Filtering device suitable for gas-assisted backwashing

Abstract

The utility model discloses a filter device suitable for gas-assisted backwashing, which structurally comprises a filter tank, a partition plate for dividing the filter tank into a front filter cavity and a rear filter cavity is arranged in the filter tank, and a plurality of groups of filter elements are embedded downwards in the partition plate; a liquid outlet is formed in the side wall of the after-filtration cavity, a first air inlet communicated with a first air path is formed in the top of the after-filtration cavity, and a pneumatic butterfly valve and a first check valve are arranged on the first air path; a liquid inlet and a back-flushing drain outlet are formed in the lower part of the pre-filtering cavity, a second air inlet communicated with a second air path is formed in the side wall close to the partition plate, an electromagnetic valve and a second check valve are arranged on the second air path, and pneumatic ball valves are arranged at the liquid inlet, the back-flushing drain outlet and the liquid outlet. According to the utility model, the filter element is cleaned by adopting gas-assisted backwashing, a gas space is always kept in the post-filtration cavity through the design of the position of the liquid outlet and the arrangement of the second gas path, and liquid in the pre-filtration cavity is promoted to be quickly discharged during backwashing, so that the gas-liquid acting surface is large, the backwashing force is strong, the removal rate of solid particulate matters is high, and the service life of the filter element is prolonged. And the backwashing effect is good.

Description

Technical Field

[0001] The utility model belongs to the technical field of backwashing of filtering devices, and particularly relates to a filtering device suitable for gas-assisted backwashing. Background Technique

[0002] During the backwashing process, the removal rate of solids directly determines the service life and maintenance cycle of the filter. In the prior art, the gas-assisted liquid backwashing technology is a backwashing technology with relatively high removal efficiency and can be carried out online in the backwashing mode of filtering devices. In the existing gas-assisted liquid backwashing filter, during the backwashing process, a high-pressure gas source is connected to the post-filter cavity, and a pressure difference is formed on both sides of the filter medium by the high-pressure gas, and then the post-filter liquid is pushed to pass through the filter medium in the reverse direction at a high speed, so that the solid particulate matter on the surface of the filter medium and inside the filter holes is separated from the filter medium to achieve cleaning. This backwashing method can control the cleaning effect and cleaning frequency of the filter medium only by adjusting the gas source pressure and the ventilation interval. The backwashing process is simple and the removal rate is higher.

[0003] However, the existing gas-assisted liquid backwashing filters usually set the liquid outlet at the top of the filter. During normal forward filtration, both the pre-filter cavity and the post-filter cavity are in a state of being filled with liquid. During backwashing, due to factors such as too slow opening speed of the valve, too small gas-liquid action surface, and too slow drainage speed of the pre-filter cavity resulting in liquid flow resistance, the pressure difference on both sides of the filter medium is easily weakened, resulting in a decrease in the removal rate of solid particulate matter and affecting the backwashing effect. Summary of the Utility Model

[0004] The purpose of the utility model is to provide a filtering device suitable for gas-assisted backwashing to solve the problems that when the existing gas-assisted liquid backwashing filter is used, the gas-liquid action surface is too small, the drainage speed of the pre-filter cavity is too slow, weakening the pressure difference on both sides of the filter medium, and thus affecting the backwashing effect of the filter medium.

[0005] The utility model is realized by the following technical solutions:

[0006] The utility model provides a filtering device suitable for gas-assisted backwashing, the structure of which includes a filter tank. A partition plate is arranged in the filter tank, and the partition plate divides the filter tank into a pre-filter cavity and a post-filter cavity. A plurality of filter elements are embedded downward in the partition plate. The lower part of the pre-filter cavity is communicated with a liquid inlet and a backwash sewage discharge port. The post-filter cavity is communicated with a liquid outlet and a first air inlet. The first air inlet is communicated with a high-pressure gas source through a first air path; the liquid outlet is arranged on the side wall of the post-filter cavity, the first air inlet is arranged on the top of the post-filter cavity, a second air inlet is arranged on the side wall of the pre-filter cavity close to the partition plate, and the second air inlet is communicated with the high-pressure gas source through a second air path; a pneumatic butterfly valve and a first check valve are arranged on the first air path, a solenoid valve and a second check valve are arranged on the second air path, and pneumatic ball valves are arranged at the liquid inlet, the backwash sewage discharge port and the liquid outlet;

