CN113389739A

CN113389739A - Direct-current permanent magnet type self-suction composite shield pump with gas-liquid mixing cavity

Info

Publication number: CN113389739A
Application number: CN202110758493.5A
Authority: CN
Inventors: 陈荣国
Original assignee: Individual
Current assignee: Individual
Priority date: 2021-07-05
Filing date: 2021-07-05
Publication date: 2021-09-14
Anticipated expiration: 2041-07-05
Also published as: CN113389739B

Abstract

The invention discloses a direct-current permanent magnet type self-priming composite shield pump with a gas-liquid mixing cavity. The centrifugal booster pump comprises a pump inlet, a gas-liquid mixing cavity, a centrifugal end, a buffer boosting cavity, a gas-liquid separation chamber and a pump outlet, wherein the pump inlet is connected with the inlet of the gas-liquid mixing cavity; the buffer pressurizing cavity is used for rapidly decelerating and pressurizing the high-speed pressurized fluid at the outlet of the centrifugal end; in the exhaust self-priming stage, the flow velocity of gas-liquid mixed fluid is reduced, and meanwhile, the bubble breakage is reduced; in the non-exhaust stage, the flow resistance is reduced, the pressure loss is reduced, and simultaneously the buffer pressurization of the fluid at the outlet of the centrifugal end is realized. The invention adopts the direct current permanent magnet motor to combine the gas-liquid mixing cavity and the shield pump, so that the shield pump has the characteristics of strong self-absorption and good hydraulic property, the spatial position and the internal structure of the buffer pressurizing cavity are skillfully arranged, and the technical problem of difficult gas-liquid separation caused by serious bubble breakage in the composite shield pump at high rotating speed is effectively solved.

Description

Direct-current permanent magnet type self-suction composite shield pump with gas-liquid mixing cavity

Technical Field

The invention relates to a self-priming composite canned motor pump, in particular to a direct-current permanent magnet type self-priming composite canned motor pump with a gas-liquid mixing cavity, and belongs to the field of fluid machinery.

Background

As is known, a shield pump is a pump with a full-static sealing structure, no leakage risk and high reliability, can be very small in size, has the advantage of ultra-strong silence, is widely applied to various fields such as chemical industry, civil water supply and drainage, household appliance matching and the like, particularly plays a key technical support role in conveying fluid media such as precious, flammable and explosive, radioactive, corrosive and the like, has huge requirements on wall-mounted furnaces and water heaters in recent years, and the incomplete statistics of the product output value of the two fields in China breaks through 20 hundred million. The canned motor pump has a unique structure, the motor and the pump body can be partially sealed in a certain canned motor pump cavity, pumping media fill the inner wall of the pump cavity, and the canned motor pump is free of a dynamic sealing element in the whole structure and safe in operation. Meanwhile, the circulating medium can effectively solve the problem of motor temperature rise, a motor cooling fan is not needed, the noise of a shield pump is reduced, and the circulating medium has very strong product competitiveness in the scenes with mute requirements of household appliances, hospital detection instruments and the like.

The shield pump is used as a no-dynamic seal pump, a pump impeller is fixedly connected with a shield motor rotor and is sealed in a shield pump cavity filled with a pumped medium, only a static seal is arranged in a pump body of the shield pump, and a wire winding provides a rotating magnetic field and drives the rotor. Nevertheless, most of the existing canned motor pumps do not have a self-priming function, the existing ejector structure of the injection pump is directly adopted for realizing self-priming, and the technical scheme that a centrifugal impeller is driven by a conventional asynchronous motor is adopted, but the problems that the energy conversion rate is reduced, the temperature of the asynchronous motor is increased and the like are caused by the structures of the majority of the ejectors, the efficiency of the self-priming canned motor pumps is seriously reduced, and in order to make up for the performance reduction of the composite canned motor pumps caused by the efficiency loss, a larger-power motor and an impeller with a larger diameter are generally required to be replaced, so that the efficient popularization in engineering is difficult. The current dilemma is how to improve the hydraulic efficiency of the shield pump, and simultaneously, the shield pump has a basic self-absorption function and keeps the advantages of original ultra-silence.

Disclosure of Invention

Aiming at the problems that most existing canned motor pumps do not have self-suction or have weak suction and limited energy efficiency, the invention aims to provide a direct-current permanent magnet type self-suction composite canned motor pump which has the advantages of self-suction, outstanding performance such as flow, lift, suction lift and the like, strong safety and compact structure.

In order to achieve the purpose, the invention adopts the technical scheme that:

the composite shield pump comprises a pump inlet, a gas-liquid mixing cavity, a centrifugal end, a buffer pressurizing cavity, a gas-liquid separation chamber and a pump outlet, wherein the pump inlet is connected with the inlet of the gas-liquid mixing cavity;

the centrifugal end specifically comprises a direct-current permanent magnet motor, a centrifugal impeller and a centrifugal water pressurizing chamber, the centrifugal impeller is positioned in the centrifugal water pressurizing chamber and is connected with a rotor of the direct-current permanent magnet motor, and the rotor of the direct-current permanent magnet motor is isolated from a stator through a shielding sleeve; the maximum rotating speed of the direct current permanent magnet motor at least reaches 3600 revolutions per minute;

the buffer pressurizing cavity is used for rapidly decelerating and pressurizing the high-speed pressurized fluid at the outlet of the centrifugal end; in the exhaust self-priming stage, the flow velocity of gas-liquid mixed fluid is reduced, and meanwhile, the bubble breakage is reduced; in the non-exhaust stage, the flow pressure loss is reduced, and simultaneously the buffering pressurization of the fluid at the outlet of the centrifugal end is realized.

