CN207169595U - The mixing system of fracturing blender truck - Google Patents

Abstract

The utility model proposes a kind of mixing system of fracturing blender truck, including the first blender, base fluid feeding member and powder feeding member, first blender is ejector mixing, the base fluid input of first blender is connected with the base fluid feeding member, the powder input of first blender is connected with the powder feeding member, first blender is parallel with the parallel pipeline that can convey base fluid, the base fluid input of the parallel pipeline connects with the base fluid output end of the base fluid feeding member, first blender is in series with the second blender, second blender is changeable flow ejector mixing, the fracturing fluid input of second blender is connected with the fracturing fluid output end of first blender, the base fluid input of second blender is connected with the base fluid output end of the parallel pipeline.The utility model can meet to fracturing fluid discharge capacity and with fluid viscosity requirement simultaneously.

Description

The mixing system of fracturing blender truck

Technical field

The utility model belongs to fracturing technique field, more particularly to a kind of mixing system of fracturing blender truck.

Background technology

Fracturing technique refers in oil recovery or gas production process, is acted on using fluid pressure, the reservoir of oil, gas is formed crackA kind of method, its concrete operations is the pump using high-pressure large-displacement, using the principle of liquid pressure transmission, by the liquid with certain viscosityBody (i.e. fracturing fluid), injected with the pressure of the absorbability more than reservoir to reservoir, and then forming tool near shaft bottom in stratumThere is the sand packed fracture of certain physical dimension and high flow conductivity, well is reached the purpose of increasing yield and injection.Due to current both domestic and externalPressing crack construction operation field (the especially pressing crack construction scene of shale gas) needs substantial amounts of fracturing fluid, therefore to mixing vehicle discharge capacityWith the requirement more and more higher with fluid viscosity.

Chinese invention patent application CN103990410A discloses a kind of mixed technology of fracturing fluid, and it uses suction pumpingBase fluid (base fluid as fracturing fluid solvent is generally water or oil) is taken, by setting up water channel in parallel, and makes it with mixing water channel simultaneouslyConnection, make base fluid while enter in two paths of mixing water channel and water channel in parallel, rather than fully enter in mixing water channel, avoidLimited caused by mixing the smaller efficiency to mixture of channel flows, shorten compounding time, and the set-up mode of dual pathFracturing fluid is formed by multiple mixture, mixing uniformity is improved, the quality of fracturing fluid has been obtained furtherOptimization.

But the mixed technology of above-mentioned fracturing fluid is in the case of fracturing fluid huge discharge operation, if secondary mixer is setFor conventional vortex diffusion type blender, then mixed effect is limited, especially in the case where guanidine glue is poor quality, does not allow moreIt is easily well mixed；If secondary mixer is arranged to pipeline mixer (such as ejector mixing), or by water channel in parallel withMixing water channel is connected with secondary mixer again after being connected in exit, then the back pressure of mixed once device can be promoted to raise, so as to tightThe mixed effect of blender is have impact on again, or even easily causes mixed once device to fail, and then is unable to reach mixed once deviceThe ability of normal work under huge discharge handling situations；Therefore, above-mentioned mixed technology is difficult to meet to fracturing fluid more huge discharge, withAnd requirement of the lifting with fluid viscosity.

The content of the invention

The utility model is difficult to meet to glue fracturing fluid huge discharge, and lifting with liquid for existing fracturing fluid mixed technologyDesired technical problem is spent, proposes that one kind can meet to fracturing fluid huge discharge simultaneously, and lifting is with the mixed of fluid viscosity requirementThe mixing system of sand car.

In order to achieve the above object, the technical solution adopted in the utility model is：

A kind of mixing system of fracturing blender truck, including the first blender, base fluid feeding member and powder feeding member, described first is mixedClutch is ejector mixing, and the base fluid input of first blender is connected with the base fluid feeding member, and described first is mixedThe powder input of clutch is connected with the powder feeding member, and first blender is parallel with the parallel transistor that can convey base fluidRoad, the base fluid input of the parallel pipeline connect with the base fluid output end of the base fluid feeding member, the first blender stringThe second blender is associated with, second blender is changeable flow ejector mixing, and the fracturing fluid of second blender is defeatedEnter end to be connected with the fracturing fluid output end of first blender, base fluid input and the parallel transistor of second blenderThe base fluid output end connection in road.

