CN215860823U

CN215860823U - Self-suction type multistage composite shield pump and combined type self-suction type multistage composite shield pump

Info

Publication number: CN215860823U
Application number: CN202122061162.4U
Authority: CN
Inventors: 陈荣国
Original assignee: Individual
Current assignee: Individual
Priority date: 2021-08-30
Filing date: 2021-08-30
Publication date: 2022-02-18
Anticipated expiration: 2031-08-30

Abstract

The utility model discloses a self-suction type multistage composite shield pump and a combined self-suction type multistage composite shield pump. The utility model introduces the secondary centrifugal end on the basis of the self-priming composite shield pump, and the introduction of the secondary centrifugal end can provide controlled negative pressure traction for the outlet of the primary centrifugal end and the primary gas-liquid separation chamber, thereby effectively improving the self-priming capability and the self-priming speed of the whole pump. In the self-suction stage, the negative pressure traction obviously enhances the flow of the bubbles in the primary gas-liquid separation chamber to the secondary centrifugal end, and then the bubbles are discharged from the outlet of the secondary centrifugal end through the pump outlet. The flow mechanism can reduce the retention of bubbles in the primary gas-liquid separation chamber and enhance the exhaust capacity of the primary shield; the self-priming capacity of the shield and the stability of the self-priming effect are thereby significantly enhanced.

Description

Self-suction type multistage composite shield pump and combined type self-suction type multistage composite shield pump

Technical Field

The utility model belongs to the field of fluid machinery, and particularly relates to a self-suction type multistage composite canned motor pump and a combined self-suction type multistage composite canned motor pump.

Background

The canned motor pump is a pump product with no dynamic sealing structure, no leakage risk and high reliability, and is widely applied to the fields of water supply and drainage, food engineering, chemical engineering, energy, hydraulic engineering, structural engineering and the like. The canned motor pump has unique structure, can seal the motor and the pump body part in a certain canned motor pump chamber, and pumping medium fills the pump chamber inner wall, and the overall structure does not have movable sealing member, and the operation is very safe. Therefore, the shielding pump is particularly suitable for pumping special fluid media such as expensive, inflammable and explosive, radioactive and corrosive media. The canned motor pump can effectively satisfy the motor heat dissipation through the inner loop of guide working medium, need not motor cooling fan, greatly reduced pump noise, make it can satisfy the ultralow noise requirement of domestic appliance, hospital's detecting instrument etc. market potential is huge.

The pump impeller is connected with a drive motor rotor and then sealed in a pump cavity of the canned motor pump, and usually a plurality of pairs of wire windings provide a rotating magnetic field and drive the rotor, so that the impeller is driven to do work; therefore, the canned motor pump has only a static seal, and although there are many advantages, most canned motor pumps do not have a self-priming function. In order to achieve self-priming, the ejector structure in the existing ejector pump is directly adopted in the shield pump, and the ejector structure is integrated into the pump body of the conventional shield pump. Considering that the structure of the ejector will cause the reduction of the energy conversion rate, and the tiny bubbles introduced by the ejector are easy to generate a low-pressure area and cavitation in the narrow heat dissipation flow channel of the canned motor pump, the efficiency and the silence of the self-priming canned motor pump with the structure are seriously influenced. On the other hand, the structure is sensitive to the rotating speed of the motor, when the rotating speed of the motor is too high, the speed of the bubbles in the pump cavity is obviously increased, and a considerable part of the bubbles cannot leave the liquid level and are retained in the pump cavity. The part of the retained bubbles are broken by means of fluid shearing, wall surface collision and the like under the drive of high-speed fluid in the pump to form bubbles with smaller size, so that the gas proportion of pre-filled fluid in the pump is rapidly increased in the self-priming process, the entrainment capacity of fluid in the pump at the inlet of the pump is greatly reduced, the gas-liquid separation is finally caused to be invalid, and the shield pump loses the self-priming function. Aiming at the problem of self-priming failure, the self-priming capability of the self-priming shield pump can be improved by additionally arranging a buffering pressurization unit in the pump. However, with the aid of the buffer pressurizing cavity, the introduction of the ejector can achieve self-priming of the canned pump, but the ejector generally increases the energy consumption of the pump, reduces the pump head and the flow rate, and a single ejector reduces the hydraulic efficiency of the pump by about 40%, even resulting in the performance of the ejector not meeting the actual requirement. In other words, the suction lift for self-priming is apparently a loss in head. This causes the shield pump head which originally would not be left free to lose effective pump performance after self-priming consumption; when a gas-liquid mixer similar to a self-priming centrifugal pump is used for realizing self-priming, the problem of insufficient performance cannot be avoided.

Disclosure of Invention

Aiming at the two problems that the existing self-priming canned motor pump is slow in self-priming speed and the pump performance cannot meet the actual requirement, the utility model aims to provide a self-priming multistage composite canned motor pump which has self-priming capability, excellent working performances such as flow, lift and suction lift, high safety and compact structure.

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

the self-priming multi-stage composite canned motor pump comprises a pump inlet, a self-priming device, a primary centrifugal end, a primary gas-liquid separation chamber, a secondary pump inlet, a secondary centrifugal end and a pump outlet;

the inlet of the pump is connected with the inlet of a self-priming device, the outlet of the self-priming device is connected with the inlet of a first-stage centrifugal end, and the outlet of the first-stage centrifugal end is communicated with a first-stage gas-liquid separation chamber; the primary gas-liquid separation chamber is connected with an inlet of a secondary pump, the inlet of the secondary pump is connected with an inlet of a secondary centrifugal end, and an outlet of the secondary centrifugal end is communicated with an outlet of the pump;

the first-stage centrifugal end comprises a first-stage motor, a first-stage centrifugal impeller and a first-stage centrifugal water pressurizing chamber, the first-stage centrifugal impeller is positioned in the first-stage centrifugal water pressurizing chamber and is connected with a rotor of the first-stage motor, and the rotor of the first-stage motor is isolated from a stator through a shielding sleeve;

the secondary centrifugal end comprises a secondary motor, a secondary centrifugal impeller and a secondary centrifugal pressurized-water chamber.