The gas-liquid mixing cavity is provided with a backflow hole and is communicated with the gas-liquid separation chamber through the backflow hole.

Further, the outlets of the buffer pressurizing cavities are distributed along the circumferential direction or the radial direction in a plane, or the pores are arranged in space.

Furthermore, the buffer pressurizing cavity is a porous single-layer plate, a porous laminated plate series structure, a porous space structure, a porous medium filling structure, a single circuitous flow passage combined structure or a plurality of circuitous flow passages combined structure.

Furthermore, a fixed or rotary guide vane is additionally arranged in the buffering pressurization cavity of the multi-pore laminate series structure, or an inlet and an outlet of the buffering pressurization cavity are set as rotatable guide vanes.

Further, the buffer pressurizing cavity and the centrifugal impeller are distributed up and down or concentrically. When the centrifugal end is distributed up and down, the outlet of the centrifugal end is communicated with the buffer pressurizing cavity through the flow guide cavity.

Furthermore, a check valve is arranged at the position of a backflow hole of the gas-liquid mixing cavity, when the self-priming stage of the composite canned motor pump is finished, the check valve is closed under the driving of the internal and external pressure difference of the gas-liquid mixing cavity, liquid in the gas-liquid separation chamber cannot enter the gas-liquid mixing cavity through the position of the backflow hole, and the internal circulation flow of the pump is stopped.

Furthermore, at least one buffer pressurizing cavity, at least one centrifugal end and at least one centrifugal end outlet are formed.

The invention also provides a combined self-suction type composite shield pump, which comprises the self-suction type composite shield pump and at least one centrifugal pump, wherein inlets of the self-suction type composite shield pump and the centrifugal pump are connected in parallel, and outlets of the self-suction type composite shield pump and the centrifugal pump are connected in parallel.

By adopting the technical scheme, the invention has the beneficial effects that:

1. compare the big impeller of traditional asynchronous machine cooperation and the drawback that the ejector can only solve the compound pump from inhaling the performance and can't solve efficiency, direct current permanent-magnet machine makes things convenient for compound canned motor pump intelligent control and performance monitoring, high rotational speed centrifugation leaflet wheel utilizes the form of high rotational speed cooperation direct current motor, and complete machine power is little when reaching with the performance equivalence ability of traditional compound canned motor pump, and operating efficiency is high, improves the water pump efficiency and compromises performance and security simultaneously, and easily realizes miniaturation, has high market value.

2. The direct-current permanent magnet motor is combined with the characteristics of the gas-liquid mixing cavity and the shielding pump, so that the shielding pump has the functions of strong self-suction, good hydraulic characteristics, energy conservation and cavitation resistance, the spatial position and the internal structure of the buffering pressurization cavity are ingeniously arranged, and the technical problem that gas-liquid separation is difficult due to serious bubble breakage in the composite shielding pump at a high rotating speed is effectively solved.

3. The buffer pressurizing cavity has various structural forms, convenient material taking and low cost ratio, but can greatly improve the gas-liquid separation capacity in the pump and realize the strong self-absorption performance of the canned motor pump.

4. Fixed or rotary type stator can be add to the buffering pressure boost intracavity, perhaps changes buffering pressure boost chamber structure, imports and exports the buffering chamber and sets up to the rotary type stator, further strengthens buffering pressure boost effect.

5. The centrifugal end is independently provided with a centrifugal impeller, a centrifugal pumping chamber and a direct-current permanent magnet motor, and according to different application requirements, one or more pumps are connected in parallel at the inlet end of the pump, so that the self-priming composite shield pump with higher performance can be combined as required.

6. The inlet position of the backflow hole of the gas-liquid mixing cavity can be provided with a check valve or an elastic separation blade, when in a self-priming working stage, the check valve or the elastic separation blade is in an open state, and liquid in the gas-liquid separation chamber flows into the gas-liquid mixing cavity through the position of the backflow hole, so that the gas-liquid mixing process is completed; during the working phase, check valve or elasticity separation blade are closed, and the liquid in the gas-liquid separation chamber can't flow into the gas-liquid mixture cavity through backward flow hole position again, can further promote the working phase efficiency.

7. The composite shield pump can balance the pump performance and the specific requirements of gas-liquid separation according to actual needs, and the number of the buffer pressurizing cavities is not limited to one.

8. The self-priming centrifugal pump structure keeps the characteristics of a shield pump mechanism without dynamic seal, is suitable for pumping corrosive, toxic, harmful and flammable media, and has extremely high safety by adopting a low-voltage direct-current motor.

9. The self-priming composite canned motor pump comprises a gas-liquid mixing cavity, a centrifugal impeller, a centrifugal pumping chamber, a buffer pressurizing cavity, a gas-liquid separation chamber and the like, is compact in structure, small in size and high in integration level, skillfully combines the advantages of a canned motor pump and the gas-liquid mixing cavity, and can cover the requirements of various civil pumps and industrial pumps at present.

