CN219689489U - Membrane bioreactor for sewage treatment - Google Patents

Abstract

The utility model relates to a membrane bioreactor for sewage treatment, which comprises a box body in a cuboid shape, wherein the inside of the box body is divided into a left inner cabin and a right inner cabin by a grid plate, the top of the left side of the box body is provided with a water inlet pipe communicated with the left inner cabin, the top of the right side of the box body is provided with a water outlet pipe communicated with the right inner cabin, the bottom of the left inner cabin is provided with a sewage outlet, a gate valve is arranged on the sewage outlet, a pushing mechanism for pushing sundries to the sewage outlet is arranged in the left inner cabin, a cleaning component is arranged on one side, close to the grid plate, of the right inner cabin, the cleaning component is communicated with an external clean water source, the cleaning component shoots water flow towards the grid plate to flush sundries hung on one side of the left inner cabin of the grid plate, the cleaning component is arranged on a lifting mechanism, the lifting mechanism enlarges the water flow coverage area by adjusting the height of the cleaning component, and the membrane bioreactor is arranged in the right inner cabin. The utility model can clean the grid plate during sewage treatment without suspending, ensures sewage treatment efficiency, has convenient sundry discharge and small workload of staff.

Description

Membrane bioreactor for sewage treatment

Technical Field

The utility model relates to the technical field of sewage treatment, in particular to a membrane bioreactor for sewage treatment.

Background

The membrane bioreactor maintains a high activated sludge concentration in the bioreactor, increases the biological treatment organic load, thereby reducing the wastewater treatment facility footprint, and reduces the amount of excess sludge by maintaining a low sludge load.

The sewage is often doped with various solid impurities, which are easy to cause blockage problem after entering the membrane bioreactor, and in order to avoid the interference of the membrane bioreactor, a grid plate is required to be arranged at the water inlet to block the impurities. Along with the increase of sewage treatment time, sundries can be gradually accumulated on the grid plate and the grid holes are blocked, so that the water inlet effect is affected, and therefore, sewage treatment operation needs to be periodically suspended, and the grid plate at the water inlet part is cleaned during the period, so that the workload of workers is increased, and the sewage treatment efficiency is reduced.

Disclosure of Invention

The utility model aims to provide a membrane bioreactor for sewage treatment, which can clean grid plates when sewage treatment operation is carried out, the work of cleaning the grid plates is completed by matching a cleaning assembly and a lifting mechanism, the sewage treatment efficiency is not affected, the workload of workers is reduced, and sundries accumulated afterwards can be pushed to a sewage outlet through a pushing mechanism for delivery, so that the cleaning is convenient.

The technical scheme of the utility model is as follows:

the utility model provides a membrane bioreactor for sewage treatment, includes the box that the shape is the cuboid, the box is inside to divide into left interior cabin and right interior cabin by the grid tray, the left side top of box is equipped with the inlet tube that leads to left interior cabin, the right side top of box is equipped with the outlet pipe that leads to right interior cabin, left side interior cabin bottom is equipped with the drain, be equipped with the gate valve on the drain, be equipped with the pushing away thing mechanism that pushes away debris to the drain in the left side interior cabin, the right side is equipped with cleaning module in the interior cabin of side near the grid tray, cleaning module communicates external clean water source, cleaning module is through the debris that jets out water stream to grid tray left side interior cabin to hang, cleaning module establishes on elevating system, elevating system enlarges the coverage that cleaning module jetted out water stream through adjusting cleaning module's height, be equipped with membrane bioreactor in the right side interior cabin is equipped with the aeration pipe below membrane bioreactor, the box is equipped with the air-blower with the aeration pipe outside.

Preferably, the pushing mechanism comprises a motor A, a threaded rod A, a rotating seat A, a sliding rod, a pushing plate and a threaded sleeve, the threaded rod A along the left and right directions is arranged in the left inner cabin, the rotating seat A is rotationally connected to the left wall of the left inner cabin, the left end of the threaded rod A is coaxially connected with the rotating seat A, the motor A is arranged on the left side outside the box body, a driving rod of the motor A penetrates into the box body and is coaxially connected with the rotating seat A, the threaded sleeve is in threaded connection with the threaded rod A, a sliding rod parallel to the threaded rod A is arranged below the threaded rod A, the left end of the sliding rod is connected with the left wall of the left inner cabin, the pushing plate along the front and rear directions is arranged on the sliding rod, the top of the pushing plate is connected with the lower surface of the threaded sleeve, the bottom of the pushing plate is propped against the bottom of the left inner cabin, and the front and rear ends of the pushing plate are propped against the inner wall of the left inner cabin, and drain openings are symmetrically arranged on the left and right sides of the bottom of the left inner cabin.

