CN110404314A - Pre-filter with top-controlled backwash - Google Patents

Abstract

The invention relates to a pre-filter with a top-controlled backwashing function, which includes: a machine head with a water inlet and a water outlet, and a filter bottle with a sealable sewage discharge member matched with the machine head. There is a filtering and backwashing mechanism inside the bottle. The gap between the outside of the filtering and backwashing mechanism and the filter bottle forms a raw water chamber, and the interior of the filtering and backwashing mechanism forms a purified water chamber. The filtering and backwashing mechanism includes filter elements and The backwashing element arranged on the same axis, the raw water chamber can be connected with the water inlet of the filter element, and the purified water chamber can be connected with the water outlet. The backwashing element can be driven by external force to move axially relative to the filter element. It is fixedly connected mechanically with the external force output mechanism, and the external force output mechanism is arranged on the top of the machine head. The invention has reasonable structural design, simple and convenient assembly, and can realize reverse flushing by switching flow channels.

Description

Pre-filter with top-controlled backwash

technical field

The invention relates to a pre-filter with top-controlled backwashing function, belonging to the technical field of water treatment and purification equipment.

Background technique

The pre-filter in the prior art includes: a machine head, a filter bottle whose upper end is connected to the machine head, a drain seal connected to the lower end of the filter bottle, and a drain ball valve connected to the drain seal, and a filter screen skeleton is arranged inside the filter bottle , the outer wall of the filter screen skeleton is provided with a filter screen. During use, water flows into the gap between the filter bottle and the filter screen from the water inlet of the machine head, flows into the center of the filter screen frame after being filtered by the filter screen, and then flows from the center of the filter screen frame to the water outlet of the machine head.

With this pre-filter, drinking water from a drinking water supply can be filtered before it is available at the tap. The impurities accumulated in the filter gradually clog the filter. As a result, an undesired pressure drop is caused. Affect the service life of the pre-filter. In the prior art, the manual disassembly and cleaning is low in cleaning efficiency and easy to damage the components. Therefore, it is necessary to design a pre-filter component that can be backwashed. By switching the flow channel and backwashing, it will pass through the filter in the opposite direction. The water flow of the net cleans the filter net again, and the water that receives impurities during the reverse flushing process is discharged through the drain ball valve.

The present invention aims to solve this technical problem, and provides a pre-filter with top-controlled backwashing function.

Contents of the invention

One of the objectives of the present invention is to solve the deficiencies of the prior art, and provide a pre-filter with top-controlled backwashing function.

The technical solution adopted by the present invention to solve its technical problems is:

A pre-filter with a top-controlled backwashing function, which includes: a machine head with a water inlet and a water outlet, and a filter bottle with a closed sewage discharge member matched with the machine head, and the filter bottle is equipped with a filter and the backwashing mechanism, the gap between the outside of the filtering and backwashing mechanism and the filter bottle forms the raw water cavity, and the interior of the filtering and backwashing mechanism forms the purified water cavity, the filtering and backwashing mechanism includes a filter element and a concentrically arranged reflector The flushing element, the raw water chamber can communicate with the water inlet of the filter element, the purified water chamber can communicate with the water outlet, and the backwash element can move axially relative to the filter element driven by external force, so as to realize the switching between the filter function and the backwash function, The backwashing element is fixedly connected mechanically with the external force output mechanism, and the external force output mechanism is arranged on the top of the machine head.

Preferably, the filter element is composed of a filter screen body, a filter screen skeleton, and water inlet end caps and drain end caps located at both ends of the filter mesh skeleton. The end cap is connected with the inlet of the machine head, and a raw water cavity is formed between the filter body and the filter bottle;

The backwashing element includes a backwashing filter body, a backwashing filter frame and a backwashing filter lower seal with a drainage channel. The backwash filter body assembly cavity in the head is sealed at both ends. The lower seal of the backwash filter passes through the drain end cover and is detachably connected to the backwash filter frame, and the drain end cover is circumferentially sealed with the lower end of the backwash filter frame. , the backwash filter skeleton can move axially relative to the filter element synchronously with the backwash filter body;

After a certain stroke in the downward axial direction, the working surface under the assembly part can close the water inlet end cover, and the backwash filter body leaks out, realizing the switching of the flow channel and entering the backwashing working mode;

After moving upward for a certain distance, the working surface under the assembly part opens the water inlet cover, and the backwash filter body is closed to realize flow channel switching and enter the filter working mode.