[0007] Based on the above technical solution, by arranging the liquid outlet on the side wall of the filtered chamber, a gas space is always maintained in the filtered chamber, and a second gas path is arranged at the upper part of the pre-filter chamber. When backwashing is required, the liquid in the pre-filter chamber can be quickly discharged in advance through the second gas path, and the reserved gas space in the filtered chamber can expand the gas-liquid action surface, thereby reducing the influence of the liquid flow resistance and the valve opening resistance on the pressure difference on both sides of the filter element, effectively ensuring the pressure difference peak value during backwashing and achieving a better backwashing effect.

[0008] Preferably, the backwash drain port is arranged below the filter tank, and a liquid return pipeline is arranged between the backwash drain port and the filter tank. One end of the liquid return pipeline communicates with the bottom of the pre-filter chamber, and the other end communicates with the liquid return port and the backwash drain port respectively through two pneumatic ball valves. This design can re-circulate the liquid in the pre-filter chamber before backwashing to the original liquid storage place, effectively avoiding waste or reducing the amount of pollution.

[0009] Preferably, the installation position of the liquid outlet is not lower than half of the height of the filtered chamber. This design can ensure that the amount of clarified liquid retained in the filtered chamber is not less than 50%, so as to ensure that there is enough liquid volume for backwashing the filter element during the backwashing process, thereby guaranteeing the cleaning effect.

[0010] Preferably, the filter element is a tubular filter element made of a sintered metal mesh roll. A joint is arranged at the upper end of the filter element, and the joint is connected to the partition plate. A plug is arranged at the lower end of the filter element. Using a sintered metal mesh as the filtering element can make the filter element more suitable for being cleaned by backwashing while ensuring relatively high filtering performance.

[0011] Furthermore, the sintered metal mesh is formed by sintering multiple layers of woven metal wire meshes. This method can form a sintered mesh with a relatively appropriate filtering pore size through the mesh size of the single-layer metal wire mesh and the staggered arrangement of different layers of metal wire meshes.

[0012] Furthermore, the pore density of the sintered metal mesh gradually increases from the outside to the inside. On the one hand, it forms a filtering structure in which large particles are intercepted first and small particles are intercepted later, improving the filtering effect of the filter element. On the other hand, during backwashing, due to the relatively small pore density and small flow area, the backwashing pressure can be increased accordingly. This structure is conducive to maintaining a relatively high backwashing pressure throughout the sintered metal mesh, enabling all layers of solid particulate matters to be effectively washed away, thereby effectively improving the backwashing effect.

[0013] Preferably, a support layer is arranged on the inner surface of the filter element, and the support layer is a metal wire mesh layer or a metal frame to maintain the shape of the filter element and improve the pressure-bearing capacity of the filter element.

[0014] Preferably, a sealing ring is arranged between the joint and the partition plate to prevent unfiltered liquid from entering the filtered chamber through the joint.

[0015] Preferably, a pneumatic three-way ball valve is provided at the connection between the liquid return pipeline and the pre-filter chamber. The pneumatic three-way ball valve is connected to a pickling system. The pickling system includes an acid solution tank, an acid addition pipeline, and an acid solution recovery pipeline. One end of the acid addition pipeline is connected to the pneumatic three-way ball valve, and the other end is connected to the acid solution tank. One end of the acid solution recovery pipeline is connected to the acid solution tank, and the other end opens on the side wall of the pre-filter chamber close to the partition plate. This design can deeply clean the filter element through the pickling system when the backwashing effect fails to meet the preset requirements, effectively reducing the disassembly and cleaning frequency of the filter tank and making maintenance simpler.