Furthermore, at least one secondary centrifugal end, at least one inlet of the secondary centrifugal end, at least one outlet of the secondary centrifugal end, at least one inlet of the primary centrifugal end, at least one outlet of the primary centrifugal end, at least one primary gas-liquid separation chamber and at least one self-priming device are arranged;

when a plurality of secondary centrifugal ends exist, according to the flowing direction, the outlet of the upstream secondary centrifugal end is connected with the inlet of the adjacent downstream secondary centrifugal end, namely, the two secondary centrifugal ends are connected in series, so that the lift is further improved; the outlet of the last stage secondary centrifugal end is communicated with the pump outlet, and the device also comprises a secondary gas-liquid separation chamber.

Furthermore, a buffer pressurizing cavity is arranged in the primary gas-liquid separation chamber and 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 buffer pressurizing cavity reduces the flow velocity of gas-liquid mixed fluid, simultaneously reduces the breakage of bubbles, enhances the fusion and increase of the bubbles in the buffer cavity, powerfully improves the gas-liquid separation capacity and enhances the self-priming; and in the non-exhaust stage, the pressure loss is controlled, and simultaneously the buffer pressurization of the outlet fluid of the first-stage centrifugal end is realized.

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

Furthermore, the buffer pressurizing cavity is of a multi-hole laminate series structure, a fixed guide vane or a rotary guide vane is additionally arranged in the buffer pressurizing cavity of the multi-hole laminate series structure, or an inlet and an outlet of the buffer pressurizing cavity are arranged to be rotatable guide vanes.

Furthermore, the buffer pressurizing cavity is 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, the self-priming device is an ejector or a gas-liquid mixer, and the self-priming device comprises at least one inlet and at least one outlet.

Furthermore, a check valve or an elastic separation blade is arranged at the position of a nozzle inlet of the ejector, when the self-priming stage of the composite shield pump is finished, the check valve or the elastic separation blade is closed under the driving of the internal and external pressure difference of the ejector, liquid in the gas-liquid separation chamber cannot enter the ejector through the position of the nozzle any more, and the internal circulation flow of the pump is stopped.

Furthermore, a check valve or an elastic retaining sheet is arranged at a return hole of the gas-liquid mixer, 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 mixer, the liquid in the gas-liquid separation chamber can not enter the gas-liquid mixer through the return hole, and the internal circulation flow of the pump is stopped.

The utility model provides a modular from inhaling formula multistage composite shield pump, includes at least one inhale formula multistage composite shield pump and at least one centrifugal pump, inhale formula multistage composite shield pump arbitrary level centrifugal end import and centrifugal pump's import and connect in parallel, inhale formula composite shield pump export and centrifugal pump's export and connect in parallel.

By adopting the technical scheme, the utility model has the beneficial effects that:

1. compared with a single-stage self-suction type shielding composite pump, the self-suction type multi-stage shielding composite pump breaks through the performance limitation of the self-suction type single-stage shielding composite pump, solves the problem that the low-power single-stage shielding composite pump has low lift after suction lift, and widens the application. Can combine the shielding compound pump that accords with actual flow, lift requirement according to different market demands, remain simultaneously and be based on the advantage from inhaling formula shielding compound pump: low noise, miniaturization, compact structure, high efficiency of the whole pump, high reliability, high safety and the like, and has practical and market values, strong market competitiveness and applicability of products.

2. The introduction of the secondary centrifugal end can provide a controlled negative pressure traction for the outlet of the primary centrifugal end and the primary gas-liquid separation chamber, so that the self-priming capacity and the self-priming speed of the whole pump are effectively improved. In the self-suction stage, the negative pressure traction obviously enhances the flow of the bubbles in the primary gas-liquid separation chamber to the secondary centrifugal end, and then the bubbles are discharged from the outlet of the secondary centrifugal end through the pump outlet. The flow mechanism can reduce the retention of bubbles in the primary gas-liquid separation chamber and enhance the exhaust capacity of the primary pump; the self-priming capacity and the stability of the self-priming effect of the entire pump are thereby significantly enhanced.

3. The gas-liquid separation chamber can be additionally arranged in other secondary pumps behind the first-stage gas-liquid separation chamber, the buffer pressurizing cavity is additionally arranged, the layout and the internal structure of the buffer pressurizing cavity in the multistage pump are ingeniously arranged, the technical problem that the gas-liquid separation is difficult due to serious bubble breakage in the composite shielding pump at a high rotating speed is effectively solved, even the fusion of bubbles in the buffer pressurizing cavity can be enhanced, and the self-absorption and cavitation resistance of the shielding pump are further improved.

4. The centrifugal end is independently provided with a centrifugal impeller, a centrifugal pumping chamber and a motor, and the self-priming composite shield pump with various performance specifications can be flexibly combined as required by connecting one or more pumps in parallel at the inlet end of the pump according to different performance specification requirements.

5. Check valve or elasticity separation blade can be arranged to self-priming ware working fluid entry position, and during the self-priming working phase, check valve or elasticity separation blade are in the open mode, and the inside liquid of gas-liquid separation room flows into the self-priming ware through self-priming ware working fluid entry, accomplishes the gas-liquid mixture process in the self-priming ware intracavity. During the working phase, check valve or elasticity separation blade are closed, and the liquid in the gas-liquid separation chamber can't get into self priming ware again, and the pump inner loop stops, can further promote working phase hydraulic efficiency.

6. The multistage composite canned motor pump can balance pump performance and specific requirements of gas-liquid separation according to actual needs, and is provided with a plurality of buffer pressurizing cavities.

7. The self-priming centrifugal pump structure keeps the characteristics of a shield pump mechanism without dynamic seal, is high in silence, is suitable for pumping corrosive, toxic, harmful and flammable media, can adopt a low-voltage direct-current permanent magnet motor, and has extremely high safety.

