

I claim:

l. A pumping system comprising a plurality of pumps, a discharge line connected to the outlets of said pumps, means responsive solely to the rate of iiuid flow through said line during operation of one of said pumps for bringing into action another of said pumps, means responsive to pressure in said discharge line, means controlled by said pressure responsive means for varying the speed of one of said pumps, and connections controlled by said flow responsive means for bringing said pressure responsive means into operation.

2. A pumping system comprising a plurality of pumps, a discharge line connected to the outlets of said pumps, means responsive to the rate of fluid iiow through said discharge line, means responsive to pressure in said discharge line, arneans :controlled .by .'saidgpressure Lresponsive means ttorVV varying-.the :speedy-of :operation lof -saidr pumps, connections 1- controlled t by said flow responsive means for bringing :said lpressure responsive -means into Yaction, `and connections .t controlled iby said Siiow `responsive means .for bringingone -of said pumps into action-.in responseto increase in flow rate to-anpredetermined amount during -operationofanother of saidjpumps.

3. .A ,pumping system .comprising -a pluralityof, pumps, a discharge Ylineazonnected -to .the outlets `of said pumps, means responsive to the rate of iiuid iiow through .said discharge line, means `controlled by said `flow responsive means for 4.varyingthe speedtoftone of -sadpumpsin accordance -with .the pressure -insaid discharge line, :means controlled -by said .iiow responsive means for bringing la second :one f of -said pumps finto action in response `to .creasesin flow rate ,-to Ia predetermined amount in said discharge line, .andmeans controlled-by said ilow responsive rmeans .-for varying the speed of -said second pump t in `accordancewith the pressure in said discharge line.

4. Apumpingsystem comprising a,pluralityfof pumps, a idischarge yline connected-.to the-outlets of said pumps, means responsive .to therateof uid tlow throughtsai'd discharge line, apressure :switch for controlling `the speed of tone of said pumps to'maintan.apredeterminedvpressureinisaid discharge line, -means controlled by `said iiow .responsive-means :for maintaining said .pressure switch in `action for aipredetermin'ed `range of ilow rates, 'a second .pressure switch for fcontrollingthe speed of said ,pump tto maintain 4a predetermined :higher .pressureinsaid disfchargelline., means `controlled by said 'flow responsive means .for cutting outthe `first pressurefswitch and-.bringing finto :action .the .second pressureswitch in response ytoi-increase in flow rateto .apredetermined amount, and Vmeans controlled `by=said owresponsive means for bringing a second pump `.into vact-ion .in vresponse 4to -.a further increase flow rate.

5. 1A pumpingsystemcomprising a plurality of pumps, a `discharge `line connected` to 4the `outlets of saidpumps, .means responsive to the rate .of `fluid flow through .said 1discharge line, .a pressure switch for controlling the speed .of one tof -said pumps to maintain a predetermined -pres- -sure .in saiddischarge-line,-means controlled-.by saidow responsive means for maintaining said 'pressure -switch 4in action .for .apredetermined range of flow rates, asecond pressure `switch --for controlling Vthe speediof :Said pump to maintain a predetermined higher pressure in said discharge line, means controlled by said flow responsive means for cutting out the first pressure switch and bringing into action the second pressure switch in response to an increase in flow rate to a predetermined amount, means controlled by said flow responsive means for bringing a second pump into action in response to a further increase in iiow rate, a third pressure switch for controlling the speed of said second pump to maintain a predetermined pressure in said discharge line, and means controlled by said ow responsive means for bringing said third pressure switch into action.

6. A pumping system comprising a plurality of pumps, a discharge line connected to the outlets of said pumps, means responsive to the rate of fluid dow through said discharge line, means controlled by said flow responsive means for maintaining one of said pumps in operation for a predetermined range of flow rates, means controlled by said flow responsive means for maintaining another of said pumps in operation for a predetermined higher range of ilow rates, and pressure responsive means controlled by said iiow responsive means for varying the speeds of said pumps to maintain diierent pressures in said discharge line for different rates of ow therein.