Preferably, being fixedly installed varying-arca channel and Flow-rate adjustment component in second blender, described become cutsThe fracturing fluid input in facial canal road is connected with the fracturing fluid output end of first blender, and the base fluid of the varying-arca channel is defeatedEnter end to be connected with the base fluid output end of the parallel pipeline, the fracturing fluid output end of the varying-arca channel mixes with described secondThe fracturing fluid output end connection of device, the base fluid input that the Flow-rate adjustment component corresponds to the varying-arca channel are set, withAdjust the flow of the varying-arca channel base fluid input.

Preferably, the Flow-rate adjustment component includes reciprocating moving member, and the moving member can be drivenThe actuator of motion, the moving member is set corresponding to the varying-arca channel base fluid input, to adjust the varying cross-section ductThe flow of road base fluid input, the clutch end of the actuator are connected with the moving member, the fixing end of the actuatorIt is fixedly connected with second blender.

Preferably, the varying-arca channel includes nozzle, base fluid input and the parallel pipeline of the nozzleBase fluid output end connects, and the base fluid output end of the nozzle connects with the fracturing fluid output end of second blender, the shiftingThe base fluid input that moving part corresponds to the nozzle is set.

Preferably, the nozzle is taper, the area of section of the base fluid input of the nozzle is more than the nozzle baseThe area of section of liquid output end, the moving member are shaped as spindle, and the moving member conical surface corresponds to the cone of the nozzleFace is set.

Preferably, the actuator is driving cylinder, the cylinder body portion of the actuator is fixed with second blender to be connectedConnect, the cylinder rod portion of the actuator is connected with the moving member, to drive the moving member linearly to move back and forth.

Preferably, the varying-arca channel also includes netted shield, one end of the netted shield is socketed on the sprayOutside the base fluid output end of mouth, the mesh portion of the netted shield connects with the fracturing fluid output end of first blender.

Preferably, the varying-arca channel also includes Venturi tube, the fracturing fluid input socket of the Venturi tubeIn in the other end of the netted shield, the fracturing fluid output end of the Venturi tube and the fracturing fluid of second blender are defeatedGo out end connection.

Preferably, first blender is in series with the pump housing, the base fluid output end of the pump housing mixes with described firstThe base fluid input connection of device, the base fluid input of the pump housing are connected with the base fluid output end of the base fluid feeding member.

Preferably, the quantity of first blender is arranged to two, between two first blenders after parallel connectionConnected with second blender and the base fluid feeding member.

Compared with prior art, it is the advantages of the utility model with good effect：

(1) mixing system of the utility model fracturing blender truck on the basis of first blender by connecting described secondBlender, it is converted into the kinetic energy that the parallel pipeline is conveyed to base fluid and is mixed with what first blender conveying fracturing fluid mixedNegative pressure is produced after closing energy, on the one hand can make the back pressure of first blender reduce, and then it is mixed to improve described firstThe working condition of clutch, fracturing fluid is converted into turbulence state from laminar condition, and then do not increase kinetic equation lossIn the case of, the mixed effect of raising powder and base fluid.Therefore, the mixing system of the utility model fracturing blender truck can improve pressure breakThe mixed effect of liquid, while improve the operating mode of first blender, and then to pressure break when can meet huge discharge operation simultaneouslyLiquid discharge capacity and the requirement with fluid viscosity.

(2) the utility model can effectively lift the operating pressure of blender by setting the pump housing, while can reduce baseThe discharge pressure of liquid feeding member, and then energy consumption is reduced, and make full use of the purpose of fluid dynamic energy

Brief description of the drawings

Fig. 1 is the overall structure diagram of the utility model embodiment；

Fig. 2 is the structural representation of the second blender in the utility model embodiment；

Above in each figure：1st, the first blender；2nd, base fluid feeding member；3rd, powder feeding member；4th, the second blender；5th, become and cutFacial canal road；501st, Venturi tube；502nd, netted shield；503rd, nozzle；6th, static mixer；7th, suction header；8th, the pump housing；9th,Three blenders；10th, blending tank；11st, excavationg pump；12nd, discharge manifold；13rd, parallel pipeline；14th, Flow-rate adjustment component；1401st, moveMoving part；1402nd, actuator.