8. The self-suction type multistage composite canned motor pump is formed by combining a first-stage canned motor pump and other stages of centrifugal pumps, has compact structure, small volume, high integration level and good interchangeability, skillfully combines the self-suction capabilities of the canned motor pump and the self-suction pump, complements the advantages of the canned motor pump and the self-suction pump, and can cover the requirements of various civil pumps and industrial pumps at present.

Drawings

FIG. 1 is a schematic overall view of a two-stage compound canned motor pump;

FIG. 2a is a schematic longitudinal sectional view of a two-stage composite canned motor pump without a secondary gas-liquid separation chamber when the self-primer is an ejector;

FIG. 2b is a schematic longitudinal sectional view of a two-stage composite canned motor pump with a secondary gas-liquid separation chamber when the self-priming device is an ejector

FIG. 2c is a schematic longitudinal sectional view of a two-stage composite canned motor pump with a secondary gas-liquid separation chamber when the self-priming device is a gas-liquid mixer

FIG. 3 is a sectional view of a partial structure of a primary centrifugal end and a secondary centrifugal end of the two-stage composite shield pump;

FIG. 4 is a sectional view of a primary-stage DC permanent magnet motor and a schematic view of a multi-pore laminate series-structured buffer pressurizing cavity;

FIG. 5a is a schematic diagram of a structure in which the filling medium of the buffer pressurizing cavity is spherical particles;

FIG. 5b is a schematic view of a filling structure of a wire-mesh-shaped multi-gap laminate for a buffer pressurizing cavity;

FIG. 5c is a schematic view of a buffer plenum employing an irregular particle multi-void fill configuration;

FIG. 6 is a cross-sectional view of a secondary DC permanent magnet motor;

FIG. 7a is a schematic longitudinal cross-sectional view of a two-stage compound canned motor pump with a resilient flap at the inlet of the ejector;

FIG. 7b is a schematic longitudinal cross-sectional view of a two-stage compound canned motor pump configuration with a check valve at the inlet of the injector;

FIG. 8a is a schematic view of an injector with a spring flap

FIG. 8b is a schematic view of the open state of the check spring plate at the inlet of the injector nozzle and its structural section;

FIG. 8c is a schematic cross-sectional view of the injector nozzle inlet check spring flap closed and its structure;

FIG. 9a is a schematic view of an injector with a check valve in its entirety

FIG. 9b is a schematic cross-sectional view of the injector nozzle inlet check valve in an open position and its configuration;

FIG. 9c is a schematic cross-sectional view of the injector nozzle inlet check valve in its closed position and its configuration;

FIG. 10a is a longitudinal sectional view of a two-stage composite canned motor pump with an elastic baffle at the reflux hole of the gas-liquid separator;

FIG. 10b is a schematic longitudinal sectional view of a two-stage compound canned motor pump with a check valve at the return orifice of the gas-liquid separator;

FIG. 11a is the overall view of a gas-liquid mixer with a check elastic baffle

FIG. 11b is a schematic sectional view of an opened state of a check elastic retaining sheet of a backflow hole of a gas-liquid mixer and a structure thereof;

FIG. 11c is a schematic sectional view of a check elastic baffle of a backflow hole of a gas-liquid mixer in a closed state and its structure;

FIG. 12a is an overall view of a gas-liquid mixer with a check valve

FIG. 12b is a schematic sectional view of the check valve of the backflow hole of the gas-liquid mixer in an open state and its structure;

FIG. 12c is a cross-sectional view of the check valve of the backflow hole of the gas-liquid mixer in a closed state and its structure;

FIG. 13 is a schematic view of a parallel structure of a self-priming multi-stage composite canned motor pump and a centrifugal pump

FIG. 14a is a schematic flow diagram of a self-priming stage of a two-stage compound canned motor pump with a secondary gas-liquid separation chamber when the self-primer is an ejector;

FIG. 14b is a schematic flow diagram of the operating phase of a two-stage compound canned motor pump with a secondary gas-liquid separation chamber when the self-primer is an ejector;

FIG. 15a is a schematic flow diagram of a self-priming stage of a two-stage compound canned motor pump with a secondary gas-liquid separation chamber when the self-priming device is a gas-liquid mixer;

FIG. 15b is a schematic flow diagram of a working phase of a two-stage compound canned motor pump with a secondary gas-liquid separation chamber when the self-priming device is a gas-liquid mixer;

FIG. 16a is a schematic flow diagram of a self-priming stage of a two-stage compound canned motor pump without a secondary gas-liquid separation chamber when the self-primer is an ejector;

FIG. 16b is a schematic flow diagram of a working phase of a two-stage compound canned motor pump without a secondary gas-liquid separation chamber when the self-primer is an ejector;

FIG. 17 is a schematic view of buffering, decelerating and fusing real measurement images of bubbles in a pressurizing cavity at a self-priming stage;

FIG. 18 is a real image of the motion transients of the bubbles in the secondary pump during the self-priming phase.

Detailed Description

In order to make the technical solutions of the present invention better understood, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. Based on the embodiments of the utility model, all other embodiments obtained by a person skilled in the art without creative efforts shall fall within the protection scope of the utility model.