Preferably, a rubber layer is arranged at the bottom of the pushing plate, and the rubber layer is propped against the bottom of the left inner cabin.

Preferably, the cleaning assembly comprises a lifting plate, a water delivery hose, a butt joint, a mounting plate and spray heads, wherein the lifting plate is connected with the lifting mechanism, the mounting plate is arranged at one end of the lifting plate, which faces towards the grid plate, the mounting plate is parallel to the grid plate, the butt joint is arranged at the top of the lifting plate, a plurality of spray heads are uniformly arranged at one side of the mounting plate, which faces towards the grid plate, of the lifting plate, water delivery passages leading to the spray heads from the butt joint are arranged in the lifting plate and the mounting plate, the butt joint is connected with the water delivery hose, the water delivery hose is communicated with an external clean water source, a through hole for the water delivery hose to pass through is formed at the top of the box, and the water delivery hose can slide at the through hole.

Preferably, a sealing ring is arranged on the through hole, and the sealing ring is tightly attached to the outer wall of the water delivery hose.

Preferably, the mounting plate is cuboid along the fore-and-aft direction, the left side wall of mounting plate evenly is equipped with the shower nozzle along the length limit direction, the right side wall middle part of mounting plate links to each other with the lifter plate, the length of mounting plate is equivalent with the length of grid tray in the fore-and-aft direction.

Preferably, elevating system includes motor B, threaded rod B, sliding chamber, rotates seat B and base constitution, be equipped with in the right side in the cabin along the threaded rod B of vertical direction, threaded rod B's top is equipped with rotates seat B, rotate seat B and right side in the cabin top and rotate and be connected, the box top is equipped with motor B, motor B's actuating lever penetrates the box downwards and rotates seat B coaxial coupling, right side in the cabin bottom be equipped with the base, threaded rod B's bottom is rotated with the base and is connected, be equipped with the screw hole that corresponds threaded rod B on the lifter plate, threaded rod B and screw hole threaded connection, right side in the cabin be equipped with along vertical direction's sliding chamber, the upper and lower both ends of sliding chamber link to each other with the top and the bottom in the right side in the cabin respectively, be equipped with the sliding block on the lifter plate, the sliding block slides along the sliding chamber.

Preferably, square through holes along the vertical direction are symmetrically formed in the left side and the right side of the sliding cavity, and the lifting plate penetrates through the sliding cavity from the square through holes.

The utility model has the beneficial technical effects that:

1. the sewage that needs to handle is from inlet tube box, when sewage passes through the grid tray, the debris that the size is greater than the grid tray upper grid hole is left in the left interior cabin and sink to the bottom of left interior cabin under the influence of gravity, the left side at the grid tray can be hung before sinking takes place to fractional debris and accumulation gradually, make the high-speed rivers that jet to the grid tray from the right side through cleaning assembly, wash down the debris of hanging from the grid tray, realize the effect of clearance grid tray, the problem that the grid tray is piled up because of the debris and is blockked up has been solved, and need not to pause sewage treatment for special clearance grid tray, do not influence sewage treatment efficiency, the clearance work manual participation degree of grid tray is low, staff's work load has been reduced.

2. The washed sundries sink to the bottom of the left inner cabin under the action of gravity, are converged with the naturally settled sundries, and then are sent out of the box body from the sewage outlet together, when sundries are cleaned, sundries scattered at all positions of the bottom of the left inner cabin are pushed to the sewage outlet by the pushing mechanism, meanwhile, the gate valve of the sewage outlet is opened, and the sundries leave the box body from the exposed sewage outlet, so that the cleaning is convenient.

Drawings

The technical scheme of the utility model is further described below with reference to the accompanying drawings.

Fig. 1 is a cross-sectional view of the main view of the present utility model.

Fig. 2 is a top view of the cleaning assembly of the present utility model.

FIG. 3 is an internal schematic view of the cleaning assembly of the present utility model.

Fig. 4 is a top view of the left inner compartment of the present utility model.