Drawings

FIG. 1 is a schematic longitudinal sectional view of a composite canned motor pump configuration;

FIG. 2 is a sectional view of a part of the structure of the composite canned motor pump;

FIG. 3 is a schematic overall view of a compound canned motor pump;

FIG. 4a is a schematic flow direction cross-sectional view of a flow guide cavity;

fig. 4b is a schematic partial cross-sectional view of a flow guide cavity;

FIG. 5 is a schematic sectional view of a primary buffer chamber of a buffer pressurizing chamber with a multi-pore laminate series structure;

FIG. 6 is a schematic sectional view of a secondary buffer chamber of a buffer pressurizing chamber with a multi-pore laminate series structure;

FIG. 7a is a schematic diagram of a configuration in which the buffer plenum fill media is spherical particles;

FIG. 7b is a schematic view of a filling structure of a buffer pressurizing cavity with a wire-mesh multi-gap laminate;

FIG. 7c is a schematic view of a buffer plenum employing an irregular particle multi-void fill configuration;

FIG. 8 is a schematic view of a partial cross-sectional structure of a gas-liquid mixing chamber of the compound pump;

FIG. 9a is a schematic diagram of a centrifuge tip configuration;

FIG. 9b is a schematic structural diagram of a DC permanent magnet motor;

FIG. 10 is a flow diagram of a self-priming stage of a compound canned motor pump;

FIG. 11 is a schematic flow diagram of a composite canned motor pump at an operating stage;

FIG. 12 is a structural diagram illustrating the open state of the check valve at the inlet of the return hole of the gas-liquid mixing chamber;

FIG. 13 is a schematic structural view showing a closed state of an inlet check valve of a return hole of a gas-liquid mixing chamber;

FIG. 14 is a schematic structural view of an open state of a check elastic retaining sheet at an inlet of a return hole of a gas-liquid mixing cavity;

FIG. 15 is a schematic structural view of a gas-liquid mixing chamber return hole inlet check elastic retaining sheet in a closed state;

FIG. 16 is a schematic view of the concentric arrangement of the buffer plenum and the centrifugal end;

FIG. 17 is a schematic view of the internal flow of the buffer plenum and the centrifugal end concentrically arranged;

fig. 18 is a schematic diagram of a parallel structure of a compound canned motor pump and a centrifugal pump.

Detailed Description

In order to make those skilled in the art better understand the technical solution of the present invention, the following will make clear and complete description of the technical solution of the present invention with reference to the drawings in the present application, and it is obvious that the description is only a part of the embodiments of the present invention, not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the invention without making creative efforts, shall fall within the protection scope of the invention.

In contrast, the direct-current permanent magnet motor is adopted, the overall size of the pump body is reduced by greatly reducing the centrifugal impeller and increasing the rotating speed of the motor, and the overall performance of the pump is ensured to meet the actual application requirement. By utilizing the reasonable configuration of the gas-liquid mixing cavity and the buffer pressurizing cavity, the self-priming function of the composite shield pump is realized, and meanwhile, higher hydraulic efficiency is obtained. Meanwhile, compared with the traditional asynchronous motor, the direct current permanent magnet motor has extremely high safety, and even if electricity is leaked, the direct current permanent magnet motor has no fatal damage to a human body; the composite shield pump can be self-priming, has small overall size and compact structure, has outstanding product advantages and has wide market prospect.

The composite shield pump comprises a pump inlet, a gas-liquid mixing cavity, a centrifugal end, a buffer pressurizing cavity, a gas-liquid separation chamber and a pump outlet; the gas-liquid mixing cavity consists of a gas-liquid mixing cavity inlet, a gas-liquid mixing cavity, a backflow hole and a gas-liquid mixing cavity outlet, and the position of the backflow hole can be additionally provided with a check valve or an elastic retaining sheet; the centrifugal end comprises a centrifugal impeller, a centrifugal guide vane, a centrifugal water pressing chamber and a direct-current permanent magnet motor, and the maximum rotating speed of the direct-current permanent magnet motor at least reaches 3600 revolutions per minute; the inlet of the pump is connected with the inlet of the gas-liquid mixing cavity, the outlet of the gas-liquid mixing cavity is connected with the inlet of the centrifugal end, the outlet of the centrifugal end is communicated with the inlet of the buffer pressurizing cavity, the outlet of the buffer pressurizing cavity is communicated with the gas-liquid separating chamber, and the gas-liquid separating chamber is communicated with the outlet of the pump; the centrifugal impeller is connected with the motor rotor, the motor rotor is isolated from the stator through the shielding sleeve, and the whole pump is free of dynamic seal.

The buffer pressurizing cavity is a flow channel for rapidly decelerating and pressurizing the high-speed pressure fluid at the outlet of the centrifugal end, so that the flow speed of the gas-liquid mixed fluid is effectively reduced and the bubble breakage is reduced at the exhaust self-suction stage, and the buffer pressurizing of the fluid at the outlet of the centrifugal end is realized at the non-exhaust stage while the flow resistance is effectively reduced and the pressure loss is reduced.

