CN111648966A

CN111648966A - 2-stage or multi-stage centrifugal pump using final-stage flow dividing main impeller

Info

Publication number: CN111648966A
Application number: CN202010422354.0A
Authority: CN
Inventors: 何巨堂; 何艺帆
Original assignee: Luoyang Ruihua New Energy Technology Development Co ltd
Current assignee: Luoyang Ruihua New Energy Technology Development Co ltd
Priority date: 2020-05-13
Filing date: 2020-05-13
Publication date: 2020-09-11

Abstract

A kind of 2 or multi-stage centrifugal pump using main impeller of final stage of partial flow, the centrifugal pump KPUMP using flushing liquid is to the partial flow discharge conveying of the liquid material 1F such as containing solid residual oil, its main impeller NS of final stage is called the partial flow impeller, its diameter is usually lower than the diameter of the main impeller MS of secondary final stage; the discharge liquid MP of the impeller MS is divided into at least 2 paths, part of the discharge liquid MP is discharged out of the pump cavity to be used as a first output liquid 1P, and part of the discharge liquid NP is mixed with flushing liquid after being pressurized by NS and is finally discharged out of the pump cavity to be used as a second output liquid 2P, so that the flushing liquid in the 2P can be recycled; the simplest structure is a 2-stage impeller pump, wherein a first-stage impeller is used as MS, a second-stage impeller is used as NS, most of 1F enters 1P, and a small part of 1F enters 2P; the small-diameter flow dividing impeller can reduce the flow of flushing oil, reduce NS lift, reduce pressure loss, reduce the axial force of the impeller, simplify the structure of the pump cavity, reduce the volume of the pump cavity, and ensure that the pump shaft can be supported by a cantilever and can be vertically arranged and the diameter is thick.

Description

2-stage or multi-stage centrifugal pump using final-stage flow dividing main impeller

Technical Field

The invention relates to a 2-stage or multistage centrifugal pump using a final-stage splitter main impeller, suitable for delivering a liquid charge 1F, such as a solid residue-containing split discharge, using a centrifugal pump KPUMP for flushing fluids, the final-stage main impeller NS of which is called splitter impeller and generally has a diameter lower than that of the penultimate main impeller MS; the discharge liquid MP of the impeller MS is divided into at least 2 paths, part of the discharge liquid MP is discharged from the pump cavity as a first output liquid 1P, and part of the discharge liquid MP is mixed with flushing liquid after being pressurized by the final-stage main impeller NS and is finally discharged from the pump cavity as a second output liquid 2P, so that the flushing liquid in the 2P can be recycled; the simplest structure is a 2-stage impeller pump, wherein a first-stage impeller is used as MS, a second-stage impeller is used as NS, most of 1F enters 1P, and a small part of 1F enters 2P; the small-diameter flow dividing impeller can reduce the flow of flushing oil, reduce NS lift, reduce pressure consumption, reduce the axial force of the impeller, simplify the structure of a pump cavity, reduce the volume of the pump cavity, and ensure that a pump shaft can be supported by a cantilever and can be vertically arranged and has a large diameter; a shaftless motor such as a canned motor may be used in combination.

Background

The main medium 1F refers to a process fluid which needs to be conveyed through a pump, and can be solid-containing slurry or liquid, and also can contain a small amount of gas phase or bubbles which do not influence the normal operation of the process fluid; the main medium 1F before pressurization enters the main impeller cavity from the main medium inlet 1FN of the pump shell, is pressurized by the main impeller, and is discharged from the main medium outlet APN after self pressurization.

The back pump chamber KV of the centrifugal pump of the present invention refers to a chamber between the back cover plate 63 of the back side main impeller KS nearest to the back pump cover 30 and the pump case, and is generally a chamber between the back cover plate 63 of the last stage main impeller and the pump chamber back cover 30.

The back pump cavity flushing fluid CXY of the centrifugal pump refers to flushing fluid for flushing the back pump cavity KV.

The back pump cavity flushing fluid CXY disclosed by the invention generally flows in a main body direction of passing through the back pump cavity KV, firstly enters an inner side area of the back pump cavity KV, which is close to a pump shaft (or a shaft sleeve), then flows through a middle area of the back pump cavity to reach an outer side area of the back pump cavity KV, which is far away from the pump shaft, then leaves the back pump cavity KV, and continuously flows and is discharged out of a pump body.

The back blade BYP refers to a blade which is arranged in the back pump cavity KV and can rotate along with the pump shaft, and can be a back blade 64 of the main impeller.

The main impeller back vane 64 of the present invention is a vane provided on the back surface of the back cover 63 of the main impeller KS closest to the back pump cover 30.

The main body flow direction of the flushing liquid CXY passing through the rear pump cavity KV is that the flushing liquid CXY firstly enters the inner side area of the rear pump cavity KV close to the pump shaft, then reaches the outer side area of the rear pump cavity KV far away from the pump shaft, then leaves the rear pump cavity KV, and continuously flows and is discharged out of the pump body.

According to the back pump cavity flushing fluid CKY, when the back blade BYP is arranged in the centrifugal pump, the main flow direction of the flushing fluid CXY passing through the back pump cavity KV is that the flushing fluid firstly enters the inner side inlet area of the back blade BYP, then flows through the back blade cavity, is thrown out of the back blade cavity after energy is applied by the back blade BYP, then leaves the back pump cavity KV, and continuously flows and is discharged out of a pump body.

Conventional centrifugal pump does not establish dedicated back pump chamber flush fluid discharge port BPN, and back pump chamber flush fluid discharges the pump chamber in the lump after mixing in the pump chamber with main medium, and at this moment, the discharge path system of back pump chamber flush fluid: leave behind the pressure boost of pump chamber flush fluid entering pressure boost back main medium's runner intracavity, flow in the lump with pressure boost back main medium after mixing, finally, through pressure boost back main medium row mouth APN discharge pump cavity in the lump, because pressure boost back flush fluid and pressure boost back main medium mix completely together, its advantage is that the discharge simple structure of pump case, compactness, but has following shortcoming:

firstly, the components of the flushing liquid cannot be recovered at low cost, because the flushing liquid after being pressurized in a small quantity is diluted by a large quantity of pressurized main media; when the value of the flushing liquid is higher than that of the main medium, the value of the flushing liquid is reduced, and the loss is large;

secondly, the main medium is polluted by the washing liquid after pressurization, and the scale of a subsequent treatment system is increased.

The present invention relates to the transportation of a slurry having a high concentration of solid particles and a high concentration of asphaltenes, and will be described below by way of example.

Based on the existing scheme for discharging flushing liquid in the rear pump cavity of the centrifugal pump, the oil residue conveying pump at the bottom of the vacuum fractionating tower for generating oil in the reaction processes of direct coal hydrogenation liquefaction, residual oil suspension bed hydrocracking, residue oil boiling bed hydrocracking and the like typically adopts a structure that the flushing liquid (flushing oil) and an auxiliary impeller are used for protecting a sealing part of a mechanical sealing system MFU of a pump shaft, the pump PAST-KPUMP, between the pump shaft mechanical sealing system MFU and main pump impeller, the flushing mechanism or sealing mechanism is characterized by that an auxiliary impeller, fixed guide vanes and main impeller back blades are set, the flushing oil (or sealing oil) can be passed through the auxiliary impeller and pressurized, then flows through the fixed guide vane to prevent the rotational flow from entering an inlet area of a back blade of the main impeller, and then is pressurized by the back blade of the main impeller, and then leaves a back cavity of the main pump to enter a discharge flow channel (such as a volute) of the main pump to be mixed with a main medium discharged by the main impeller and then is recovered or treated together. According to other material conditions and operation requirements of a factory, the oil residue delivery pump PAST-KPUMP can be provided without one or more of an auxiliary impeller, a fixed guide vane and a main impeller back vane.

The oil residue delivery pump PAST-KPUMP has the advantages of compact and mature structure, and has the defect that the flushing oil and the main fluid discharged by the pump are completely mixed together, so that the dilution degree of the main fluid discharged by the pump reaches the maximum, the recycling of the flushing oil is not facilitated, and the recycling cost of the flushing oil is increased.

Taking a bottom oil residue delivery pump PAST-KPUMP of a KT tower of a vacuum fractionating tower of a coal hydrogenation direct liquefaction reaction process for generating oil with the yield of distilled oil of a coal hydrogenation direct liquefaction product of 100 ten thousand tons/year as an example, the loss amount is large according to a conventional oil rear pump cavity flushing fluid discharge mode; the flushing oil is wax oil distillation oil separated from oil generated by direct coal hydrogenation liquefaction through a vacuum fractionating tower KT or hydrogen-supplying solvent wax oil and/or heavy diesel oil separated from oil generated in a hydrogen-supplying solvent oil hydrogenation reaction process, and because the recovery of the flushing oil from the direct coal hydrogenation liquefaction residue is extremely difficult or too high in cost, the flushing oil mixed into the direct coal hydrogenation liquefaction residue is usually used as a substitute of coal for combustion of a circulating fluidized bed boiler or gas making of a gasification furnace, and the price is only 500-700 yuan/ton. Thus, the value of the flushing oil is 4000-5000 yuan/ton (calculated as 4500 yuan/ton below) higher than that of the liquefied residue, calculated according to 7600 hours/year of the device operation, 400-600 kg/hour of the flushing oil consumed by each pump is 3040-4560 tons/year, and the loss amount is as high as 1368-2052 yuan/year because the flushing oil cannot be recovered. Although 100-200% of KT tower bottom oil of discharged liquefaction residues is generally recycled and returned to the bottom of the vacuum tower for tangential feeding to form rotational flow in order to prevent coking at the bottom of the vacuum tower, a small amount of flushing oil can be separated, or 50-100% of KT tower bottom oil of discharged liquefaction residues is returned to recycled gasification flushing oil in a feeding flash evaporation section of the vacuum tower (actually, the recycle ratio of the operation cannot be too high to prevent repeated heating and coking of asphaltenes) can be separated by 33-50% of flushing oil at most, and the economic loss caused by the loss of the final flushing oil is still huge and can reach 684-1354 ten thousand yuan/year. The above analysis is only statistical data of the operation mode using 1 working pump (while 1 pump is standby), and if the operation mode using 2 working pumps (while 1 pump is standby) is used to ensure the operation reliability, the loss is increased by almost 1 time, and the loss amount is more huge.