Embodiment

Below, the utility model is specifically described by exemplary embodiment.It should be appreciated, however, that do not havingIn the case of being further discussed below, element, structure and features in an embodiment can also be advantageously incorporated into other implementationsIn mode.

, it is necessary to which explanation, term " first ", " second ", " the 3rd " are only used for describing in description of the present utility modelPurpose, and it is not intended that instruction or hint relative importance.

Referring to Fig. 1 and Fig. 2, a kind of mixing system of fracturing blender truck, including the first blender 1, can be to first blender 1The base fluid feeding member 2 of base fluid (such as clear water or oil) is provided, and powder (such as guanidine glue can be provided to first blender 1Powder or particle) powder feeding member 3, first blender 1 is ejector mixing, and first blender 1 is usedMixed in by powder and base fluid, to form fracturing fluid, while sprayed the fracturing fluid formed using pressure, thus it is describedBase fluid input, powder input and fracturing fluid output end are necessarily offered on first blender 1；First blender 1Base fluid input is connected with the base fluid feeding member 2, the powder input of first blender 1 and the powder feeding member 3Connection, first blender 1 are parallel with the parallel pipeline 13 that can convey base fluid, the base fluid input of the parallel pipeline 13 withThe base fluid output end connection of the base fluid feeding member 2, first blender 1 are in series with the second blender 4, second mixingDevice 4 is the pressure of changeable flow ejector mixing, the fracturing fluid input of second blender 4 and first blender 1The connection of liquid output end is split, the base fluid input of second blender 4 is connected with the base fluid output end of the parallel pipeline 13, instituteThe size of the second blender 4 regulation input flow rate is stated, to be converted into the kinetic energy that the parallel pipeline 13 is conveyed into base fluid and instituteAfter the mixed tensor for stating the conveying fracturing fluid mixing of the first blender 1, on the one hand make the back pressure of first blender 1 less than specifiedValue, the fracturing fluid on the other hand making to convey in first blender 1 are sufficiently mixed.

The mixing system of the utility model fracturing blender truck is described second mixed by being connected on the basis of first blender 1Clutch 4, it is converted into the kinetic energy that the parallel pipeline 13 is conveyed into base fluid and conveys what fracturing fluid mixed with first blender 1Negative pressure is produced after mixed tensor, on the one hand can make the back pressure of first blender 1 reduce, and then described first can be improvedThe working condition of blender 1, fracturing fluid is converted into turbulence state from laminar condition, and then do not increase power damageIn the case of consumption, the mixed effect of powder and base fluid is improved.Therefore, the mixing system of the utility model fracturing blender truck can improve pressureTo pressure when splitting the mixed effect of liquid, while improve the operating mode of first blender 1, and then can meet huge discharge operation simultaneouslySplit liquid discharge capacity and the requirement with fluid viscosity.

In addition, the utility model makes base fluid only be partly into first mixing by setting parallel pipeline 13Fracturing fluid is mixed to form in device 1 and with powder, and another part is entered in the parallel pipeline 13 and by the parallel transistorRoad 13 is delivered in second blender 4, then makes the base fluid of the conveying of parallel pipeline 13 and first blender 1 defeatedThe fracturing fluid gone out is more fully mixed, so avoid because the flow of the first blender 1 is smaller and to fracturing fluidLimitation caused by mixture efficiency, while improve the mixing uniformity of fracturing fluid itself.

As a kind of embodiment of the present utility model, it is concretely：

As shown in figure 1, the base fluid feeding member 2 is preferably to suck centrifugal pump, the powder feeding member 3 is preferably powderTank, first blender 1 are preferably constant flow ejector mixing, and constant flow ejector mixing sprays relative to changeable flowThe formula blender of penetrating can ensure the constant of jet coefficient, so as to be easier to ensure that pigment mixed effect and avoid first mixingThe phenomenon that the failure of device 1 is turned one's coat occurs.