The composite shield pump comprises a pump inlet, a self-priming device, a primary centrifugal end, a primary gas-liquid separation chamber, a secondary pump inlet, a secondary centrifugal end and a pump outlet. The self-priming device can be implemented in the structural forms of an ejector, a gas-liquid mixer and the like. In one embodiment, the ejector consists of an ejector inlet, a nozzle, a throat and a diffusion section, wherein the inlet of the ejector nozzle can be additionally provided with a check valve or an elastic baffle plate; in another embodiment, the gas-liquid mixer consists of a gas-liquid mixer inlet, a gas-liquid mixing cavity, a backflow hole and a gas-liquid mixer outlet, and a check valve or an elastic retaining sheet can be additionally arranged at the backflow hole of the gas-liquid mixer. The first-stage centrifugal end comprises a first-stage motor, a first-stage centrifugal impeller and a first-stage centrifugal water pressurizing chamber, the first-stage centrifugal impeller is positioned in the first-stage centrifugal water pressurizing chamber and is connected with a rotor of the first-stage motor, and the rotor of the first-stage motor is isolated from a stator by a shielding sleeve; in one embodiment, the primary motor is a dc permanent magnet motor, and the maximum rotation speed of the dc permanent magnet motor reaches at least 3600 rpm. The secondary centrifugal end at least comprises a secondary centrifugal end inlet, a secondary centrifugal end outlet, a secondary motor, a secondary centrifugal impeller and a secondary centrifugal water pressing chamber.

The inlet of the pump is connected with the inlet of a self-priming device, the outlet of the self-priming device is connected with the inlet of a first-stage centrifugal end, and the outlet of the first-stage centrifugal end is communicated with a first-stage gas-liquid separation chamber; the primary gas-liquid separation chamber is connected with an inlet of a secondary pump, the inlet of the secondary pump is connected with an inlet of a secondary centrifugal end, and an outlet of the secondary centrifugal end is communicated with an outlet of the pump; the centrifugal impeller of the first-stage centrifugal end is connected with the first-stage motor rotor, the first-stage motor rotor is isolated from the stator through a 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, bubbles are reduced and broken while the flow speed of the gas-liquid mixed fluid is effectively reduced in the exhaust self-suction stage, and the buffer pressurizing of the fluid at the outlet of the centrifugal end is realized while the inertia dissipation is effectively reduced and the pressure loss is controlled in the non-exhaust stage.

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 porous single-layer plate, a porous plate series structure, an irregular porous plane, a porous space structure, a porous 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 are distributed concentrically, and when the buffer pressurizing cavity and the centrifugal impeller are distributed up and down, the outlet of the centrifugal end is communicated with the buffer pressurizing cavity through the flow guide cavity.

A check valve or an elastic retaining sheet can be arranged at the inlet position of the ejector nozzle or the return hole of the gas-liquid mixer, 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 ejector or the gas-liquid mixer, liquid in the gas-liquid separation chamber can not enter the self-priming device through the ejector nozzle or the return hole of the gas-liquid mixer, the internal circulation flow of the pump is stopped, and the efficiency is improved.

The centrifugal separator comprises at least one secondary centrifugal end, at least one inlet of the secondary centrifugal end, at least one outlet of the secondary centrifugal end, at least one inlet of the primary centrifugal end, at least one outlet of the primary centrifugal end, at least one primary gas-liquid separation chamber and at least one self-sucking device.

The secondary centrifugal ends can be provided with a plurality of combined self-absorption shielding compound pumps which are combined in series to form different performance specifications; when a plurality of secondary centrifugal ends exist, according to the flowing direction, the outlet of the upstream secondary centrifugal end is connected with the inlet of the adjacent downstream secondary centrifugal end, namely, the upstream centrifugal end and the downstream centrifugal end are connected in series, so that the lift is increased; the outlet of the last stage secondary centrifugal end is communicated with the outlet of the pump.

The inlet of the self-priming device can be simultaneously communicated with one or more pump inlets to form a parallel pump set; the centrifugal end inlet of any stage of the self-suction multi-stage composite shielding pump can be simultaneously communicated with one or more pump inlets, 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 utility model is as follows:

when the self-priming composite shield pump is in a self-priming exhaust stage, the pump and the primary motor are sealed in a composite shield pump cavity filled with a pumped medium, and a pre-filled fluid is stored in the self-priming device, the centrifugal end, the buffer pressurizing cavity and the gas-liquid separation chamber. The first-stage centrifugal end of the utility model adopts a higher-speed motor, so that higher-speed working fluid is obtained, but under the condition that the centrifugal impeller and the pump cavity are both reduced, the gas-liquid separation of the composite shield pump in the self-suction stage is more difficult, and the high-speed impeller is easily air bound, so that the self-suction function of the composite shield pump is difficult to stabilize. 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 broken more easily in the impeller, and are clamped by the scale of the bubbles and the high-speed flow in the pump, and the size of the bubbles in the pump is smaller than that of a common self-priming pump and has higher followability, so that the difficulty of the bubbles floating up and leaving a water body is increased sharply, gas-liquid separation almost fails, and the composite shielding pump cannot complete self-priming smoothly. Therefore, in order to avoid the gas-liquid separation problem caused by the high rotating speed of the motor, after the gas-liquid slow mixture mixed by the self-priming device is driven at a high speed by the centrifugal impeller, the gas-liquid slow mixture is firstly guided out by the drainage of the centrifugal pressurized water chamber to enter the buffer pressurizing cavity for buffer pressurizing, and meanwhile, the gas-liquid slow mixture is fused to a certain extent in the buffer pressurizing cavity, so that the specific gravity of small bubbles is effectively reduced, finally, the bubbles in the pump in the self-priming stage are distributed in a larger scale, and the gas-liquid separation is completed within more sufficient floating time.

The buffer pressurizing cavity with the multi-pore double-layer plate series structure is provided with buffer fins arranged in a certain range, high-speed fluid is guided by the buffer fins of the primary buffer cavity, the speed is rapidly reduced, the fluid is discharged from an outlet of the primary buffer cavity and flows into the secondary buffer cavity, the fluid medium is further decelerated, and bubble fusion occurs to a certain degree in the buffer cavities among the layers, so that the size of the bubbles is integrally deviated towards a large scale and is discharged from an outlet of the secondary buffer cavity and then enters a gas-liquid separation chamber or enters the next-stage buffer pressurizing cavity. The utility model effectively converts the kinetic energy obtained by driving the fluid from the high-speed centrifugal impeller into potential energy in a multi-stage buffering mode, completes the speed reduction and pressurization of the working medium, controls the pressure loss of the fluid and simultaneously meets the requirements of gas-liquid separation.