The buffer pressurizing cavity is relatively independent from the gas-liquid separation chamber, and only the outlet of the buffer pressurizing cavity is connected with the gas-liquid separation chamber.

The outlets of the buffer pressurizing cavity can be distributed in a plurality of ways such as arrangement of pores along the circumferential direction, the radial direction or a certain space region, and the number of the outlets is not less than one.

The buffer pressurizing cavity can be a flow channel which can simultaneously reduce bubble breakage and efficiently buffer pressurizing, such as a multi-hole laminate series structure, an irregular multi-hole plane, a multi-hole space structure, a multi-hole medium filling structure, a single or a structure formed by combining a plurality of circuitous flow channels and the like.

Fixed or rotary guide vanes can be additionally arranged in the buffering pressurization cavity of the multi-pore laminate series structure, or the inlet and the outlet of the buffering pressurization cavity are set as rotatable guide vanes.

The buffer pressurizing cavity and the centrifugal impeller are distributed up and down or concentrically. When the centrifugal end is distributed up and down, the outlet of the centrifugal end is communicated with the buffer pressurizing cavity through the flow guide cavity.

The direct current permanent magnet motor mainly comprises a shielding sleeve, a stator, a rotor and a motor shaft, wherein the shielding sleeve isolates the motor rotor from the stator in a static sealing mode, and the rotor and an impeller directly run in a working medium.

The inlet position of the backflow hole of the gas-liquid mixing cavity can be provided with a check valve or an elastic retaining sheet, after the self-priming stage of the composite shield pump is finished, the check valve is closed under the driving of the internal and external pressure difference of the gas-liquid mixing cavity, liquid in the gas-liquid separation chamber can not enter the gas-liquid mixing cavity through the backflow hole, the internal circulation of the pump is stopped, and the efficiency is improved.

At least one buffer pressurizing cavity, at least one centrifugal end and at least one centrifugal end outlet.

The inlet of the gas-liquid mixing cavity can be simultaneously communicated with one or more pump inlets to form a parallel pump set, the exhaust is not influenced in the self-suction exhaust stage, the performance of the pump is improved in the non-self-suction normal working stage, and different application requirements are met.

The working process of the invention is as follows:

when the self-priming composite shield pump is in a self-priming exhaust stage, the pump and the driving motor are sealed in a composite shield pump cavity filled with a pumped medium, and pre-filled fluid is stored in the gas-liquid mixing cavity, the centrifugal end, the flow guide cavity, the buffer pressurizing cavity and the gas-liquid separation chamber. Compared with the traditional asynchronous motor, the direct-current permanent magnet motor with higher safety and efficiency is adopted, and although the direct-current permanent magnet motor drives fluid to obtain higher-speed working fluid, under the condition that both a centrifugal impeller and a pump cavity are reduced, the gas-liquid separation of the composite shield pump in a self-suction stage is more difficult, and the high-speed impeller is easily subjected to gas binding, so that the self-suction function of the composite shield pump is difficult to realize. Specifically, on one hand, the bubbles are easy to collide with the wall surface or an impeller and break under the high-speed flowing state, and then cannot freely float up and leave the water body in the pump; on the other hand, the impeller rotating at a high speed forms a very strong circumferential shear, bubbles are more easily broken in the impeller, and are clamped by the rapid reduction of the size of the bubbles and the high-speed flow in the pump, so that the bubbles float and leave the water body more difficultly, the gas-liquid separation is almost ineffective, and the composite shield pump cannot smoothly complete self-priming. Therefore, in order to avoid the problem of gas-liquid separation caused by the high rotating speed of the direct current permanent magnet motor, after the fluid mixed in the gas-liquid mixing cavity is driven by the centrifugal impeller at a high speed to do work, the fluid is firstly guided out by the centrifugal water pressurizing chamber and enters the buffer pressurizing cavity to be buffered and pressurized, so that bubbles in the pump in the self-priming stage can obtain longer free floating time to complete gas-liquid separation.

The buffer pressurizing cavity with the multi-pore double-layer plate series structure is provided with a certain arrangement of buffer fins, high-speed fluid is guided by the buffer fins of the primary buffer cavity, the speed of the high-speed fluid is rapidly reduced, the high-speed fluid is discharged from an outlet of the primary buffer cavity, the high-speed fluid flows into the secondary buffer cavity, the fluid medium is further decelerated, and the fluid medium is discharged from an outlet of the secondary buffer cavity. And the secondary stage enters a gas-liquid separation chamber or a next-stage buffer pressurizing cavity. The kinetic energy obtained by driving the fluid from the high-speed centrifugal impeller is effectively converted into potential energy in a multi-stage buffering mode, the speed reduction and pressurization of the working medium are completed, the hydraulic loss is reduced, and meanwhile the gas-liquid separation requirement is met.

The fluid flowing out of the outlet of the buffer pressurizing cavity directly enters the gas-liquid separation chamber, the speed of a fluid medium in the gas-liquid separation chamber is obviously reduced due to the functions of flow guiding and the buffer pressurizing cavity, the working fluid is fully retained in the gas-liquid separation chamber, and the gas-liquid separation of the compound pump is realized. If the buffer cavity is not arranged, the high-speed fluid after the direct-current permanent magnet motor drives the centrifugal impeller cannot be fully decelerated, so that gas-liquid separation cannot be completed, the air-bound phenomenon of the impeller is dominant, and self-absorption failure can be directly caused.