Fig. 5 is an enlarged view of a portion a of fig. 1.

In the figure: 1-box, 2-inlet tube, 3-outlet pipe, 4-drain, 5-gate valve, 6-pushing mechanism, 7-cleaning component, 8-elevating system, 9-membrane bioreactor, 10-aeration pipe, 11-air-blower, 12-motor A, 13-threaded rod A, 14-rotating seat A, 15-sliding rod, 16-pushing plate, 17-threaded sleeve, 18-rubber layer, 19-elevating plate, 20-water hose, 21-butt joint, 22-mounting plate, 23-shower nozzle, 24-water delivery channel, 25-sealing ring, 26-motor B, 27-threaded rod B, 28-sliding cavity, 29-rotating seat B, 30-base, 31-sliding block, 32-square through hole, 33-grid plate.

Detailed Description

The utility model will be described in further detail with reference to the accompanying drawings and specific examples.

Examples:

as shown in fig. 1 to 5, the present embodiment provides a membrane bioreactor for sewage treatment, comprising a box 1 in the shape of a cuboid, wherein the inside of the box 1 is divided into a left inner chamber and a right inner chamber by a grid plate 33, the left top of the box 1 is provided with a water inlet pipe 2 which is communicated with the left inner chamber, the right top of the box 1 is provided with a water outlet pipe 3 which is communicated with the right inner chamber, the bottom of the left inner chamber is provided with a sewage outlet 4, the sewage outlet 4 is provided with a gate valve 5, the left inner chamber is internally provided with a pushing mechanism 6 which pushes sundries to the sewage outlet 4, the right inner chamber is internally provided with a cleaning component 7 at one side close to the grid plate 33, the cleaning component 7 is communicated with an external clean water source, the cleaning component 7 is used for flushing sundries hung on one side of the left inner chamber of the grid plate 33 by injecting water to the grid plate 33, the cleaning component 7 is arranged on a lifting mechanism 8, the lifting mechanism 8 is used for expanding the coverage of the water flow which is injected by adjusting the height of the cleaning component 7, the right inner chamber is provided with a membrane bioreactor 9, the right inner chamber is provided with an aerator pipe 10 below the membrane bioreactor 9, the box 1 is provided with an aerator pipe 10, and an aerator pipe 11 is arranged outside the box 1 is communicated with an aerator pipe 11.

Sewage enters the box body 1 from the water inlet pipe 2, sundries are blocked by the grid plate 33 and are left in the left inner cabin, interference to the membrane bioreactor 9 in the right inner cabin is avoided, microorganisms in the sewage entering the right inner cabin are intercepted by the membrane bioreactor 9, the air blower 11 supplies air to the aeration pipe 10, the aeration pipe 10 generates upward flowing water flow in the right inner cabin, the upward water flow acts on the membrane bioreactor 9, the pollutant attachment speed on the membrane bioreactor 9 can be relieved, and the treated sewage can leave the box body 1 from the water outlet pipe 3. When sewage to be treated passes through the grid plate 33 from the box body 1 of the water inlet pipe 2, sundries with the size larger than the grid holes on the grid plate 33 are left in the left inner cabin and sink to the bottom of the left inner cabin under the influence of gravity, a small part of sundries can be hung on the left side of the grid plate 33 before sinking and gradually accumulated, high-speed water flow which is emitted to the grid plate 33 from the right side is manufactured through the cleaning assembly 7, the hung sundries are flushed from the grid plate 33, the effect of cleaning the grid plate 33 is achieved, the problem that the grid plate 33 is blocked due to accumulation of sundries is solved, sewage treatment is not needed to be suspended for specially cleaning the grid plate 33, the sewage treatment efficiency is not influenced, the manual participation of cleaning work of the grid plate 33 is low, and the workload of workers is reduced. The washed sundries sink to the bottom of the left inner cabin under the action of gravity, are converged with the sundries which are naturally settled, and then are sent out of the box body 1 from the sewage outlet 4 together, when sundries are cleaned, sundries scattered at all positions of the bottom of the left inner cabin are pushed to the sewage outlet 4 by the pushing mechanism 6, meanwhile, the gate valve 5 of the sewage outlet 4 is opened, and the sundries leave the box body 1 from the exposed sewage outlet 4, so that the cleaning is convenient.

