CN115614327A

CN115614327A - Mixed flow pump with sewage pretreatment device

Info

Publication number: CN115614327A
Application number: CN202211090349.XA
Authority: CN
Inventors: 罗永康; 张文宇
Original assignee: Anhui Kangyu Hydropower Machinery Complete Equipment Co Ltd
Current assignee: Anhui Kangyu Hydropower Machinery Complete Equipment Co Ltd
Priority date: 2022-09-07
Filing date: 2022-09-07
Publication date: 2023-01-17

Abstract

The invention discloses a mixed flow pump with a sewage pretreatment device, which belongs to the technical field of mixed flow pumps and comprises a base, a water outlet pipe and a water inlet pipe, wherein a motor and a pump body are fixedly arranged at the top of the base, an output shaft of the motor is in transmission connection with a transmission shaft of the pump body through a coupler, a filter assembly is fixedly arranged on the left side of the pump body, an installation cover and a bolt are arranged on the left side of the filter assembly, and a filter cylinder is installed on the inner wall of the filter assembly in a pressing fit mode through the installation cover, the bolt and a fixing ring. According to the invention, the filter plate is driven to move rightwards and synchronously rotate, the second spring is driven to stretch, large granular impurities enter the dynamic filtering area through the third filtering hole, the filter plate starts to reversely push leftwards along with the increase of the entering quantity of the large granular impurities, the large granular impurities in the dynamic filtering area are driven to rotate through the matching of the filter plate and the rotating strip, the probability of a squeezing water channel is reduced, and the sewage passing efficiency is improved.

Description

Mixed flow pump with sewage pretreatment device

Technical Field

The invention relates to the technical field of mixed flow pumps, in particular to a mixed flow pump with a sewage pretreatment device.

Background

The mixed flow pump is a hydraulic machine between a centrifugal pump and an axial flow pump, axial thrust generated by rotation of an impeller is utilized to transfer water and endow high pressure to the water, conveying work is completed, the mixed flow pump is generally provided with a sewage pretreatment device when sewage is transferred, and large-particle impurities in the sewage are filtered to improve the stability of the microbial environment in the water body when the sewage is subjected to subsequent treatment and provide stable conditions for subsequent biochemical precipitation.

At present, a mixed-flow pump with a sewage pretreatment device in the prior art usually has a sewage pretreatment component arranged at a water inlet end of a pump body, and a common treatment method is to filter larger particle impurities in sewage to improve the quality of the sewage; the filtration mode is mostly multilayer filter screen and filters, in the course of the work, along with time lapse, the filter screen surface can be crowded by the impurity that accumulates gradually (rather than blockking up), these crowded phenomena can lead to rivers runner to become narrowly, because lack dynamic adjustment measure, the conveying efficiency of sewage can descend, simultaneously, more granule impurity can be preserved to constrictive water course, aggravate whole filtering component's work burden, can cause serious jam finally.

Therefore, there is a need for an automatically and dynamically adjustable filter assembly, the object of which is to improve the sewage pretreatment capacity of mixed flow pumps.

Disclosure of Invention

The invention aims to provide a mixed flow pump with a sewage pretreatment device, which aims to solve the problems of low sewage passing efficiency and poor filtering effect in the background technology.

In order to achieve the purpose, the invention provides the following technical scheme: the utility model provides a mixed flow pump with sewage pretreatment device, includes base, outlet pipe and inlet tube, the top fixed mounting of base has the motor and the pump body, the output shaft of motor passes through the shaft coupling and is connected with the transmission shaft transmission of the pump body, the left side fixed mounting of the pump body has filtering component, filtering component's left side is provided with installation lid and bolt, filtering component's inner wall is installed the cartridge filter through installation lid, bolt and solid fixed ring pressfitting, no. one filter hole and No. two filter holes have been seted up respectively to the surface of cartridge filter, the inner wall fixedly connected with of cartridge filter rotates the strip, the inner wall of cartridge filter rotates through the strip of rotating and installs the filter, no. three filter holes have been seted up in the left side of filter, no. three filter holes's cross sectional shape is the isosceles trapezoid of height from left to right, the standing groove has been seted up on the right side of filter, the inside swing joint of standing groove has two fixture blocks and has a connecting cylinder through fixture block swing joint, the other end of connecting cylinder runs through to the right side of cartridge filter, the inside activity of cartridge filter has cup jointed spliced pole and a spring, the other end fixedly connected with cartridge filter connecting plate, be provided with No. two spring connecting plates between connecting plate.