Preferably, the external force output mechanism includes: a drive shaft and a manual drive knob fixed at its end, a drive shaft assembly cavity is provided on the top of the machine head, the drive shaft is screwed to the machine head and can be sealed, and the drive shaft extends to the backwash In the frame of the filter screen, it abuts against the lower seal body of the backwash filter screen in the frame of the backwash filter screen, and can drive the skeleton of the backwash filter screen and the lower seal body of the backwash filter screen to move axially and rotate together.

Preferably, the manual driving knob includes a knob body and a positioning member, the knob body is sleeved on the positioning member and detachably connected to the end of the drive shaft, and the positioning member is screwed and fixed to the drive shaft assembly cavity.

Preferably, the external force output mechanism includes: a drive shaft, a drive motor connected to its end, and an axial stroke control mechanism. The top of the machine head is provided with a drive shaft assembly cavity, and the drive shaft is screwed to the machine head and can be sealed. It extends into the frame of the backwash filter screen and abuts against the lower seal body of the backwash filter screen in the frame of the backwash filter screen, and can drive the skeleton of the backwash filter screen and the lower seal body of the backwash filter screen to move and rotate axially together. The axial stroke control mechanism controls the forward and reverse rotation of the driving motor, and then drives the axial movement stroke of the drive shaft, and the axial stroke control mechanism includes a limit switch.

Preferably, a first limiter is provided in the frame of the backwash filter screen, and an adapted second limiter is provided on the drive shaft, and the axial displacement stroke of the drive shaft is controlled through the cooperation of the first and second limiter .

Preferably, the backwashing element is provided with a backwashing water distribution member that generates a larger flow rate with a smaller flow diameter, and the backwashing water distribution member is sleeved on the drive shaft and has a relatively fixed axial position, and can Rotate around drive shaft.

Preferably, the draining part of the filter bottle is provided with a cavity with a gradually reduced diameter in the middle and a gradually increased diameter at both ends; when in the filtering state, the outer edge of the end of the backwash filter screen lower sealing body cooperates with the smallest diameter part to realize The sewage parts are sealed. When switching to the backwashing state, the lower seal of the backwashing filter is driven by external force and moves downward, entering the part where the diameter gradually increases. The sewage channel is formed, and the sewage parts are opened; at least the outer edge of the lower seal of the backwash filter has elastic deformation and reset functions.

Preferably, the backwash water distribution member is provided with several nozzles capable of spraying water in a tangential direction, and preferably, the nozzles of the backwash water distribution member are staggered along the axial direction.

Preferably, the outside of the filter element is also provided with a directional cleaning assembly, including a guide piece and an adjustment piece. The guide piece includes at least one guide groove extending axially along the filter element and is fixed with the guide groove and can be connected with the filter element. An assembly seat with a suitable bottom shape, the assembly seat is provided with an assembly hole, and is socketed on the lower seal of the backwash filter through the assembly hole, and at least one limiter is provided at the bottom of the assembly seat;

The adjustment part is provided with an assembly hole and a chamber adapted to the assembly seat, which is socketed on the lower seal of the backwash filter through the assembly hole and can rotate synchronously. At least one limiting groove is provided on the edge of the chamber, and a at least one through hole;

When the lower sealing body of the backwash filter moves downward in the axial direction and rotates, the adjustment member is driven, and then the guide member is driven to rotate around the filter element in the circumferential direction, and the backwash water is discharged through the through hole and the sewage channel to realize the backwash discharge of large particles of impurities;

During the upward rotation and reset process of the lower seal of the backwash filter, the adjustment piece and the guide piece are dislocated, the through hole of the adjustment piece is closed, and the backwash water enters the sewage channel along the gap between the flow guide piece and the adjustment piece and is discharged to realize negative pressure. Directional backwash.

Preferably, the drive shaft adopts a split design, including an upper drive shaft and a lower drive shaft, the upper drive shaft is screwed to the machine head, and the lower drive shaft is detachably connected to the upper drive shaft.