The fluid flowing out of the outlet of the buffer pressurizing cavity directly enters the primary gas-liquid separation chamber, the speed of a fluid medium in the primary gas-liquid separation chamber is obviously reduced under the action of the flow guide and the buffer pressurizing cavity, the working fluid is fully retained in the gas-liquid separation chamber, the working fluid leaves the primary gas-liquid separation chamber after enough rising time of bubbles is left, enters the next-stage centrifugal end, and finally is discharged out of the pump outlet, so that the gas-liquid separation of the compound pump is realized. If no buffer pressurizing cavity is arranged, the high-speed fluid after the centrifugal impeller is driven by the primary motor cannot be fully decelerated, so that gas-liquid separation cannot be smoothly completed, the air-bound phenomenon of the impeller is dominant, and the self-suction effect is poor.

On the other hand, the operation of secondary centrifugal end in the stage of inhaling certainly can produce a negative pressure at the export of primary gas-liquid separation chamber and pull for the directional migration of gas-liquid mixture in the primary gas-liquid separation chamber can be to secondary pump import, carry the bubble of coming in with the self-priming ware and effectively transport to pump export direction, compare the free come-up of bubble in single-stage is from inhaling formula shielding composite pump, improved the forward migration speed of bubble, reduce this part bubble and detain, the circulation in the primary pump, increase exhaust speed and the exhaust stability of inhaling the stage soon, shorten from this time of inhaling.

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. In addition, the buffer pressurizing cavity and the centrifugal end can be concentrically distributed, and the volume of the whole pump is effectively reduced.

When the self-priming composite canned motor pump is in an actual working stage, fluid to be pumped in a pump inlet pipeline is sucked into the self-priming device along an inlet of the composite pump, and is accelerated and mixed with working fluid (fluid in an internal circulation state all the time) in the self-priming device in a cavity of the self-priming device and then enters a primary centrifugal end; then, the part of the fluid is accelerated and pressurized by the first-stage centrifugal impeller to obtain higher speed and pressure, and then is discharged from the first-stage centrifugal pressurizing water chamber, enters the buffer pressurizing cavity to be decelerated and pressurized, and is discharged from an outlet of the buffer pressurizing cavity, so that the deceleration and pressurization of the working medium are realized.

And the fluid flowing out of the buffer pressurizing cavity enters the primary gas-liquid separation chamber, and a part of the fluid is discharged through the outlet of the primary pump and enters the next-stage secondary pump. The other part of the pressurized fluid which is not discharged from the primary pump continuously circularly flows in the primary gas-liquid separation chamber: (i) when the self-priming device adopts an ejector structure, the internal circulation fluid continuously provides working fluid for an ejector nozzle, and strong negative pressure formed near the nozzle outlet continuously sucks the fluid to be pumped at the pump inlet; (ii) when the gas-liquid mixer is used as a self-priming device, the pressurized fluid enters the inlet of the primary pump through the backflow hole of the gas-liquid mixer, the gas-liquid mixing cavity and the outlet of the gas-liquid mixer. No matter what kind of self-priming device, all be equivalent to the fluid pressure who has promoted the first pump import. The process is repeated, so that the normal pumping of the fluid to be pumped by the composite shielding pump is realized, and the suction stroke of the whole pump is integrally improved. In the process, the buffer pressurizing cavity can effectively control pressure loss and realize buffer pressurizing of fluid at the outlet of the centrifugal end.

As a modification, a check valve or a spring flap may be arranged at the working fluid inlet of the self-priming device, for example at the inlet of the injector nozzle or at the return orifice of the gas-liquid mixer. From inhaling the working phase when beginning, only the fluid of irritating in advance circulates including in the pump, and the continuous replenishment of the fluid of no waiting pump sending, and check valve or elasticity separation blade both sides (self priming device inside and gas-liquid separation chamber) pressure differential are less, and check valve or elasticity separation blade are in the open mode under spring force or electromagnetic force effect, and the inside liquid of gas-liquid separation chamber gets into the self priming device through the self priming device entry, begins to smuggle the gas in the pump inlet pipeline secretly to accomplish the gas-liquid mixture in the self priming device. Along with the deepening of the self-priming stage, the pre-perfusion body in the pump continuously entrains the gas in the inlet pipeline of the pump, the gas enters the self-priming device for mixing, and the gas is discharged from the outlet of the pump through the gas-liquid separation chamber. Therefore, the gas in the inlet pipeline of the pump is continuously reduced, the air pressure is continuously reduced, the pressure difference between two sides of the structure such as the check valve or the elastic retaining sheet is continuously increased until the self-priming stage is finished, the inlet pipeline of the pump is almost free of gas, the pump is filled with the fluid and continuously supplied with water, the pressure in the first-stage gas-liquid separation chamber is increased steeply, a very large pressure difference is generated inside and outside the self-priming device, and the check valve overcomes the action of the elastic force or the electromagnetic force of the spring under the action of the pressure difference and enters a closed state. At the moment, the liquid in the gas-liquid separation chamber can not enter the self-priming device through the inlet of the self-priming device any more, and the internal circulation of the fluid in the pump is stopped; the liquid in the gas-liquid separation chamber does not flow back to the position of the nozzle 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 opening or stopping the working fluid at the inlet of the self-priming device through the check valve or the elastic retaining sheet, and meanwhile, the internal circulation of the working stage of the pump is stopped, so that the hydraulic efficiency of the pump is obviously improved.

