Backwash water and air distribution filter bricks and water and air distribution device for sulfur autotrophic denitrification filter tank

Abstract

The present application relates to a backwash water and air distribution filter brick and a water and air distribution device for a sulfur autotrophic denitrification filter tank, and relates to the technical field of sewage treatment equipment. The backwash water and air distribution filter brick for the sulfur autotrophic denitrification filter tank in the present application includes a bottom plate, a first side plate, a second side plate and a partition plate, forming a primary distribution chamber for backwash water, a secondary distribution chamber for backwash water and a secondary distribution chamber for backwash air, and realizing uniform water and air distribution through multiple through holes and a secondary particle retention component. The present application also provides a backwash water and air distribution device comprising the above-mentioned backwash water and air distribution filter brick. The structural design in the present application reduces the loss of sulfur autotrophic slow-release materials, reduces the risk of filter brick clogging, improves backwash efficiency, and at the same time reduces the construction depth of the filter tank, saving investment.

Description

Technical Field

[0001] The present application relates to the technical field of sewage treatment equipment, and in particular to a backwash water and air distribution filter brick and a water and air distribution device for a sulfur autotrophic denitrification filter tank. Background Art

[0002] In recent years, as the country's requirements for environmental protection have become increasingly stringent, in order to meet the Class A standard of the Pollutant Discharge Standard for Urban Wastewater Treatment Plants (GB18918-2002) and the local standard drainage limits, higher requirements have been made for the TN index. In some sensitive waters, the TN (total nitrogen) index has even been raised to below 5 mg / L. Under this background, the post-denitrification filter has become the standard technology for raising the total nitrogen standard in sewage treatment plants. In the early days, the post-denitrification filter engineering community generally adopted heterotrophic denitrification filters, which were filled with quartz sand or ceramsite filter materials, and additional organic carbon sources (such as methanol, sodium acetate, etc.) were added during operation for deep denitrification; in recent years, sulfur autotrophic technology has been initially applied in engineering due to its low denitrification cost (it can save 30% to 50% of carbon source costs). Sulfur autotrophic denitrification technology is a process that uses sulfur bacteria to reduce nitrates to nitrogen gas under anoxic or anaerobic conditions. This technology uses elemental sulfur, sulfide, sulfite, tetrasulfonate or thiosulfate as electron donors to generate CO2, HCO3 - 、CO3 2- Inorganic carbon such as carbon is used as a growth carbon source, and sulfur bacteria are used to reduce nitrates by oxidizing sulfur compounds in an anoxic environment, ultimately generating nitrogen. This process does not require an external carbon source, so it is called autotrophic denitrification. Sulfur autotrophic denitrification technology has begun to be used in the fields of deep denitrification of municipal sewage, deep purification of contaminated surface water environments, and remediation of nitrate-contaminated groundwater. This technology can effectively remove nitrates from water, has the ability to achieve extreme denitrification, and can reduce costs and avoid secondary pollution. At this stage, the mainstream sulfur autotrophic technology also uses the filter tank as a reactor, and uses sulfur and other mineral powders to form spherical or irregular granules as filter materials. The denitrification electron donor comes from the sulfur source in the material, so the filter material in the sulfur autotrophic denitrification filter tank is a consumable and needs to be regularly added and replenished.