As a further scheme of the invention, the water inlet pipe is fixedly arranged on the left side of the mounting cover, the water outlet pipe is fixedly arranged on the front side of the pump body, the fixing ring is fixedly connected to the left side of the inner wall of the filtering component, and the outer edge of the filtering cylinder is in pressing contact with the fixing ring.

As a further scheme of the invention, the left side of the filter plate is fixedly connected with four rotating plates which are distributed on the surface of the filter plate at equal angles, and the filter plate and the third filter holes are arranged in a staggered manner.

As a further scheme of the invention, the rotating strips are spirally distributed on the inner wall of the filter cylinder, the number of spiral turns of the filter cylinder is two, and the filter plate is clamped on the outer surface of the rotating strips in a matching manner.

As a further scheme of the invention, the cross section of the clamping block is in a T shape, the clamping block is rotationally clamped in the placing groove, and one end of the connecting cylinder, which is connected with the clamping block, is in limit contact with the right side of the filter plate.

As a further scheme of the invention, the first spring and the connecting column are sequentially sleeved in the connecting cylinder from left to right, the connecting column is elastically supported in the connecting cylinder through the first spring, the right end of the connecting cylinder is in extrusion contact with the connecting plate, and two ends of the second spring are respectively and elastically connected with the filter cylinder and the connecting plate.

As a further scheme of the invention, the first filtering hole is formed in the outer surface of the filter cylinder, the second filtering hole is formed in the right side of the filter cylinder, and the diameter value of the second filtering hole is larger than that of the first filtering hole.

As a further scheme of the invention, the first spring is compressed and arranged inside the connecting cylinder by the connecting column, and the second spring is in a stretched state under an initial condition.

As a further scheme of the invention, the diameter value of the narrowest part of the third filtering hole is larger than that of the second filtering hole.

Compared with the prior art, the invention has the beneficial effects that:

1. according to the invention, the filter plate is continuously moved rightwards and rotated along the outer surface of the rotating strip under the action of sewage pressure to create a dynamic filtering area, when sewage enters the interior of the filter cylinder and presses the filter plate, the filter plate is driven to move rightwards and synchronously rotate, the second spring is driven to stretch, large granular impurities enter the dynamic filtering area through the third filtering holes, the filter plate starts to be pushed backwards leftwards along with the increase of the entering quantity of the large granular impurities, the large granular impurities in the dynamic filtering area are driven to rotate through the matching of the filter plate and the rotating strip, the probability of extruding a water channel is reduced, and the sewage passing efficiency is improved.

2. Then, the rotating plate is connected with the filter plate through the rotating plate, the rotating plate is driven to rotate when the filter plate rotates, the kinetic energy of small particle impurities in sewage is improved, the moving speed is improved, the second filter hole is prevented from being blocked, the inner wall of the filter cylinder is synchronously scraped through the rotating filter plate, the filter cylinder is mainly beneficial to removing the blocking impurities near the first filter hole, the probability of blockage of the device is reduced, and the pretreatment capacity of the device is improved.

3. Finally, carry out the pressfitting installation to the cartridge filter through being provided with installation lid and bolt, make the cartridge filter when the degree that needs were maintained in work, only need dismantle the bolt to the dismantlement of realization to the cartridge filter, through the outside direction pulling filter to the cartridge filter, drive the connecting cylinder and remove, make a spring stretched, form a clearance gap between filter and cartridge filter, clear up the filterable large granule impurity of cartridge filter inside, thereby make the clearance become high-efficient and laborsaving.

Drawings

FIG. 1 is a schematic diagram of the overall structure of the present invention;

FIG. 2 is a schematic top view of the overall structure of the present invention;

FIG. 3 is a schematic view, partially in section, in elevation, of the general structure of the invention;

FIG. 4 is an enlarged view of the structure of FIG. 3 at A according to the present invention;

FIG. 5 is a top view partially in section of the general structure of the invention;

FIG. 6 is an enlarged view of the structure of FIG. 5 at B in accordance with the present invention;

FIG. 7 is an enlarged view of the structure of FIG. 5 at C;

FIG. 8 is a schematic illustration of the filter assembly, mounting cap, bolts, inlet tube, stationary collar, filter cartridge, rotating strip, filter plate, fixture block, rotating plate, connector cartridge, and second spring of the present invention in isolation;

FIG. 9 is a schematic diagram showing the separation of the filter plate, the clamping block, the rotating plate, the connecting cylinder, the connecting column, the first spring, the connecting plate and the second spring according to the present invention.