[0016] Preferably, a visual liquid level gauge is provided on the acid solution tank, and an acid discharge port is provided on the acid addition pipeline. A manual ball valve is provided at the acid discharge port. This design can observe the turbidity of the acid solution through the visual liquid level gauge, and then manually control whether to replace the acid solution.

[0017] Preferably, the filter tank and the high-pressure gas source are fixedly arranged in a fixed frame. An electric control device is provided on the fixed frame. The electric control device is used to control the opening and closing and the opening and closing sequence of the pneumatic butterfly valve, the solenoid valve, and the pneumatic ball valve. Through the unified deployment of the electric control device, the opening and closing of each valve can be automatically controlled to achieve automatic cleaning, and the cleaning frequency can be further set, which is beneficial to maintaining the filtering effect of the filtering device and extending its service life.

[0018] Advantageous Effects

[0019] One of the above technical solutions has the following advantages or beneficial effects:

[0020] 1) By using gas-assisted backwashing to clean the filter tank, and setting the liquid outlet on the side wall of the post-filter chamber so that there is always a gas space in the post-filter chamber, reducing the influence of liquid flow resistance and valve opening resistance on the pressure difference on both sides of the filter element. A second gas path is set in the upper part of the pre-filter chamber. During backwashing, the liquid in the pre-filter chamber is promoted to be quickly discharged through the second gas path. This filtering device has the characteristics of a large gas-liquid action surface, strong backwashing force, high removal rate of solid particulate matter, and good backwashing effect.

[0021] 2) By using a metal sintered mesh as the filtering element of the filter element, taking advantage of the large pore diameter and controllable pore density of the metal sintered mesh, the filter element is more conducive to backwashing on the basis of ensuring high filtering performance, and solid particulate matter is easier to be removed.

[0022] 3) By superimposing a pickling system on the basis of gas-assisted backwashing, the filter element can be cleaned more thoroughly, which is more conducive to the maintenance of the filter element and the extension of its service life, and correspondingly reduces the use cost of the filtering device. Description of the Drawings

[0023] Other features, objects, and advantages of the present utility model will become more apparent from the following detailed description of non-limiting embodiments read in conjunction with the accompanying drawings:

[0024] Figure 1 It is the pipeline schematic diagram of the present utility model;

[0025] Figure 2 It is the partial three-dimensional structure schematic diagram of the present utility model;

[0026] Figure 3 For the present utility model Figure 2 The schematic diagram of the AA surface structure;

[0027] Figure 4 For the present utility model Figure 3 The schematic diagram of the B part structure (the connection part between the filter element and the partition orifice plate) of the present utility model;

[0028] Figure 5 It is the schematic diagram of the filter element structure of the present utility model;

[0029] Figure 6 For the present utility model Figure 5 The schematic diagram of the C part structure in the present utility model;

[0030] In the figure: fixed frame 1; filter tank 2; pre-filter chamber 21; post-filter chamber 22; liquid inlet 2a; liquid outlet 2b; first air inlet 2c; second air inlet 2d; return liquid port 2e; backwash and sewage discharge port 2f; high-pressure gas source 3; partition plate 4; filter element 5; joint 51; metal sintered mesh 52; support layer 53; plug 54; pneumatic ball valve 6; electric control device 7; sealing ring 8; pickling system 9; acid liquid tank 9a; acid adding pipeline 9b; acid liquid recovery pipeline 9c; visual liquid level gauge 9a1; acid discharge port 9b1; manual ball valve 9b2; first gas path 101; pneumatic butterfly valve 101a; first check valve 101b; second gas path 102; solenoid valve 102a; second check valve 102b; return liquid pipeline 103; pneumatic three-way ball valve 103a. Detailed implementation manners

[0031] The present utility model will be further described in detail below in conjunction with embodiments, but the implementation manners of the present utility model are not limited thereto.