As depicted in figs. 1 and 2, varying-arca channel 5 and Flow-rate adjustment component are fixedly installed in second blender 414, the varying-arca channel 5 is used for the base fluid conveyed to the fracturing fluid and the parallel pipeline 13 of first blender 1 conveyingMixed, and mixed fracturing fluid is delivered to the fracturing fluid output end of second blender 4, the varying cross-section ductRoad 5 necessarily offers the fracturing fluid input being connected with the fracturing fluid output end of first blender 1, with the parallel pipelineThe base fluid input of 13 base fluid output end connection, and the pressure break connected with the fracturing fluid output end of second blender 4Liquid output end, the varying-arca channel 5 include nozzle 503, netted shield 502 and Venturi tube 501, and the nozzle 503 is preferredFor taper, the area of section of the base fluid input of the nozzle 503 is more than the area of section of the base fluid output end of nozzle 503,The base fluid input of the nozzle 503 connects with the base fluid output end of the parallel pipeline 13, the base fluid output of the nozzle 503End connects with the fracturing fluid input of the Venturi tube 501, and the both ends of the netted shield 502 are socketed on the nozzle respectivelyOutside 503 base fluid output ends and the fracturing fluid input of the Venturi tube 501, the mesh portion of the netted shield 502 and described theThe fracturing fluid output end connection of one blender 1, when the base fluid of the parallel pipeline 13 conveying enters in second blender 4When, base fluid is pressurized ejection and the fracturing fluid Rapid contact with being disperseed by the netted shield 502 by nozzle, now due at a high speedFluid (base fluid) produces the effect that volume is inhaled to low velocity fluid (fracturing fluid), therefore can be improved the kinetic energy of fracturing fluid, simultaneouslyThe kinetic energy of base fluid is set to change into mixed tensor, so as to form the turbulent flow for being more beneficial for mixing, and then it is more efficient to obtain fracturing fluidMixing, the fracturing fluid output end of the Venturi tube 501 connects with the fracturing fluid output end of second blender 4.

It should be noted that the mesh of the netted shield 502 is not limited to the forms such as circle, rhombus, bar shaped or a variety of shapesThe combining form of shape.

Further as depicted in figs. 1 and 2, the Flow-rate adjustment component 14 includes reciprocating moving member 1401, withAnd the actuator 1402 that the moving member 1401 can be driven to move, the moving member 1401 is preferably shaped to spindle, describedThe conical surface that the conical surface of moving member 1401 corresponds to the nozzle 503 is set, to adjust the stream of the base fluid input of varying-arca channel 5Amount, the actuator 1402 are preferably driving cylinder, and the cylinder body portion of the actuator 1402 is fixed with second blender 4 to be connectedConnect, the cylinder rod portion of the actuator 1402 is connected with the moving member 1401, to drive the moving member 1401 linearlyMove back and forth.

As shown in figure 1, the base fluid input of the base fluid feeding member 2 is connected with suction header 7, first blender 1The pump housing 8 is in series with, the pump housing 8 is preferably boosting centrifugal pump, the base fluid output end of the pump housing 8 and first blender 1Base fluid input connection, the base fluid input of the pump housing 8 is connected with the base fluid output end of the base fluid feeding member 2, describedThe pump housing 8 can effectively lift the operating pressure of blender 1, while can reduce the discharge pressure of base fluid feeding member 2, and thenEnergy consumption is reduced, and makes full use of the purpose of fluid dynamic energy；The fracturing fluid output end of the Venturi tube 501 is connected with static mixedClutch 6, the static mixer 6 take into full account the matching with the second blender, make full use of the boosting of the second blender 4 to makeWith while avoiding the phenomenon that the second blender 4 fails by high back pressure and occurring, realizing and make full use of liquid energy realNow to the function of the further mixing of fracturing fluid.

Further as shown in figure 1, the fracturing fluid output end of the static mixer 6 is connected with the 3rd blender 9, described theThree blenders 9 are preferably vortex diffusion type blender, and the 3rd blender 9 is used to further mix fracturing fluid；The fracturing fluid output end of 3rd blender 9 is connected with blending tank 10, and the blending tank 10 is used to carry out fully fracturing fluidStirring；The fracturing fluid output end of the blending tank 10 is connected with excavationg pump 11, the fracturing fluid input of the excavationg pump 11 and instituteThe fracturing fluid output end connection of blending tank 10 is stated, the fracturing fluid output end of the excavationg pump 11 is connected with discharge manifold 12, describedThe effect of excavationg pump 11 is to discharge the good fracturing fluid of mixture to upstream device through the discharge manifold 12.