The beneficial effects of the present invention are: the present invention has a reasonable structural design, is easy to assemble, and can realize reverse flushing by switching flow channels. When the filter is in working state, the water enters from the inlet of the machine head through the water inlet end cover and enters from the outside of the filter body through the raw water cavity, and the impurities are retained by the filter body, and the purified water entering the inside passes through the backwashing filter frame, and is discharged from the filter body. The top of the sealing cover flows to the outlet of the machine head; in the working state of backwashing, through the external force output mechanism, the driving shaft is driven downward, the backwashing element is down, the backwashing filter body leaks out of the sealing cover, and the assembly department of the backwashing filter skeleton works The water inlet end cover is closed on the surface, and the sewage part is opened at the same time to realize the switching of the flow channel. The imported water flows out from the inside after being filtered by the backwash filter body, and the filter body is backwashed, and the backwashed water containing impurities is filtered through the backwash filter. The drainage channel of the seal under the net flows out and is discharged through the sewage discharge member.

Description of drawings

Fig. 1 is the perspective view of pre-filter of the present invention;

Fig. 2 is the exploded view of pre-filter of the present invention;

Fig. 3 is the assembly schematic diagram of pre-filter of the present invention;

Fig. 4 is the sectional view under the filtering state of pre-filter of the present invention;

Fig. 5 is a sectional view under the backwashing state of the pre-filter of the present invention;

Fig. 6 is the front view of the pre-filter of Embodiment 2 of the present invention;

Fig. 7 is the exploded view of the pre-filter of embodiment 2 of the present invention;

Fig. 8 is a cross-sectional view of a pre-filter according to Embodiment 2 of the present invention.

Among the figure: 1, machine head, 2, sewage parts, 3, filter bottle, 4, filter element, 41, filter screen body, 42, filter screen skeleton, 43, water inlet end cover, 44, drain end cover, 5, Backwash element, 51, backwash filter body, 52, backwash filter skeleton, 52a, assembly part, 53, backwash filter body assembly cavity, 54, backwash filter lower seal, 6, drive shaft, 61. Actuating part, 6a, upper drive shaft, 6b, lower drive shaft, 7, manual drive knob, 7a, knob body, 7b, positioning part, 8, backwash water distribution part, 8a, nozzle, 9, cavity, 10. Directional cleaning assembly, 11. Flow guide, 11a, flow guide groove, 11b, assembly seat, 11c, limit piece, 12, adjustment piece, 12a, limit groove, 12b, through hole, 13, drive motor, 14, limit switch, 15, fixing seat, 16, protective cover.

Detailed ways

The technical solutions of the present invention will be further specifically described below through specific embodiments and in conjunction with the accompanying drawings.

Example 1

As shown in Fig. 1 and Fig. 3, the pre-filter with the top control backwashing function includes: a machine head 1 with a water inlet and a water outlet; filter bottle 3, the filter bottle 3 is provided with a filtering and backwashing mechanism, the gap between the outside of the filtering and backwashing mechanism and the filter bottle 3 constitutes a raw water chamber, and the inside of the filtering and backwashing mechanism forms a purified water chamber, the said The filtering and backwashing mechanism includes a filter element 4 and a backwashing element 5 arranged coaxially. The raw water chamber can communicate with the water inlet of the filter element 4, and the purified water chamber can communicate with the water outlet. The backwashing element 5 can communicate with the filter element. 4. Axial movement driven by external force. The backwashing element 5 is fixedly connected mechanically with the external force output mechanism, and the external force output mechanism is arranged on the top of the machine head 1.

Specifically to the present invention, as shown in Figure 2, the filter element 4 is composed of a filter screen body 41, a filter screen frame 42, and a water inlet end cover 43 and a discharge end cover 44 positioned at both ends of the filter screen frame 42, the water inlet end cover The external dimensions of 43 are matched with the upper end of the filter bottle 3, the water inlet end cover 43 is connected with the inlet of the machine head 1, and a raw water chamber is formed between the filter screen body 41 and the filter bottle 3;

The backwash element 5 includes a backwash filter body 51, a backwash filter frame 52, and a backwash filter lower seal 54 with a drainage channel, and the backwash filter body 51 is socketed on the assembly part of the backwash frame 52 52a, the backwash filter body assembly cavity 53 placed in the machine head 1 and sealed at both ends, the backwash filter lower seal 54 passes through the drain end cover 44 and is detachably connected to the backwash filter skeleton 52 (sleeve or abutting), the drainage end cover 44 is circumferentially sealed with the lower end of the backwash filter frame 52, and the backwash filter frame 52 can move axially relative to the filter element 4 synchronously with the backwash filter body 51;

When moving downward in the axial direction, the backwash filter state, the lower working surface of the assembly part 52a can close the water inlet cover 43, the backwash filter body 51 leaks out, and the water in the water inlet of machine head 1 can pass through the backwash filter body 51 , to realize flow channel switching and enter the backwashing working mode.

