CN115321762A

CN115321762A - Filter equipment that can back flush

Info

Publication number: CN115321762A
Application number: CN202211117228.XA
Authority: CN
Inventors: 喻黎明; 张玉胜; 李娜; 赵鑫荣
Original assignee: Kunming University of Science and Technology
Current assignee: Kunming University of Science and Technology
Priority date: 2022-09-14
Filing date: 2022-09-14
Publication date: 2022-11-11
Anticipated expiration: 2042-09-14
Also published as: CN115321762B

Abstract

The application provides a filter equipment that can back flush, including filtering jar body, one-level filtering mechanism, drive mechanism and filter residue pipeline. The first-stage filtering mechanism comprises a filter screen, a first round hole is formed in the center of the filter screen, when the conical head covers the first round hole, the filtering device is in a filtering state, and sewage flowing into the sewage inlet is guided to the filter screen through the conical head to be filtered and is discharged through the purified water outlet. The top end of the connecting rod is fixedly connected with the bottom of the conical head, and the first motor controls the connecting rod to move along the axis of the filtering tank body. The top end of the filter residue pipeline is communicated with the first round hole. After the conical head moves upwards along the axis of the filtering tank body, the filtering device is in a back washing state, the filter screen is washed by the purified water flowing in from the sewage inlet, and the filter residue on the filter screen is discharged into a sewage discharge pipeline together with the purified water through the filter residue pipeline. After working for a preset time, the self-cleaning of the filter screen is completed on the premise of not disassembling the filter layer device.

Description

Filter equipment that can back flush

Technical Field

The application relates to the technical field of filtering equipment, in particular to a filtering device capable of backwashing.

Background

The filtration equipment, also known as a multi-media filter, is one of the main equipment for water quality pretreatment. According to the water quality, a corresponding design scheme is adopted to efficiently remove impurities such as suspended matters, colloids, silt, clay, humus, particles and the like in the water body, reduce the turbidity of the water and achieve the aim of clarifying the water, and the method is commonly used in industrial production.

In the use process of the filtering equipment, a large amount of filter residues can be accumulated on the filter screen, so that the filtering effect is influenced. Regular maintenance and cleaning of the screens is therefore required.

Because the structure of filtration equipment is complicated, if clear up the filter screen and need dismantle filtration equipment, then clear up the filter screen. The disassembling process is complicated, the cleaning device needs to be installed again and the like, the operation is complicated, and the working efficiency is influenced.

In view of the foregoing, it would be desirable to provide an improved solution to the above-mentioned deficiencies of the prior art.

Disclosure of Invention

An object of this application embodiment is to provide a but filter equipment of back flush, it can do benefit to self-cleaning to the filter screen of self structure after working scheduled time.

The application specifically provides a filter equipment that can backwash, including filtering a jar body, one-level filtering mechanism, drive mechanism and filter residue pipeline.

The filtering tank body comprises a sewage inlet arranged at the top and a purified water outlet arranged at the bottom.

The one-level filtering mechanism is arranged in the filtering tank body and comprises a filtering net fixedly connected with the filtering tank body, a first round hole is formed in the center of the filtering net, a conical head is arranged on the first round hole and covers the first round hole, a filtering device is in a filtering state, and sewage flowing into the sewage inlet is guided to the filtering net through the conical head and is discharged from the purified water outlet.

The transmission mechanism comprises a connecting rod and a first motor in transmission connection with the bottom of the connecting rod, the top end of the connecting rod is fixedly connected with the bottom of the conical head, and the first motor controls the connecting rod to move along the axis of the filtering tank body.

The filter residue pipeline is arranged on the axis of the filter tank body, the top end of the filter residue pipeline is communicated with the first round hole, and the bottom of the filter residue pipeline extends downwards and is connected with a sewage discharge pipeline; the cone head moves up the back along the axis of the filtering tank body, the filtering device is in a back washing state, the purified water flowing in from the sewage inlet washes the filter screen, and the filter residue on the filter screen passes through the filter residue pipeline along with the purified water and is discharged into the sewage discharge pipeline.