In the drawings, the reference numbers indicate the following list of parts:

1. a base; 2. a motor; 3. a coupling; 4. a pump body; 5. a water outlet pipe; 6. a filter assembly; 7. installing a cover; 8. a bolt; 9. a water inlet pipe; 10. a fixing ring; 11. a filter cartridge; 12. a first filtering hole; 13. a second filtering hole; 14. rotating the strip; 15. a filter plate; 16. a clamping block; 17. a third filtering hole; 18. a placement groove; 19. a rotating plate; 20. a connecting cylinder; 21. connecting columns; 22. a first spring; 23. a connecting plate; 24. and a second spring.

Detailed Description

Referring to fig. 1-9, the present invention provides a technical solution: a mixed flow pump with a sewage pretreatment device comprises a base 1, a water outlet pipe 5 and a water inlet pipe 9, wherein a motor 2 and a pump body 4 are fixedly installed at the top of the base 1, an output shaft of the motor 2 is in transmission connection with a transmission shaft of the pump body 4 through a coupler 3, a filter assembly 6 is fixedly installed at the left side of the pump body 4, an installation cover 7 and a bolt 8 are arranged at the left side of the filter assembly 6, a filter cartridge 11 is installed on the inner wall of the filter assembly 6 through the installation cover 7, the bolt 8 and a fixing ring 10 in a pressing mode, a first filter hole 12 and a second filter hole 13 are respectively formed in the surface of the filter cartridge 11, a rotating strip 14 is fixedly connected to the inner wall of the filter cartridge 11, a filter plate 15 is rotatably installed on the inner wall of the filter cartridge 11 through the rotating strip 14, a third filter hole 17 is formed in the left side of the filter cartridge 15, the cross section of the third filter hole 17 is in the shape of an isosceles trapezoid with a high left side and a right side, a placing groove 18 is formed in the right side of the filter cartridge 15, two fixture blocks 16 are movably clamped in a movable connection barrel 20 through the connecting plate 16, the other end of the filter cartridge 20 penetrates through the filter cartridge 11, a connecting plate 21 and a connecting plate 23 is connected between the connecting plate 23 and a second connecting post 23;

when the device is installed, the whole filter cartridge 11 is in extrusion contact with the fixing ring 10, the installation cover 7 is pressed on the left side of the filter assembly 6 and is installed in a pressing mode through the bolt 8, when sewage from the water inlet pipe 9 enters the interior of the filter assembly 6, the interior of the pump body 4 is filled with the sewage and then the sewage is discharged along the water outlet pipe 5 at high pressure, at the moment, the filter plate 15 is subjected to water pressure and moves rightwards, the connecting cylinder 20 and the connecting plate 23 are driven to move rightwards through the limiting synchronous rotation of the rotating strip 14, and the spring II 24 is continuously stretched until the space inside the filter cartridge 11 is compressed to the minimum by the filter plate 15;

then large granular impurities enter the inside of the filter cylinder 11 along the fixture block 16, because the water pressure continuously acts on the filter plate 15 rightwards, the friction force between the rotating strip 14 and the filter plate 15 is matched, thereby offsetting the resilience force of the second spring 24, the large granular impurities are increasingly accumulated in a dynamic filtering area formed between the inner cavity of the filter cylinder 11 and the filter plate 15, the right side of the filter plate 15 is gradually pushed leftwards by the increased large granular impurities and gradually moves leftwards, the filter plate 15 synchronously rotates by utilizing the rotating strip 14, the large granular impurities on the two sides of the filter plate 15 are driven to rotate, and the crowding degree is reduced;

along with the increasing space of the dynamic filtering area, sewage after being pretreated after being filtered flows rightwards along the first filtering hole 12 and the second filtering hole 13 respectively, the sewage is discharged at high pressure under the action of the pump body 4, the filter plate 15 drives the rotating plate 19 to rotate and stir water flow in the filter cylinder 11 when rotating, the kinetic energy of small particle impurities in the sewage is increased, the filter plate 15 rotates when moving, the inner wall of the filter cylinder 11 is scraped to remove parts which are possibly blocked, the stirred sewage also drives large particle impurities reserved in the dynamic filtering area to rotate at the same time, and possible blocked areas near the second filtering hole 13 are removed;

during the clearance, dismantle bolt 8, will install and cover 7 and take off, then with cartridge filter 11 whole take out filter assembly 6 inside, pulling filter 15 and drive connecting cylinder 20 and remove left, make connecting cylinder 20 break away from in the surface of spliced pole 21, spring 22 is stretched, at this moment, the staff can clear up the filterable large granule impurity of cartridge filter 11 inner wall, realizes the periodic maintenance function, after the end with cartridge filter 11 installation return normal position can.

