Backwashing device and sand filter comprising same

Abstract

The utility model provides a backwashing device and a sand filter comprising the same, the backwashing device comprises an L-shaped base plate, a plurality of layers of L-shaped daughter boards are sequentially laminated on the L-shaped base plate, the height of the vertical section of each daughter board is gradually reduced along the direction far away from the base plate, and the length of the horizontal section of each daughter board is gradually increased along the direction far away from the base plate; conveying channels are respectively formed between two adjacent layers of sub-plates and between the base plate and the sub-plate closest to the base plate; backwash holes communicated with the conveying channels one by one are formed in the top of the vertical section of each layer of daughter board, and the spraying directions of the backwash holes extend horizontally; the horizontal section of the base plate is provided with a plurality of water inlet holes communicating with the conveying channels one by one. The backwashing device is arranged on the periphery of the sand filter, and the generated transverse water flow directly acts on the filter material, so that the hardened filter material is easier to separate from the filter wall, the disturbance to the filter material layer is enhanced, and the crushing and dispersion of the hardened filter material are accelerated.

Description

Technical Field

[0001] The utility model relates to the technical field of water treatment, in particular to a backwashing device and a sand filter tank comprising the device. Background Art

[0002] Sand filters are widely used in water treatment plants. They filter impurities by trapping them in the water using granular materials such as quartz sand and pebbles. However, as the impurities accumulate, the sand filter's throughput gradually decreases. To remove these impurities, the filter needs to be backwashed for a period of time to restore normal operation. In actual operation, the filter heads are evenly distributed on the filter plates at the bottom of the filter tank. If backwashing is not performed for a long time, the excessive amount of filtered impurities will cause the filter media to become compacted. When backwashing is performed again, a phenomenon often occurs: while the backwashing effect in the center of the filter tank is significant, the filter media surrounding it is bonded to the tank wall, resulting in high backwash resistance. The backwashing water or air flow is insufficient to dislodge the compacted filter media. The center filter head, on the other hand, has less backwash resistance, causing more backwash water or air to flow out of the center filter head, reducing the backwashing force at the surrounding filter heads and further preventing the compaction of the filter media. This compaction not only reduces the filter's treatment efficiency but also increases operating costs. Therefore, it is necessary to develop a device that can quickly solve the problem of filter material compaction around the sand filter. Utility Model Content

[0003] In order to overcome the problem of insufficient compaction of filter media around the edges of sand filters that is difficult to handle in the prior art, the utility model provides a backwashing device that utilizes lateral flushing close to the pool wall to reduce the adhesion between the compacted filter media and the pool wall, enhance the fluid disturbance around the edges of the sand filter, thereby quickly breaking up the compacted filter media and achieving regeneration of the filter media in this area.

[0004] The utility model adopts the following technical solutions.

[0005] A backwash device comprises an L-shaped base plate, on which a plurality of L-shaped sub-plates are sequentially stacked, wherein the height of the vertical sections of the sub-plates gradually decreases in a direction away from the base plate, and the length of the horizontal sections of the sub-plates gradually increases in a direction away from the base plate;

[0006] Conveying channels are formed between two adjacent layers of sub-boards, and between the base board and the sub-board closest to the base board;

[0007] The top of the vertical section of each sub-plate is provided with a backwash hole connected to each conveying channel one by one, and the spray direction of the backwash hole extends horizontally;

[0008] The horizontal section of the base plate is provided with a plurality of water inlet holes which are connected with each conveying channel one by one.

[0009] Preferably, the delivery channel is further connected to an input pipe, and the input pipe passes through the substrate.

[0010] Preferably, the backwash holes are provided with a grid mesh, and the gap width of the grid mesh is 0.7 mm.

[0011] Preferably, mounting holes are symmetrically provided on both sides of the base plate, and expansion bolts are provided in the mounting holes.

[0012] Preferably, a sealing gasket is provided on the horizontal section of the substrate.

[0013] Correspondingly, the utility model also provides a sand filter tank, which includes the above-mentioned backwash device; wherein the sand filter tank includes a filter plate and filter material, and the above-mentioned backwash device is installed at intervals on the edge of the filter plate, the backwash hole is facing the side wall of the sand filter tank closest to it, and the filter plate is provided with a plurality of sleeves that pass through the water inlet holes one by one.

[0014] Furthermore, the sand filter tank is filled with filter material, and the height of the largest backwash hole in the backwash device is half of the filter material.