[0032] As Figures 1 to 3 shown, the present utility model provides a filtration device suitable for gas-assisted backwashing, and its structure includes a fixed frame 1, a filter tank 2, and a high-pressure gas source 3. The filter tank 2 and the high-pressure gas source 3 are fixedly arranged on the fixed frame 1. A partition plate 4 is arranged in the filter tank 2. The partition plate 4 divides the filter tank 2 into a pre-filter chamber 21 and a post-filter chamber 22. Multiple groups of filter elements 5 are embedded downward in the partition plate 4.

[0033] The lower part of the pre-filter chamber 21 is connected to a liquid inlet 2a and a backflush drain port 2f. The liquid inlet 2a is connected to a water pump. A pneumatic ball valve 6 is provided at the connection between the liquid inlet 2a and the filter tank 2. The backflush drain port 2f is provided below the filter tank 2. A return liquid pipeline 103 is provided between the backflush drain port 2f and the filter tank 2. One end of the return liquid pipeline 103 is connected to the bottom of the pre-filter chamber 21, and the other end is connected to the return liquid port 2e and the backflush drain port 2f respectively through two pneumatic ball valves 6. A second air inlet 2d is provided on the side wall of the pre-filter chamber 21 close to the partition plate 4. The second air inlet 2d is connected to a high-pressure air source 3 through a second air path 102. An electromagnetic valve 102a for controlling the opening and closing of the air path and a second check valve 102b for preventing liquid backflow are provided on the second air path 102. When the second air path 102 is used for backwashing, high-pressure gas is used to promote the accelerated discharge of the liquid in the pre-filter chamber 21.

[0034] The post-filter chamber 22 is connected to a liquid outlet 2b and a first air inlet 2c. The liquid outlet 2b is provided on the side wall of the post-filter chamber 22, and the liquid outlet 2b is connected to a pneumatic ball valve 6. Preferably, as Figure 1 shown, the installation position of the liquid outlet 2b is not lower than half of the height of the post-filter chamber 22, and the retention amount of the clarified liquid in the post-filter chamber 22 is not less than 50%, so as to ensure that there is enough liquid volume for backwashing the filter element 5 during the backwashing process. The first air inlet 2c is connected to the high-pressure air source 3 through a first air path 101. The first air inlet 2c is provided at the top of the post-filter chamber 22. A pneumatic butterfly valve 101a for controlling the opening and closing of the air path and a first check valve 101b for preventing liquid backflow are provided on the first air path 101.

[0035] As Figure 2 shown, an electric control device 7 is provided on the fixed frame 1. The electric control device 7 is used to control the opening and closing and the opening and closing sequence of the pneumatic butterfly valve 101a, the electromagnetic valve 102a and the pneumatic ball valve 6. Through the unified allocation of the electric control device 7, the opening and closing of each valve can be automatically controlled to realize automatic cleaning.

[0036] As Figure 5 shown, the filter element 5 is a tubular filter element formed by winding a metal sintered mesh 52. The inner cavity of the filter element 5 is connected to the post-filter chamber 22. A joint 51 is provided at the upper end of the filter element 5. The joint 51 is connected to the partition plate 4. A plug 54 is provided at the lower end of the filter element 5. Both the joint 51 and the plug 54 are fixedly embedded into the inner cavity of the tubular filter element 5. A support layer 53 is provided on the inner surface of the filter element 5. The support layer 53 is a metal wire mesh layer or a metal frame to maintain the shape of the filter element 5 and improve the pressure-bearing capacity of the filter element 5. As Figure 4As shown, a sealing ring 8 is further provided between the joint 51 and the partition plate 4. The sealing ring 8 is used to prevent unfiltered liquid from entering the post-filter chamber 22 from the joint 51. The sintered metal mesh 52 is formed by sintering multiple layers of woven metal wire meshes. As Figure 6 shown, in this embodiment, the sintered metal mesh 52 is formed by sintering five layers of woven metal wire meshes; preferably, the pore density of the sintered metal mesh 52 gradually increases from the outside to the inside.