Meanwhile, in order to keep the compact structure and the better buffering effect of the composite canned motor pump, the secondary buffer cavity and the primary buffer cavity of the buffering pressurization cavity can be kept concentric, and the outlets of the secondary buffer cavity are distributed (uniformly or non-uniformly) along the circumferential direction, the radial direction or in a certain area of the cover plate of the secondary buffer cavity. Meanwhile, the buffer pressurizing cavity and the centrifugal end can be concentrically distributed, and the compactness of the whole structure can be effectively improved.

When the self-priming composite shield pump is in an actual working stage, fluid to be pumped in a pump inlet pipeline flows into a gas-liquid mixing cavity along an inlet of the composite pump, and high-speed working fluid which flows back from a backflow hole is mixed by the gas-liquid mixing cavity and then enters a centrifugal end; then, the part of the fluid is accelerated and pressurized by the centrifugal impeller to obtain higher speed and pressure, and then is discharged from the centrifugal pressurizing water chamber, enters the buffer pressurizing cavity for speed reduction and pressurization, and is discharged from an outlet of the buffer pressurizing cavity, so that the speed reduction and pressurization of the working medium are realized.

The fluid flowing out of the buffer pressurizing cavity enters the gas-liquid separation chamber, and a part of the fluid is discharged through the outlet of the composite pump to finish pumping the fluid; and the other part of the pressurized fluid which is not discharged out of the pump continuously and circularly flows in the gas-liquid separation chamber to provide working fluid for the return hole of the gas-liquid mixing chamber, and the working fluid is driven by the centrifugal end to do work again, so that the process is repeated, and the normal pumping of the fluid to be pumped by the composite shielding pump is realized. In the process, the buffer pressurizing cavity is required to effectively reduce the flow resistance and reduce the pressure loss, and simultaneously, the buffer pressurizing of the fluid at the outlet of the centrifugal end is realized (if the fluid with too high speed passes through the buffer pressurizing cavity, the kinetic energy is converted into pressure potential energy, if the buffer pressurizing cavity is not arranged, the energy dissipation is caused by strong impact, and the flow resistance can be reduced by reducing the speed, namely, the energy dissipation is reduced).

As an improvement, a check valve or an elastic baffle plate can be arranged at the position of a backflow hole of the gas-liquid mixing cavity, when a self-priming working stage begins, only pre-filled fluid circulates in the pump, continuous supplement of fluid to be pumped is avoided, the pressure difference between two sides of the check valve or the elastic baffle plate (the inner part of the gas-liquid mixing cavity and the gas-liquid separating chamber) is small, the check valve or the elastic baffle plate is in an open state under the action of spring elasticity, the elasticity of the elastic baffle plate or electromagnetic force, and liquid in the gas-liquid separating chamber flows into the gas-liquid mixing cavity through the position of the backflow hole, so that the gas-liquid mixing process is completed; along with the deepening of the self-priming stage, the pre-filled fluid in the pump is continuously acted by the processes of centrifugal impeller driving acting, buffer structure speed reduction and pressurization and the like, the pressure difference at two sides of a structure such as a check valve or an elastic retaining sheet is continuously increased until the self-priming stage is finished, and the check valve overcomes the action of spring force or electromagnetic force under the action of larger pressure difference and enters a closed state; at this time, the liquid in the gas-liquid separation chamber cannot enter the gas-liquid mixing chamber through the position of the backflow hole any more, and the internal circulation of the fluid in the pump is stopped. In the self-priming stage, disturbance of a high-rotation-speed centrifugal impeller on fluid at an inlet is utilized, fluid interface instability is pre-filled in a gas-liquid mixing cavity, effective entrainment is formed on gas in the gas-liquid mixing cavity, then the part of gas-liquid mixing fluid enters the inlet of the centrifugal end under the traction of the high-rotation-speed centrifugal impeller, the part of gas-liquid mixing fluid is pressurized and accelerated by the centrifugal impeller, and is decelerated and pressurized by a buffering pressurization cavity, and gas-liquid separation is completed in the gas-liquid separation, so that the self-priming function of the composite canned motor pump is realized; during the working stage, the liquid in the gas-liquid separation chamber does not flow back to the position of the backflow hole any more, and the liquid which completes the work is directly discharged through the outlet of the composite shielding pump. The self-priming function is realized by starting or stopping the working fluid of the backflow hole, and meanwhile, the internal circulation of the actual working stage is stopped, so that the hydraulic efficiency of the pump is effectively improved.