After moving upward for a certain stroke, the lower working surface of the assembly part 52a opens the water inlet end cover 43, and the backwash filter screen body 51 is closed to realize flow channel switching and enter the filtering working mode.

Specifically to the present invention, as shown in Figure 2, the external force output mechanism includes: a drive shaft 6 and a manual drive knob 7 fixed on its end, the top of the machine head 1 is provided with a drive shaft 6 assembly cavity, the drive shaft 6 and the machine The head 1 is screwed and can be sealed. The drive shaft 6 extends into the backwash filter frame 52, abuts against the backwash filter bottom seal 54 in the backwash filter frame 52, and can drive the backwash filter frame 52 and The lower sealing body 54 of the backwash filter screen moves axially and rotates together.

In order to prevent the drive shaft 6 from being accidentally separated from the machine head 1, the manual drive knob 7 includes a knob body 7a and a positioning member 7b, the knob body 7a is sleeved on the positioning member 7b and is detachably connected to the end of the drive shaft 6 (a polygonal clip Connecting the limit is a means of realization), and the positioning part 7b is screwed with the drive shaft assembly cavity.

More specifically, the backwash filter frame 52 is provided with a first limiting member 52c, and the drive shaft 6 is provided with an adapted second limiting member 6a, and is controlled through the cooperation of the first and second limiting members. Drive shaft 6 axial displacement strokes.

For a better backwashing effect, the backwashing element 5 is provided with a backwashing water distributor 8 that produces a larger flow rate with a smaller flow diameter, and the backwashing water distribution member 8 is sleeved on the drive shaft 6 And the axial position is relatively fixed, and can rotate around the drive shaft 6 .

In the present invention, as shown in Fig. 4 and Fig. 5, the blowdown member 2 of the filter bottle 3 is provided with a cavity 9 whose middle diameter gradually decreases and the diameter of both ends gradually increases; The outer edge of the end part of the body 54 cooperates with the part with the smallest diameter to realize the sealing of the sewage discharge part 2. When switching to the backwashing state, the lower sealing body 54 of the backwashing filter screen will move downward under the action of external force, and the diameter will gradually increase. For the large part, the sewage channel is formed between the backwash filter lower seal body 54 and the cavity 9, and the sewage discharge part 2 is opened; at least the outer edge of the backwash filter screen lower seal body 54 has elastic deformation and reset functions, and the And reset, can realize the closed function, also can realize the open function.

In the present invention, in order to achieve a better effect of backwash water distribution, the backwash water distribution member 8 is provided with several nozzles 8a, which can spray water in a tangential direction. Preferably, the nozzles of the backwash water distribution member 8 8a are arranged staggeredly along the axial direction.

In order to further realize negative pressure directional backwashing and improve the backwashing effect, a directional cleaning assembly 10 is also provided outside the filter element 4, including a flow guide 11 and an adjustment piece 12. The flow guide 11 includes at least one filter element 4 along the The axially extending diversion groove 11a and the assembly seat 11b that is fixed to the diversion groove 11a and can be adapted to the shape of the bottom of the filter element 4, the assembly seat 11b is provided with an assembly hole, and is sleeved on the lower seal of the backwash filter through the assembly hole. body 54, and at least one stopper 11c is provided at the bottom of the assembly seat 11b;

The adjustment member 12 is provided with an assembly hole and a cavity adapted to the assembly seat 11b, through which the assembly hole is sleeved on the lower seal body 54 of the backwash filter and can rotate synchronously. At least one limit groove 12a is provided on the edge of the cavity, and the cavity The side of the body is provided with at least one through hole 12b;

When the lower seal body 54 of the backwash filter moves downward in the axial direction and rotates, the adjustment member 12 is driven, and then the guide member 11 is driven to rotate around the filter element 4, and the backwash water is discharged through the through hole 12b and the sewage channel to realize the removal of large particles of impurities. backwash discharge;

During the upward rotation and reset process of the lower seal body 54 of the backwash filter, the adjustment piece 12 and the guide piece 11 are misaligned, the through hole 12b of the adjustment piece 12 is closed, and the backwash water enters along the gap between the flow guide piece 11 and the adjustment piece 12 The sewage channel is discharged to realize negative pressure directional backwashing.