In one embodiment, the connecting rod is provided with a support plate, the support plate is arranged at the lower part of the filter screen and corresponds to the filter screen in shape, a second round hole is arranged at the center of the support plate, and the support plate is sleeved outside the filter residue pipeline through the second round hole; after the supporting plate moves upwards through the connecting rod, when the filtering device is placed in a back flushing state, the supporting plate is attached to the filtering net and supports the filtering net.

In one embodiment, the sewage inlet is coaxially arranged with the cone, the cone moves upwards along the axis of the filtering tank and is inserted into the sewage inlet, the water inlet area of the sewage inlet is reduced, and the water inlet pressure at the sewage inlet is increased.

In one embodiment, the filter screen comprises a plurality of folded surfaces, and the folded surfaces are uniformly distributed around the circumference of the filter screen.

In one embodiment, the included angle between two adjacent folded surfaces is 85-95 degrees; the outer edge of the filter screen is turned upwards, and the turning angle is 25-40 degrees.

In an embodiment, the water purification delivery port is including directly arranging mouth and backward flow mouth, directly arrange the mouth be used for with the water purification union coupling, discharge the water purification after filtering, the backward flow mouth pass through the backflow pipeline with sewage water inlet intercommunication, it is right to use the water purification after filtering the filter screen carries out the back flush.

In one embodiment, a tee joint is arranged at the sewage inlet, and comprises a first water inlet, a second water inlet and a water outlet; the first water inlet is communicated with the return pipeline, the second water inlet is communicated with an external water purifying pipe, and the water outlet is communicated with the filtering tank body.

In one embodiment, the sewage treatment device further comprises a second-stage filtering mechanism arranged at the bottom of the filter screen, wherein the second-stage filtering mechanism is a biological membrane filtering mechanism, and the biological membrane filtering mechanism is used for filtering out organic matters in the sewage and then discharging the organic matters downwards.

In an embodiment, still including locating the tertiary filter mechanism of biomembrane filtering mechanism bottom, tertiary filter mechanism is including adding the medicine agitator tank body and locating add the income medicine mouth on the medicine agitator tank body, it is used for adding chemical reagent and carries out chemical filtration to sewage to go into the medicine mouth.

In one embodiment, the three-stage filtering mechanism comprises a stirring part arranged at the bottom of the dosing stirring tank body, and the stirring part is controlled to rotate by a second motor.

Compared with the prior art, the beneficial effect of this application is:

in the technical scheme of this application, but the back flush filter equipment who provides has filtration state and back flush state. After the filter device works for a preset time, the connecting rod and the conical head are controlled to move upwards through the transmission mechanism, the filter residue pipeline is opened, purified water is introduced into the sewage inlet to wash the filter screen, the filter screen is washed into the filter residue pipeline, and the filter screen is self-cleaned on the premise of not disassembling the filter layer device. The distance between the filter screen and the support plate is controlled by adjusting the moving distance of the connecting rod, so that the hydraulic performance of high-pressure water can be changed, and the adjustment of the flushing amplitude is realized; and the dirt after being washed can be discharged into the filter residue pipeline, so that the blockage phenomenon caused by long-term unclean washing is avoided.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained from the drawings without inventive effort.

FIG. 1 is a front view of a backflushable filter device provided in accordance with the present embodiment;

FIG. 2 is a side view of a backflushable filter device provided in accordance with the present embodiment;

fig. 3 is a schematic view of the internal structure of the backwash-capable filter device provided according to the present embodiment;

fig. 4 is a longitudinal sectional view in a filtering state of the backflushable filtering device according to the embodiment;

fig. 5 is a longitudinal sectional view in a flushing state of the backflushable filter device provided according to the embodiment;

FIG. 6 is a schematic structural diagram of a transmission mechanism in the backwash-available filter device according to the present embodiment;

FIG. 7 is a schematic structural diagram of a cone head in the backwash-available filter device according to the present embodiment;

fig. 8 is a schematic structural diagram of a flow-dredging heating plate in the back-flushable filtering device according to the present embodiment;

FIG. 9 is a schematic structural diagram of a biofilm filtering mechanism in the backwash-available filtering apparatus according to the present embodiment;