The invention adopts the direct-current permanent magnet high-speed motor, the small-size direct-current motor is adopted to drive the smaller centrifugal impeller due to high rotating speed, the whole size of the pump body is small, the efficiency problem of the conventional asynchronous motor is greatly improved by the direct-current permanent magnet motor, the rotating speed of the direct-current motor is improved (the highest rotating speed is more than 3600rpm and even can reach 10000 rpm), and the design of a gas-liquid mixing cavity, a flow guide and a buffer structure is matched, so that the self-priming function of the composite canned motor pump is realized, and meanwhile, higher hydraulic efficiency is obtained. Meanwhile, compared with the traditional asynchronous motor, the direct current permanent magnet motor has extremely high safety, when the direct current safe voltage of 36V or below is adopted, even if the direct current safe voltage leaks electricity, the direct current safe motor has no life threat to human bodies, and the composite shield pump has small integral size, compact structure and wide market application prospect.

The invention is further illustrated by the following examples in conjunction with the accompanying drawings:

as shown in fig. 1, 2 and 3, the composite canned motor pump with the multi-pore-layer plate series structure specifically includes a pump inlet 1, a gas-liquid mixing chamber 2, a centrifugal end, a diversion chamber 6, a buffer pressurization chamber 7, a gas-liquid separation chamber 8, a composite canned motor pump housing 10 and a pump outlet 9, the gas-liquid mixing chamber is composed of a gas-liquid mixing chamber inlet 201, a gas-liquid mixing chamber 202, a backflow hole 203 and a gas-liquid mixing chamber outlet 204 (fig. 8), the centrifugal end specifically includes a centrifugal impeller 3, a centrifugal water pressing chamber 11 and a direct current permanent magnet motor 5 (as shown in fig. 9a and 9 b), wherein a direct current permanent magnet motor rotor 503 is isolated from a stator 502 by a canned sleeve 501, the motor rotor 503 is fixedly connected with the centrifugal impeller 3 by a motor shaft 504, the direct current permanent magnet motor is provided with a motor housing 505, and the pump body is free of dynamic sealing. The inlet of the pump is connected with the inlet of the gas-liquid mixing cavity, the outlet of the gas-liquid mixing cavity is connected with the inlet of the centrifugal end, the outlet of the centrifugal end is connected with the inlet of the buffer pressurizing cavity, the outlet of the buffer pressurizing cavity is connected with the gas-liquid separation chamber, and the gas-liquid separation chamber is communicated with the outlet of the pump. The buffer pressurizing cavity and the centrifugal impeller are distributed up and down or concentrically (figure 16). When the centrifugal pump is distributed up and down, the outlet of the centrifugal end is connected with the buffer pressurizing cavity through the flow guide cavity.

As shown in fig. 4a and 4b, the diversion cavity 6 includes a diversion cavity bottom plate 6-1, a diversion cavity 6-2, and a diversion cavity enclosure plate 6-3; as shown in FIG. 5, the buffer pressurizing cavity of the multi-pore laminate series structure comprises a primary buffer cavity 7-1 and a secondary buffer cavity 7-2, wherein the primary buffer cavity comprises a primary buffer cavity inlet 7-100, buffer fins 7-101, a primary buffer bottom plate 7-102, a primary buffer cavity outlet 7-103, a primary buffer cavity outlet cover plate 7-104 and a primary buffer cavity 7-105; the secondary buffer chamber 7-2 comprises a secondary buffer chamber 7-201, a secondary buffer chamber cover plate 7-202 and a secondary buffer chamber outlet 7-203 (shown in fig. 6);

as shown in fig. 7, the buffer pressurizing cavity can have a plurality of pore medium filling structures for effectively reducing the flow rate of the fluid and achieving the effect of fluid pressurization, wherein fig. 7a shows that the filling medium is spherical particles, fig. 7b shows a mesh-like multi-gap laminate filling structure, and fig. 7c shows an irregular particle multi-gap filling structure.

When the self-priming composite shield pump is in a self-priming exhaust stage, the pump and the driving motor are sealed in a composite shield pump cavity filled with a pumped medium, and pre-filled fluid is stored in the gas-liquid mixing cavity, the centrifugal end, the flow guide cavity, the buffer pressurizing cavity and the gas-liquid separation chamber. The embodiment adopts the direct current permanent magnet motor with higher safety and efficiency, and compared with the traditional asynchronous motor, although the direct current permanent magnet motor drives the fluid to obtain the working fluid with higher speed, the gas-liquid separation of the composite canned motor pump is more difficult, the high-speed impeller is easily attached, and the self-absorption function of the composite canned motor pump cannot be realized.

Therefore, as shown in fig. 10, in order to avoid the problem of gas-liquid separation caused by the high rotation speed of the motor, after the fluid mixed in the gas-liquid mixing cavity is driven at a high speed by the centrifugal impeller, the fluid is firstly guided out by the centrifugal pumping chamber and enters the buffer pressurizing cavity for buffer pressurizing, so that the bubbles in the pump at the self-priming stage can obtain longer free floating time to complete gas-liquid separation. The buffer pressurizing cavity with the multi-pore double-layer plate series structure is provided with a certain arrangement of buffer fins, high-speed fluid is guided by the buffer fins of the primary buffer cavity, the speed of the high-speed fluid is rapidly reduced, the high-speed fluid is discharged from an outlet of the primary buffer cavity, the high-speed fluid flows into the secondary buffer cavity, the fluid medium is further decelerated, and the fluid medium is discharged from an outlet of the secondary buffer cavity. And the secondary stage enters a gas-liquid separation chamber or a next-stage buffer pressurizing cavity. The kinetic energy obtained by driving the fluid from the high-speed centrifugal impeller is effectively converted into potential energy in a multi-stage buffering mode, the speed reduction and pressurization of the working medium are completed, the hydraulic loss is reduced, and meanwhile the gas-liquid separation requirement is met.