In order to overcome the above-mentioned drawbacks or to reduce the extent thereof, the invention proposes to improve the construction of a centrifugal pump using a rear pump chamber flushing liquid in order to achieve at least a relative separation of the flushing liquid discharge from the main medium discharge, whereby it is necessary to improve the discharge path of the flushing liquid discharged from the rear pump chamber of the centrifugal pump away from the pump housing, possibly involving a change of the discharge path of the partially pressurised main medium away from the pump housing.

Because the flushing oil enters the discharge space of the main impeller to be mixed with the main medium after leaving the outer edge of the main impeller, the relative separation of the flushing oil and the main medium can hardly be realized or the structure is too complex.

The basic idea of the invention is: a2-stage or multistage centrifugal pump using a final stage splitter main impeller adapted to deliver a split discharge of a liquid charge 1F, such as a solid residue-containing oil, using a centrifugal pump KPUMP for flushing liquid, the final stage main impeller NS of which is called splitter impeller and is generally of a diameter lower than that of the penultimate stage main impeller MS; the discharge liquid MP of the impeller MS is divided into at least 2 paths, part of the discharge liquid MP is discharged from the pump cavity as a first output liquid 1P, and part of the discharge liquid MP is mixed with flushing liquid after being pressurized by the final-stage main impeller NS and is finally discharged from the pump cavity as a second output liquid 2P, so that the flushing liquid in the 2P can be recycled; the simplest structure is a 2-stage impeller pump, wherein a first-stage impeller is used as MS, a second-stage impeller is used as NS, most of 1F enters 1P, and a small part of 1F enters 2P; the small-diameter flow dividing impeller can reduce the flow of flushing oil, reduce NS lift, reduce pressure consumption, reduce the axial force of the impeller, simplify the structure of a pump cavity, reduce the volume of the pump cavity, and ensure that a pump shaft can be supported by a cantilever and can be vertically arranged and has a large diameter; a shaftless motor such as a canned motor may be used in combination.

Compared with the discharge scheme of the conventional centrifugal pump after all flushing liquid and main medium are mixed, the invention has the advantages that at least relative separation discharge of the flushing liquid and the main medium can be realized, at least one part of 2P has different purposes than at least one part of 1P, low-cost recycling of the flushing liquid in the 2P is facilitated, and the purity of the 1P can be improved; the delivery pump KPUMP and 2P used as the bottom oil residue of KT in the vacuum fractionating tower containing solid and easily coking slurry, such as coal hydrogenation direct liquefaction reaction generated oil, can directly enter the feeding or discharging section of a KT feeding heating furnace tube or a KT flash evaporation section to separate flushing liquid and residual oil, and can also return to the hydrogenation reaction process for cyclic reaction, and the benefit is obviously increased by reducing the loss of the flushing liquid.

The invention is different from a 2-stage or multi-stage centrifugal pump with at least 2 liquid discharge ports with different lifts in the invention patent application with the application number of 201810043423.X in that the concept of a splitter impeller is definitely provided, and the diameter of the splitter impeller is smaller than that of a main impeller at the last stage, so that the flow of flushing oil can be reduced, NS lift and pressure reduction power consumption are reduced, the axial force of the impeller is reduced, the structure of a pump cavity is simplified, the volume of the pump cavity is reduced, and a cantilever support mode is favorably adopted for a pump shaft.

The invention is suitable for the delivery pumps of various media, and therefore has a certain universal application value in the related fields.

The technical scheme similar to the invention is not reported.

A first object of the invention is to propose a 2-stage or multistage centrifugal pump using a final stage splitter main impeller.

The second purpose of the invention is to provide a 2-stage or multistage centrifugal pump using a final-stage shunting main impeller, and simultaneously using a shunting impeller back blade, a fixed guide vane and an auxiliary impeller, wherein flushing oil sequentially passes through the auxiliary impeller, the fixed guide vane and the shunting impeller back blade, a mechanical sealing part of a pump shaft is arranged on one side of the auxiliary impeller, which is far away from a main pump cavity, and the outside of the mechanical sealing, which is far away from one side of the auxiliary impeller, is an environmental space.

The third purpose of the invention is to provide a 2-stage or multi-stage centrifugal pump using a final-stage shunting main impeller, which belongs to a non-shaft seal centrifugal pump.

The fourth purpose of the invention is to provide a 2-stage or multi-stage centrifugal pump using a final-stage flow-dividing main impeller, wherein the main medium belongs to the bottom oil residue of KT tower of a vacuum fractionating tower for generating oil in the hydrogenation reaction process of heavy hydrocarbon.

Disclosure of Invention

The invention relates to a 2-stage or multi-stage centrifugal pump using a final-stage flow dividing main impeller, which is characterized by comprising the following parts:

the centrifugal pump KPUMP is used for conveying the main liquid medium 1F under pressure;

a pump cavity housing Q10 of the centrifugal pump KPUMP is composed of a pump cavity assembly including at least a front pump cover 50 and a rear pump cover 30;

in a pump cavity shell Q10 of the centrifugal pump KPUMP, at least 2 stages of main impellers working in series are used for conveying a main medium 1F possibly containing solid particles in a pressurizing way, and a flushing liquid CXY is used for flushing a rear pump cavity KV;

the centrifugal pump KPUMP uses 2-stage or multi-stage main impellers working in series, and comprises a first-stage main impeller 1S, a penultimate-stage main impeller MS and an ultimate-stage main impeller NS;

the final-stage main impeller NS refers to the final-stage main impeller, when the centrifugal pump KPUMP works, a liquid main medium 1F flows through the main impeller groups working in series, and the final-stage main impeller which is contacted with the main medium 1F in the process of flowing through all the main impellers is the final-stage main impeller NS;

the final-stage main impeller NS is the one closest to the rear pump cover 30, and is also referred to as a splitter impeller NS;

the secondary final-stage main impeller MS refers to a superior main impeller adjacent to the final-stage main impeller NS, and when the centrifugal pump KPUMP works, a liquid main medium 1F flows through the secondary final-stage main impeller MS and then enters the final-stage main impeller NS;

the back pump cavity KV of the centrifugal pump KPUMP refers to a gap through which a flushing fluid CXY can flow, which exists between the back pump cover 30 and the cover plate 63 of the final-stage main impeller NS on the side facing the back pump cover 30;

the centrifugal pump KPUMP, when using the main impeller that 2 grades of series work, the first main impeller 1S and the secondary final main impeller MS are the main impeller of the same stage;

a main medium inlet 1FN, a secondary final stage main impeller discharge outlet 1PN and a back pump cavity flushing liquid inlet BFN are arranged on the cavity wall of a pump cavity shell Q10 of the centrifugal pump KPUMP;

when the centrifugal pump KPUMP works, a main medium 1F enters a pump cavity shell Q10 through a main medium inlet 1FN, enters a flow channel of a first-stage main impeller blade 1SM through an inlet of the first-stage main impeller 1S, increases speed under the rotation pushing action of the first-stage main impeller blade 1SM to obtain energy, and then is discharged out of a blade cavity of the first-stage main impeller 1S;

a discharge liquid flow passage of the vane NSM of the final stage main impeller NS is defined as a splitter impeller medium flow passage V70; the liquid material 2P flowing through the flow path V70 includes a main medium and a rinse liquid;

the liquid material 2P leaves the flow channel V70 to continue flowing and finally is discharged out of the pump cavity shell Q10 through the discharge port 2PN of the final-stage main impeller;

when the centrifugal pump KPUMP normally works, externally supplied back pump cavity KV flushing fluid CXY enters the inner side area of the back pump cavity KV close to the pump shaft through a back pump cavity flushing fluid inlet BFN, then reaches the outer side area of the back pump cavity KV far away from the pump shaft, then leaves the back pump cavity KV to enter a flow channel V70, and is mixed with a main medium discharged by a final-stage main impeller NS to form liquid material 2P;

a pump cavity shell Q10 of the centrifugal pump KPUMP is also provided with a discharge port MPN of a secondary final-stage main impeller MS; when the centrifugal pump KPUMP normally works, a part of main media discharged by the secondary final-stage main impeller MS is discharged out of the pump body through the discharge port MPN and does not pass through the final-stage main impeller NS;

when the centrifugal pump KPUMP works normally, the operation result is as follows: the main medium flowing through the secondary final-stage main impeller MS partially leaves the pump chamber housing Q10 through the discharge port MPN, and partially leaves the pump chamber housing Q10 through the discharge port NPN after flowing through the final-stage main impeller NS; the flushing liquid enters the material 2P but not the material 1P;

the impeller diameter of the secondary-final-stage main impeller MS is MS-D, the impeller diameter of the splitter impeller NS is NS-D, the ratio of the NS-D value to the MS-D value is K100, K100 is (NS-D)/(MS-D), and K100 is less than 0.8.

In the invention, the K100 value of the centrifugal pump KPUMP can be selected from 1 of the following types:

①K100＝0.50～0.70；

②K100＝0.30～0.50；

③K100＝0.20～0.30；

④K100＜0.20。

in the invention, generally, the centrifugal pump KPUMP uses a 2-stage main impeller, the first-stage main impeller is used as a secondary final-stage main impeller MS, the second-stage main impeller is used as a splitter impeller NS, more than 50% of the main liquid medium 1F enters the material flow 1P, and less than 50% of the main liquid medium 1F enters the material flow 2P.