7. A pumping system comprising a plurality of pumps, a discharge line connected to the outlets of said pumps, means responsive tothe rate of iiuid flow through said discharge line, electrical contact means controlled by saidflow responsive means for maintaining one of said pumps in operation for a predetermined range of ow rates, electrical contact means controlled by said flow responsive means for maintaining another of said pumps in operation for a predetermined higher range of flow rates, pressure responsive means, means controlled thereby for varying the speeds of said pumps, and electrical contact means controlled Yby said ow responsive means for varying the speeds of said pumps to maintain different pressures in said discharge line for dilerent rates of flow therein.

8. A pumping system comprising a plurality of pumps, a discharge line connected to the outlets of said pumps, means responsive to the rate of fluid ow through said discharge line, pressure responsive means for regulating the speeds of operation of said pumps to maintain predetermined pressures in said discharge line, electrical contact means controlled by said flow responsive means for maintaining the respective pumps in operation through predetermined ow rate ranges in said discharge means, and means controlled by said flow responsive means for rendering said pressure responsive means effective to regulate the speeds of said pumps.

9. A pumping system comprising a plurality of pumps, a discharge line connected to the outlets of said pumps, means responsive to pressure in said line for bringing one of said pumps into operation, means responsive to rate of ow in said discharge line in excess of a predetermined amount for bringing another pump into operation and stopping the first pump, means responsive to pressure in said line for varying the operation of one of said pumps to increase the pressure in said line when said pressure is below a predetermined amount, and means responsive to rate of i'low in said discharge line in excess of a predetermined amount for bringing the last mentioned pressure responsive means into action.

10. A pumping system comprising a plurality of pumps, a discharge line connected to the outlets of said pumps, means responsive to pressure in said line for bringing one of said pumps into operation, means responsive to rate of low in said discharge line in excess of a predetermined amount for bringing another pump into operation and stopping the first pump, means responsive to a further increase in said rate of ow for again bringing the first pump into operation, means responsive to pressure in said line for varying the operation of one of said pumps to increase the pressure in said line when said pressure is below a predetermined amount, and means responsive to rate of iiow in said discharge line in excess of a predetermined amount for bringing the last mentioned pressure responsive means into action.

l1. A pumping system comprising a plurality of pumps, a discharge line connected to the outlets of said pumps, means for bringing one of said pumps into action, means responsive to rate of fluid ow in said line for bringing another pump into action, normally ineffective means responsive to pressure in said discharge line for varying the operation of one of said pumps to increase the pressure in said line, and means controlled by said rate of iluid ow for bringing said pressure responsive means into action.

12. A pumping system comprising a plurality of pumps, a discharge line connected to the outlets of said pumps, means responsive to pressure in said discharge line for bringing one of said pumps into action, means responsive to rate of fluid flow in said line for bringing another pump into action, normally ineffective means responsive to pressure in said discharge line for varying the operation of one of said pumps to increase the pressure in said line, and means controlled by said W rate for bringing the last-mentioned pressure responsive means into action.

References Cited in the le of this patent UNITED STATES PATENTS 528,822 Stowe Nov. 6, 1894 1,154,467 Wilkinson Sept. 21, 1915 1,383,258 'Holman June 28, 1921 1,390,829 Smoot Sept. 13, 1921 1,562,561 Hoiter Nov. 24, 1925 1,563,337 Caputo Dec. l, 1925 1,819,774 Durdin Aug. 18, 1931 2,347,196 Hulman et al. Apr. 25, 1944 2,406,854 Samarin Sept. 3, 1946 2,408,851 Hillier Oct. 8, 1946 2,432,553 Zilly Dec. 16, 1947 2,486,256 Buck Oct. 25, 1949 FOREIGN PATENTS 73,716 Switzerland Dec. 22, 1915 430,701 France 1911 513,330 Germany 1930

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