Preferably, the primary centrifugal end power source of the utility model can adopt a direct current permanent magnet high-speed motor, and a smaller direct current motor is adopted to drive a smaller centrifugal impeller in consideration of the high rotating speed of the motor, so that the overall size of the pump body is reduced. The efficiency problem of conventional asynchronous motor is improved by a wide margin to the direct current permanent-magnet machine, through improving direct current motor rotational speed (the maximum rotational speed is more than 3600rpm, can reach 10000rpm even), cooperates the design of self-priming device and buffering booster cavity structure, obtains higher hydraulic efficiency and stronger silence effect when realizing that compound canned motor pump is from inhaling the function. Meanwhile, compared with the traditional asynchronous motor, the direct current permanent magnet motor has extremely high safety, and when the direct current safety voltage of 36V or below is adopted, even if electricity is leaked, the direct current permanent magnet motor has no life threat to a human body. The composite canned motor pump has small integral size, compact structure and wide market application prospect.

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

as shown in fig. 1, 2a, 2b and 2b, this embodiment specifically includes a pump inlet 1, a pump outlet 2, a self-priming device, a primary centrifugal end 4, a primary gas-liquid separation chamber 5, a secondary pump inlet 6, a secondary centrifugal end 7, a pump housing 8, a diversion cavity 9, and a buffer pressurizing cavity 10, where the self-priming device may be in the form of an ejector 301 or a gas-liquid mixer 302, when the ejector 301 is a self-priming device, the pump inlet 1 is connected to an ejector inlet 301-1, an end of an ejector diffuser 301-4 is an ejector outlet 301-5, the ejector outlet 301-5 is connected to a primary centrifugal end inlet 401, an inlet of an ejector nozzle 301-2 is communicated with the primary gas-liquid separation chamber 5, an outlet 405 of the primary centrifugal end is communicated with an inlet 101 of the buffer pressurizing cavity, an outlet 102 of the buffer pressurizing cavity is communicated with the primary gas-liquid separation chamber 5, the primary gas-liquid separation chamber is communicated with the secondary pump inlet 6 via the diversion cavity 9, the outlet 705 of the secondary centrifugal end is connected with the outlet 2 of the pump; when a secondary gas-liquid separation chamber is available, the secondary centrifugal end outlet 705 is connected with the secondary gas-liquid separation chamber 11, and the secondary gas-liquid separation chamber 11 is communicated with the pump outlet 2. When the gas-liquid mixer is a self-priming device, an inlet 302-1 of the gas-liquid mixer is connected with an inlet 1 of the pump, an outlet 302-4 of the gas-liquid mixer is connected with an inlet 401 of a centrifugal end of a primary pump, and a backflow hole 302-3 of the gas-liquid mixer is communicated with a primary gas-liquid separation chamber 5.

The injector 301 consists of an injector inlet 301-1, a nozzle 301-2, a throat 301-3, a diverging section 301-4 and an injector outlet 301-5 (see fig. 8a and 9a), and a resilient flap 13 (fig. 7a, 8b and 8c) or a check valve 14 (fig. 7b, 9b and 9c) may be arranged at the inlet of the nozzle 301-2 for opening and closing the internal circulation of the pump. The gas-liquid mixer 302 is composed of a gas-liquid mixer inlet 302-1, a mixing cavity 302-2, a backflow hole 302-3 and a gas-liquid mixer outlet 302-4 (as shown in fig. 11a and 12a), and an elastic baffle 13 (fig. 10a, 11b and 11c) or a check valve 14 (fig. 10b, 12b and 12c) can be arranged at the backflow hole 302-3 for opening and closing the internal circulation of the pump.

The primary centrifugal end 4 specifically includes a primary centrifugal end inlet 401, a primary permanent magnet motor 402, a primary centrifugal impeller 403, a primary centrifugal pumping chamber 404, and a primary centrifugal end outlet 405 (as shown in fig. 3), and the secondary centrifugal end 7 specifically includes a secondary centrifugal end inlet 701, a secondary permanent magnet motor 702, a secondary centrifugal impeller 703, a secondary centrifugal pumping chamber 704, and a secondary centrifugal end outlet 705 (as shown in fig. 3).

The primary permanent magnet motor 402 (as shown in fig. 4) is provided with a motor rotor 402-3 and a stator 402-2 which are isolated by a shielding sleeve 402-1, the motor rotor 402-3 is fixedly connected with a primary centrifugal impeller 403 by a motor shaft 402-4, the direct current permanent magnet motor is provided with a motor shell 402-5, and a pump body is not provided with dynamic seal. When the secondary motor is also a permanent magnet motor, the secondary permanent magnet motor 702 (as shown in fig. 6) is provided, wherein a motor rotor 702-3 is isolated from a stator 702-2 by a shielding sleeve 702-1, the motor rotor 702-3 is fixedly connected with a secondary centrifugal impeller 703 by a motor shaft 702-4, the motor is provided with a motor housing 702-5, the pump body is not provided with dynamic seal, and the inlet 101 and the outlet 102 of the buffer pressurizing cavity are respectively arranged on two sides of the laminate 1001.

As shown in fig. 5a, 5b and 5c, the buffer pressurizing cavity can have a plurality of pore medium filling structure forms for effectively reducing the flow rate of the fluid and achieving the effect of fluid pressurization, wherein fig. 5a shows that the filling medium is spherical particles, fig. 5b shows a silk-screen-shaped multi-gap laminate filling structure, and fig. 5c shows an irregular particle multi-gap filling structure.

When the self-priming composite shield pump is in a self-priming exhaust stage, the first-stage centrifugal impeller 403 and the first-stage direct-current permanent magnet motor 402 are sealed in a pump cavity of the first-stage composite shield pump filled with pumped media, and pre-filled fluid is stored in the ejector 301 or the gas-liquid mixer 302, the first-stage centrifugal end 4, the buffer pressurizing cavity 10 and the first-stage gas-liquid separation chamber 5. This embodiment adopts the higher direct current permanent magnet machine of security and efficiency, compare traditional asynchronous machine, direct current permanent magnet machine drives the fluid and obtains the working fluid of higher speed, but make the bubble in the first level pump not have sufficient time to float to the surface of water and leave the water, the bubble breakage under the high-speed motion in the narrow and small pump chamber is serious, the gas-liquid separation of compound canned motor pump is consequently more difficult, very easily lead to high rotational speed impeller air to bind, the bubble volume in the first level gas-liquid separation room 5 accounts for the steep increase, compound canned motor pump from inhaling the function can't realize.