[0015] The beneficial effects of the utility model are:

[0016] The utility model provides a backwash device and a sand filter tank containing the device. By arranging the backwash device around the sand filter tank, a high-speed water flow in the horizontal direction along the tank wall is generated. This horizontal flushing can directly act on the contact surface between the compacted filter media and the tank wall, weakening the adhesion between the two, making it easier for the compacted filter media to separate from the tank wall. At the same time, it forms a combined force with the original vertical flushing of the sand filter tank, enhancing the disturbance of the filter media layer and accelerating the crushing and dispersion of the compacted filter media. The fluid flow state around the filter tank is improved, the formation of dead corners is reduced, and the uniformity of backwashing is improved. Furthermore, the backwash heads at each height have independent conveying channels and are connected to independent input pipes in sequence, thereby effectively preventing the water or gas in the flow channel from tending to flow out from the top backwash head with lower pressure when the three are connected, which will lead to a reduction in the water or gas output of the middle and bottom backwash heads. In extreme cases, it will result in insufficient water or gas to flush the filter sand in the pores. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0018] Figure 1 This is a schematic diagram of the three-dimensional structure of a backwash device in one embodiment of the present utility model;

[0019] Figure 2 This is a cross-sectional view of a backwash device in one embodiment of the present invention;

[0020] Figure 3 This is a top view of a sand filter tank in one embodiment of the present utility model;

[0021] Figure 4 This is an installation elevation view of a sand filter tank in one embodiment of the present invention.

[0022] Description of reference numerals:

[0023] 1. Backwash device; 11. Base plate; 111. Water inlet; 12. Sub-plate; 121. Backwash hole; 13. Conveying channel; 14. Grid; 15. Expansion bolt; 16. Sealing gasket; 2. Sand filter; 3. Filter plate; 4. Filter material. DETAILED DESCRIPTION

[0024] The following will clearly and completely describe the technical solutions in the embodiments of the present application in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application. In addition, it should be understood that the specific implementation methods described herein are only used to illustrate and explain the present application, and are not used to limit the present application. In this application, unless otherwise specified, the directional words used, such as "up", "down", "left", and "right", generally refer to the up, down, left, and right in the actual use or working mode of the device, specifically the drawing direction in the drawings. The drawings are for illustrative purposes only and cannot be understood as limitations on this patent; in order to better illustrate this embodiment, some parts of the drawings may be omitted, enlarged, or reduced, and do not represent the size of the actual product.

[0025] It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings. The drawings are for illustrative purposes only and should not be construed as limiting the present invention.

[0026] The technical solution of the present utility model is further described below with reference to the accompanying drawings and embodiments.

[0027] As attached Figure 1-2 The backwash device 1 shown includes an L-shaped base plate 11, on which multiple layers of L-shaped sub-plates 12 are stacked in sequence. The height of the vertical section of the sub-plate 12 gradually decreases in the direction away from the base plate 11, and the length of the horizontal section of the sub-plate 12 gradually increases in the direction away from the base plate 11.

[0028] Conveying channels 13 are formed between two adjacent layers of sub-boards 12 and between the base plate 11 and the sub-board 12 closest to the base plate 11 .

[0029] A backwash hole 121 is opened at the top of the vertical section of each layer of the sub-plate 12 and is connected to each of the conveying channels 13 one by one. The spraying direction of the backwash hole 121 extends horizontally.

[0030] The horizontal section of the base plate 11 is provided with a plurality of water inlet holes 111 which are connected to each of the delivery channels 13 one by one.

[0031] In some embodiments, the backwash holes 121 are provided with a grid 14 having a gap width of 0.7 mm. The grid 14 effectively blocks the filter material 4 from passing through the gaps in the grid 114, thereby blocking the backwash head 11. The effective particle size of quartz sand is typically 0.9-1.0 mm. Furthermore, it prevents excessive resistance to water or air outflow caused by too small a gap.

[0032] In some embodiments, mounting holes are symmetrically defined on both sides of the base plate 11, each of which is provided with expansion bolts 15. Four expansion bolts 15 are evenly distributed on each side to ensure uniform force is applied to the base plate 11 during installation. The expansion bolts 15 secure the backwash device 1 to the bottom of the sand filter 2.

[0033] In some embodiments, a sealing gasket 16 is provided on the lower end surface of the base plate 11. The sealing gasket 16 is made of rubber. During installation of the backwash device 1, the sealing gasket 16 is squeezed and deformed, filling the gap between the water inlet 111 and the base plate 11 and the bottom of the sand filter 2. This effectively prevents water or gas from escaping through the gap during the backwash process, thereby affecting the water or gas output of the backwash head 11 at different heights.