[0003] The operation of sulfur autotrophic denitrification filter is different from that of traditional heterotrophic filter in the following ways: ① The sulfur autotrophic filter material is a consumable filter material (the quartz sand or ceramsite of traditional heterotrophic filter will not undergo essential changes in the filter material structure). The filter material particles are gradually consumed from large particles (generally 2-6 mm) to small particles. At the same time, as a slow-release material, it will also decompose into fine particles (as fine as about 0.1 mm) during sewage immersion. If the fine particles are not intercepted, they will eventually flow out with the effluent, which undoubtedly increases the consumption of materials and increases the operating costs; ② The sulfur autotrophic denitrification microbial flora is cultivated slowly (chemoautotrophic type), and is more sensitive to dissolved oxygen, with a thin biofilm. On the contrary, traditional heterotrophic denitrification (chemoheterotrophic type) has a faster cultivation speed and a thicker biofilm; In engineering applications, the backwashing intensity of the two is different. The gas impulse intensity required for sulfur autotrophic denitrification (about 40-50m 3 / m 2 ·h) is only half of heterotrophic denitrification (about 90-110m 3 / m 2 ·h), therefore, the backwash water and air distribution holes in the sulfur autotrophic denitrification filter are more likely to be blocked due to insufficient flushing intensity, resulting in local compaction of the filter bed and affecting the denitrification efficiency; ③, the denitrification rate of sulfur autotrophic denitrification is slow, which is reflected in the low nitrate nitrogen volume load in engineering applications, with a general design value of 0.2-0.5 kg / m³·d, while the heterotrophic denitrification filter can reach 0.5-1.0 kg / m³·d, so in the design of the sulfur autotrophic filter, the filter material filling height is generally high, reaching 2.0-3.2 m, and this filling height is difficult to achieve in the transformation of the existing sewage plant project; the reason is that the filter tank of the existing sewage plant generally adopts the form of filter plate filter head water and air distribution, the device occupies a large pool depth, the device is about 1.2 m high, and in order to prevent the loss of filter material, a pebble support layer structure is generally added, and the pebble support layer structure layer is close to 0.5 m high; if this type of filter tank is transformed into a sulfur autotrophic filter tank, the height of the above two devices must be compressed to obtain more pool capacity and depth.

[0004] The pool design of the filter is mostly developed around the backwash water and air distribution device. The existing technology is less developed for sulfur autotrophic denitrification filters, and more directly borrows the model of traditional heterotrophic filters. Therefore, the most critical unit to solve the current shortcomings of the above-mentioned sulfur autotrophic denitrification filter is to optimize its backwash water and air distribution device. The quality of its backwash performance directly determines the use effect of the filter.

[0005] Although the post-denitrification filter water and air distribution device set in the related art adopts the filter interception plate technology and does not need a pebble layer to save pool capacity, its water and air distribution device is prone to fouling (small particles brought by sulfur autotrophic slow-release materials block and penetrate the filter interception plate) because the air and water distribution holes are arranged vertically upward, and the air and water share a chamber, which can easily cause filter loss in the early stage of air-water combined backwashing (the first step of filter backwashing is air washing, and the second step is air-water combined backwashing. When the first step of air washing is completed, a large amount of air remains in the first-stage water and air distribution channel. At this time, the second step of air-water combined backwashing will quickly compress the remaining air in the first-stage channel, causing it to be released to the tail end of the filter with high intensity, which will cause the loss of filter material in the upper filter layer).

[0006] There is also a structure in the related art that adopts inclined micropores to distribute water and air holes, which can effectively alleviate the problem of air and water hole blockage, and its microporous structure can eliminate the pebble supporting layer to solve the problem of insufficient pool capacity and depth, but its microporous form of air and water distribution holes is customized for non-consumable particle filter media (that is, air and water distribution holes smaller than the filter media particles are manufactured to achieve the purpose of retaining the filter media), and this form cannot intercept the more fine particles released by the sulfur autotrophic slow-release material. At the same time, most of such devices are trapezoidal structures, and the devices are complex and have poor pressure-bearing structures. Summary of the invention

[0007] In order to effectively intercept small particle filter material and ensure the efficient operation of a sulfur autotrophic denitrification filter, the present application provides a backwash water and air distribution filter brick and a water and air distribution device for a sulfur autotrophic denitrification filter.

[0008] In the first aspect, the backwash water and air distribution filter bricks of a sulfur autotrophic denitrification filter provided in the present application adopt the following technical solution:

[0009] A backwash water and air distribution filter brick for a sulfur autotrophic denitrification filter tank comprises a bottom plate, a first side plate obliquely fixed on the bottom plate, and a second side plate obliquely fixed on the bottom plate.