Specifically in the present invention, for the convenience of processing and better adaptation, the drive shaft 6 adopts a split design, including an upper drive shaft 6a and a lower drive shaft 6b, and the upper drive shaft 6a is screwed to the machine head 1 , the lower drive shaft 6b is detachably connected to the upper drive shaft 6a (such as clamping or screwing), and the split design also has the following advantages: the upper drive shaft 6a can match the size of the machine head 1, making it a larger size, and the lower drive shaft The shaft 6b can be made smaller in size, so as to ensure that the space in the backwashing element 5 is not occupied too much.

Example 2

As shown in Figures 6-8, as an alternative, other structures are basically the same as in Embodiment 1, except that the external force output mechanism includes: a drive shaft 6, a drive motor 13 connected to its end and Axial stroke control mechanism, the top of the machine head 1 is provided with a drive shaft assembly cavity, the drive shaft 6 is screwed to the machine head 1 and can be sealed, the drive shaft 6 extends into the backwash filter frame 52, and the backwash filter frame 52 The inner backwash filter screen lower seal body 54 abuts, and can drive the backwash filter screen skeleton 52 and the backwash filter screen lower seal body 54 to move and rotate together in the axial direction, through the axial travel control mechanism (such as the limit switch 14) The forward and reverse rotation of the drive motor 13 is controlled, thereby driving the axial movement stroke of the drive shaft 6 . Specifically, there are two limit switches 14, which are respectively an upper limit switch and a lower limit switch, wherein the upper and lower limit switches are assembled on the fixing seat 15, and the drive motor 13 can be detachably connected (screwed or clamped) There is a protective cover 16, and the assembly spacing of the upper and lower limit switches meets the requirements of the axial stroke. The operation of the upper and lower limit switches 14 is controlled by the touch portion 61 provided on the drive shaft 6 .

The embodiment described above is only a preferred solution of the present invention, and does not limit the present invention in any form. There are other variations and modifications on the premise of not exceeding the technical solution described in the claims.

Claims (10)

1. the fore filter with top control backwashing function comprising: the head with inlet and outlet, with machine The filter flask for having the closed blowdown part of energy of head cooperation, the filter flask is interior to be equipped with filtering and backwash mechanism, filters and backwashes Gap outside mechanism between filter flask constitutes raw water chamber, and filtering and backwash mechanism Inner Constitution purify water cavity, the filtering And backwash mechanism includes the backwash element of filter element and concentric setting, the water inlet of raw water chamber and filter element can Connection, purification water cavity are connected to water outlet, which is characterized in that the backwash element can be with respect to filter element by outer power drive Axial movement, to realize the switching of filtering function and backwashing function, the backwash element it is fixed export machine with external force Structure mechanical connection, and external force output mechanism is set to the top of head.

2. the fore filter according to claim 1 with top control backwashing function, which is characterized in that the filtering Element is formed by filter screen ontology, filtering network framework and positioned at the intake end cover and draining end cap for filtering network framework both ends, into The external dimensions of water end (W.E.) lid is adapted to the upper end of filter flask, the inlet communication of intake end cover and head, filter screen ontology and filter flask Between formed raw water chamber；

The backwash element includes under reverse flushing filter screen ontology, reverse flushing filter screen skeleton and reverse flushing filter screen with drainage channel Feng Ti, reverse flushing filter screen ontology are socketed on the department of assembly of reverse flushing filter screen skeleton, the reverse flushing filter screen ontology dress being placed in head With chamber and both ends seal, and reverse flushing filter screen lower sealed body passes through draining end cap and is detachably connected with reverse flushing filter screen skeleton, discharge ends Lid and reverse flushing filter screen skeleton lower end circumferential seal, reverse flushing filter screen skeleton can be synchronous with reverse flushing filter screen ontology relative to filtering The axial activity of element；

After being axially moved certain stroke down, working face can close intake end cover under department of assembly, and reverse flushing filter screen ontology leaks out, real Existing runner switching, into backwash operating mode；

After being up axially moved certain stroke, working face opens intake end cover under department of assembly, and the closing of reverse flushing filter screen ontology is realized Runner switching, into filtration mode.