According to the invention, the filter cartridge 11 which is installed in a pressing manner is used for carrying out large particle impurity filtering type pretreatment operation on sewage, the rotating strip 14 and the filter plate 15 are arranged, when the sewage enters the interior of the filter cartridge 11 and presses the filter plate 15, the filter plate 15 is driven to move rightwards and synchronously rotates, the second spring 24 is driven to stretch, the third filter hole 17 is arranged to allow large particle impurities to enter a dynamic filtering area, the filter plate 15 starts to reversely push leftwards along with the increase of the number of the large particle impurities, the dynamic balancing force of the filter plate 15 is destroyed, the filter plate 15 is driven to move leftwards and rotate, and the large particle impurities in the dynamic filtering area are driven to move in the rotating process of the filter plate 15, so that the probability of crowded water channels is reduced, and the sewage passing efficiency is improved.

Simultaneously, filter 15 that is pushed backward and remove left rotates under the effect of rotor bar 14, stir the inside sewage of cartridge filter 11 through rotor plate 19, make the small particle impurity kinetic energy in the sewage increase, improve the velocity of motion, avoid blockking up No. two filtration pores 13, and simultaneously, at the in-process that filter 15 rotates and removes, scrape the removal of cartridge filter 11 inner wall through filter 15 surface, clear away the card and filter the inside small particle impurity of pore 12 No. one, reduce the jam probability of device, improve the preprocessing ability of device.

Finally, carry out the pressfitting installation to cartridge filter 11 through being provided with installation lid 7 and bolt 8, make cartridge filter 11 when the degree that needs the maintenance work, dismantle bolt 8, thereby dismantle cartridge filter 11, outside direction pulling filter 15 to cartridge filter 11, drive connecting cylinder 20 and remove, make spring 22 stretched, form a clearance gap between filter 15 and cartridge filter 11, large granule impurity clearance with the inside filterable of cartridge filter 11, thereby make the clearance become high-efficient and laborsaving.

Wherein, the water inlet pipe 9 is fixedly arranged at the left side of the mounting cover 7, the water outlet pipe 5 is fixedly arranged at the front side of the pump body 4, the fixing ring 10 is fixedly connected at the left side of the inner wall of the filtering component 6, and the outer edge of the filtering cylinder 11 is in extrusion contact with the fixing ring 10;

sewage enters the interior of the filter assembly 6 and the filter cartridge 11 along the water inlet pipe 9, and is filtered through the double layers of the filter plate 15 and the filter cartridge 11, so that the pretreated sewage enters the pump body 4 and is discharged in a high-pressure mode along the water outlet pipe 5, as shown in fig. 3, the left side of the outer edge of the filter cartridge 11 is in extrusion contact with the mounting cover 7, the right side of the outer edge of the filter cartridge 11 is in extrusion contact with the fixing ring 10, the filter cartridge 11 can be fixed in the interior of the filter assembly 6 under the action of the bolt 8, and the sealing function can be realized.

Wherein, the left side of the filter plate 15 is fixedly connected with a rotating plate 19, the number of the rotating plates 19 is four, and the rotating plates are distributed on the surface of the filter plate 15 at equal angles, and the filter plate 15 and the third filter holes 17 are arranged in a staggered manner;

the rotating plate 19 is driven by the rotating filter plate 15 to stir the sewage inside the filter cartridge 11, so that small particle impurities in the sewage can be driven to increase kinetic energy, and the blocking phenomenon which may occur in a low kinetic energy moving state is avoided.

Wherein, the rotating strips 14 are spirally distributed on the inner wall of the filter cartridge 11, the number of spiral turns of the filter cartridge 11 is two, and the filter plate 15 is clamped on the outer surface of the rotating strips 14 in a matching way;

rotation strip 14 and the 15 adaptation blocks of filter that are the spiral and distribute make filter 15 when receiving external force and remove, can take place to rotate along the surface that rotates strip 14, just can make the large granule impurity removal in "dynamic filtration region" at filter 15 pivoted in-process, reduce the jam degree of water course to supplementary sewage passes through more efficiently, simultaneously, can also drive rotor plate 19 and rotate.