As shown in fig. 1 and 4, the pushing mechanism 6 includes a motor a12, a threaded rod a13, a rotating seat a14, a sliding rod 15, a pushing plate 16 and a threaded sleeve 17, the left inner cabin is provided with the threaded rod a13 along the left-right direction, the rotating seat a14 is rotatably connected on the left wall of the left inner cabin, the left end of the threaded rod a13 is coaxially connected with the rotating seat a14, the motor a12 is arranged on the left side outside the box body 1, a driving rod of the motor a12 penetrates into the box body 1 and is coaxially connected with the rotating seat a14, the threaded rod a13 is in threaded connection with the threaded sleeve 17, a sliding rod 15 parallel to the threaded rod a13 is arranged below the threaded rod a13, the left end of the sliding rod 15 is connected with the left wall of the left inner cabin, the sliding rod 15 is provided with the pushing plate 16 along the front-rear direction, the pushing plate 16 slides along the direction of the sliding rod 15, the top of the pushing plate 16 is connected with the lower surface of the threaded sleeve 17, the bottom of the pushing plate 16 is propped against the bottom of the left inner cabin, the front-rear ends of the pushing plate 16 are propped against the inner wall of the left inner cabin, and the left inner cabin bottom of the left inner cabin is symmetrically provided with a sewage draining port 4.

The motor a12 drives the threaded rod a13 to rotate, and the threaded sleeve 17 is in threaded connection with the threaded rod a13, so that the movement direction of the pushing plate 16 connected with the threaded sleeve 17 is limited by the sliding rod 15, and the pushing plate 16 can move in the left-right direction when the threaded rod a13 rotates. The initial position of the pushing plate 16 is in the middle of the bottom of the left inner cabin, the drain outlets 4 are symmetrically arranged on the left side and the right side of the bottom of the left inner cabin, and when the pushing plate 16 reciprocates between the two drain outlets 4, sundries on the left side and the right side of the pushing plate 16 can be pushed to the corresponding drain outlets 4 respectively, and when the gate valve 5 is opened, the sundries are discharged from the drain outlets 4 to the box body 1. The bottom, front and rear ends of the pushing plate 16 are propped against the inner wall of the left inner cabin, so that the pushing plate 16 can clean sundries which are tightly attached to the bottom of the left inner cabin conveniently.

Further, a rubber layer 18 is arranged at the bottom of the pushing plate 16, and the rubber layer 18 is propped against the bottom of the left inner cabin. The rubber layer 18 is propped against the bottom of the left inner cabin, so that abrasion caused by the fact that the pushing plate 16 is propped against the bottom of the left inner cabin directly is reduced, and gaps between the pushing plate 16 and the bottom of the left inner cabin are reduced through the rubber layer 18 with elasticity, and the effect of pushing sundries is improved.

As shown in fig. 2, 3 and 5, the cleaning assembly 7 comprises a lifting plate 19, a water delivery hose 20, a butt joint 21, a mounting plate 22 and spray heads 23, wherein the lifting plate 19 is connected with the lifting mechanism 8, the mounting plate 22 is arranged at one end of the lifting plate 19 facing the grid plate 33, the mounting plate 22 is parallel to the grid plate 33, the butt joint 21 is arranged at the top of the lifting plate 19, a plurality of spray heads 23 are uniformly arranged at one side of the mounting plate 22 facing the grid plate 33, water delivery passages 24 leading from the butt joint 21 to the spray heads 23 are arranged in the lifting plate 19 and the mounting plate 22, the butt joint 21 is connected with the water delivery hose 20, the water delivery hose 20 is communicated with an external clean water source, a through hole for the water delivery hose 20 to pass through is arranged at the top of the box 1, and the water delivery hose 20 can slide at the through hole.

The clean water provided from the outside is sent to the butt joint 21 along the water hose 20, then sent to each spray head 23 along the water delivery channel 24 in the lifting plate 19 and the mounting plate 22, water flow which is shot to the grid plate 33 is generated at the spray heads 23, meanwhile, the lifting plate 19 moves back and forth in the vertical direction under the action of the lifting mechanism 8, the spray heads 23 move along with the mounting plate 22 connected with the lifting plate 19, and the water flow sweeps up and down each part of the grid plate 33 in the moving process, impurities hung at each part of the grid plate 33 are washed down, and the cleaning of the grid plate 33 is realized.