3. the fore filter according to claim 1 with top control backwashing function, which is characterized in that the external force Output mechanism includes: drive shaft and the manual actuation knob for being fixed on its end, is equipped with drive shaft assembly cavity at the top of head, drives Moving axis and head are spirally connected and can seal, and drive shaft extends in reverse flushing filter screen skeleton, with the intraskeletal recoil of reverse flushing filter screen Filter wash net lower sealed body abuts, and reverse flushing filter screen skeleton and reverse flushing filter screen lower sealed body can be driven to be axially moved and rotate jointly.

4. the fore filter according to claim 1 with top control backwashing function, which is characterized in that described manual Drive knob includes knob body and locating piece, and knob body is socketed on locating piece and is detachably connected with driveshaft end, fixed Position part and drive shaft assembly cavity are spirally connected fixation.

5. the fore filter according to claim 1 with top control backwashing function, which is characterized in that the external force Output mechanism includes: drive shaft, the driving motor coupled with its end and axial stroke control mechanism, is equipped with and drives at the top of head Moving axis assembly cavity, drive shaft and head are spirally connected and can seal, and drive shaft extends in reverse flushing filter screen skeleton, with reverse flushing filter screen Intraskeletal reverse flushing filter screen lower sealed body abuts, and reverse flushing filter screen skeleton and reverse flushing filter screen lower sealed body can be driven axially to transport jointly Dynamic and rotation is controlled the positive and negative rotation of driving motor by axial stroke control mechanism, and then drives the axial movement row of drive shaft Journey, the axial stroke control mechanism includes limit switch.

6. the fore filter with top control backwashing function according to claim 3 or 4 or 5, which is characterized in that institute It states and is equipped with the first locating part in reverse flushing filter screen skeleton, drive shaft is equipped with the second locating part of adaptation, passes through the first and second limit The cooperation of part controls drive shaft axial displacement stroke.

7. the fore filter with top control backwashing function according to claim 3 or 4 or 5, which is characterized in that institute It states and is equipped with the backwashing water distribution part for generating bigger flow velocity with smaller flow diameter, the backwashing water in backwash element Distribution part is sheathed on drive shaft and axial position is relatively fixed, and can rotate around drive shaft, and the backwashing water distribution part is equipped with Several nozzles, can injection water along a tangential direction, it is preferred that the nozzle of the backwashing water distribution part in axial direction interlocks Setting.

8. the fore filter with top control backwashing function according to claim 3 or 4 or 5, which is characterized in that institute The blowdown part for stating filter flask is equipped with a mid diameter and gradually reduces, the type chamber that both ends diameter incrementally increases；When filtration condition, backwash The end outer rim of strainer lower sealed body and diameter minimum portion cooperate, and realize the sealing of blowdown part, when switching into backwashing state, recoil Filter wash net lower sealed body moves down under the action of by outer power drive, the part incrementally increased into diameter, under reverse flushing filter screen Drain outlet is constituted between Feng Tiyu type chamber, blowdown part is opened；Reverse flushing filter screen lower sealed body at least end outer rim has elastic shape Change and reset function.

9. the fore filter according to claim 1 with top control backwashing function, which is characterized in that the filtering Element-external is additionally provided with directional cleaning component, including conducting element and adjustment part, and conducting element includes at least one along filter element axis The assembling stand fixed and can be adapted to filter element bottom shape to the diversion trench of extension and with diversion trench, assembling stand are equipped with assembly Hole is socketed on reverse flushing filter screen lower sealed body by pilot hole, and assembling stand bottom is additionally provided at least one locating part；

Adjustment part is equipped with pilot hole and the cavity that is adapted to assembling stand, by pilot hole be socketed on reverse flushing filter screen lower sealed body and It can rotate synchronously, cavity edge is equipped at least one limiting slot, and cavity side is equipped at least one through-hole；

When reverse flushing filter screen lower sealed body axial direction downlink and rotation, adjustment part is driven, and then drives conducting element around filter element circumferential direction Rotation, backwashing water are discharged via through-hole and drain outlet, realize large granular impurity backwash discharge；

Reverse flushing filter screen lower sealed body uplink rotates in reseting procedure, and adjustment part and conducting element dislocation, adjustment part through-hole are closed, instead Gap of the flushing water between conducting element and adjustment part enters drain outlet discharge, realizes negative pressure orientation backwash.

10. the fore filter with top control backwashing function according to claim 3 or 4, which is characterized in that described Drive shaft uses split-type design, including upper drive shaft and lower drive shaft, upper drive shaft to be spirally connected with head, lower drive shaft and upper drive Moving axis is detachably connected.