[0037] Furthermore, to improve the cleaning effect of the filter element 5, a pneumatic three-way ball valve 103a is provided at the connection between the liquid return pipeline 103 and the pre-filter chamber 21. The pneumatic three-way ball valve 103a is connected to a pickling system 9. The pickling system 9 includes an acid solution tank 9a, an acid addition pipeline 9b, and an acid solution recovery pipeline 9c. One end of the acid addition pipeline 9b is connected to the pneumatic three-way ball valve 103a, and the other end is connected to the acid solution tank 9a. One end of the acid solution recovery pipeline 9c is connected to the acid solution tank 9a, and the other end opens on the side wall of the pre-filter chamber 21 close to the partition plate 4; preferably, a visible liquid level gauge 9a1 is provided on the acid solution tank 9a, and an acid discharge port 9b1 is provided on the acid addition pipeline 9b. A manual ball valve 9b2 is provided at the acid discharge port 9b1. This design can observe the turbidity of the acid solution through the visible liquid level gauge 9a1, and then manually control whether to replace the acid solution.

[0038] In the filtering device of this embodiment, when used in the forward direction, the liquid to be filtered is under the action of a water pump and enters the pre-filter chamber 21 from the liquid inlet 2a at a certain pressure. Then, under the action of the osmotic pressure difference, it penetrates into the side wall of the filter element 5, that is, the metal sintered mesh 52. The solid particles therein are intercepted by the metal sintered mesh 52 in sequence according to their particle sizes. The filtered liquid, that is, the clarified liquid, flows into the post-filter chamber 22 from the inner cavity of the filter element 5 and then is discharged from the liquid outlet 2b. During backwashing, the electric control device 7 closes the liquid inlet 2a and the liquid outlet 2b, opens the pneumatic three-way ball valve 103a and the pneumatic ball valve 6 at the liquid return port 2e to connect the liquid return pipeline 103, and at the same time opens the solenoid valve 102a of the second air circuit 102 to input high-pressure gas into the pre-filter chamber 21. The pre-filter chamber 21 starts to drain, and the drained liquid flows back to the original liquid storage place; when the liquid in the pre-filter chamber 21 is lower than the plug 54 of the filter element 5 or the pressure in the filter tank 2 is lower than the preset value, the pneumatic ball valve 6 at the liquid return port 2e is closed, and the pneumatic butterfly valve 101a of the first air circuit 101 and the pneumatic ball valve 6 at the backwashing sewage outlet are opened to start backwashing. The high-pressure gas pushes the clarified liquid to flow reversely into the inner cavity of the filter element 5. Due to the pressure difference on both sides of the filter element 5, the clarified liquid flushes the metal sintered mesh 52 and makes the solid particles attached thereto detach. The solid particles flow out from the bottom of the filter tank 2 along with the backwashing liquid and flow out through the backwashing sewage outlet, completing the entire backwashing process. When the forward filtering efficiency is still relatively low after backwashing, the pickling system 9 can be enabled. The electric control device 7 closes the liquid inlet 2a and the liquid outlet 2b, opens the pneumatic three-way ball valve 103a and the pneumatic ball valve 6 on the acid liquid recovery pipeline 9c. The acid liquid in the acid liquid tank 9a is pumped into the pre-filter chamber 21 and flows back to the acid liquid tank 9a from the acid liquid recovery pipeline 9c. After the solid particles on the filter element 5 react with the acid liquid and detach from the filter element 5, the pneumatic ball valve 6 on the acid liquid recovery pipeline 9c is closed, and the backwashing process is executed once or multiple times to make the solid particles fully detach from the filter element 5, achieving deep cleaning.

[0039] The above is only a preferred embodiment of the present invention, and does not impose any limitation on the technical scope of the present invention. Therefore, any minor modification, equivalent change, and modification made to the above embodiments based on the technical essence of the present invention still fall within the protection scope of the present invention.