[0010] A partition is fixedly arranged between the first side plate and the second side plate; a primary backwash water distribution chamber is arranged between the inner side of the second side plate and the bottom plate; a secondary backwash water distribution chamber is formed by the inner side of the first side plate, the outer side of the second side plate and the partition, and a secondary backwash gas distribution chamber is formed by the inner side of the first side plate, the outer side of the second side plate, the partition and the bottom plate, and the secondary backwash water distribution chamber is located above the secondary backwash gas distribution chamber;

[0011] The outer side of the first side plate is provided with a plurality of first through holes connected to the backwash water secondary distribution chamber and a plurality of second through holes connected to the backwash gas secondary distribution chamber; the first side plate is provided with arc-shaped shielding portions on the outer sides of the first through holes and the second through holes;

[0012] The outer side of the second side plate is located in the secondary distribution chamber of backwash water and is fixed with a plurality of secondary particle retention components; the secondary particle retention component has a secondary retention inner cavity inside, and the outer peripheral surface of the secondary particle retention component has a plurality of secondary retention water holes connected to the secondary retention inner cavity; the secondary retention inner cavity of the secondary particle retention component is connected to the primary distribution chamber of backwash water.

[0013] The backwashing water and air distribution filter brick in the present application is suitable for the backwashing water and air distribution device in the sulfur autotrophic denitrification filter tank to ensure the efficient operation of the sulfur autotrophic filter tank. By adopting the above technical scheme, the backwashing water and air distribution filter brick in the present application realizes the uniform distribution of gas and water during the backwashing process of the sulfur autotrophic denitrification filter tank, and improves the backwashing effect of the filter tank. Specifically, by designing a unique two-stage distribution chamber structure, the uniform distribution of backwash water and backwash gas is ensured, and the problem of local excessive impact or inadequate flushing of the filter material caused by uneven distribution of gas and water is avoided. At the same time, by setting an arc-shaped shielding portion on the first side plate, the probability of free particles in the slow-release filter material escaping with the outlet water during the filtration process is effectively reduced, and the loss of filter material is reduced. In addition, the design of the particle secondary interception component not only intercepts the fine filter material particles in the filtered water to prevent them from being lost with the water flow, but also plays a role of secondary distribution during the backwashing process, further enhancing the backwashing effect and ensuring the long-term stable operation of the filter tank.

[0014] Optionally, there are two first side panels and two second side panels, the two first side panels are symmetrically arranged on the bottom plate, the two second side panels are also symmetrically arranged on the bottom plate, and the two first side panels are distributed on the outsides of the two second side panels; the upper sides of the two first side panels and the two second side panels are fixedly connected together, the inclination angle of the first side panel on the bottom plate is smaller than the inclination angle of the second side panel on the bottom plate, and the two second side panels and the bottom plate together form the first-level distribution chamber for backwash water.

[0015] By adopting the above technical solution, the two first side plates and the two second side plates are symmetrically arranged on the bottom plate, and together with the bottom plate form a structure with a triangular cross-section, and combined with the partition plate, the interior of the backwash water and air distribution filter brick is divided into multiple chambers. This design not only makes the water and air distribution more uniform, improves the backwash effect, reduces the consumption of filter materials, and reduces the structural depth of the filter tank due to the support layer structure, but also greatly improves the working efficiency of the entire device through double-sided filtration.

[0016] Optionally, the arcuate shielding portion is formed by the first side plate protruding outward from the upper side edges of the first through hole and the second through hole and extending downward, and the lower side of the arcuate shielding portion is lower than the lower side edges of the corresponding first through hole and the second through hole; the inner side and the outer side edges of the arcuate shielding portion both have arcuate guide surfaces; the lower side of the arcuate shielding portion has a first barb protrusion facing the outer side edge of the first side plate, and the lower side edges of the first through hole and the second through hole have a second barb protrusion facing the inner side edge of the arcuate shielding portion; the first barb protrusion and the second barb protrusion are staggered and a primary interception channel is formed therebetween.