FIG. 10 is a longitudinal sectional view of a biofilm filtering mechanism in the backwashable filtering apparatus according to the present embodiment;

FIG. 11 is a schematic structural view of a cylindrical dosing tank in the backwash-capable filter device according to the present embodiment;

FIG. 12 is a perspective view of a tertiary filter mechanism in a backwashable filter device provided in accordance with the present embodiment;

fig. 13 is a schematic view showing an assembly of support plates in the backwash-possible filter device according to the present embodiment;

fig. 14 is a schematic perspective view of a support plate in the backwash filter device according to this embodiment;

fig. 15 is a schematic structural diagram of a filter screen in the backwash-capable filter device according to the embodiment.

Reference numerals:

1. a primary filtering mechanism; 11. filtering the tank body; 12. a filter screen; 13. a conical head; 14. a fin-shaped flow deflector; 15. a support plate; 151. a sloping plate; 16. a residue filtering pipeline; 161. a slag discharge hole; 17. a return line; 18. a digital display screen; 2. a sewage inlet; 21. a first water inlet; 22. a second water inlet; 3. a purified water outlet; 31. a straight discharge port; 32. a return port; 4. a connecting rod; 41. a first motor; 42. a gear; 43. a rack; 5. a secondary filtering mechanism; 51. a flow-dredging heating disc; 52. a tubular membrane; 6. a third stage filtering mechanism; 61. a cylindrical dosing tank; 62. a pull rod; 63. and a stirring part.

Detailed Description

The following describes embodiments of the present invention in further detail with reference to the accompanying drawings. These embodiments are merely illustrative of the present invention and are not intended to limit the present invention.

In the description of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood according to specific situations by those of ordinary skill in the art.

In addition, in the description of the present invention, "a plurality" means two or more unless otherwise specified.

Referring to fig. 1 to 12, the present application specifically provides a filtering apparatus capable of backwashing, which includes a filtering tank 11, a primary filtering mechanism 1, a transmission mechanism, and a residue filtering pipeline 16.

As shown in fig. 1, the filtering tank 11 includes a sewage inlet 2 at the top and a clean water outlet 3 at the bottom.

As shown in fig. 1 to 6, the primary filtering mechanism 1 is disposed in the filtering tank 11, and includes a filtering net 12 fixedly connected to the filtering tank 11, a first circular hole is disposed at a center of the filtering net 12, and a conical head 13 is disposed on the first circular hole, as shown in fig. 4, when the conical head 13 covers the first circular hole, the filtering device is in a filtering state, and sewage flowing in from the sewage inlet 2 is guided to the filtering net 12 through the conical head 13 to be filtered, and is discharged through the purified water outlet 3.

The transmission mechanism comprises a connecting rod 4 and a first motor 41 in transmission connection with the bottom of the connecting rod 4, the top end of the connecting rod 4 is fixedly connected with the bottom of the conical head 13, and the first motor 41 controls the connecting rod 4 to move along the axis of the filtering tank body 11.

It should be noted that a gear 42 is coaxially disposed on an output shaft of the first motor 41, a rack 43 is disposed on the link 4, the first motor 41 and the link 4 are in transmission connection through a rack 43 transmission mechanism, the first motor 41 controls the gear 42 to rotate forward or backward, and the rack 43 controls the link 4 to move up or down.

The filter residue pipeline 16 is arranged on the axis of the filtering tank body 11, the top end of the filter residue pipeline 16 is communicated with the first round hole, and the bottom of the filter residue pipeline 16 extends downwards and is connected with a sewage discharge pipeline; after the conical head 13 moves upwards along the axis of the filtering tank body 11, the filtering device is in a back flushing state, the filter screen 12 is flushed by the purified water flowing in through the sewage inlet 2, and the filter residues on the filter screen 12 are discharged into a sewage discharge pipeline through the filter residue pipeline 16 together with the purified water.

It should be noted that, as shown in fig. 7, a fin-shaped deflector 14 is disposed on a side surface of the conical head 13, and it is considered that the purified water flowing in through the sewage inlet 2 passes through the fin-shaped deflector 14 and is pressurized to flush the filter screen 12.