In the invention, the flow rate of the main medium in the material 2P discharged by the splitter impeller NS of the centrifugal pump KPUMP can be selected from 1 of the following:

the total weight of the main medium 1F entering the pump KPUMP is 30-50%;

secondly, the total weight of 1F of the main medium entering the pump KPUMP is 10-30 percent;

thirdly, 5-10 wt% of the total amount of 1F of the main medium entering the pump KPUMP;

fourthly, 2 to 5 weight percent of the total amount of 1F of the main medium entering the pump KPUMP;

is less than 2 wt% of the total 1F of the main medium entering the pump KPUMP.

In the invention, a centrifugal pump KPUMP is provided with a multistage series-connected pressurized main impeller, and a discharge port HPN of an upstream main impeller discharging HP is arranged by taking a normal main flow path of a main medium as a reference forward direction;

an upstream main impeller, meaning any main impeller upstream of the penultimate main impeller MS;

a portion of at least one upstream main impeller discharge HP1 is discharged out of the pump chamber housing Q10 through a discharge opening HP1N provided in the pump chamber housing Q10, and the remainder of the discharge HP2 enters the downstream main impeller to continue to be pressurized.

In the invention, the centrifugal pump KPUMP and the number of the discharge ports of the liquid material 1P can be 1 or 2 or more.

In the invention, the centrifugal pump KPUMP and the number of the discharge ports of the liquid material 2P can be 1 or 2 or more.

In the present invention, in general, in the centrifugal pump KPUMP, back blades 64 are provided on the plate surface of the cover plate on the side of the splitter impeller NS close to the rear pump cover 30.

In the present invention, centrifugal pump KPUMP, the back vane 64 of splitter impeller NS is typically a straight radial vane.

In the present invention, the flow path of the external flushing fluid CXY of the centrifugal pump KPUMP before being input to the back pump chamber KV may be selected from one of the following:

firstly, after entering a rear pump cavity KV flushing fluid input flow channel, entering the rear pump cavity KV;

pressurizing the gas by flowing through the auxiliary impeller chamber, then flowing through the optical back of the auxiliary impeller cover plate on one side of the auxiliary impeller, and entering a back pump cavity KV;

thirdly, the gas flows through the auxiliary impeller cavity for pressurization, then flows through an anti-rotation flow channel formed by the light back surface of an auxiliary impeller cover plate on one side of the auxiliary impeller, which faces the main impeller, and the fixed guide vane, and then enters a back pump cavity KV;

fourthly, the oil flows through the axial clearance at the outer side of the pump shaft or the pump shaft sleeve and enters the rear pump cavity KV;

the centrifugal pump KPUMP belongs to the centrifugal pump of the motor without shaft seal, the external supply flushing liquid enters the motor chamber through the flushing liquid inlet of the motor chamber, then leaves the motor chamber after flowing through the motor chamber, then flows through the anti-backflow channel from the motor chamber to the back pump chamber KV, and enters the back pump chamber KV;

and the centrifugal pump KPUMP belongs to a non-shaft seal motor centrifugal pump, washing liquid is externally supplied, enters a motor chamber through a washing liquid inlet of the motor chamber, flows through the motor chamber, is boosted through an auxiliary impeller arranged in the motor chamber, leaves the motor chamber, flows through the motor chamber to a backflow prevention channel of a back pump cavity KV, and enters the back pump cavity KV.

In the invention, the prime mover at the driving end of the centrifugal pump KPUMP can be selected from 1 of the following:

firstly, a motor; a second frequency conversion motor; thirdly, a hydraulic motor; fourthly, the oil engine; gas engine; a pneumatic motor; and (c) a steam turbine.

According to the invention, when the centrifugal pump KPUMP uses an external driver, a pump shaft mechanical sealing system is arranged.

According to the centrifugal pump KPUMP, when at least one part of the pump shaft is exposed to the environment, a pump shaft sealing system U80 for preventing a main medium from leaking to the environment is arranged on the pump shaft of the centrifugal pump.

According to the centrifugal pump KPUMP, flushing liquid CXY flows through the auxiliary impeller and then enters the pump cavity shell Q10;

the pump shaft sealing system U80 is located on the outer side of the auxiliary impeller to form a spatial relationship that the auxiliary impeller, the pump shaft sealing system U80 and the external driver are close to each other in sequence, the inner side of the pump shaft sealing system U80 is adjacent to the auxiliary impeller chamber, and the outer side of the pump shaft sealing system U80 is adjacent to the environment.

The centrifugal pump KPUMP is a shaft seal-free centrifugal pump and can be selected from one of a shielding electric centrifugal pump, a submerged electric centrifugal pump and a magnetic centrifugal pump.

In the invention, the centrifugal pump KPUMP is a shaftless electric centrifugal pump, and an auxiliary liquid FZL input system is usually arranged;

the auxiliary liquid FZL is used as flushing liquid and is used for preventing a main medium in a pump cavity shell Q10 from being connected into a cavity of a motor without a shaft seal in series, the operating pressure of an auxiliary liquid input system is greater than the operating pressure of the main medium in a pump cavity shell Q10, so that at least a part of the auxiliary liquid FZL enters a rear pump cavity KV in the pump cavity shell Q10 through a flow passage and is discharged out of the pump cavity shell Q10 after flowing through the rear pump cavity KV;

auxiliary liquid FZL which is flushing liquid CXY for the rear pump cavity KV;

the used motor without shaft seal is provided with an injection interface E-K1 of lubricating liquid and/or cooling liquid EL of a cavity of the motor without shaft seal; the lubricating liquid and/or the cooling liquid EL refer to a liquid for cooling and lubricating the rotor and the cavity of the motor without the shaft seal;

the discharge of the lubricating and/or cooling fluid EL from the motor cavity without shaft seal serves to prevent the auxiliary fluid FZL and/or the main medium in the pump cavity from flowing into the motor cavity without shaft seal.

the auxiliary liquid FZL is used as flushing liquid and is used for preventing a main medium in the pump cavity shell Q10 from being connected into a cavity of the motor in series, the operating pressure of an auxiliary liquid input system is greater than the operating pressure of the main medium in the pump cavity shell Q10, so that at least a part of the auxiliary liquid FZL enters a rear pump cavity KV in the pump cavity shell Q10 through a flow channel and is discharged out of the pump cavity shell Q10 after flowing through the rear pump cavity KV;

the lubricating liquid and/or the cooling liquid EL of the shaft seal-free motor cavity are discharged to prevent the auxiliary liquid FZL and the main medium in the pump cavity from flowing into the shaft seal-free motor cavity;

when the shaftless motor works normally, the operating pressure of a liquid existing area in the cavity of the shaftless motor is greater than the operating pressure of a main medium in the pump cavity shell Q10 and is also greater than the operating pressure of fluid in the auxiliary liquid FZL of the canned motor pump, so that at least a part of lubricating liquid EL enters the auxiliary liquid system through the flow channel and is mixed with the auxiliary liquid FZL to form mixed liquid EL-FZL, at least a part of the mixed liquid EL-FZL enters the rear pump cavity KV in the pump cavity shell Q10 through the flow channel and flows through the rear pump cavity KV and then is discharged out of the pump cavity shell Q10;

and the mixed solution EL-FZL is the flushing fluid CXY for the rear pump cavity KV.

The arrangement mode of the centrifugal pump KPUMP can be selected from 1 of the following modes:

firstly, horizontally arranging a pump shaft;

secondly, the pump shaft is vertically arranged, and the motor is positioned above the pump cavity;

and thirdly, the pump shaft is vertically arranged, and the motor is positioned below the pump cavity.

The centrifugal pump KPUMP can arrange a cavity wall lining inside a pump cavity shell Q10, and the purpose of the lining is selected from 1 or more of the following:

firstly, an erosion-resistant bushing;

② wear-resisting lining

Thirdly, corrosion-resistant lining;

fourthly, the thermal shock resistant bushing;

low temperature resistant lining.

The invention, centrifugal pump KPUMP, can arrange the use of the inner wall bushing of the inlet connecting pipe and/or inner wall bushing of the drain connecting pipe in pump chamber shell Q10, is selected from 1 or several of the following:

firstly, an erosion-resistant bushing;

② wear-resisting lining

Thirdly, corrosion-resistant lining;

fourthly, the thermal shock resistant bushing;

low temperature resistant lining.

In the centrifugal pump KPUMP, an inducer can be arranged at the inlet of the first-stage main impeller.

In the present invention, generally, in the centrifugal pump KPUMP, the pump shaft is arranged in a single-sided cantilevered arrangement.

The main medium delivered by the centrifugal pump KPUMP can have 1 or more of the following media:

contains solid components;

② contains corrosive components;

③ containing a combustion component;

fourthly, toxic components are contained;

containing radioactive components;

sixthly, the volatile component is contained;

contains easily coagulated components;

eighthly, containing bubble liquid;

ninthly, high-temperature liquid;

low temperature liquid charge in the red cavity;

high-pressure liquid material.

The operating conditions of the centrifugal pump KPUMP can be selected from 1 or more of the following:

the main medium 1F conveyed by a centrifugal pump KPUMP is bottom oil residue of a KT tower of a vacuum fractionating tower for directly liquefying coal to generate oil by hydrogenation, and the operation conditions are as follows: the temperature is 280-380 ℃, and the solid concentration is 35-60 wt%;

secondly, the main medium 1F conveyed by the centrifugal pump KPUMP is bottom oil residue of a KT tower of a vacuum fractionating tower for generating oil by hydrocracking a residual oil suspension bed, and the operating conditions are as follows: the temperature is 300-380 ℃, and the solid concentration is 0.05-10 wt%;

thirdly, the main medium 1F conveyed by the centrifugal pump KPUMP is the bottom oil residue of a KT tower of a vacuum fractionating tower for generating oil by residue oil boiling bed hydrocracking, and the operating conditions are as follows: the temperature is 300-380 ℃, and the content of asphaltene is 20-80 wt%;

④ the operation conditions of the main medium 1F conveyed by the centrifugal pump KPUMP are that the temperature is-150-650 ℃, the pressure is 0.1-40.0 MPa, and the volume flow rate of the main medium 1F is 0.1-10000 m³The solid concentration is 0.01-50 wt%;

⑤ the operation conditions of the main medium 1F conveyed by the centrifugal pump KPUMP are that the temperature is-150-650 ℃, the pressure is 0.1-40.0 MPa, and the volume flow rate of the main medium 1F is 0.1-10000 m³The solid concentration is 0.01-50 wt%, and the pump main impeller applies energy to the main medium 1F to increase the pressure by 0.10-5.0 MPa.