In order to further improve the mixing efficiency of fracturing fluid, as shown in figure 1, the quantity of first blender 1 is arranged toTwo, connect between two first blenders 1, pass through with second blender 4 and the base fluid feeding member 2 after parallel connectionMultiple first blenders 1 are connected in parallel, the powder in the powder feeding member 3 is divided multiple-channel output, so as on the one hand makeVarious powders are mixed into possibility simultaneously, while reduce the energy and space cost when a variety of powders mix, on the other handDispersion mixing of the powder of the same race by multiple first blenders 1 can be realized, and then is advantageous to lift mixing uniformity；ThisOutside, first blender 1 can also be in series or in parallel with shearing pump type blender, and now the pump housing 8 can choose to install, i.e. instituteStating the pump housing 8 can connect with first blender 1, can also be without using shearing pump type blender generally use efficient rotorWith the stator composition with space, fluid is then made by high speed shear by rotor rotation, such as rapidly by the bulky grain in liquidHydrate is cut into particulate of 100 mesh even below 200 mesh, to produce the mixed effect of strength, but is necessary to ensure that when in useThe clean and tidy degree of fluid, while the cost of operation and maintenance is higher, and then there is larger limitation in use.

In addition, first blender 1 may be replaced by shearing pump type blender.

The present embodiment also provides a kind of compounding method of fracturing fluid, using the mixing system of fracturing blender truck as described above,Referring to Fig. 1 and Fig. 2, it comprises the following steps：

S1：Base fluid is sucked by suction header 7 using the base fluid feeding member 2；

S2：The base fluid of suction base fluid feeding member 2 is delivered to the pump housing 8 all the way, and is supplied through the pump housing 8 to first blenderIn 1；

S3：The base fluid another way of suction base fluid feeding member 2 is directly fed to described second by the parallel pipeline 13 and mixedIn clutch 4；

S4：The base fluid and the powder feeding member 3 for being provided the base fluid feeding member 2 by first blender 1 carryThe powder of confession is mixed and forms fracturing fluid, at the same using kinetic energy by fracturing fluid to the spray feed of the second blender 4；

S5：The size of input flow rate is adjusted by second blender 4, the parallel pipeline 13 is being conveyed into base fluidAfter kinetic energy is converted into the mixed tensor mixed with first blender 1 conveying fracturing fluid, make the back pressure of first blender 1Less than rated value；

S6：Fracturing fluid is ejected in the static mixer 6 by second blender 4, and makes fracturing fluid in instituteState and mixed in static mixer 6；

S7：Fracturing fluid in the static mixer 6 is transported in the 3rd blender 9 and mixed；

S8：By the 3rd blender 9 to the further mixing of fracturing fluid, and mixed fracturing fluid is delivered to describedIn blending tank 10；

S9：The blending tank 10 is expelled to outside discharge manifold 12 after fracturing fluid is stirred through excavationg pump 11.

For above-mentioned steps S5, it specifically may include following steps：

S501：Netted shield 502 in second blender 4 is disperseed the fracturing fluid that first blender 1 conveys；

S502：The base fluid that the parallel pipeline 13 supplies is ejected to institute by the nozzle 503 in second blender 4In the ring cavity for stating netted shield 502, and the fracturing fluid for making base fluid be conveyed with first blender 1 is mixed；

S503：The moving member 1401 in second blender 4 is back and forth transported under the driving of the actuator 1402Dynamic, when the distance of the moving member 1401 and the nozzle 503 reduces, the flow of the base fluid input of nozzle 503 reduces；

S504：Mixed fracturing fluid is conveyed by the Venturi tube 501 in second blender 4, while to pressure breakLiquid is mixed.

The compounding method of the utility model fracturing fluid is converted into and institute in the kinetic energy that the parallel pipeline 13 is conveyed into base fluidNegative pressure is produced after stating the mixed tensor of the first blender 1 conveying fracturing fluid mixing, on the one hand can make first blender 1Back pressure reduces, and then can improve the working condition of first blender 1, fracturing fluid is converted from laminar conditionFor turbulence state, and then in the case where not increasing kinetic equation loss, the mixed effect of powder and base fluid is improved.Therefore, this practicalityThe mixing system of new fracturing blender truck can improve the mixed effect of fracturing fluid, while improve the operating mode of first blender 1, enterAnd to fracturing fluid discharge capacity and the requirement with fluid viscosity when can meet huge discharge operation simultaneously.