The application provides a but filter equipment of back flush has filtration state and back flush state. After the filtering device works for a preset time, the connecting rod 4 and the conical head 13 are controlled to move upwards through the transmission mechanism, the filter residue pipeline 16 is opened, purified water is introduced into the sewage inlet 2 to wash the filter screen 12, filter residues are washed into the filter residue pipeline 16, and the filter screen 12 is self-cleaned on the premise of not disassembling the filtering layer device.

In one embodiment, a support plate 15 is arranged on the connecting rod 4, the support plate 15 is arranged at the lower part of the filter screen 12 and corresponds to the shape of the filter screen 12, a second round hole is arranged at the center of the support plate 15, and the support plate 15 is sleeved outside the filter residue pipeline 16 through the second round hole; as shown in fig. 5, after the support plate 15 is moved up by the connecting rod 4, the support plate 15 is attached to the filter screen 12 and supports the filter screen 12 when the filter device is placed in the backwashing state. Because the water pressure of the washing water that inserts is great, consequently through the setting of backup pad 15, for filter screen 12 provides the holding power, guarantee to wash under the prerequisite of effect, guarantee that filter screen 12 is intact.

In one embodiment, the sewage inlet 2 and the conical head 13 are coaxially arranged, as shown in fig. 5, the conical head 13 moves up along the axis of the filtering tank 11 and is inserted into the sewage inlet 2, the water inlet area of the sewage inlet 2 is reduced, the water inlet pressure at the sewage inlet 2 is increased, the back washing acting force of the filtering net 12 is increased through the conical head 13, and the washing effect of the filtering net 12 is ensured.

In one embodiment, the filter screen 12 comprises a plurality of folded surfaces, the plurality of folded surfaces are uniformly distributed around the circumference of the filter screen 12, and the included angle between two adjacent folded surfaces is 85-95 degrees, preferably 90 degrees. Through the setting of folded surface, can increase the filter area of filter screen 12 in the finite space of the filter tank body 11, guarantee the filter effect.

In one embodiment, the outer edge of the filter screen 12 is folded upwards at an angle of 25-40 degrees, preferably 30 degrees. By turning the outer edge of the filter screen 12 upwards, the filter residue slides more easily into the filter residue duct 16 under the action of the high pressure purified water and its own gravity.

As shown in fig. 14 and 15, the shape of the support plate 15 is the same as that of the filter screen 12, and therefore, in the filtering state, the plurality of folded surfaces of the support plate 15 function to guide the flow, and at this time, the support plate 15 functions to reduce the impact force of the water flow.

It should be noted that, as shown in fig. 13 and 14, a plurality of slag discharge holes 161 are disposed at the top of the slag filtering pipeline 16, and the plurality of slag discharge holes 161 are uniformly distributed around the circumference of the slag filtering pipeline 16. The center of the supporting plate 15 comprises a plurality of sloping plates 151, one side of the sloping plates 151 is connected with the folding surface of the supporting plate 15, and the other side of the sloping plates 151 inclines downwards and points to the slag discharge hole 161. When the water flow washes the filter residue on the filter screen 12 to the upper surface of the support plate 15, the filter residue flows into the residue discharge hole 161 along the inclined plate 151 and is discharged through the filter residue pipeline 16.

In one embodiment, as shown in fig. 4 and 5, the purified water outlet 3 includes a straight discharge port 31 and a return port 32, the straight discharge port 31 is used for connecting with a purified water pipe and discharging filtered purified water, the return port 32 is communicated with the sewage inlet 2 through a return pipe 17, and the filter screen 12 is backwashed with the filtered purified water. Through the arrangement of the return pipeline 17, the filter screen 12 can complete self-cleaning on the premise of not being connected with an external water purifying facility.

In one embodiment, as shown in fig. 2, a tee is arranged at the sewage inlet 2, and the tee comprises a first inlet 21, a second inlet 22 and an outlet; the first water inlet 21 is communicated with the return pipeline 17, the second water inlet 22 is communicated with an external purified water pipe, and the water outlet is communicated with the filtering tank body 11. Through the setting of tee bend, under the condition that the clean water yield that self filtration produced is not enough to satisfy the cleaning requirement, insert external clean water source, wash filter screen 12, strengthened the adaptability of equipment in different environment.

In one embodiment, the sewage treatment device further comprises a secondary filtering mechanism 5, wherein the secondary filtering mechanism 5 is a biological membrane filtering mechanism arranged at the bottom of the filter screen 12, and the biological membrane filtering mechanism is used for filtering out organic matters in the sewage and then discharging the organic matters downwards.

Specifically, as shown in fig. 8 and 10, the biofilm filtering mechanism includes a membrane treatment tank, a flow-dredging heating plate 51 is disposed on the top of the membrane treatment tank, and a tubular membrane 52 is disposed on the bottom of the flow-dredging heating plate 51. The heat conduction material is adopted to the heat dispersion heating plate 51, and the heat dispersion heating plate has a heating function, and is used for heating and dispersing water flow flowing in from the primary filtering mechanism 1, a plurality of flow guide walls and flow guide holes are uniformly distributed on the heat dispersion heating plate 51, and the water flow is uniformly conveyed into the tubular membrane 52 to be filtered through the arrangement of the heat dispersion heating plate 51.

In one embodiment, as shown in fig. 10, the heat insulating layer is detachably disposed outside the tubular membrane 52, and the heat insulating layer can maintain the tubular membrane 52 at a specific water temperature, so that the filtering efficiency of the tubular membrane 52 is maximized.

In one embodiment, the tubular membrane 52 within the membrane treatment canister may be replaced after a predetermined period of use.

In an embodiment, this application is still including locating tertiary filter mechanism 6 of biomembrane filter mechanism bottom, and tertiary filter mechanism 6 is used for adding chemical reagent and carrying out chemical filtration to sewage including adding the medicine agitator tank body and locating the income medicine mouth on adding the medicine agitator tank body into the medicine mouth including.

Specifically, as shown in fig. 11, the cylindrical dosing tank 61 is inserted into the dosing agitator tank through the medicine inlet, the cylindrical dosing tank 61 includes a pull rod 62 disposed on the outer surface, the cylindrical dosing tank 61 is pulled out from the medicine inlet through the pull rod 62, and the cylindrical dosing tank 61 is filled with medicine. The operations of disinfection, desulfurization and the like are carried out on the sewage by controlling the type and concentration of the medicament in the cylindrical medicament adding tank 61.

In one embodiment, as shown in fig. 12, the three-stage filtering mechanism 6 includes a stirring portion 63 disposed at the bottom of the chemical-adding stirring tank, and the stirring portion 63 is controlled by the second motor to rotate to stir the solution in the chemical-adding stirring tank, so as to accelerate the dissolution of the chemical. The second motor includes a proximity switch in communicative connection with the second motor. Proximity switch includes that the metal detects body and induction zone, and the metal detects body and connecting rod 4 fixed connection, and induction zone locates on adding medicine agitator tank body. When the metal detection body is in a flushing state and moves upwards through the connecting rod 4, the metal detection body is far away from the induction area, the proximity switch is powered off, and the second motor controls the stirring part 63 to stop stirring. When the metal detection body is in a filtering state and moves downwards through the connecting rod 4, the metal detection body is close to the induction area, the proximity switch is electrified, and the second motor controls the stirring part 63 to rotate. Energy waste can be reduced through the arrangement.

It should be noted that the tank bodies of the first filtering mechanism, the second filtering mechanism and the third filtering mechanism are all connected by detachable flanges.

In one embodiment, a digital display screen 18 is disposed on the filtering tank 11, and parameters such as the flow rate and pressure of the current device can be reflected by the digital display panel.

Specifically, a water level sensor is arranged on the top surface in the filtering tank body 11 and is in communication connection with the sewage inlet 2, and when the water level in the filtering tank body 11 is higher than a limit value in a filtering state, the water level sensor feeds back a signal to the sewage inlet 2 and controls the sewage inlet 2 to be closed, and the water level value is transmitted to the digital display disc to be displayed.

In summary, the filtering apparatus capable of backwashing provided by the present application has a filtering state and a backwashing state. After the filtering device works for a preset time, the connecting rod 4 and the conical head 13 are controlled to move upwards through the transmission mechanism, the filter residue pipeline 16 is opened, purified water is introduced into the sewage inlet 2 to wash the filter screen 12, filter residues are washed into the filter residue pipeline 16, and the filter screen 12 is self-cleaned on the premise of not disassembling the filtering layer device. The distance between the filter screen 12 and the support plate 15 is controlled by adjusting the moving distance of the connecting rod 4, so that the hydraulic performance of high-pressure water can be changed, and the adjustment of the flushing amplitude is realized; and the flushed dirt can be discharged into the filter residue pipeline 16, so that the blockage caused by long-term unclean flushing is avoided.

The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and substitutions can be made without departing from the technical principle of the present invention, and these modifications and substitutions should also be regarded as the protection scope of the present invention.

Claims

1. A backflushable filter device, comprising:

the filtering tank body comprises a sewage inlet arranged at the top and a purified water outlet arranged at the bottom;

the primary filtering mechanism is arranged in the filtering tank body and is fixedly connected with a filtering net on the inner wall of the filtering tank body, a first round hole is formed in the center of the filtering net, a conical head is arranged on the first round hole, when the conical head covers the first round hole, the filtering device is in a filtering state, and sewage flowing in from the sewage inlet is guided to the filtering net through the conical head to be filtered and is discharged through the purified water outlet;

the transmission mechanism comprises a connecting rod and a first motor in transmission connection with the bottom of the connecting rod, the top end of the connecting rod is fixedly connected with the bottom of the conical head, and the first motor controls the connecting rod to move along the axis of the filtering tank body;

2. The backwashing filter device of claim 1, wherein a support plate is arranged on the connecting rod, the support plate is arranged at the lower part of the filter screen and corresponds to the filter screen in shape, a second round hole is arranged at the center of the support plate, and the support plate is sleeved outside the filter residue pipeline through the second round hole; after the supporting plate moves upwards through the connecting rod, when the filtering device is placed in a back flushing state, the supporting plate is attached to the filtering net and supports the filtering net.

3. The backflushable filter device of claim 2, wherein the sewage inlet is coaxially arranged with the cone, the cone moves up along the axis of the filter tank and is inserted into the sewage inlet, the water inlet area of the sewage inlet is reduced, and the water inlet pressure at the sewage inlet is increased.

4. The backflushable filter device of claim 2, wherein the filter screen includes a plurality of folds that are evenly spaced around the circumference of the filter screen; the included angle between two adjacent folding surfaces is 85-95 degrees.

5. The backflushable filter device of claim 4, wherein the outer edge of the filter screen is folded upwards at an angle of 25-40 degrees.

6. The backflushable filter device according to claim 1, wherein the purified water outlet includes a straight discharge port and a return port, the straight discharge port is used for being connected with a purified water pipe to discharge filtered purified water, the return port is communicated with the sewage inlet through a return pipe, and the filter screen is backflushed with filtered purified water.

7. The backflushable filtering device according to claim 6, wherein a tee is arranged at the sewage inlet, and the tee comprises a first water inlet, a second water inlet and a water outlet; the first water inlet with the return line intercommunication, the second water inlet communicates with external water purification pipe, the delivery port with filter jar body intercommunication.

8. The backflushable filtering device according to any one of claims 1 to 7, further comprising a secondary filtering mechanism arranged at the bottom of the filtering net, wherein the secondary filtering mechanism is a biomembrane filtering mechanism, and the biomembrane filtering mechanism is used for filtering out organic matters in sewage and then discharging the organic matters downwards.

9. The backwashing filtering device of claim 8, further comprising a third filtering mechanism disposed at the bottom of the biofilm filtering mechanism, wherein the third filtering mechanism comprises a dosing agitation tank and a chemical inlet disposed on the dosing agitation tank, and the chemical inlet is used for adding a chemical reagent and chemically filtering sewage.

10. The backflushable filter device according to claim 9, wherein the tertiary filter mechanism includes a stirring portion disposed at the bottom of the chemical adding stirring tank, and the stirring portion is controlled to rotate by a second motor.