In the invention, the main medium 1F conveyed by the centrifugal pump KPUMP can be oil residue at the bottom of a KT tower of a reduced pressure fractionating tower for directly liquefying R10 in the reaction process of hydrogenation of heavy hydrocarbon; the direction of the material 2P discharged by the splitter impeller NS of the transfer pump KPUMP is selected from 1 of the following:

feeding the material into a furnace tube of a feeding heating furnace of a KT (vacuum distillation column);

feeding the material into a discharge material of a KT feeding heating furnace tube of a vacuum fractionating tower;

thirdly, entering a flash evaporation section of a KT (vacuum fractionating tower);

and fourthly, removing the heavy hydrocarbon material and performing a hydrogenation reaction in the R10 cycle reaction process.

Drawings

The drawings are intended to depict only the invention, but not to limit the invention to the precise form, function, and application of the invention.

The invention is described below on the basis of a delivery pump for KT tower bottom oil residue of a vacuum fractionating tower for directly liquefying coal to generate oil by hydrogenation.

FIG. 1 is a schematic view of a first flushing oil flow path of a centrifugal PUMP OLD-PUMP of a conventional structure for conveying bottom oil residue of a vacuum fractionating tower KT for directly liquefying coal to generate oil by hydrogenation.

Fig. 2 is a partial enlarged view of the flushing oil flow path shown in fig. 1.

Fig. 1 shows an electric centrifugal pump with a sealed pump shaft, which typically uses a 1-stage impeller or a 2-stage impeller in series, and adopts a closed impeller, a single-suction feeding manner and an impeller cantilever supporting manner, wherein the pump shaft can be fixed with a motor shaft through an elastic pin coupling.

In fig. 1, components similar to the dynamic seal of the expeller (expeller, stay vanes, back blades) are shown.

In fig. 1, 1 is a pump shaft; an auxiliary impeller cover plate 21, auxiliary impeller blades 22, an auxiliary impeller axial gap 23 and an auxiliary impeller radial gap 24; 31 is a pump cavity rear inner cover, and 32 is a pump cavity rear outer cover; 42 is a fixed guide vane, 43 is a fixed guide vane liquid discharge flow gap, which is an axial gap flow passage and is also a pump cavity flushing oil inlet flow passage 43; 50 is a pump cavity front cover; 62 is the main impeller closest to the rear pump cover 30, namely the last-stage main impeller 9S, and is also the last-stage main impeller; 63 is the back cover plate of the main impeller of the last stage, 64 is a back blade (usually a radial back blade), 65 is the axial clearance of the back blade, and 66 is the radial clearance of the back blade; v70 is the flow path or radial gap of the main medium thrown out by the final stage main impeller 9S and is connected to the existing volute flow path. The parts not shown in fig. 1 include a pump shaft seal, which is provided on the outside (side remote from the main impeller) of the secondary impeller 20 to prevent the main medium from leaking into the environment.

As shown in fig. 1, when the centrifugal PUMP OLD-PUMP of the conventional structure normally works, the pressurized main medium AP discharged from the last-stage main impeller 60 is liquefied oil residue containing about 50 wt% of solid particles and about 50 wt% of liquid-phase components such as easily-coked asphaltenes, and the liquefied oil residue passes through the radial gap V70 and the volute flow channel, and then is discharged from the centrifugal PUMP OLD-PUMP at the pressurized main medium discharge port APN and enters the delivery pipe. Taking a coal hydrogenation direct liquefaction device with oil product yield of 100 ten thousand tons/year as an example, the typical operation conditions of the centrifugal PUMP OLD-PUMP are as follows: the temperature is 311 ℃, the inlet pressure is 0.093MPa, the outlet pressure is 1.50MPa, and the rated flow is 200 cubic meters per hour.

As shown in fig. 1, in order to prevent liquefied oil sludge containing solid particles and easily coking asphaltenes from entering into the sealing parts of the mechanical seal, a flushing oil CXY and a flushing oil path mechanism are used. The flushing oil is decompression wax oil which is wax oil at the bottom of a fractionating tower from oil generated by a hydrogen supply solvent hydrogenation stabilizing device, the normal working temperature is 120-150 ℃, the pressure of a flushing oil pipeline is 1.80MPa, and the CXY flow of the flushing oil is 500kg/h, namely 0.5 ton/h.

As shown in fig. 1, regarding the flow path of the flushing oil CXY, when the centrifugal PUMP OLD-PUMP normally operates, the external flushing fluid CXY enters the inlet region of the auxiliary impeller blade cavity through the flushing oil inlet, then enters the auxiliary impeller blade cavity and is energized by the auxiliary impeller blade, the auxiliary impeller blade rotating at high speed along with the shaft 1 gives the flushing fluid a rotating speed, and is thrown out of the auxiliary impeller blade cavity under the centrifugal force to enter the auxiliary impeller radial gap 24; then, the flushing oil CXY leaving 24 turns to flow into the anti-rotation flow channel cavity of the fixed vane 42 for centripetal radial linear flow towards the pump shaft; the flushing oil CXY leaving the stay vanes 42 turns to flow into the stay vane drainage flow gap 43 (axial flow channel) for flow parallel to the pump shaft; the flushing oil CXY leaving 43 is diverted to flow into the inlet region of the blade cavity of the back-blade 64 and then enters the back-blade cavity of the main impeller where it is energized by the back-blade 64, the back-blade rotating at high speed with the shaft 1 imparts a rotational speed to the flushing liquid, and is thrown out of the back-blade cavity under the action of centrifugal force into the back-blade radial gap 66; finally, the flushing oil CXY leaving the back-vane radial gap 66 is mixed with the pressurized main medium in V70 (main vane KS radial gap or flow channel), and the pressurized main medium discharge APN exits the centrifugal PUMP OLD-PUMP into the delivery pipe.

FIG. 3 is a schematic view of the flow path of the flushing oil of 2 nd type for conveying the bottom oil residue of a vacuum fractionating tower KT of the direct liquefaction produced oil by coal hydrogenation by using a centrifugal PUMP OLD-PUMP with a conventional structure.

The flushing oil CXY flow path shown in fig. 3 differs from the flushing oil flow path shown in fig. 2 in that: the fixed guide vanes 42 are not provided, so that the flushing oil CXY leaving 24 turns to flow into the gap between the sub-impeller shroud 21 and the pump chamber rear inner cover 31, and flows in a rotational flow direction while flowing radially close to the pump shaft.

FIG. 4 is a schematic view of the 3 rd flushing oil flow path of a centrifugal PUMP OLD-PUMP of a conventional structure for conveying bottom oil residue of a vacuum fractionating tower KT for directly liquefying coal to generate oil by hydrogenation.

The flushing oil CXY flow path shown in fig. 4 differs from the flushing oil flow path shown in fig. 3 in that: the back blades 64 are not arranged, so that the flushing oil CXY flows through the back pump cavity KV between the main impeller back cover plate 63 and the pump back covers 31 and 32, the energy is not increased basically, the function of generating centrifugal force is not provided, solid particles possibly entering the back pump cavity KV are not thrown away, and the pressure of the central area of the back pump cavity is not reduced; in addition, the flow field of the flushing oil in the rear pumping chamber KV is less stable, and there is a possibility that a part of the pressurized main medium from the space V70 enters the outer annular region (near the radial clearance space 66) of the rear pumping chamber KV and forms a swirling flow.

Fig. 5 is a schematic view of the flushing oil flow path of a conventional centrifugal pump using a back pumping chamber flushing liquid.

As shown in fig. 5, no matter how the washing liquid enters the back pump cavity KV, the washing oil entering the flow channel 43 through the back pump cavity CXY is turned to flow into the inlet region of the blade cavity of the back blade 64, and then enters the back blade cavity of the main impeller to be energized by the back blade, the back blade 64 rotating at high speed along with the shaft 1 is given a rotation speed of the washing liquid, and is thrown out of the back blade cavity into the back blade radial gap 66 under the centrifugal force; finally, the flushing oil CXY leaving the radial clearance 66 of the back vane is mixed with the pressurized main medium in V70 (main vane radial clearance or flow channel), and the pressurized main medium outlet APN is discharged out of the centrifugal PUMP OLD-PUMP into the delivery pipe. The back-leaf 64 may not be provided, as desired.

The present invention is generally provided with a dorsal flap 64, and the dorsal flap 64 may be omitted as desired.

The invention can be implemented in many ways, and in principle, the structure should be as simple as possible, so as to facilitate manufacture, assembly, disassembly, and maintenance, and facilitate the discharge of solid particles that may enter the pump cavity KV after entering the main pump.

The drive machine associated with the pump may be any suitable prime mover, such as a conventional electric motor requiring a pump shaft seal, or a motor without a shaft seal.

In the piping system outside the centrifugal pump KPUMP, in the discharge piping system, a flow meter and a control valve are usually provided; the piping system, which communicates with the back pump chamber flushing liquid inlet BFN, is usually provided with a filter, a one-way valve.

Detailed Description

The pressure in the present invention refers to absolute pressure.

The concentrations of the components described in the present invention, when not particularly specified, are weight concentrations, i.e., mass concentrations.