Further, a sealing ring 25 is arranged on the through hole, and the sealing ring 25 is tightly attached to the outer wall of the water delivery hose 20. The gap between the water hose 20 and the through hole is reduced, and the leakage of sewage is avoided.

Further, the mounting plate 22 is a cuboid along the front-rear direction, the spray heads 23 are uniformly arranged on the left side wall of the mounting plate 22 along the long side direction, the middle part of the right side wall of the mounting plate 22 is connected with the lifting plate 19, and the length of the mounting plate 22 is equivalent to the length of the grid plate 33 along the front-rear direction. The length of mounting panel 22 is equivalent with the width of grid tray 33, and mounting panel 22 evenly is equipped with shower nozzle 23 towards one side of grid tray 33, increases the coverage of rivers, reduces the dead angle area that can't be washed by rivers on the grid tray 33, improves the clearance effect.

Further, elevating system 8 includes motor B26, threaded rod B27, sliding chamber 28, rotate seat B29 and base 30 constitution, be equipped with along the threaded rod B27 of vertical direction in the right side in the cabin, the top of threaded rod B27 is equipped with rotates seat B29, rotate seat B29 and right side in the cabin top and rotate and be connected, box 1 top is equipped with motor B26, the actuating lever of motor B26 penetrates box 1 downwards and rotates seat B29 coaxial coupling, right side in the cabin bottom is equipped with base 30, the bottom and the base 30 rotation of threaded rod B27 are connected, be equipped with the screw hole that corresponds threaded rod B27 on the lifter plate 19, threaded rod B27 and screw hole threaded connection, right side in the cabin be equipped with along vertical direction's sliding chamber 28, the upper and lower both ends of sliding chamber 28 link to each other with the top and the bottom in the right side in the cabin, be equipped with slider 31 on the lifter plate 19, slider 31 slides along sliding chamber 28.

The motor B26 drives the threaded rod B27 to rotate, and the lifting plate 19 is in threaded connection with the threaded rod B27 through the threaded hole, so that the moving direction of the lifting plate 19 is limited by the sliding cavity 28 through the sliding block 31 on the lifting plate 19, and the lifting plate 19 can move in the vertical direction when the threaded rod B27 rotates, so that the effect of adjusting the height of the lifting plate 19 is achieved.

The sliding cavity 28 is symmetrically provided with square through holes 32 along the vertical direction on the left and right sides, and the lifting plate 19 passes through the sliding cavity 28 from the square through holes 32.

The working principle and the using flow of the utility model are as follows:

sewage enters the box body 1 from the water inlet pipe 2, sundries are blocked by the grid plate 33 and are left in the left inner cabin, interference to the membrane bioreactor 9 in the right inner cabin is avoided, microorganisms in the sewage entering the right inner cabin are intercepted by the membrane bioreactor 9, the air blower 11 supplies air to the aeration pipe 10, the aeration pipe 10 generates upward flowing water flow in the right inner cabin, the upward water flow acts on the membrane bioreactor 9, the pollutant attachment speed on the membrane bioreactor 9 can be relieved, and the treated sewage can leave the box body 1 from the water outlet pipe 3. The lifting mechanism 8 controls the cleaning assembly 7 to reciprocate up and down, and the cleaning assembly 7 produces a water flow to the grid plate 33 in the right inner compartment to wash down the sundries hung on the grid plate 33. Sundries settled at the bottom of the left inner cabin under the action of gravity can be pushed to the sewage outlet 4 by the pushing mechanism 6, and the sundries are discharged out of the box body 1 from the sewage outlet 4 after the gate valve 5 is opened.

The foregoing is merely a specific application example of the present utility model, and the protection scope of the present utility model is not limited in any way. All technical schemes formed by equivalent transformation or equivalent substitution fall within the protection scope of the utility model.

Claims (8)

1. A membrane bioreactor for sewage treatment, characterized in that: including the box that the shape is the cuboid, the box is inside to divide into left interior cabin and right interior cabin by the grid tray, the left side top of box is equipped with the inlet tube that leads to left interior cabin, the right side top of box is equipped with the outlet pipe that leads to right interior cabin, left side interior cabin bottom is equipped with the drain, be equipped with the gate valve on the drain, be equipped with the pushing away thing mechanism that pushes away debris to the drain in the left side interior cabin, the right side is interior to be equipped with cleaning element in one side near the grid tray, cleaning element communicates external clean water source, cleaning element is through penetrating out the rivers to the grid tray and dashing down the debris of hanging in grid tray left side interior cabin one side, cleaning element establishes on elevating system, elevating system enlarges the coverage that cleaning element penetrated rivers through the adjustment cleaning element's height, be equipped with the membrane bioreactor in the right side interior cabin, the right side is equipped with the aeration pipe below the membrane bioreactor, the box is equipped with the air-blower with the aeration pipe switch-on.