The fluid flowing out of the outlet of the buffer pressurizing cavity directly enters the gas-liquid separation chamber, the speed of a fluid medium in the gas-liquid separation chamber is obviously reduced due to the functions of flow guiding and the buffer pressurizing cavity, the working fluid is fully retained in the gas-liquid separation chamber, and the gas-liquid separation of the compound pump is realized. If the buffer cavity is not arranged, the high-speed fluid after the direct-current permanent magnet motor drives the centrifugal impeller cannot be fully decelerated, so that gas-liquid separation cannot be completed, the air-bound phenomenon of the impeller is dominant, and self-absorption failure can be directly caused. Meanwhile, for example, in order to keep the compact structure and the better buffering effect of the composite canned motor pump, the secondary buffer cavity and the primary buffer cavity of the buffering pressurization cavity can be kept concentric, and the outlets of the secondary buffer cavity are distributed (uniformly or non-uniformly) along the circumferential direction, the radial direction or a certain area of the cover plate of the secondary buffer cavity. In addition, the buffer pressurizing cavities and the centrifugal end can be concentrically distributed (shown in figure 16), and the compactness of the whole structure can be effectively improved.

When the self-priming composite shield pump is in an actual working stage, as shown in the flow schematic diagrams of the working stages of the composite shield pump in fig. 11 and 17, fluid to be pumped in a pump inlet pipeline is sucked into a gas-liquid mixing cavity along an inlet of the composite pump, and the fluid and high-speed working fluid reflowing from a backflow hole enter a centrifugal end after being mixed by the gas-liquid mixing cavity; then, the part of the fluid is accelerated and pressurized by the centrifugal impeller to obtain higher speed and pressure, and then is discharged from the centrifugal pressurizing water chamber, enters the buffer pressurizing cavity for speed reduction and pressurization, and is discharged from an outlet of the buffer pressurizing cavity, so that the speed reduction and pressurization of the working medium are realized. The fluid flowing out of the buffer pressurizing cavity enters the gas-liquid separation chamber, and a part of the fluid is discharged through the outlet of the composite pump to finish pumping the fluid; and the other part of the pressurized fluid which is not discharged outside the pump continuously and circularly flows in the gas-liquid separation chamber to provide working fluid for a backflow hole of the gas-liquid mixing chamber, the liquid level in the gas-liquid mixing chamber is continuously unstable and continuously carries the fluid to be pumped in the pump inlet to enter the centrifugal end inlet, and the process is repeated so as to realize the normal pumping of the fluid to be pumped by the composite shielding pump. In the process, the buffer pressurizing cavity is required to effectively reduce the flow resistance and reduce the pressure loss, and simultaneously, the buffer pressurizing of the fluid at the outlet of the centrifugal end is realized.

As shown in fig. 12 and 14, a check valve 12 or an elastic baffle 13 may be disposed at the position of the backflow hole of the gas-liquid mixing chamber, when the self-priming operation phase begins, only the pre-filled fluid circulates in the pump, and the fluid to be pumped is not continuously supplemented, the pressure difference between two sides of the check valve or the elastic baffle (the inside of the gas-liquid mixing chamber and the gas-liquid separating chamber) is small, the check valve or the elastic baffle is in an open state under the action of the spring force, the elastic force of the elastic baffle or the electromagnetic force, and the liquid in the gas-liquid separating chamber flows into the gas-liquid mixing chamber through the position of the backflow hole, so that the gas-liquid mixing process is completed; along with the deepening of the self-priming stage, the pre-filled fluid in the pump is continuously acted by the processes of centrifugal impeller driving acting, buffer structure speed reduction and pressurization and the like, the pressure difference at two sides of a structure such as a check valve or an elastic retaining sheet is continuously increased until the self-priming stage is finished, and the check valve overcomes the action of spring force or electromagnetic force under the action of larger pressure difference and enters a closed state; as shown in fig. 13 and 15, when the check valve or the elastic stopper is in the closed state, the liquid in the gas-liquid separation chamber cannot enter the gas-liquid mixing chamber any more through the position of the return hole, and the internal circulation of the fluid in the pump is stopped. In the self-priming stage, disturbance of a high-rotation-speed centrifugal impeller on fluid at an inlet is utilized, fluid interface instability is pre-filled in a gas-liquid mixing cavity, effective entrainment is formed on gas in the gas-liquid mixing cavity, then the part of gas-liquid mixing fluid enters the inlet of the centrifugal end under the traction of the high-rotation-speed centrifugal impeller, the part of gas-liquid mixing fluid is pressurized and accelerated by the centrifugal impeller, and is decelerated and pressurized by a buffering pressurization cavity, and gas-liquid separation is completed in the gas-liquid separation, so that the self-priming function of the composite canned motor pump is realized; during the working stage, the liquid in the gas-liquid separation chamber does not flow back to the position of the backflow hole any more, and the liquid which completes the work is directly discharged through the outlet of the composite shielding pump. The self-priming function is realized by starting or stopping the working fluid of the backflow hole, and meanwhile, the internal circulation of the actual working stage is stopped, so that the hydraulic efficiency of the pump is effectively improved.