The centrifugal pump KPUMP, the arrangement mode of the main impeller with 2 or more stages in series in the pump cavity can be selected from 1 mode in the following modes:

arranging 2-stage or multi-stage impellers in a cantilever manner on one side;

secondly, a 2-stage or multi-stage impeller is arranged on one side in a supporting mode, the supporting piece consists of a bearing and a bearing sleeve, and the bearing sleeve is fixedly positioned;

thirdly, 2, arranging 2-stage or multi-stage impellers in a cantilever manner on the side;

fourthly, arranging 2-stage or multi-stage impellers in a single-side opposite mode;

two-side opposite arrangement of 2-stage or multi-stage impellers.

The invention is mainly described based on a single-sided cantilevered impeller arrangement, however, this does not limit the scope of application of the invention.

The pump cavity shell Q10 of the centrifugal pump KPUMP mainly has the functions of installing a main impeller and forming a rear pump cavity so as to apply energy to a main medium flowing through and flush the rear pump cavity.

The pump cavity shell Q10 of the centrifugal pump KPUMP of the invention, together with other components such as a back pump cavity flushing system, a pump shaft mechanical sealing system and a pipeline system for feeding and discharging materials, form a closed system for conveying main media.

The pump cavity shell Q10 of the centrifugal pump KPUMP at least comprises a rear pump cover 30 and a front pump cover 50 which can be disassembled and assembled for installation and maintenance, a pump shaft extends into the pump cavity from an opening BZSRK in the middle of the rear pump cover 30, and a main impeller is installed on the pump shaft of the inner part of the pump.

For the sake of convenience in installation and maintenance, the pump chamber housing Q10 of the centrifugal pump KPUMP of the present invention has the rear pump cover 30 divided into 2 or more parts, and the front pump cover 50 divided into 2 or more parts, thereby constituting a multi-part pump chamber housing Q10.

The pump cavity shell Q10 of the centrifugal pump KPUMP can be a cavity formed by a front pump cover and a rear pump cover, and can be a cavity formed by cavity pieces between the front pump cover and the rear pump cover as well as between the front pump cover and the rear pump cover.

In the pump cavity shell Q10 of the centrifugal pump KPUMP, guide vanes, a liquid inlet flow passage, a liquid discharge flow passage and the like can be installed according to requirements.

The pump cavity casing Q10 of the centrifugal pump KPUMP of the present invention is a part of the entity of the rear main impeller KS, which is usually closest to the rear pump cover 30, that is sleeved on the pump shaft, and extends into or through the opening BZSRK in the middle of the rear pump cover 30.

On the cavity wall of a pump cavity shell Q10 of the centrifugal pump KPUMP, interfaces such as a pump shaft insertion port, a main medium inlet 1FN, a pressurized main medium discharge port APN, a rear pump cavity flushing liquid inlet BFN, a discharge port BPN for discharging flushing oil KVP and the like are arranged, wherein 1 or more interfaces are arranged on the rear pump cover 30, and the rest interfaces are arranged on the front pump cover 50 according to requirements.

In the cavity wall of the pump chamber housing Q10 or inside the pump housing of the centrifugal pump KPUMP, a flow path for pump feed or discharge (e.g. a discharge volute flow path) can be provided, facilitating free arrangement of the location of the external interface.

The back pump cavity KV of the centrifugal pump KPUMP of the present invention refers to a gap through which the flushing fluid CXY can flow, which exists between the back pump cover 30 and the adjacent cover plate 63 of the main impeller KS closest to the back pump cover 30.

An important application of the centrifugal pump is to convey KT tower bottom oil residue of a vacuum fractionating tower for directly liquefying coal to generate oil by hydrogenation, and typical operating conditions are as follows: the temperature is 280-380 ℃, the solid concentration of the main medium is 45-55 wt%, and the asphaltene concentration of the main medium is 25-35 wt%.

When the centrifugal pump KPUMP is used for conveying slurry containing solids and asphaltine, an auxiliary impeller, a fixed guide vane and a back blade are generally used as flow path parts of back pump cavity flushing liquid to increase the safety of a pump shaft mechanical seal and a back pump cavity and prevent a main medium from entering the pump shaft mechanical seal through the back pump cavity to contact a sealing element.

In fig. 1, components similar to the expeller power seal (expeller, stay vanes, back vanes) are used and, therefore, the expeller power seal is described below with reference to fig. 1, except that the expeller power seal does not use a continuous injection of flushing fluid, but a shutdown seal is provided.

Since much of the monograph on the dynamic seal of the expeller is available and the details of the relevant information, the dynamic seal of the expeller will be described in detail below, which can be used as a reference for the present invention when using the same type of parts.

The dynamic seal of the auxiliary impeller, also known as hydrodynamic seal, is a non-contact radial seal with fixed clearance, it can overcome the deficiency of packing seal and mechanical seal, suitable for other sealed hard to be competent occasions, such as high speed, high temperature, transport medium with strong corrosivity or poisonous or suspended solid particle, especially when transporting the medium containing solid particle, can throw the solid particle off the shaft (or axle sleeve), protect the shaft (or axle sleeve) from wearing and tearing, therefore get the extensive application in the impurity pump, chemical slurry pump, become the basic configuration.

The auxiliary impeller power seal is a centrifugal force generated by the rotation of the liquid (or isolation liquid) leaked out of the main impeller driven by the auxiliary impeller, and the centrifugal force and the pressure of the leaked liquid reach pressure balance, so that the liquid is prevented from leaking. Thus, the expeller power seal is also known as a centrifugal seal or hydrodynamic seal.

The auxiliary impeller power seal is a rotary seal structure, generally comprises back blades, fixed guide blades, an auxiliary impeller, a parking seal and the like, and each part of the auxiliary impeller power seal is used as follows:

the back blade is a narrow blade which is arranged on the back cover plate (viewed along the fluid flow direction) of the radial impeller or the mixed flow impeller in the radial direction and can be used for balancing the axial thrust of the pump; for pumps for conveying fluid containing solid particles, such as slurry pumps, back blades play a role in reducing the pressure of a back cavity of the pump, balancing an impeller shaft and reducing the probability of impurity particles entering a shaft sealing device;

secondly, fixed guide vanes, also called anti-rotation vanes, play a role in eliminating liquid rotation, and are generally provided with radial guide vanes; when no fixed guide vane is arranged, the liquid on the light back side of the auxiliary impeller rotates at an angular speed of omega/3-omega/2 approximately, the pressure is distributed in a parabolic rule, and the pressure on the lower part (close to the central part) of the light back side of the auxiliary impeller is smaller than the pressure on the outer diameter part of the auxiliary impeller; the fixed guide vanes are arranged, so that liquid on the light back side of the auxiliary impeller can be prevented from rotating and flowing, the difference between the pressure on the lower part of the light back side of the auxiliary impeller and the pressure on the outer diameter of the auxiliary impeller is not large, namely, the pressure on the lower part (close to the central part) of the light back side of the auxiliary impeller is improved, and the plugging pressure of the auxiliary impeller is also improved;

and thirdly, the auxiliary impeller is actually a small centrifugal impeller, and high-pressure fluid at the outlet of the main impeller is sealed and leaked outwards (outside the mechanical seal of the shaft) by the pressure generated by the auxiliary impeller. When the pump is stopped, the auxiliary impeller does not work, so that the dynamic seal of the auxiliary impeller and the stop seal device need to be matched for use.

The structures of the back blade and the sub-impeller are described in detail below.

The back blade, its structural parameter can be any suitable parameter, usually make several open radial ribs on the back cover plate plane of the impeller, usually, its shape can adopt the radial straight blade or back bend blade like pump impeller; the number of the back blades is 4-16 blades, and the width of the blades is 5-10 mm; the clearance (back pump cavity clearance) size of back blade and pump case back wall is great to the performance influence, and the back pump cavity clearance value should be better more less on theory, but if back pump cavity clearance undersize, back blade easily causes the friction to generate heat and damages the part when the pump is in operation, so generally get, back pump cavity clearance than the blade width widen 0.3 ~ 3mm to guarantee that back blade freely rotates.

The structural parameters of the expeller, expeller vane can be any suitable parameters, and generally, the shape of the expeller vane is roughly 4:

firstly, forward bending blades (an inlet angle is more than 90 degrees);

secondly, the inlet part is inclined by an angle of 30 degrees and then is a radial straight blade;

thirdly, the impeller is a backward bending blade (the inlet angle is less than 90 degrees) like the main impeller of the pump;

the radial straight blades are generally backward bent blades or radial straight blades, the number of the blades of the moon wheel is 6-16, the width of the blades of the auxiliary impeller is 5-30 mm, and the sealing capacity can be improved by increasing the width and the number of the blades; the axial clearance between the auxiliary impeller blade and the side wall is usually 0.8-1.2 mm, the radial clearance at the outer edge of the auxiliary impeller is usually 1-1.3 mm, and the smaller the clearance, the better the sealing and pressing capacity is.

The use of the rear pump cavity flushing liquid has the following effects:

firstly, the pump cavity can be continuously washed, no outward leakage exists when the pump runs, no mechanical abrasion exists on the pump shaft, the reliability is high, and the service life is long;

the sealing device is suitable for sealing media under various harsh conditions, such as the sealing and conveying of media with high temperature, strong corrosion, solid particles and the like; the dynamic seal of the auxiliary impeller can prevent the leakage of toxic and harmful materials and reduce the environmental pollution;

thirdly, the main impeller back blade and/or the auxiliary impeller are/is used for dynamic sealing, some additional power is consumed, mainly on the friction loss between the auxiliary impeller and liquid, and the power needs to be increased by 2-15% under most conditions;

fourthly, based on the external flushing liquid pressure, the device is suitable for a wider pressure range;

the axial force of the auxiliary impeller can balance part of the axial force of the main impeller.