Claims

1. A filtration device suitable for gas-assisted backwashing, the structure of which includes a filter tank (2), a partition plate (4) is arranged in the filter tank (2), and the partition plate (4) divides the filter tank (2) into a pre-filter chamber (21) and a post-filter chamber (22). A plurality of filter elements (5) are embedded downward in the partition plate (4). The lower part of the pre-filter chamber (21) is communicated with a liquid inlet (2a) and a backwashing sewage discharge port (2f). The post-filter chamber (22) is communicated with a liquid outlet (2b) and a first air inlet (2c). The first air inlet (2c) is communicated with a high-pressure gas source (3) through a first gas path (101); characterized in that: The liquid outlet (2b) is provided on the side wall of the post - filtration chamber (22), the first air inlet (2c) is provided at the top of the post - filtration chamber (22), and a second air inlet (2d) is provided on the side wall of the pre - filtration chamber (21) close to the partition plate (4). The second air inlet (2d) is connected to the high - pressure air source (3) through the second air path (102); a pneumatic butterfly valve and a first check valve (101b) are provided on the first air path (101), a solenoid valve (102a) and a second check valve (102b) are provided on the second air path (102), and pneumatic ball valves (6) are provided at the liquid inlet (2a), the back - flushing sewage outlet (2f) and the liquid outlet (2b).

2. The filtration device suitable for gas-assisted backwashing according to claim 1, characterized in that: The back - flushing sewage outlet (2f) is provided below the filter tank (2). A return liquid pipeline (103) is provided between the back - flushing sewage outlet (2f) and the filter tank (2). One end of the return liquid pipeline (103) is connected to the bottom of the pre - filtration chamber (21), and the other end is connected to the return liquid port (2e) and the back - flushing sewage outlet (2f) respectively through two pneumatic ball valves (6).

3. The filtration device suitable for gas-assisted backwashing according to claim 1, characterized in that: The setting position of the liquid outlet (2b) is not lower than half of the height of the post - filtration chamber (22).

4. The filtering device suitable for gas-assisted backwashing according to claim 1, wherein: The filter element (5) is a tubular filter element (5) formed by winding a metal sintered mesh (52). A joint (51) is provided at the upper end of the filter element (5), the joint (51) is connected to the partition plate (4), and a plug (54) is provided at the lower end of the filter element (5).

5. A filtering device suitable for gas-assisted backwashing according to claim 4, characterized in that: The metal sintered mesh (52) is formed by sintering multiple layers of woven metal wire meshes.

6. The filtering device suitable for gas-assisted backwashing according to claim 5, wherein: The pore density of the metal sintered mesh (52) gradually increases from the outside to the inside.

7. The filtering device suitable for gas-assisted backwashing according to claim 4, characterized in that: A support layer (53) is provided on the inner surface of the filter element (5), and the support layer (53) is a metal wire mesh layer or a metal frame.

8. The filtering device suitable for gas-assisted backwashing according to claim 4, wherein: A sealing ring (8) is provided between the joint (51) and the partition plate (4).

9. The filtering device suitable for gas-assisted backwashing according to claim 2, characterized in that: A pneumatic three - way ball valve (103a) is provided at the connection of the return liquid pipeline (103) and the pre - filtration chamber (21). The pneumatic three - way ball valve (103a) is connected to a pickling system (9). The pickling system (9) includes an acid liquid tank (9a), an acid adding pipeline (9b) and an acid liquid recovery pipeline (9c). One end of the acid adding pipeline (9b) is connected to the pneumatic three - way ball valve (103a), and the other end is connected to the acid liquid tank (9a). One end of the acid liquid recovery pipeline (9c) is connected to the acid liquid tank (9a), and the other end opens on the side wall of the pre - filtration chamber (21) close to the partition plate (4).

10. A filtration device suitable for gas-assisted backwashing according to claim 1, characterized in that: The filter tank (2) and the high - pressure air source (3) are fixedly arranged in a fixed frame (1). An electric control device (7) is provided on the fixed frame (1). The electric control device (7) is used to control the opening and closing and the opening and closing sequence of the pneumatic butterfly valve, the solenoid valve (102a) and the pneumatic ball valve (6).

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