In order to solve the problem of gas-liquid separation caused by high rotating speed of the direct-current permanent magnet motor, after the fluid mixed by the ejector 301 or the gas-liquid mixer 302 is driven at high speed by the first-stage centrifugal impeller 403, the fluid is firstly led out from the first-stage centrifugal water pressurizing chamber 404 and enters the buffer pressurizing cavity 10 for buffer pressurizing, so that bubbles in the pump in the self-priming stage can obtain longer free floating time to complete gas-liquid separation, and on the other hand, the dynamic accumulation of the bubbles in the buffer pressurizing cavity can enhance the fusion and increase of the bubbles, thereby obviously reducing the breakage of the bubbles in the first-stage gas-liquid separation chamber 5 and having faster floating driving force, as shown in fig. 17. The multiple structures of the buffer pressurizing cavity 10 are used for controlling hydraulic loss, accelerating bubbles to separate from a water body and enhancing self-absorption of the pump. If the buffer pressurizing cavity 10 is not arranged, the high-speed fluid behind the first-stage centrifugal impeller 403 driven by the first-stage direct-current permanent magnet motor 402 cannot be sufficiently decelerated, so that bubble breakage in the pump cavity is continuously deteriorated, the air-bound phenomenon of the impeller 403 is dominant, and gas-liquid separation cannot be finished and self-absorption fails. In order to reasonably save space and flow layout, the buffer pressurizing cavities and the centrifugal end are concentrically distributed (shown in fig. 14a, fig. 15a and fig. 16 a), and the compactness of the whole structure is effectively improved.

Although the introduction of the buffer pressurizing cavity solves the self-absorption problem of the composite shield pump, the overall performance of the pump is reduced, and when a low-power permanent magnet motor is configured, the flow lift of the pump is too low to almost meet the requirements of most practical applications. In this case, the addition of a secondary pump can well circumvent this problem. The secondary pump mainly comprises a secondary pump inlet 6 and a secondary centrifugal end 7, and a secondary gas-liquid separation chamber 11 can be additionally arranged for enhancing the exhaust efficiency. The operation of the degassing phase with the secondary gas-liquid separation chamber 11 is schematically shown in fig. 14a and 15a, the degassing phase without the secondary gas-liquid separation chamber is schematically shown in fig. 16a, and the instantaneous state of the bubbles in the secondary pump is shown in fig. 18.

When the self-priming compound canned motor pump is in an actual working stage, the flow schematic diagram of the compound canned motor pump is shown in fig. 14b, fig. 15b and fig. 16b, and the fluid to be pumped in the pipeline at the pump inlet 1 is sucked into the ejector 301 or the gas-liquid separator 302; when the self-priming device is an ejector 301, high-speed working fluid ejected from a nozzle enters the primary centrifugal end 4 after accelerated mixing through a throat pipe of the ejector and deceleration and pressurization through a diffusion section; when the self-priming device is a gas-liquid mixer 302, the pressure fluid returned from the return hole 302-3 and the fluid to be pumped are mixed in the mixing cavity 302-2 of the gas-liquid mixer and then enter the first-stage centrifugal end 4. Then, the part of the fluid is accelerated and pressurized by the first-stage centrifugal impeller 403 to obtain higher speed and pressure, and then is discharged from the first-stage centrifugal pressurizing water chamber 404, enters the buffer pressurizing cavity 10 for deceleration and pressurization, and is discharged from the buffer pressurizing cavity outlet 102, so that the deceleration and pressurization of the working medium are realized. The fluid flowing out from the outlet 102 of the buffer pressurizing cavity enters the primary gas-liquid separation chamber 5, one part of the fluid is discharged through the outlet 2 of the composite pump, and the other part of the fluid which is not discharged out of the pump and has pressure continues to flow circularly in the primary gas-liquid separation chamber 5. Working fluid is provided for the ejector nozzle 301-2 or the gas-liquid mixer backflow hole 302-3, fluid to be pumped at the inlet of the pump is continuously sucked in the self-sucking device, and the process is repeated, so that the normal pumping of the fluid to be pumped by the composite shield pump is realized. In the process, the buffer pressurizing cavity 10 can effectively reduce the inertia dissipation of the fluid and control the pressure loss, and simultaneously realize the buffer pressurizing of the fluid at the outlet 405 of the first-stage centrifugal end.

As shown in fig. 8a, fig. 8b, fig. 8c, fig. 9a, fig. 9b, fig. 9c, fig. 11a, fig. 11b, fig. 11c and fig. 12a, fig. 12b, fig. 12c, a check valve 13 or a resilient flap 14 may be disposed at the inlet of the injector nozzle 301-2 or the gas-liquid mixer return hole 302-3, at the beginning of the self-priming operation phase, only the pre-priming fluid circulates in the pump, no continuous supplement of the fluid to be pumped is performed, the pressure difference between both sides of the check valve 13 or the resilient flap 14 is almost zero, the check valve 13 or the resilient flap 14 is in an open state under the action of the spring force, the resilient flap force or the electromagnetic force, the liquid inside the first-stage gas-liquid separation chamber 5 enters the injector throat 301-3 and the gas-liquid mixer mixing chamber 302-2 through the inlet of the injector nozzle 301-2 or the gas-liquid mixer return hole 302-3, the gas-liquid mixing process is completed. Along with the deepening of the self-priming stage, the pre-filled fluid in the pump is subjected to continuous actions of processes such as accelerating pressurization through a self-priming device, driving work by a first-stage centrifugal impeller 403, decelerating pressurization through a buffer pressurization cavity 10 and the like, the gas in the pipeline of the pump inlet 1 is less and less, the pressure difference between two sides of the check valve 13 or the elastic separation blade 14 is increased continuously until the self-priming stage is finished, the pipeline of the pump inlet is filled with fluid working media, and the pressure difference between two sides of the upstream and the downstream of the check valve 13 or the elastic separation blade 14 is increased steeply, so that the action of the spring force or the electromagnetic force is overcome, and the check valve 13 or the elastic separation blade 14 enters a closed state. As shown in fig. 8c, 9c, 11c and 12c, the check valve or the elastic flap is in a closed state, and at this time, the liquid in the gas-liquid separation chamber cannot enter the self-priming device any more, and the internal circulation of the fluid in the pump stops. The check valve 13 or the elastic baffle plate 14 is used for opening or stopping the working fluid at the inlet of the ejector nozzle 301-2 or the backflow hole 302-3 of the gas-liquid mixer, so that the internal circulation of the actual working stage is stopped while the self-suction function is realized, the energy internal consumption of the pump is practically reduced, and the hydraulic efficiency of the pump is powerfully improved.