The back pump cavity flushing mode of the invention can combine the continuous injection of flushing liquid with the dynamic sealing of the auxiliary impeller, and essentially uses the uninterrupted updating of the media in the spaces such as the auxiliary impeller chamber, the fixed guide vane flow channel, the back blade chamber flow channel of the main impeller and the like by the flushing liquid, thereby fundamentally preventing the non-clean liquid from remaining in the spaces, ensuring the cleanness of the spaces, thoroughly preventing (blocking) the possibility that the non-clean liquid (the main medium conveyed by the main impeller) enters the pump shaft seal (such as a mechanical seal or a packing seal mechanism), ensuring the long-term safe operation of the pump shaft seal mechanism, and preventing the leakage of the non-clean liquid to the environment.

Since the conventional expeller power seal does not use a continuous injection of flushing fluid, but only sealing fluid, there is no loss problem of a large amount of continuous flushing oil, but the pump back cavity forms a relative flow dead zone.

When the invention continuously uses the continuous flushing liquid and the dynamic sealing parts (back blades, fixed guide blades and auxiliary impellers), the continuously injected flushing liquid is pressurized by the auxiliary impellers, then is input into the inner side of a back blade chamber of the main impeller through the fixed guide blades, and then is pressurized by the back blades of the main impeller and then is discharged out of a back pump chamber, so that a relative flow dead zone can be prevented from being formed in a back cavity of the pump.

Compared with the conventional auxiliary impeller power seal, the continuous flushing oil injection system is used for replacing a parking sealing mechanism, so that a large amount of flushing liquid is used due to the continuous flushing of the flushing liquid, the problem of recovering the flushing liquid is caused in order to reduce the loss amount of the flushing liquid, and the recovery mode of the flushing oil of the pump power seal is required to be changed correspondingly, so that the recovery mode is different from the conventional auxiliary impeller power seal (only a small amount of sealing oil is used, and continuous injection of the sealing oil is not required).

The power form (prime mover form) of the centrifugal pump of the present invention is not limited and may be any suitable form of drive machine. A

The centrifugal pump can be a centrifugal pump with a pump shaft sealed against the environment, and can be a centrifugal pump without a shaft seal.

Therefore, the pump cavity of the centrifugal pump KPUMP of the invention is a functional space for installing the main impeller for overflowing in the process of boosting the pressure of the process fluid main medium 1F, and guide vanes, flow channels and liquid discharge buffer spaces may be arranged in the pump cavity shell Q10 in a matching manner as required, and the pump cavity shell Q10 at least comprises a front pump cover and a rear pump cover.

The pump cavity shell Q10 of the centrifugal pump KPUMP can be divided into functional blocks (a front pump cover and a rear pump cover) according to requirements to form a combined structure which is convenient to disassemble and assemble, and at the moment, the pump cavity shell Q10 is a combined unit of 1 or 2 or more middle pump cavities among the front pump cover, the rear pump cover, the front pump cover and the rear pump cover.

The pump shaft seal of the invention refers to the seal of the centrifugal pump shaft to the external environment (not to the motor chamber), and is used for preventing the pumping main medium from leaking out of the pump group and entering the environment.

When the centrifugal pump disclosed by the invention uses a driving machine without a pump shaft seal, such as a motor without a shaft seal, the pump cavity shell Q10 rear pump cover can be the front end of a motor part, or the front end of a motor chamber, or the front end of a connecting body between the motor chamber and the pump cavity.

When the centrifugal pump is not a non-shaft seal pump set but a shaft seal pump set, a pump shaft sealing mechanism needs to be configured.

The impeller of the main pump can be an impeller with any suitable structure or shape, can be a main impeller group which uses 2-stage or multi-stage impellers in series, and can use 2 or more impellers with different shapes in combination.

The impeller of the main pump of the centrifugal pump can be provided with guide vanes at the inlet of the first-stage impeller and can be provided with a homogenizing impeller or an emulsifying impeller or a homogenizer or an emulsifier for crushing slurry.

The invention relates to a centrifugal pump main pump impeller, wherein a balance ring can be fixed at the back of a final stage main impeller.

According to the requirement, a balance drum (a balance disc or a disc drum combination) can be arranged at the outlet end of the centrifugal pump with the multistage impellers connected in series to balance the axial force, generally 90-95% of the axial force is balanced, and the residual axial force is borne by a thrust bearing; a back-to-back arrangement of impellers may also be used to balance most of the axial forces.

The invention is characterized in that the shunting impeller is used to realize the classified discharge of the main medium and the flushing liquid, and the shunting impeller is used to mix part of the main medium after boosting the pressure of the main medium with the flushing liquid, thereby preventing the main medium discharged by the secondary-stage main impeller from mixing with the flushing liquid, therefore, the shunting impeller is also an anti-mixing impeller or a limited flow mixing impeller, and therefore, the shunting impeller is required to be used to accurately control the flow of 2P materials discharged.

According to the centrifugal pump KPUMP of the invention, one or several of the secondary impeller 20, the stationary guide vane 42 and the main impeller back blade 64 may be provided as required.

The pump cavity of the invention can be provided with external auxiliary components according to requirements, for example, when the pumped main medium is a main medium which has a low condensation point and is easy to solidify or has a rapidly increased viscosity after being cooled, the pump cavity is generally required to be provided with a heat-insulating jacket.

The arrangement mode of the centrifugal pump KPUMP can be any suitable arrangement mode, but a pump shaft vertical arrangement scheme is preferred.

To simplify the pump chamber structure, the pump shaft is preferably cantilevered and the pump shaft is preferably large in diameter to increase stiffness.

The CXY flushing fluid used in the centrifugal pump of the present invention is described in detail below.

The CXY performance index of the flushing liquid used by the centrifugal pump is selected according to specific working conditions, but the general basic requirements comprise no particle, the mixing of the main medium in the process, better requirements of non-corrosiveness, non-toxicity, no pollution to the environment and optimal requirements of convenience, easy obtaining and convenient recycling. Because the flushing fluid CXY is typically in contact with the rotating seal components of the pump shaft (e.g., mechanical seals, packing seals), it preferably has good lubrication properties. For a shaft seal-free centrifugal pump, because the flushing fluid CXY flows through the motor chamber, the flushing fluid CXY is also generally required to meet certain indexes such as insulation strength, volatile component content, condensation point, compatibility with a cable insulation material (deterioration due to no interaction), and the like, and the requirement at this time is more severe.

The centrifugal pump KPUMP is characterized in that a typical main medium is oil residue at the bottom of a vacuum fractionating tower KT, which is used for generating oil through direct coal hydrogenation liquefaction, residual oil suspension bed hydrocracking and residue oil boiling bed hydrocracking, at the moment, the operating conditions of a bottom oil residue conveying pump KPUMP of the vacuum fractionating tower KT can be any suitable operating conditions, and generally comprise the following steps: the temperature is 280-420 ℃, the inlet pressure is 0.04-0.099 MPaA, the outlet pressure is 0.5-3.5 MPaA, the weight concentration of solid particles is 0-65%, and the volume flow rate of liquid at the inlet of the pump cavity is 20-350 m³H is used as the reference value. In this case, the flushing fluid (flushing oil) is usually a medium wax oil and/or heavy diesel oil component, and the flow rate of the flushing fluid: typically 200-800 kg/hr of flushing oil is consumed per pump, typically 400-600 kg/hr of flushing oil is consumed per pump.

The centrifugal pump KPUMP is characterized in that a typical main medium is coal hydrogenation direct liquefaction with small flow, residual oil suspension bed hydrocracking, residue boiling bed hydrocracking to generate oil vacuum fractionating tower KT bottom oil residue, and at the moment, the operation condition of a KT bottom oil residue conveying pump KPUMP of the vacuum fractionating tower can be any suitable operation condition, and generally comprises the following steps: the temperature is 280-420 ℃, the inlet pressure is 0.04-0.099 MPaA, the outlet pressure is 0.5-3.5 MPaA, the weight concentration of solid particles is 0-65%, and the volume flow rate of liquid at the inlet of the pump cavity is 0.1-20 m³H is used as the reference value. In this case, the flushing fluid (flushing oil) is usually a medium wax oil and/or heavy diesel oil component, and the flow rate of the flushing fluid: typically 50-100 kg/hr of flushing oil is consumed per pump, typically 100-200 kg/hr of flushing oil is consumed per pump, it can be seen that the ratio of the flushing oil flow to the main medium flow is very large and the flushing oil losses are not tolerable.

The invention relates to a vacuum fractionating tower system KT-UNIT for generating oil by direct coal hydrogenation liquefaction, residual oil suspension bed hydrocracking and residual oil boiling bed hydrocracking, which is a separation system at least comprising a vacuum fractionating tower and is used for separating a vacuum distillation raw material based on generated oil into residue and distillation oil.

The vacuum fractionating tower system KT-UNIT provided by the invention can comprise a heating furnace F100-FUNR for fractionating a raw material F100, at the moment, at least one part of a material F100-FUNR-P discharged by the heating furnace F100-FUNR enters a fractionating tower KT, for example, all the F100-FUNR-P enters the fractionating tower KT, all the F100-FUNR-P is mixed with gas steam and then enters the fractionating tower KT, all the F100-FUNR-P enters the fractionating tower KT through steam obtained by a flash tank V10, and liquid phase obtained by a flash tank V10 enters a bottom oil residue conveying pump KPUMP of the vacuum fractionating tower KT for pressurization conveying.

The operating conditions of the KT-UNIT vacuum fractionator system may be any suitable operating conditions, typically: the temperature at the top of the tower is 280-420 ℃, the pressure at the inlet is 0.04-0.099 MPaA, the pressure at the outlet is 0.5-2.5 MPaA, the weight concentration of solid particles is 0-65%, and the volume flow rate of liquid at the inlet of the pump cavity is 0.1-150 m³H is used as the reference value. In this case, the flushing fluid (flushing oil) is usually a medium wax oil and/or heavy diesel oil component, and the flow rate of the flushing fluid: typically 200-800 kg/hr of flushing oil is consumed per pump, typically 400-600 kg/hr of flushing oil is consumed per pump.