As shown in fig. 18, the self-priming compound canned motor pump of the present invention can also form a pump stack 20 in a parallel configuration with a single centrifugal pump. The self-suction composite shield pump 203 and the centrifugal pump 206 share a pump set inlet 201 and a pump set outlet 202, namely the pump set inlet 201 is respectively communicated with a self-suction composite shield pump inlet 204 and a centrifugal pump inlet 207; the self-suction composite shield pump outlet 205 and the centrifugal pump outlet 208 are respectively communicated with the pump group outlet 202. The pump set does not influence the exhaust in the self-suction exhaust stage, improves the performance of the pump in the non-self-suction normal working stage and meets different application requirements.

In conclusion, the invention keeps the characteristics of compact integral structure and high integration degree of the canned motor pump, and simultaneously realizes gas-liquid separation and self-absorption of the canned motor pump under the high-rotating-speed working condition and improves the hydraulic characteristic of the canned motor pump by driving the centrifugal impeller by the direct-current permanent magnet motor and matching the buffer pressurizing cavity and the gas-liquid mixing cavity on the premise of not increasing the running noise of the canned motor pump, the maximum suction lift can reach more than 9m, and the technical problem of gas-liquid separation in a high-rotating-speed small pump cavity is solved.

While the invention has been described in connection with specific embodiments thereof, it will be understood that these should not be construed as limiting the scope of the invention, which is defined in the following claims, and any variations which fall within the scope of the claims are intended to be embraced thereby.

Claims

1. Direct current permanent magnetism formula is from inhaling compound canned motor pump with gas-liquid mixing chamber, including pump inlet, gas-liquid mixing chamber, centrifugation end, buffering pressure boost chamber, gas-liquid separation room and pump export, its characterized in that: the inlet of the pump is connected with the inlet of the gas-liquid mixing cavity, the outlet of the gas-liquid mixing cavity is connected with the inlet of the centrifugal end, the outlet of the centrifugal end is communicated with the inlet of the buffer pressurizing cavity, the outlet of the buffer pressurizing cavity is communicated with the gas-liquid separating chamber, and the gas-liquid separating chamber is communicated with the outlet of the pump;

the buffer pressurizing cavity is used for rapidly decelerating and pressurizing the high-speed pressurized fluid at the outlet of the centrifugal end; in the exhaust self-priming stage, the flow velocity of gas-liquid mixed fluid is reduced, and meanwhile, the bubble breakage is reduced; in the non-exhaust stage, the flow pressure loss is reduced, and simultaneously the buffering pressurization of the fluid at the outlet of the centrifugal end is realized;

2. The direct-current permanent magnet type self-priming composite canned pump with a gas-liquid mixing cavity according to claim 1, characterized in that: the outlets of the buffer pressurizing cavities are distributed along the circumferential direction or the radial direction in a plane, or pores are arranged in space.

3. The direct-current permanent magnet type self-priming composite canned pump with a gas-liquid mixing cavity according to claim 1, characterized in that: the buffer pressurizing cavity is a structure formed by connecting porous laminated plates in series, a porous space structure, a porous medium filling structure, a single roundabout flow channel combination structure or a structure formed by combining a plurality of roundabout flow channels.

4. The direct-current permanent magnet type self-priming composite canned pump with a gas-liquid mixing cavity according to claim 3, characterized in that: the multi-hole laminate series structure is characterized in that a fixed guide vane or a rotary guide vane is additionally arranged in the buffering pressurization cavity, or an inlet and an outlet of the buffering pressurization cavity are arranged into a rotatable guide vane.

5. The direct-current permanent magnet type self-priming composite canned pump with a gas-liquid mixing cavity according to claim 1, characterized in that: the buffer pressurizing cavity and the centrifugal impeller are distributed up and down or concentrically; when the centrifugal pump is distributed up and down, the outlet of the centrifugal end is communicated with the buffer pressurizing cavity through the flow guide cavity.

6. The direct-current permanent magnet type self-priming composite canned pump with a gas-liquid mixing cavity according to claim 1, characterized in that: and a check valve is arranged at the position of a backflow hole of the gas-liquid mixing cavity, after the self-priming stage of the composite shield pump is finished, the check valve is closed under the driving of the internal and external differential pressure of the gas-liquid mixing cavity, the liquid in the gas-liquid separation chamber cannot enter the gas-liquid mixing cavity through the position of the backflow hole, and the internal circulation flow of the pump is stopped.

7. The direct-current permanent magnet type self-priming composite canned pump with a gas-liquid mixing cavity according to claim 1, characterized in that: at least one buffer pressurizing cavity, at least one centrifugal end and at least one centrifugal end outlet.

8. A combined self priming compound canned motor pump comprising at least one self priming compound canned motor pump of any one of claims 1 to 7 and at least one centrifugal pump, characterized in that: the inlet of the self-suction type composite shield pump is connected with the inlet of the centrifugal pump in parallel, and the outlet of the self-suction type composite shield pump is connected with the outlet of the centrifugal pump in parallel.