As shown in fig. 13, the self-priming multi-stage composite canned motor pump 153 of the present invention may also form a pump group in a parallel configuration with a single centrifugal pump 156. The self-suction multi-stage composite shield pump 153 and the centrifugal pump 156 share a pump set inlet 151 and a pump set outlet 152, namely the pump set inlet 151 is respectively communicated with a self-suction composite shield pump inlet 154 and a centrifugal pump inlet 157; the self-suction composite shielding pump outlet 155 and the centrifugal pump outlet 158 are respectively communicated with the pump group outlet 152. The pump set does not influence the exhaust in the self-priming exhaust stage, the performance of the pump is improved in the non-self-priming normal working stage, the self-priming multistage composite shielding pump set with different parameter specifications is constructed, and different requirements are met.

In conclusion, the utility model keeps the characteristics of compact integral structure and high integration degree of the canned motor pump. On the premise of not increasing the running noise of the pump, the centrifugal impeller is driven by the primary motor and matched with the buffer pressurizing cavity and the self-priming device, so that gas-liquid separation and self-priming under the high-rotating-speed working condition of the canned motor pump are realized, more importantly, the whole flow lift performance of the pump is improved by introducing the secondary centrifugal end, the active traction of the secondary pump on gas-liquid mixed fluid in the primary gas-liquid separation cavity is exerted, and the whole self-priming stability and capacity of the pump are enhanced.

While the utility model 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 utility model, 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. The utility model provides a from inhaling formula multistage compound canned motor pump which characterized in that: comprises a pump inlet, a self-priming device, a primary centrifugal end, a primary gas-liquid separation chamber, a secondary pump inlet, a secondary centrifugal end and a pump outlet;

2. The self-priming multistage compound canned motor pump according to claim 1, characterized in that: the centrifugal device comprises at least one secondary centrifugal end, at least one inlet of the secondary centrifugal end, at least one outlet of the secondary centrifugal end, at least one inlet of the primary centrifugal end, at least one outlet of the primary centrifugal end, at least one primary gas-liquid separation chamber and at least one self-priming device;

when a plurality of secondary centrifugal ends exist, according to the flowing direction, the outlet of the upstream secondary centrifugal end is connected with the inlet of the adjacent downstream secondary centrifugal end, namely, the two secondary centrifugal ends are connected in series, so that the lift is further improved; the outlet of the last-stage secondary centrifugal end is communicated with the outlet of the pump; when the secondary gas-liquid separation chamber is available, the outlet of the secondary centrifugal end of the last stage is connected with the secondary gas-liquid separation chamber, and the secondary gas-liquid separation chamber is communicated with the pump outlet.

3. The self-priming multistage composite canned motor pump according to claim 1 or 2, characterized in that: the first-stage gas-liquid separation chamber is internally provided with a buffer pressurizing cavity for rapidly decelerating and pressurizing the high-speed pressurized fluid at the outlet of the centrifugal end;

4. The self-priming multistage compound canned motor pump according to claim 3, characterized in that: the outlets of the buffer pressurizing cavities are distributed along the circumferential direction or the radial direction in a plane, or a plurality of holes are arranged in space.

5. The self-priming multistage compound canned motor pump according to claim 3, characterized in that: the buffering pressure boost chamber is porous plywood series structure, porous plywood series structure's buffering pressure boost intracavity add fixed or rotary type stator, perhaps imports and exports the buffering pressure boost chamber and set up to rotatable stator.

6. The self-priming multistage compound canned motor pump according to claim 3, characterized in that: the buffer pressurizing cavity is 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.

7. The self-priming multistage composite canned motor pump according to claim 1 or 2, characterized in that: the self-priming device is an ejector or a gas-liquid mixer, and the self-priming device comprises at least one inlet and at least one outlet.

8. The self-priming multistage compound canned motor pump according to claim 7, characterized in that: a check valve or an elastic separation blade is arranged at the position of a nozzle inlet of the ejector, when the self-priming stage of the composite shield pump is finished, the check valve or the elastic separation blade is closed under the driving of the internal and external differential pressure of the ejector, liquid in the gas-liquid separation chamber cannot enter the ejector through the position of the nozzle, and the internal circulation flow of the pump is stopped.

9. The self-priming multistage compound canned motor pump according to claim 7, characterized in that: a check valve or an elastic retaining sheet is arranged at a return hole of the gas-liquid mixer, 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 mixer, the liquid in the gas-liquid separation chamber can not enter the gas-liquid mixer through the return hole, and the internal circulation flow of the pump is stopped.

10. A combined self priming multistage composite canned motor pump comprising at least one self priming multistage composite canned motor pump of any one of claims 1 to 9 and at least one centrifugal pump, characterized in that: the inlet of any centrifugal end of the self-suction multi-stage composite shielding pump is connected with the inlet of the centrifugal pump in parallel, and the outlet of the self-suction composite shielding pump is connected with the outlet of the centrifugal pump in parallel.