2. A membrane bioreactor for sewage treatment according to claim 1, wherein: the utility model provides a push away thing mechanism includes motor A, threaded rod A, rotates seat A, slide bar, pushes away thing board and thread bush, left side inner compartment is equipped with along left and right sides's threaded rod A, rotate on the left wall of left side inner compartment and be connected with rotation seat A, threaded rod A's left end and rotate seat A coaxial coupling, the box outside left side is equipped with motor A, motor A's actuating lever penetrates in the box and rotates seat A coaxial coupling, threaded rod A goes up threaded connection and has the thread bush, threaded rod A below is equipped with the slide bar that parallels with threaded rod A, the left end of slide bar links to each other with the left wall of left side inner compartment, be equipped with on the slide bar along the push away thing board of fore-and-aft direction, push away thing board top and thread bush lower surface and link to each other, push away the bottom of thing board and left inner compartment bottom counterbalance, push away the front and back both ends and left inner compartment inner wall of thing board, left side inner compartment bottom left and right sides symmetry is equipped with the drain.

3. A membrane bioreactor for sewage treatment according to claim 2, wherein: the bottom of the pushing plate is provided with a rubber layer, and the rubber layer is propped against the bottom of the left inner cabin.

4. A membrane bioreactor for sewage treatment according to claim 1, wherein: the cleaning assembly comprises a lifting plate, a water delivery hose, a butt joint, a mounting plate and spray heads, wherein the lifting plate is connected with a lifting mechanism, the mounting plate is arranged at one end of the lifting plate, which faces towards the grid plate, the mounting plate is parallel to the grid plate, the butt joint is arranged at the top of the lifting plate, a plurality of spray heads are uniformly arranged at one side of the mounting plate, which faces towards the grid plate, of the lifting plate, water delivery passages leading to the spray heads from the butt joint are arranged in the lifting plate and the mounting plate, the butt joint is connected with the water delivery hose, the water delivery hose is communicated with an external clean water source, a through hole for the water delivery hose to pass through is formed in the top of the box, and the water delivery hose can slide at the through hole.

5. A membrane bioreactor for sewage treatment according to claim 4, wherein: and a sealing ring is arranged on the through hole and is clung to the outer wall of the water delivery hose.

6. A membrane bioreactor for sewage treatment according to claim 4, wherein: the mounting plate is cuboid along fore-and-aft direction, the left side wall of mounting plate evenly is equipped with the shower nozzle along the length limit direction, the right side wall middle part of mounting plate links to each other with the lifter plate, the length of mounting plate is equivalent with the length of grid tray in fore-and-aft direction.

7. A membrane bioreactor for sewage treatment according to claim 4, wherein: the lifting mechanism comprises a motor B, a threaded rod B, a sliding cavity, a rotating seat B and a base, wherein the threaded rod B in the vertical direction is arranged in the right inner cabin, the top end of the threaded rod B is provided with the rotating seat B, the rotating seat B is rotationally connected with the top of the right inner cabin, the top of the box body is provided with the motor B, a driving rod of the motor B penetrates into the box body downwards and is coaxially connected with the rotating seat B, the bottom of the right inner cabin is provided with the base, the bottom of the threaded rod B is rotationally connected with the base, a threaded hole corresponding to the threaded rod B is formed in the lifting plate, the threaded rod B is in threaded connection with the threaded hole, the sliding cavity in the vertical direction is formed in the right inner cabin, the upper end and the lower end of the sliding cavity are respectively connected with the top and the bottom of the right inner cabin, and the sliding block is arranged on the lifting plate and slides along the sliding cavity.

8. A membrane bioreactor for sewage treatment according to claim 7, wherein: the left side and the right side of the sliding cavity are symmetrically provided with square through holes along the vertical direction, and the lifting plate penetrates through the sliding cavity from the square through holes.