The hydrocarbon material of the invention comprises hydrocarbon powder such as coal and hydrocarbon liquid such as inferior heavy oil.

The heavy hydrocarbon material at least comprises part of solid hydrocarbon powder (such as coal) and/or vacuum residue components.

The heavy hydrocarbon material comprises solid hydrocarbon powder (such as coal) or vacuum residue components.

The hydrogenation reaction process of the hydrocarbon material can be a direct coal hydrogenation liquefaction reaction process, an inferior heavy oil hydrogenation reaction process, a kerosene co-hydrogenation reaction process and an oil product hydrogenation reaction process.

The hydrogenation reaction process of the heavy hydrocarbon material can be a direct coal hydrogenation liquefaction reaction process, an inferior heavy oil hydrogenation reaction process, a kerosene co-hydrogenation reaction process and an oil product hydrogenation reaction process.

The hydrogenation reaction of hydrocarbon material in the invention refers to the hydrogenation reaction of liquid and/or solid such as oil and/or coal containing carbon and hydrogen elements under the condition of hydrogen existence and pressurization, the raw oil of the hydrogenation process of hydrocarbon oil is subjected to hydrofining and/or hydro-thermal cracking reaction to generate at least a part of products with lower molecular weight, and the raw coal of the hydrogenation direct liquefaction reaction process of coal is subjected to thermal swelling, primary pyrolysis, secondary thermal cracking of intermediate products, free radical hydrogenation stabilization, thermal condensation and other reactions to generate at least a part of hydrocarbon products with conventional boiling points lower than 450 ℃.

Typical examples of the hydrogenation reaction process of the hydrocarbon material of the invention are a high-temperature coal tar suspension bed hydrogenation deep refining reaction process, a medium-low temperature coal tar suspension bed hydrogenation thermal cracking reaction process, a coal hydrogenation direct liquefaction reaction process, an oil-coal co-refining hydrogenation reaction process, a petroleum-based heavy oil suspension bed or a fluidized bed hydrocracking reaction process.

The reaction product BASE-ARP of the hydrogenation reaction of the hydrocarbon material in the invention usually contains vacuum residue components and/or solid particles, and is usually at least a gas-liquid two-phase material flow, and most of the materials belong to a gas-liquid-solid three-phase material flow. The effluent ARP-X of the hydrogenation reaction is used for discharging a hydrogenation reaction product BASE-ARP, appears in the form of 1-path or 2-path or multi-path materials, and is a gas phase or liquid phase or gas-liquid mixed phase or gas-liquid-solid three-phase material flow.

The oil produced by the hydrogenation reaction of the hydrocarbon material refers to a product hydrocarbon component produced by the hydrogenation reaction of the hydrocarbon material, and the product hydrocarbon component may contain solid particles, soluble gas, light hydrocarbon and other components.

The shaft seal-free pump package is described in detail below.

The shaft seal-free pump set refers to a pump rotating shaft which is completely arranged in a closed container and is not exposed to the environment.

The shaft seal-free pump set KPUMP can be selected from one of a shielding electric centrifugal pump, a submerged electric centrifugal pump and a magnetic centrifugal pump.

The centrifugal canned motor pump of the invention refers to a canned motor driven centrifugal pump.

The invention relates to a canned motor pump, which is a non-shaft seal pump, wherein an impeller is sealed in a pressure container which is filled with pumped media and drives a motor rotor to be sealed in a special cooling and lubricating medium with similar operating pressure and essentially belongs to a communicating vessel, the pressure container is only statically sealed, and the motor stator provides a rotating magnetic field to drive the rotor. The structure cancels a dynamic sealing device of a rotating shaft of the traditional centrifugal pump to the environment, so the structure can completely avoid leakage and can be widely applied to the fields of refrigeration, air conditioning, medicine, chemical industry, petroleum and the like.

In the canned motor pump of the present invention, the impeller is usually installed at the outward extending end of the motor shaft (in the pump impeller cavity), and the impeller, the pump shaft and the motor rotor jointly form a rotating part. The impeller in the pump shell of the canned motor pump is coaxial with the canned motor rotor, and the basic components of the canned motor pump at least comprise a pump body, a canned motor and a connecting body for manufacturing, assembling and maintaining; when the connecting body is used, one end of the connecting body is in butt joint with a pump shell, the other end of the connecting body is in butt joint with a shielding motor, and a shaft of a rotor of the shielding motor penetrates through the connecting body and then enters the front end part in the pump shell to be used as a shaft for mounting a pump impeller.

The present invention relates to a non-shaft seal submersible electric centrifugal pump, generally refers to a centrifugal pump driven by a liquid immersion type electric motor, such as a non-shaft seal oil immersion type electric pump for conveying oil products and a non-shaft seal water immersion type electric pump for conveying boiler water, and is characterized in that a 'wet' stator is used, and a stator winding group is immersed in liquid. At present, manufacturers of shaft seal-free wet electric pumps in China include fertilizer-mixing and Wan electric motor technology development company with limited responsibility and the like.

The shaftless canned motor pump of the present invention is generally considered to have been developed after the advent of the shaftless submersible motor pump, and the difference between the shaftless canned motor pump and the shaftless submersible motor pump is the use of canned motors. Generally, the inner surface of a stator of a shielded motor is isolated by a non-magnetic corrosion-resistant sheet sleeve to form a stator shielding sleeve, the outer surface of a rotor of the shielded motor is isolated by a non-magnetic corrosion-resistant sheet sleeve to form a rotor shielding sleeve, and power (torque between the stator and the rotor) is transmitted from the stator to the rotor through a magnetic force field; the stator shielding sleeve and the rotor shielding sleeve are pressure containers in nature, the ends of the shields are statically sealed by flanges or welded structures, and are separated from the conveyed liquid, so that the stator winding iron core and the rotor iron core are not corroded, and the stator shielding sleeve and the rotor shielding sleeve are filled with resin possibly. The shield is made of a non-magnetic, corrosion resistant, high strength metal material, typically hastelloy (hastelloy c) alloy. At present, manufacturers of canned motor pumps in China include Hefei Hu canned motor pump company, Dalian empire national canned motor pump company, HAYWARDTYLER electric canned motor pump company, and the like.

The electric pump without shaft seal has various structural main part arrangement schemes due to the requirements of manufacturing, assembling and maintaining, and at least comprises the following 2 typical schemes:

the pump comprises a pump cover, a motor body without a shaft seal, a rear cover (or other substitute parts) of the motor without the shaft seal, a radial subdivision structure (also called non-subdivision) of a pump body part, and an independent circulating pump body part which only comprises the pump cover; the installation scheme is that the outlet and the inlet of the pump cover are butted with a process pipeline, and the structural part of the motor shell without the shaft seal, which is close to one end of the pump body, serves as the rest structural parts (the rear pump cover) of the pump shell;

the scheme of four structural main parts comprises a pump cover, a connecting body, a motor body without a shaft seal, a rear cover (or other substitute parts) of the motor without the shaft seal, a radial subdivision structure (also called as non-subdivision) of the pump body part, and one end of the connecting body is butted with the pump cover, and the other end of the connecting body is butted with the shielding motor body.

The electric pump without shaft seal according to the present invention may further comprise other auxiliary components such as an integrated cooler, as required.

The electric pump without shaft seal according to the present invention may further comprise other auxiliary components such as an auxiliary circulating pump for a cooler, if necessary, for example, the present invention may be used in combination with the "high temperature fluid-shielded electric pump system with emergency circulation function of main motor coolant" of the invention patent application No. 201710588184.1.

The electric pump without the shaft seal can be provided with a cooling part or a cooling system of the electric pump body without the shaft seal.

The electric pump without the shaft seal, the motor and the pump body can share one integral base.

The arrangement position of the auxiliary liquid FZL input system of the electric pump without the shaft seal can be at any suitable position of any suitable main part, and can be at any suitable position in a pump body (generally not a pump cover part) or a connecting body or a motor body without the shaft seal or a rear cover plate of a motor chamber or a part used as the rear cover plate of the motor chamber.

The arrangement position of the lubricating liquid (also cooling liquid) EL input system of the shaft seal-free motor cavity of the shaft seal-free electric pump can be at any suitable position of any suitable main part, and is usually at a suitable position in the shaft seal-free motor body and is usually at one end of the shaft seal-free motor body far away from the pump body.

The shaft seal-free electric pump can add a back blade on the back of the main impeller for a medium containing particles, and has the function of timely discharging solid particles to prevent the solid particles from accumulating; meanwhile, the axial unbalanced force can be reduced, the abrasion damage speed of the arranged thrust bearing is favorably reduced, and the service life of the thrust bearing is favorably prolonged.

When the overflowing medium of the shaft seal-free electric pump is a high-concentration solid liquid, a wear-resistant bushing or a wear-resistant shell can be used for prolonging the service life of the overflowing part of the pump cavity.

The shaft seal-free electric pump can be provided with the auxiliary impeller on the motor part to drive cooling liquid in the motor cavity to circularly work, and the axial force generated by the auxiliary impeller can be used for balancing the axial force generated by part of pump impellers because the auxiliary impeller is coaxial with the main impeller.

The mounting mode of the electric pump without the shaft seal can be vertical arrangement or horizontal arrangement.

The installation mode of the vertical electric pump without the shaft seal can be that the motor is positioned above and the pump body is positioned below, or the motor is positioned below and the pump body is positioned above.

According to the installation mode of the vertical electric pump without the shaft seal, the motor is positioned below and the pump body is positioned above, so that the gas in a cavity of the motor and the cavity of the pump can be discharged conveniently, and the gas accumulation is prevented.