The cross section of the clamping block 16 is in a T shape, the clamping block 16 is rotationally clamped in the placing groove 18, and one end of the connecting cylinder 20, which is connected with the clamping block 16, is in limit contact with the right side of the filter plate 15;

the clamping block 16 distributed in the T shape is used for connecting the connecting cylinder 20 and the filter plate 15, and the filter plate 15 needs to rotate when moving, so that the clamping block 16 can freely rotate along the inside of the placing groove 18, the clamping block is guaranteed not to block the rotation of the filter plate 15, and the filter plate 15 can drive the connecting cylinder 20 to move.

The first spring 22 and the connecting column 21 are sequentially sleeved inside the connecting cylinder 20 from left to right, the connecting column 21 is elastically supported inside the connecting cylinder 20 through the first spring 22, the right end of the connecting cylinder 20 is in extrusion contact with the connecting plate 23, and two ends of the second spring 24 are respectively in elastic connection with the filter cartridge 11 and the connecting plate 23;

spliced pole 21 and spring 22 are used for connecting cylinder 20 and connecting plate 23, and under normal operating condition, the connecting cylinder 20 and the state of extrusion contact appear in connecting plate 23, even connecting cylinder 20 removes left, also only the extrusion degree reduces, consequently, cooperate No. two springs 24 and connecting plate 23, can last to exert pressure to filter 15 through spring 22 left, guarantee to realize that filter 15 rotates filterable function.

The first filtering hole 12 is formed in the outer surface of the filtering cylinder 11, the second filtering hole 13 is formed in the right side of the filtering cylinder 11, and the diameter value of the second filtering hole 13 is larger than that of the first filtering hole 12;

no. one filter pore 12 and No. two filter pores 13 are used for supplying sewage to pass through to filter the small particle impurity, because the surface that has filter 15 near the position of No. one filter pore 12 clears up when rotating, consequently, the jam pressure of No. one filter pore 12 will be less than No. two filter pores 13, and No. two filter pores 13 is probably blocked No. two filter pores 13 for a short time at certain position of pivoted that the large particle impurity that the hydraulic pressure effect drove, and this is fatal, need suitably enlarge No. two diameter values of filtering pores 13 and solve this hidden danger.

Wherein, the first spring 22 is compressed and arranged inside the connecting cylinder 20 by the connecting column 21, and the second spring 24 is in a stretched state under an initial condition;

spring 22 and spliced pole 21 are used for connecting cylinder 20 and connecting plate 23, and under normal operating condition, connecting plate 23 and No. two spring 24 extrusion contact all the time, when the clearance, can obtain reset pressure through tensile spring 22 with filter 15 to the outside direction pulling of cartridge filter 11, when carrying out the clearance to cartridge filter 11 inside, it is available to have the clearance, can assist after the clearance to reset.

Wherein, the diameter value of the narrowest part of the third filtering hole 17 is larger than that of the second filtering hole 13;

the narrow design in the left side of No. three filtration pores 17 is mainly in order to prevent that the large granule impurity backward flow in "dynamic filtration region" from passing through No. three filtration pores 17, and No. three filtration pores 17's diameter value is greater than No. two filtration pores 13's diameter value, avoids inside large granule impurity flows into the pump body 4.

The working principle is as follows:

firstly, a filter cylinder 11 is arranged inside a filter assembly 6 and is fixed through an installation cover 7 and a bolt 8, a water inlet pipe 9 is externally connected with a sewage source, a motor 2 is started and drives a pump body 4 to operate, so that sewage enters the filter assembly 6 and the pump body 4 and is discharged along a water outlet pipe 5, the sewage pushes a filter plate 15 rightwards and drives the filter plate 15 to rotate, and a connecting cylinder 20 and a connecting plate 23 are driven to move rightwards and stretch a second spring 24;

then, large particle impurities in the sewage enter a dynamic filtering area through a third filtering hole 17, then the large particle impurities are gradually increased and pushed leftwards, so that the filtering plate 15 rotates when moving, the large particle impurities in the dynamic filtering area are driven to rotate, the inner wall of the filtering cylinder 11 is synchronously scraped to remove blockage, the filtering plate 15 simultaneously drives the rotating plate 19 to rotate, water flow in the filtering cylinder 11 is stirred, the kinetic energy of the small particle impurities in the sewage is increased, the filtered sewage enters the right side of the inner wall of the filtering component 6, and then is driven by an impeller which rotates at a high speed in the pump body 4 to be discharged along the water outlet pipe 5;

finally, dismantle bolt 8, will install and cover 7 and take off, then with cartridge filter 11 whole take out filter assembly 6 inside, pulling filter 15 and drive connecting cylinder 20 and remove left, make connecting cylinder 20 break away from in the surface of spliced pole 21, spring 22 is stretched, at this moment, the staff can clear up the filterable large granule impurity of cartridge filter 11 inner wall, realize the periodic maintenance function, after the end with cartridge filter 11 installation return normal position can.