[0034] Example 1:

[0035] See also Figure 3 The present invention also provides a sand filter 2, which includes the above-mentioned backwash device 1; it also includes a filter plate 3 and filter media 4. The backwash device 1 is installed at intervals on the edge of the filter plate 3 by means of expansion bolts 15 on the base plate 11, with the backwash hole 121 facing the side wall of the sand filter 2 closest to it. The filter plate 3 is provided with a plurality of sleeves that pass through the water inlet holes 111 one by one. The backwash device 1 is arranged in an intermittent manner to surround the entire filter tank and is arranged alternately with the original filter heads at the bottom of the sand filter 2. In this way, the advantages of the original filter head backwash system at the bottom of the sand filter 2 can be fully utilized, and the disadvantage of the filter media 4 around the sand filter 2 being difficult to eliminate due to compaction can be compensated.

[0036] Example 2:

[0037] See also Figure 4In the backwashing device 1 of the present invention, the top height of the sub-plate 12 with the longest vertical section length needs to be processed and adjusted according to the filling height of the filter media 4 in the sand filter 2 to ensure that the top height of the sub-plate 12 with the longest vertical section length is about half of the filling height of the filter media 4 in the sand filter 2. When the top height of the sub-plate 12 with the longest vertical section length exceeds half of the filling height of the filter media 4 in the sand filter 2, the improvement in the backwashing effect is limited, which is not proportional to the material cost of the device caused by this, and the economy is poor; but when the top height of the sub-plate 12 with the longest vertical section length is too low, the improvement in the backwashing effect brought by the backwashing device 1 is not obvious compared to the original bottom filter head method. Weighing the degree of improvement in the backwashing effect and economy, it is most appropriate to set the top height of the sub-plate 12 with the longest vertical section length to about half of the filling height of the filter media 4 in the sand filter 2.

[0038] The working principle of this utility model is as follows:

[0039] When backwashing is performed, water or gas enters the delivery channel 13 from the water inlet 111, and finally is ejected from the backwash hole 121 corresponding to each delivery channel 13. Since each delivery channel 13 is independently provided, it fundamentally avoids the situation where if each backwash hole 121 shares the same delivery channel 13, the top backwash hole 121 will have a smaller resistance to water or gas outflow, followed by the middle backwash hole 121, and the backwash hole 121 at the lower position will have the largest resistance. This will cause the water or gas in the delivery channel 13 to tend to flow out from the top backwash hole 121 with lower pressure, which will result in a reduction in the amount of water or gas outflow from the backwash hole 121 located in the middle or lower position, which will not be enough to flush the filter material 4 at the pores. After the filter material 4 is impacted by the water flow or air flow ejected horizontally from the backwash holes 121 at different heights, the adhesion between the filter material 4 and the wall of the sand filter tank 2 will be significantly reduced. At this time, combined with the impact of the water flow or air flow in the vertical direction, the filter material 4 compacted around the sand filter tank 2 can be quickly loosened, achieving a better backwash regeneration effect.

[0040] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the implementation methods of the present invention. A person skilled in the art will be able to make other variations or modifications based on the above description. It is not necessary and impossible to enumerate all implementation methods here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A backwash device, characterized in that: The invention comprises an L-shaped base plate, on which a plurality of L-shaped sub-plates are sequentially stacked, wherein the height of the vertical section of the sub-plate gradually decreases as it moves away from the base plate, and the length of the horizontal section of the sub-plate gradually increases as it moves away from the base plate; Conveying channels are formed between two adjacent layers of sub-boards, and between the base board and the sub-board closest to the base board; The top of the vertical section of each sub-plate is provided with a backwash hole connected to each conveying channel one by one, and the spray direction of the backwash hole extends horizontally; The horizontal section of the base plate is provided with a plurality of water inlet holes which are connected with each conveying channel one by one.

2. A backwashing device according to claim 1, characterized in that: The backwash hole is provided with a grid mesh, and the gap width of the grid mesh is 0.7 mm.

3. A backwashing device according to claim 1, characterized in that: Mounting holes are symmetrically provided on both sides of the base plate, and expansion bolts are arranged in the mounting holes.

4. A backwashing device according to claim 1, characterized in that: The horizontal section of the base plate is provided with a sealing gasket.

5. A sand filter, comprising a filter plate and filter material, characterized in that: The backwashing device according to any one of claims 1 to 4 is installed at intervals on the edge of the filter plate, the backwashing holes of the backwashing device are facing the side wall of the sand filter tank closest to it, and the filter plate is provided with multiple sleeves that pass through the water inlet holes one by one.

6. A sand filter according to claim 5, characterized in that: The sand filter tank is filled with filter material, and the height of the filter material is twice the height of the largest backwash hole in the backwash device.

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