Claims (10)

1. a kind of mixing system of fracturing blender truck, including the first blender (1), base fluid feeding member (2) and powder feeding member (3), instituteIt is ejector mixing to state the first blender (1), base fluid input and the base fluid feeding member of first blender (1)(2) connect, the powder input of first blender (1) is connected with the powder feeding member (3), first blender(1) parallel pipeline (13) of base fluid can be conveyed by being parallel with, and base fluid input and the base fluid of the parallel pipeline (13) supplyThe base fluid output end connection of part (2), it is characterised in that：First blender (1) is in series with the second blender (4), and describedTwo blenders (4) are changeable flow ejector mixing, and the fracturing fluid input of second blender (4) is mixed with described firstThe fracturing fluid output end connection of clutch (1), the base fluid input of second blender (4) and the base of the parallel pipeline (13)Liquid output end connects.

2. the mixing system of fracturing blender truck according to claim 1, it is characterised in that：It is fixed in second blender (4)It is provided with varying-arca channel (5) and Flow-rate adjustment component (14), the fracturing fluid input of the varying-arca channel (5) and described theThe fracturing fluid output end connection of one blender (1), base fluid input and the parallel pipeline (13) of the varying-arca channel (5)Base fluid output end connection, the fracturing fluid output end of the varying-arca channel (5) and the fracturing fluid of second blender (4) are defeatedGo out end connection, the base fluid input that the Flow-rate adjustment component (14) corresponds to the varying-arca channel (5) is set, to adjustState the flow of varying-arca channel (5) base fluid input.

3. the mixing system of fracturing blender truck according to claim 2, it is characterised in that：The Flow-rate adjustment component (14) includesReciprocating moving member (1401), and the actuator (1402) that the moving member (1401) can be driven to move, the shiftingMoving part (1401) is set corresponding to the varying-arca channel (5) base fluid input, defeated to adjust the varying-arca channel (5) base fluidEnter the flow at end, the clutch end of the actuator (1402) is connected with the moving member (1401), the actuator(1402) fixing end is fixedly connected with second blender (4).

4. the mixing system of fracturing blender truck according to claim 3, it is characterised in that：The varying-arca channel (5) includes sprayMouth (503), the base fluid input of the nozzle (503) connect with the base fluid output end of the parallel pipeline (13), the nozzle(503) base fluid output end connects with the fracturing fluid output end of second blender (4), and the moving member (1401) corresponds toThe base fluid input of the nozzle (503) is set.

5. the mixing system of fracturing blender truck according to claim 4, it is characterised in that：The nozzle (503) is taper, describedThe area of section of the base fluid input of nozzle (503) is more than the area of section of the nozzle (503) base fluid output end, the movementPart (1401) is shaped as spindle, and the conical surface that moving member (1401) conical surface corresponds to the nozzle (503) is set.

6. the mixing system of fracturing blender truck according to claim 3, it is characterised in that：The actuator (1402) is drivingCylinder, the cylinder body portion of the actuator (1402) are fixedly connected with second blender (4), the cylinder rod of the actuator (1402)Portion is connected with the moving member (1401), to drive the moving member (1401) linearly to move back and forth.

7. the mixing system of fracturing blender truck according to claim 4, it is characterised in that：The varying-arca channel (5) also includesNetted shield (502), one end of the netted shield (502) are socketed on outside the base fluid output end of the nozzle (503), the netThe mesh portion of shape shield (502) connects with the fracturing fluid output end of first blender (1).

8. the mixing system of fracturing blender truck according to claim 7, it is characterised in that：The varying-arca channel (5) also includesVenturi tube (501), the fracturing fluid input of the Venturi tube (501) are socketed on the other end of the netted shield (502)Interior, the fracturing fluid output end of the Venturi tube (501) connects with the fracturing fluid output end of second blender (4).

9. the mixing system of the fracturing blender truck according to any one of claim 1-8, it is characterised in that：First blender(1) pump housing (8) is in series with, the base fluid output end of the pump housing (8) is connected with the base fluid input of first blender (1),The base fluid input of the pump housing (8) is connected with the base fluid output end of the base fluid feeding member (2).

10. the mixing system of the fracturing blender truck according to any one of claim 1-8, it is characterised in that：First mixingThe quantity of device (1) is arranged to two, between two first blenders (1) after parallel connection with second blender (4) and instituteState base fluid feeding member (2) series connection.