Claims

1. The utility model provides a mixed flow pump with sewage pretreatment device, includes base (1), outlet pipe (5) and inlet tube (9), the top fixed mounting of base (1) has motor (2) and pump body (4), the output shaft of motor (2) passes through shaft coupling (3) and is connected with the transmission shaft transmission of the pump body (4), the left side fixed mounting of the pump body (4) has filtering component (6), its characterized in that: the left side of the filtering component (6) is provided with a mounting cover (7) and a bolt (8), the inner wall of the filter component (6) is provided with a filter cartridge (11) through a mounting cover (7), a bolt (8) and a fixing ring (10) in a pressing fit manner, the surface of the filter cartridge (11) is respectively provided with a first filter hole (12) and a second filter hole (13), the inner wall of the filter cartridge (11) is fixedly connected with a rotating strip (14), the inner wall of the filter cylinder (11) is rotatably provided with a filter plate (15) through a rotating strip (14), the left side of the filter plate (15) is provided with a third filter hole (17), the cross section of the third filtering hole (17) is in the shape of an isosceles trapezoid with a high left and a low right, a placing groove (18) is arranged at the right side of the filter plate (15), two clamping blocks (16) are movably clamped in the placing groove (18) and are movably connected with a connecting cylinder (20) through the clamping blocks (16), the other end of the connecting cylinder (20) penetrates to the right side of the filter cylinder (11), a connecting column (21) and a first spring (22) are movably sleeved in the filter cartridge (11), the other end of the connecting column (21) is fixedly connected with a connecting plate (23), a second spring (24) is arranged between the connecting plate (23) and the filter cylinder (11).

2. A mixed flow pump with a sewage pretreatment device according to claim 1, characterized in that: inlet tube (9) fixed mounting is in the left side of installation lid (7), outlet pipe (5) fixed mounting is in the front of the pump body (4), solid fixed ring (10) fixed connection is in the left side of filtering component (6) inner wall, the outward flange and solid fixed ring (10) extrusion contact of cartridge filter (11).

3. A mixed flow pump with a sewage pretreatment device according to claim 1, characterized in that: the left side fixedly connected with rotating plate (19) of filter (15), the quantity of rotating plate (19) is four and be the surface of angular distribution at filter (15) such as, filter (15) are staggered arrangement with No. three filtration pore (17).

4. A mixed flow pump with a sewage pretreatment device according to claim 1, characterized in that: the rotating strip (14) is spirally distributed on the inner wall of the filter cartridge (11), the number of spiral turns of the filter cartridge (11) is two, and the filter plate (15) is clamped on the outer surface of the rotating strip (14) in an adaptive mode.

5. A mixed flow pump with a sewage pretreatment device according to claim 1, characterized in that: the cross section of the clamping block (16) is T-shaped, the clamping block (16) is rotationally clamped in the placing groove (18), and one end of the connecting cylinder (20) connected with the clamping block (16) is in limit contact with the right side of the filter plate (15).

6. A mixed flow pump with a sewage pretreatment device according to claim 1, characterized in that: a spring (22) and spliced pole (21) turn right from a left side and establish in proper order the inside at connecting cylinder (20), spliced pole (21) support in the inside of connecting cylinder (20) through a spring (22) elastic support, the right-hand member and connecting plate (23) extrusion contact of connecting cylinder (20), the both ends of No. two spring (24) respectively with cartridge filter (11) and connecting plate (23) elastic connection.

7. A mixed flow pump with a sewage pretreatment device according to claim 1, characterized in that: no. one filter pore (12) set up the surface at cartridge filter (11), no. two filter pore (13) set up the right side at cartridge filter (11), no. two diameter values of filtering pore (13) are greater than the diameter value of a filter pore (12).

8. A mixed flow pump with a sewage pretreatment device according to claim 1, characterized in that: the first spring (22) is compressed by the connecting column (21) and arranged inside the connecting cylinder (20), and the second spring (24) is in a stretched state under an initial condition.

9. A mixed flow pump with a sewage pretreatment device according to claim 1, characterized in that: the diameter value of the narrowest part of the third filtering hole (17) is larger than that of the second filtering hole (13).