The impeller of the electric pump without the shaft seal is mainly in the form of a centrifugal pump impeller, the impeller can generate cavitation under certain working conditions, an inducer can be additionally arranged in front of the centrifugal impeller, and the cavitation erosion resistance of the pump is improved.

The electric pump without shaft seal can be combined with the technical proposal that a canned motor pump with two auxiliary liquid input systems is arranged under the application number of 201710063971.4.

The electric pump without shaft seal can combine the shielding motor of half-stroke external cooling chamber for the internal stator of the motor shell with application number 201710451303.9 and the technical proposal of the shielding electric pump.

The characteristic parts of the present invention are described below.

①K100＝0.50～0.70；

②K100＝0.30～0.50；

③K100＝0.20～0.30；

④K100＜0.20。

the total weight of the main medium 1F entering the pump KPUMP is 30-50%;

is less than 2 wt% of the total 1F of the main medium entering the pump KPUMP.

auxiliary liquid FZL which is flushing liquid CXY for the rear pump cavity KV;

firstly, horizontally arranging a pump shaft;

firstly, an erosion-resistant bushing;

② wear-resisting lining

Thirdly, corrosion-resistant lining;

fourthly, the thermal shock resistant bushing;

low temperature resistant lining.

firstly, an erosion-resistant bushing;

② wear-resisting lining

Thirdly, corrosion-resistant lining;

fourthly, the thermal shock resistant bushing;

low temperature resistant lining.

contains solid components;

② contains corrosive components;

③ containing a combustion component;

fourthly, toxic components are contained;

containing radioactive components;

sixthly, the volatile component is contained;

contains easily coagulated components;

eighthly, containing bubble liquid;

ninthly, high-temperature liquid;

low temperature liquid charge in the red cavity;

high-pressure liquid material.

The invention has the advantages that:

the flushing oil and the main medium can be discharged in a classified manner, so that the discharging purity of the flushing oil and the main medium is improved, the flushing oil is recovered or reused, and the pollution degree of the main medium is reduced;

the improved part of the pump body has simple structure and is convenient to manufacture, overhaul and replace;

the device can reduce the loss of flushing oil (such as wax oil) by about 0.3-0.4 ten thousand tons per year and has obvious benefit for the device with the yield of the coal liquefaction oil of 100 ten thousand tons per year;

the device can be applied to a new device and can also be applied to the reconstruction of the existing device (namely, the replacement or reconstruction of the pump).

Examples

The yield of coal liquefaction oil is 108 ten thousand tons/year, a bottom oil residue delivery pump of a KT tower of a coal hydrogenation direct liquefaction reaction process for generating oil, the liquefaction residue consists of 50 wt% of asphaltene and 50 wt% of solids (catalyst, coal ash and unconverted carbon), flushing oil is mixed oil of heavy diesel oil components and wax oil components separated from the oil generated in the reaction process of a hydrogen supply solvent oil hydrogenation device, the scheme that the conventional flushing oil is mixed into the materials of the liquefaction residue is adopted according to the conventional oil residue delivery pump PAST-KPUMP working mode, and the device operation is 7600 hours/year, and each pump consumes 400-600 kg/hour of flushing oil, namely 3040-4560 tons/year.

The conveying pump adopts a 2-stage impeller pump with the simplest structure, wherein a first-stage impeller is used as MS, a second-stage impeller is used as NS, most 1F enters 1P, and a small part of 1F enters 2P; the impeller arrangement scheme is single-side cantilever type arrangement; the concentration of flushing oil in the discharged material 2P is 25 wt%, the concentration of liquefaction residues is 75 wt%, and the flushing oil and the liquefaction residues are returned to the feeding middle or discharging middle of a vacuum tower KT feeding heating furnace tube KFP or a vacuum tower KT flash evaporation section to be separated by pressure reduction flash evaporation; the flushing oil enters heavy diesel oil XP100 and side wax oil XP200 at the top of a distillate tower KT of the vacuum tower and is recovered; the heavy diesel oil XP100 and the side wax oil XP200 enter a hydrogenation device of the hydrogen supply solvent oil for cyclic reaction in the reaction process.

In this example, the main medium discharge 1P is used to transport the vast majority of the liquefied residue 1F, which is free of flushing oil.

Claims

1. A centrifugal pump of 2 or more stages using a final stage splitter main impeller, characterized by comprising:

2. The centrifugal pump of claim 1, wherein:

the centrifugal pump KPUMP, K100 value is selected from 1 in the following:

①K100＝0.50～0.70；

②K100＝0.30～0.50；

③K100＝0.20～0.30；

④K100＜0.20。

3. the centrifugal pump of claim 1, wherein:

the centrifugal pump KPUMP uses a 2-stage main impeller, a first-stage main impeller is used as a secondary final-stage main impeller MS, a second-stage main impeller is used as a splitter impeller NS, more than 50% of liquid main medium 1F enters the material flow 1P, and less than 50% of liquid main medium 1F enters the material flow 2P.

4. The centrifugal pump of claim 1, wherein:

the flow rate of the main medium in the material 2P discharged by the splitter impeller NS of the centrifugal pump KPUMP is selected from 1 of the following:

the total weight of the main medium 1F entering the pump KPUMP is 30-50%;

is less than 2 wt% of the total 1F of the main medium entering the pump KPUMP.

5. The centrifugal pump of claim 1, wherein:

the centrifugal pump KPUMP is provided with a multistage series-connected pressurized main impeller, and a discharge port HPN of an upstream main impeller discharge HP is arranged in a forward direction by taking a normal main flow path of a main medium as a reference;

6. The centrifugal pump of claim 1, wherein:

the number of the discharge ports of the centrifugal pump KPUMP and the liquid material 1P is 1 or 2 or more.

7. The centrifugal pump of claim 1, wherein:

the number of the discharge ports of the centrifugal pump KPUMP and the liquid material 2P is 1 or 2 or more.

8. The centrifugal pump of claim 1, wherein:

in the centrifugal pump KPUMP, back blades 64 are provided on the surface of the cover plate on the side of the splitter impeller NS close to the rear pump cover 30.

9. The centrifugal pump of claim 8, wherein:

centrifugal pump KPUMP, back vane 64, is a radial straight vane.

10. The centrifugal pump of claim 1, wherein:

the flow path of the external flushing liquid CKY of the centrifugal pump KPUMP before it is fed into the rear pump chamber KV is selected from one of the following:

11. The centrifugal pump of claim 1, wherein:

the prime mover at the drive end of centrifugal pump KPUMP is selected from 1 of the following:

12. The centrifugal pump of claim 1, wherein:

centrifugal pump KPUMP uses an external drive, with a pump shaft mechanical seal system.

13. The centrifugal pump of claim 1, wherein:

in the centrifugal pump KPUMP, at least one part of the pump shaft is exposed to the environment, and a pump shaft sealing system U80 for preventing the main medium from leaking to the environment is arranged on the pump shaft of the centrifugal pump.

14. The centrifugal pump of claim 13, wherein:

a centrifugal pump KPUMP, wherein flushing liquid CXY flows through the auxiliary impeller and then enters a pump cavity shell Q10;

15. The centrifugal pump of claim 1, wherein:

the centrifugal pump KPUMP is a shaft seal-free centrifugal pump and is selected from one of a shielding electric centrifugal pump, a submerged electric centrifugal pump and a magnetic centrifugal pump.

16. The centrifugal pump of claim 1, wherein:

the centrifugal pump KPUMP is a shaftless electric centrifugal pump and is provided with an auxiliary liquid FZL input system;

auxiliary liquid FZL which is flushing liquid CXY for the rear pump cavity KV;

17. The centrifugal pump of claim 1, wherein:

18. The centrifugal pump of claim 1, wherein:

the arrangement mode of the centrifugal pump KPUMP is selected from 1 of the following modes:

firstly, horizontally arranging a pump shaft;

19. The centrifugal pump of claim 1, wherein:

centrifugal pump KPUMP, inside pump chamber shell Q10 a chamber wall liner is arranged, the purpose of which is selected from 1 or several of the following:

firstly, an erosion-resistant bushing;

② wear-resisting lining

Thirdly, corrosion-resistant lining;

fourthly, the thermal shock resistant bushing;

low temperature resistant lining.

20. The centrifugal pump of claim 1, wherein:

centrifugal pump KPUMP, the use of a liner arranged in the pump chamber housing Q10 on the inner wall of a liquid inlet pipe and/or a liner arranged on the inner wall of a liquid outlet pipe, selected from 1 or several of the following:

firstly, an erosion-resistant bushing;

② wear-resisting lining

Thirdly, corrosion-resistant lining;

fourthly, the thermal shock resistant bushing;

low temperature resistant lining.

21. The centrifugal pump of claim 1, wherein:

the centrifugal pump KPUMP, the inlet of the first-stage main impeller is provided with an inducer.

22. The centrifugal pump of claim 1, wherein:

the centrifugal pump KPUMP has a pump shaft arranged in a single-side cantilever type manner.

23. The centrifugal pump of claim 1, wherein:

the main medium conveyed by the centrifugal pump KPUMP is provided with 1 or more of the following media:

contains solid components;

② contains corrosive components;

③ containing a combustion component;

fourthly, toxic components are contained;

containing radioactive components;

sixthly, the volatile component is contained;

contains easily coagulated components;

eighthly, containing bubble liquid;

ninthly, high-temperature liquid;

low temperature liquid charge in the red cavity;

high-pressure liquid material.

24. The centrifugal pump of claim 1, wherein:

the operating conditions of the centrifugal pump KPUMP are selected from 1 or more of the following:

25. The centrifugal pump of claim 1, wherein:

the main medium 1F conveyed by the centrifugal pump KPUMP is oil residue at the bottom of a KT tower of a reduced pressure fractionating tower for directly liquefying R10 by hydrogenation of heavy hydrocarbon; the direction of the material 2P discharged by the splitter impeller NS of the transfer pump KPUMP is selected from 1 of the following: