Special filtering equipment for ferrous sulfate crystal solid in steel pickling solution

Abstract

The utility model discloses special filtering equipment for ferrous sulfate crystal solid in steel pickling solution, which relates to the technical field of steel pickling, and comprises a lower side filtering box body and a drainage valve, the drainage valve is installed and connected at the front end position of the lower side filtering box body, the upper end of the lower side filtering box body is provided with an upper side filtering box body, and the lower end of the upper side filtering box body is provided with a lower side filtering box body. A lower-side liquid level sensor is arranged on the inner side of the lower end of the upper-side filtering box body and located in the lower-side filtering box body, a lower backwashing pipeline is arranged on the upper-side filtering box body and located on the outer side of the lower-side liquid level sensor, and a lower draw-off pump is arranged at the outer end of the lower backwashing pipeline. According to the utility model, through the structures of the lower draw-off pump and the upper draw-off pump, ferrous sulfate crystal solids filtered out by the upper part and the lower part of the rotary filtering mechanism can be effectively drawn through the lower backwashing pipeline and the upper backwashing pipeline, and the rotary filtering mechanism can rotate circumferentially, so that the ferrous sulfate crystal solids can be cleaned by rotating circumferentially.

Description

Technical Field

[0001] The utility model relates to the technical field of steel pickling, in particular to a special filtering device for ferrous sulfate crystal solids in steel pickling liquid. Background Art

[0002] Steel pickling means to make the strip steel have a clean and active surface to ensure the surface quality of the produced steel. In order to obtain such a surface and remove the iron oxide scale on the surface, there is ferrous sulfate crystalline solid in the steel pickling liquid. In order to remove the ferrous sulfate crystalline solid in the steel pickling liquid, a special ferrous sulfate crystalline solid filtration equipment is needed.

[0003] The existing Chinese patent CN211987482U disclosed on November 24, 2020 a special filtering equipment for crystalline solid ferrous sulfate in steel pickling solution, which solves the problems of slow filtration speed, poor processing capacity, low working efficiency, easy clogging, affecting the normal operation of the equipment, inconvenient internal cleaning, incomplete cleaning, and poor use effect of the special filtering equipment for crystalline solid ferrous sulfate in steel pickling solution currently on the market. The equipment includes a placement box, a support rod is fixed at the bottom of the inner cavity of the placement box, an installation box is fixed on the top of the support rod, a retaining block is fixed on the side of the installation box, a drive motor is installed on the top of the retaining block, a drive gear is installed on the output shaft of the drive motor, a transmission gear is meshed on the side of the drive gear, and an adjustment rod is installed on the top of the transmission gear.

[0004] However, when cleaning the above device, the whole device needs to be disassembled for cleaning, and it cannot be effectively cleaned automatically, which makes the cleaning not very efficient. Utility Model Content

[0005] The utility model aims to solve the shortcomings of the prior art and proposes a special filtering device for ferrous sulfate crystalline solids in steel pickling liquid. A lower extraction pump and an upper extraction pump pass through a lower backwash pipe and an upper backwash pipe, thereby effectively extracting the ferrous sulfate crystalline solids filtered out by the upper and lower parts of a rotating filtering mechanism. The rotating filtering mechanism can rotate in a circle, thereby performing circular rotation cleaning.

[0006] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0007] A special filtering device for ferrous sulfate crystal solids in steel pickling liquid comprises a lower filter box and a drain valve, wherein the drain valve is installed and connected to the front end position of the lower filter box, an upper filter box is arranged at the upper end of the lower filter box, a lower liquid level sensor is arranged inside the lower filter box on the inner side of the lower end of the upper filter box, a lower backwash pipe is arranged on the outer side of the lower liquid level sensor located on the upper filter box, a lower extraction pump is arranged on the outer end of the lower backwash pipe, a rotating filtering mechanism is arranged in the middle of the upper end of the upper filter box, an upper liquid level sensor is arranged on the left side of the rotating filtering mechanism on the upper filter box, an upper backwash pipe is arranged on the right side of the rotating filtering mechanism on the upper filter box, an upper extraction pump is arranged on the outer end of the upper backwash pipe, and the rotating filtering mechanism, the upper liquid level sensor, the lower liquid level sensor, the lower extraction pump and the upper extraction pump are electrically connected to an external controller through a connecting line.

[0008] Through the above technical scheme: the upper filter box receives the steel pickling liquid to be filtered for filtering, and the steel pickling liquid passes through the upper part of the rotating filter mechanism in the upper filter box to achieve the first filtration, and the filtered ferrous sulfate crystalline solids remain in the upper part of the rotating filter mechanism, and then the liquid falls into the lower filter box, so that it passes through the lower part of the rotating filter mechanism for secondary filtration, and the filtered steel pickling liquid can be discharged to the outside through the drain valve for collection. When the upper liquid level sensor and the lower liquid level sensor sense that the internal liquid level has risen, the lower extraction pump and the upper extraction pump pass through the lower backwash pipe and the upper backwash pipe, thereby effectively extracting the ferrous sulfate crystalline solids filtered out from the upper and lower parts of the rotating filter mechanism, and the rotating filter mechanism can rotate in a circle, so that it can be cleaned in a circular rotation.

[0009] The utility model is further configured as follows: the upper filter box includes a receiving pipe, an upper box shell, assembly screws, an upper filter limit plate and an upper cross brush plate; a receiving pipe is provided on the outer side of the upper end of the upper box shell, an upper filter limit plate is provided inside the upper box shell, an upper cross brush plate is provided on the upper box shell below the upper filter limit plate, assembly screws are provided on the circumference of the lower end of the upper box shell, and the upper box shell is connected to the lower filter box through the assembly screws.

[0010] Through the above technical solution: due to the structure of the upper filtering box, it can be placed in a limited position for use.

[0011] The utility model is further configured as follows: the lower filter box includes a lower filter limit plate, a lower box shell, a placement chassis, a liquid storage chamber and a lower cross brush plate; a placement chassis is provided at the lower end of the lower box shell, a lower filter limit plate is provided inside the lower box shell, a lower cross brush plate is provided on the lower box shell below the lower filter limit plate, and the lower box shell is connected to the upper filter box.

[0012] Through the above technical solution: due to the structure of the lower filtering box, the lower side limit position can be placed for use.

[0013] The utility model is further configured as follows: the rotating filtering mechanism includes a lower filter screen, an intermediate rotating rod, an upper filter screen, a coupling and a rotating motor, the output end of the rotating motor is provided with a coupling, the lower end of the coupling is provided with an intermediate rotating rod, the circumferential side of the intermediate rotating rod is provided with an upper filter screen, a lower filter screen is provided on the intermediate rotating rod below the upper filter screen, the rotating motor is connected to the upper end position of the upper filter box, the upper filter screen is sleeved inside the upper filter box, and the lower filter screen is sleeved inside the lower filter box.

[0014] Through the above technical solution: the filter mechanism structure can be rotated for cleaning, and filtering can be performed when it stops.

[0015] The utility model is further configured such that the upper backwash pipe includes a hollow duckbill plate, an adsorption transverse tube, a mounting disc and an extraction vertical tube, the peripheral side of the extraction vertical tube is provided with a mounting disc, the lower end of the extraction vertical tube is provided with an adsorption transverse tube, the lower end of the adsorption transverse tube is provided with a hollow duckbill plate, and the mounting disc is connected to the upper filter box.

[0016] Through the above technical solution: due to the backwash pipeline structure, it can be extracted for cleaning.

[0017] The utility model is further configured such that the lower end of the rotating filter mechanism is sleeved in the middle of the upper filter box and the lower filter box.

[0018] Through the above technical solution: because the lower end of the rotating filter mechanism is sleeved in the middle of the upper filter box and the lower filter box, it can be rotated in a limited position for cleaning.

[0019] The utility model is further configured that the upper filter box is connected to an external steel pickling liquid input pipe.

[0020] Through the above technical solution: because the upper filter box is connected to the external steel pickling liquid input pipe, it is convenient to connect, receive and use.

[0021] The utility model is further configured that a sealing rubber pad is provided at the connection between the upper filter box body and the lower filter box body, and the inside is penetrated.

[0022] Through the above technical solution: since the connection between the upper filter box and the lower filter box is provided with a sealing rubber pad and the inside is penetrated, the fixing is tighter and more firm.

[0023] The beneficial effects of the utility model are:

[0024] 1. Through the lower extraction pump and the upper extraction pump structure, the ferrous sulfate crystal solid filtered out from the upper and lower parts of the rotating filter mechanism can be effectively extracted through the lower backwash pipe and the upper backwash pipe. The rotating filter mechanism can rotate in a circle, so it can be cleaned in a circle.

[0025] 2. A rotating filter mechanism structure is provided so that it can be rotated for cleaning. The rotating motor of the rotating filter mechanism is connected to the upper end of the upper filter box through screws, so that the rotating motor is easy to install and place. When the output end of the rotating motor rotates, the rotating motor can drive the coupling to rotate, and the coupling can drive the middle rotating rod to rotate. The middle rotating rod can drive the lower filter screen plate and the upper filter screen plate on the peripheral side to rotate, making it easy to rotate and clean. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a three-dimensional structural schematic diagram of a special filtering device for ferrous sulfate crystal solids in steel pickling liquid proposed by the utility model;

[0027] Figure 2 This is a schematic diagram of the upper filter box structure of a special filtering device for ferrous sulfate crystal solids in steel pickling liquid proposed by the utility model;

[0028] Figure 3 This is a schematic diagram of the structure of the lower filter box of a special filtering device for ferrous sulfate crystal solids in steel pickling liquid proposed by the utility model;

[0029] Figure 4 This is a schematic diagram of the structure of a rotating filtering mechanism of a special filtering device for ferrous sulfate crystal solids in steel pickling liquid proposed by the utility model;

[0030] Figure 5 The utility model discloses a schematic diagram of the upper backwash pipeline structure of a special filtering device for ferrous sulfate crystal solids in steel pickling liquid.

[0031] In the figure: 1. Rotating filter mechanism; 11. Lower filter screen; 12. Middle rotating rod; 13. Upper filter screen; 14. Coupling; 15. Rotating motor; 2. Upper liquid level sensor; 3. Upper filter box; 31. Receiving pipe; 32. Upper box shell; 33. Assembly screws; 34. Upper filter limit plate; 35. Upper cross brush plate; 4. Lower liquid level sensor; 5. Lower filter box; 51. Lower filter limit plate; 52. Lower box shell; 53. Placement chassis; 54. Liquid storage chamber; 55. Lower cross brush plate; 6. Drain valve; 7. Lower extraction pump; 8. Upper extraction pump; 9. Lower backwash pipe; 10. Upper backwash pipe; 101. Hollow duckbill plate; 102. Adsorption horizontal pipe; 103. Installation disc; 104. Extraction vertical pipe. DETAILED DESCRIPTION

[0032] The technical solution of this patent is further described in detail below in conjunction with specific implementation methods.

[0033] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0034] In the description of this patent, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing this patent and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this patent.

[0035] In the description of this patent, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "set" should be understood in a broad sense, for example, it can be fixedly connected or set, or it can be detachably connected or set, or connected or set in one piece. For ordinary technicians in this field, the specific meanings of the above terms in this patent can be understood according to specific circumstances.

[0036] Reference Figure 1-Figure 5, a special filtering equipment for ferrous sulfate crystal solid in steel pickling liquid, comprising a lower filter box 5 and a drain valve 6, the drain valve 6 is installed and connected to the front end position of the lower filter box 5, the upper end of the lower filter box 5 is provided with an upper filter box 3, the lower end inner side of the upper filter box 3 is located inside the lower filter box 5 and a lower liquid level sensor 4 is provided, the outer side of the lower liquid level sensor 4 is located on the upper filter box 3 and a lower backwash pipe 9 is provided, the outer end of the lower backwash pipe 9 is provided with a lower extraction pump 7, a rotating filter mechanism 1 is provided in the middle of the upper end of the upper filter box 3, the left side of the rotating filter mechanism 1 is located on the upper filter box 3 and an upper liquid level sensor 2 is provided, the right side of the rotating filter mechanism 1 is located on the upper filter box 3 and an upper backwash pipe 10 is provided, the outer end of the upper backwash pipe 10 is provided with an upper extraction pump 8, the rotating filter mechanism 1, the upper liquid level sensor 2, the lower liquid level sensor 4, the lower The extraction pump 7 and the upper extraction pump 8 are electrically connected to the external controller through a connecting line. When in use, the upper filter box 3 receives the steel pickling liquid to be filtered for filtering. The steel pickling liquid passes through the upper part of the rotating filter mechanism 1 in the upper filter box 3, so that the first filtration is achieved. The filtered ferrous sulfate crystalline solids remain in the upper part of the rotating filter mechanism 1, and then the liquid falls into the lower filter box 5, so that it passes through the lower part of the rotating filter mechanism 1 for secondary filtration. The filtered steel pickling liquid can be discharged to the outside for collection through the drain valve 6. When the upper liquid level sensor 2 and the lower liquid level sensor 4 sense that the internal liquid level has risen, the lower extraction pump 7 and the upper extraction pump 8 pass through the lower backwash pipe 9 and the upper backwash pipe 10, so that the ferrous sulfate crystalline solids filtered out from the upper and lower parts of the rotating filter mechanism 1 can be effectively extracted. The rotating filter mechanism 1 can rotate in a circle, so that it can be cleaned in a circle.

[0037] Specifically, the upper filter box 3 includes a receiving pipe 31, an upper box shell 32, an assembly screw 33, an upper filter limit plate 34 and an upper cross brush plate 35. The upper end outer side of the upper box shell 32 is provided with a receiving pipe 31, the upper filter limit plate 34 is provided inside the upper box shell 32, and the upper cross brush plate 35 is provided on the upper box shell 32 below the upper filter limit plate 34. The lower end periphery of the upper box shell 32 is provided with an assembly screw 33. The upper box shell 32 is connected to the lower filter box 5 by the assembly screw 33. The shell 32 is fixedly connected to the lower filter box 5 by assembling screws 33, so that the upper box shell 32 is easy to install and place. The upper box shell 32 can receive external steel pickling liquid due to the receiving pipe 31. The internal area of ​​the upper filter limit plate 34 allows the upper filter screen 13 of the rotating filter mechanism 1 to be limited and rotated. When the upper filter screen 13 rotates, the upper cross brush plate 35 under the upper filter limit plate 34 can brush out the ferrous sulfate crystal solids filtered in the upper filter screen 13, so that the ferrous sulfate crystal solids can be efficiently sucked out and cleaned by the upper backwash pipe 10.

[0038] Specifically, the lower filter box 5 includes a lower filter limit plate 51, a lower box shell 52, a placement chassis 53, a liquid storage chamber 54 and a lower cross brush plate 55. The lower end of the lower box shell 52 is provided with a placement chassis 53, the lower box shell 52 is provided with a lower filter limit plate 51, and the lower filter limit plate 51 is located below the lower filter limit plate 51. The lower cross brush plate 55 is provided on the lower box shell 52. The lower box shell 52 is connected to the upper filter box 3. The lower box shell 52 of the lower filter box 5 is placed at the lower end. The bottom plate 53 is placed so that it can be placed. The lower box shell 52 has a liquid storage chamber 54, so that the filtered steel pickling liquid can be stored for discharge. The internal area of ​​the lower filter limit plate 51 allows the lower filter screen plate 11 of the rotating filter mechanism 1 to be limited and rotated, and can block filtering. The lower filter screen plate 11 contacts the lower cross brush plate 55 when rotating, so that the ferrous sulfate crystal solids filtered in the lower filter screen plate 11 can be brushed out, so that the ferrous sulfate crystal solids can be efficiently sucked out and cleaned by the lower backwash pipe 9.

[0039] Specifically, the rotary filter mechanism 1 includes a lower filter screen 11, an intermediate rotating rod 12, an upper filter screen 13, a coupling 14 and a rotary motor 15. The output end of the rotary motor 15 is provided with a coupling 14, the lower end of the coupling 14 is provided with an intermediate rotating rod 12, the circumference of the intermediate rotating rod 12 is provided with an upper filter screen 13, and the lower filter screen 11 is provided on the intermediate rotating rod 12 below the upper filter screen 13. The rotary motor 15 is connected to the upper end position of the upper filter box 3, and the upper filter screen 13 is sleeved on the upper filter box 3. The lower filter screen plate 11 is sleeved inside the lower filter box 5, and the rotating motor 15 that rotates the filter mechanism 1 is connected to the upper end position of the upper filter box 3 by screws, so that the rotating motor 15 is easy to install and place. When the output end of the rotating motor 15 rotates, the rotating motor 15 can drive the coupling 14 to rotate, and the coupling 14 can drive the intermediate rotating rod 12 to rotate, and the intermediate rotating rod 12 can drive the lower filter screen plate 11 and the upper filter screen plate 13 on the peripheral side to rotate, so that it is easy to rotate for cleaning.

[0040] Specifically, the upper backwash pipeline 10 includes a hollow duckbill plate 101, an adsorption transverse pipe 102, a mounting disc 103 and an extraction vertical pipe 104. The mounting disc 103 is arranged on the circumference of the extraction vertical pipe 104, the lower end of the extraction vertical pipe 104 is provided with an adsorption transverse pipe 102, the lower end of the adsorption transverse pipe 102 is provided with a hollow duckbill plate 101, the mounting disc 103 is connected to the upper filter box 3, and the mounting disc 103 of the upper backwash pipeline 10 is connected to the upper filter box 3 by screws. The disc 103 is installed on the upper filter box 3 to facilitate the placement of the extraction vertical pipe 104. The suction force generated by the lower extraction pump 7 can transmit the suction force of the extraction vertical pipe 104 to the adsorption horizontal pipe 102, and then the suction force of the adsorption horizontal pipe 102 is transmitted to the hollow duckbill plate 101. Then the hollow duckbill plate 101 can absorb the ferrous sulfate crystal solids filtered on the upper filter mesh plate 13 for cleaning, which is convenient for later filtration.

[0041] Specifically, the lower end of the rotating filter mechanism 1 is sleeved in the middle of the upper filter box 3 and the lower filter box 5, so that it can be rotated in a limited position for cleaning.

[0042] Specifically, the upper filter box 3 is connected to the external steel pickling liquid input pipe, so as to facilitate connection and reception for use.

[0043] Specifically, a sealing rubber pad is provided at the connection between the upper filter box 3 and the lower filter box 5, and the inside is penetrated, so that the fixing is tighter and more firm.

[0044] Working principle: When in use, the upper filter box 3 receives the steel pickling liquid to be filtered for filtering. The steel pickling liquid passes through the upper part of the rotating filter mechanism 1 in the upper filter box 3, so that the first filtration is achieved, and the filtered ferrous sulfate crystalline solids remain in the upper part of the rotating filter mechanism 1, and then the liquid falls into the lower filter box 5, so that it passes through the lower part of the rotating filter mechanism 1 for secondary filtration. The filtered steel pickling liquid can be discharged to the outside through the drain valve 6 for collection. When the upper liquid level sensor 2 and the lower liquid level sensor 4 sense that the internal liquid level has risen, the lower extraction pump 7 and the upper extraction pump 8 pass through the lower backwash pipe 9 and the upper backwash pipe 10, thereby effectively extracting the ferrous sulfate crystalline solids filtered out from the upper and lower parts of the rotating filter mechanism 1, and the rotating filter mechanism 1 can rotate in a circle, so that it can be cleaned in a circular rotation.

[0045] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes within the technical scope disclosed by the present invention according to the technical scheme and the utility model concept of the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A special filtering device for ferrous sulfate crystal solid in steel pickling liquid, comprising a lower filter box (5) and a drain valve (6), characterized in that: The drain valve (6) is installed and connected to the front end of the lower filter box (5); the upper filter box (3) is arranged at the upper end of the lower filter box (5); the lower liquid level sensor (4) is arranged inside the lower filter box (5) on the inner side of the lower end of the upper filter box (3); the lower backwash pipe (9) is arranged on the outer side of the lower liquid level sensor (4) on the upper filter box (3); the lower extraction pump (7) is arranged at the outer end of the lower backwash pipe (9); the upper middle end of the upper filter box (3) is arranged A rotating filter mechanism (1) is provided. An upper liquid level sensor (2) is provided on the left side of the rotating filter mechanism (1) and located on the upper filter box (3). An upper backwash pipe (10) is provided on the right side of the rotating filter mechanism (1) and located on the upper filter box (3). An upper extraction pump (8) is provided at the outer end of the upper backwash pipe (10). The rotating filter mechanism (1), the upper liquid level sensor (2), the lower liquid level sensor (4), the lower extraction pump (7) and the upper extraction pump (8) are electrically connected to an external controller via a connecting line.

2. The special filtering equipment for ferrous sulfate crystal solid in steel pickling liquid according to claim 1, characterized in that: The upper filter box (3) comprises a receiving pipe (31), an upper box shell (32), an assembly screw (33), an upper filter limit plate (34) and an upper cross brush plate (35); the receiving pipe (31) is arranged on the outer side of the upper end of the upper box shell (32); the upper filter limit plate (34) is arranged inside the upper box shell (32); an upper cross brush plate (35) is arranged on the upper box shell (32) below the upper filter limit plate (34); the assembly screw (33) is arranged on the circumference of the lower end of the upper box shell (32); and the upper box shell (32) is connected to the lower filter box (5) via the assembly screw (33).

3. The special filtering equipment for ferrous sulfate crystal solid in steel pickling liquid according to claim 1, characterized in that: The lower filter box (5) comprises a lower filter limit plate (51), a lower box shell (52), a placement base (53), a liquid storage chamber (54) and a lower cross brush plate (55); the lower end of the lower box shell (52) is provided with a placement base (53); the lower filter limit plate (51) is provided inside the lower box shell (52); a lower cross brush plate (55) is provided on the lower box shell (52) below the lower filter limit plate (51); and the lower box shell (52) is connected to the upper filter box (3).

4. The special filtering equipment for ferrous sulfate crystal solid in steel pickling liquid according to claim 1, characterized in that: The rotary filtering mechanism (1) comprises a lower filter screen (11), an intermediate rotating rod (12), an upper filter screen (13), a coupling (14) and a rotary motor (15); the output end of the rotary motor (15) is provided with a coupling (14); the lower end of the coupling (14) is provided with an intermediate rotating rod (12); the circumference of the intermediate rotating rod (12) is provided with an upper filter screen (13); a lower filter screen (11) is provided on the intermediate rotating rod (12) below the upper filter screen (13); the rotary motor (15) is connected to the upper end of the upper filter housing (3); the upper filter screen (13) is sleeved inside the upper filter housing (3); and the lower filter screen (11) is sleeved inside the lower filter housing (5).

5. The special filtering equipment for ferrous sulfate crystal solid in steel pickling liquid according to claim 1, characterized in that: The upper backwash pipe (10) comprises a hollow duckbill plate (101), an adsorption transverse pipe (102), a mounting disc (103) and an extraction vertical pipe (104); the mounting disc (103) is arranged on the circumference of the extraction vertical pipe (104); the adsorption transverse pipe (102) is arranged at the lower end of the extraction vertical pipe (104); the hollow duckbill plate (101) is arranged at the lower end of the adsorption transverse pipe (102); and the mounting disc (103) is connected to the upper filter box (3).

6. The special filtering equipment for ferrous sulfate crystal solid in steel pickling liquid according to claim 1, characterized in that: The lower end of the rotating filter mechanism (1) is sleeved in the middle of the upper filter box (3) and the lower filter box (5).

7. The special filtering equipment for ferrous sulfate crystal solid in steel pickling liquid according to claim 1, characterized in that: The upper filter box (3) is connected to an external steel pickling liquid input pipe.

8. The special filtering equipment for ferrous sulfate crystal solid in steel pickling liquid according to claim 1, characterized in that: The connection between the upper filter box (3) and the lower filter box (5) is provided with a sealing rubber pad, and the interior is penetrated.

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