[0017] By adopting the above technical solution, the design of the arc-shaped shielding part makes the filtered water first guided by the arc-shaped guide surface when passing through the first through hole and the second through hole, changing the flow direction, and the free fine particles of the filter material no longer flow out with the water and settle down, thereby reducing the loss of the filter material. At the same time, the staggered setting between the first barb protrusion and the second barb protrusion forms a primary interception channel, which effectively intercepts the fine particles of the filter material and prevents them from entering the interior of the filter brick, reducing the burden of the subsequent secondary interception component and improving the filtering efficiency and stability of the entire system. In addition, this design of direct contact between the filter material layer and the water and air distribution filter brick layer also helps to reduce the pool depth and reduce the capital investment in engineering construction.

[0018] Optionally, a plurality of strip through holes connected to the secondary distribution chamber of backwash water are further provided on the first side plate; the length direction of the strip through holes is arranged along the length direction of the bottom plate and all the strip through holes are arranged at intervals along the length direction of the bottom plate; the strip through holes are located between the first through holes and the second through holes and the strip through holes are arranged at a position of the first side plate close to the partition.

[0019] By adopting the above technical solution, the backwash water in the secondary backwash water distribution chamber can be evenly distributed to the filter tank through the strip-shaped through holes, which improves the uniformity of backwash water distribution, reduces the problem of excessive or insufficient backwash water flow in local areas of the filter brick, and ensures a more uniform backwash effect of the entire filter tank. At the same time, the fine particles deposited on the partition in the secondary backwash water distribution are preferentially discharged from the strip-shaped through holes to the filter material layer under the action of the backwash water, which helps to consume and utilize the fine particles in the filter material and reduce the consumption of the filter material.

[0020] Optionally, a main inlet hole for cleaning water connected to the primary distribution chamber for backwash water is provided on the bottom plate; an air distribution channel plate is fixedly provided on the bottom plate in the primary distribution chamber for backwash water; the air distribution channel plate, the second side plate and the bottom plate together form a primary distribution chamber for backwash gas, and an air cleaning inlet hole connected to the primary distribution chamber for backwash gas is provided on the bottom plate; an air distribution rectifier grid for connecting the primary distribution chamber for backwash gas with the secondary distribution chamber for backwash gas is provided on the second side plate.

[0021] By adopting the above technical solution, the independent distribution of backwash water and backwash gas is achieved, the uniformity and stability of gas-water distribution is ensured, and the phenomenon of a sharp increase in backwash intensity caused by air compression during the combined gas-water backwash process is avoided, thereby reducing the loss of filter material during the backwash process. At the same time, the design of the gas distribution rectifier grid effectively rectifies the large flow of gas, so that it is evenly distributed to each backwash gas distribution chamber, improving the backwash effect. In addition, the setting of the total inlet hole for washing water and the inlet hole for air washing simplifies the structure of the water and gas distribution device, reduces the difficulty of installation, and improves the reliability and maintenance convenience of the system.

[0022] Optionally, the particle secondary retention component includes an outer water cylinder, a middle water cylinder and an inner water cylinder which are coaxially spaced in sequence from the outside to the inside; both ends of the outer water cylinder, the middle water cylinder and the inner water cylinder are sealed and fixedly connected by end plates; the secondary retention inner cavity is located in the inner water cylinder, a secondary retention outer cavity is formed between the outer water cylinder and the middle water cylinder, and a secondary retention middle cavity is formed between the middle water cylinder and the inner water cylinder; a plurality of secondary retention water holes are provided on the outer circumferential surfaces of the outer water cylinder, the middle water cylinder and the inner water cylinder; the secondary retention water holes on the outer water cylinder are staggered with the secondary retention water holes on the middle water cylinder, and the secondary retention water holes on the middle water cylinder are staggered with the secondary retention water holes on the inner water cylinder.

[0023] By adopting the above technical solution, the three-level cylindrical structure of the particle secondary interception component effectively improves the interception ability of fine particles. The staggered secondary interception water holes of the outer water cylinder, the middle water cylinder and the inner water cylinder allow the water flow to collide multiple times when passing through each level, effectively removing free filter particles, reducing filter material loss in the filter pool, and ensuring the clarity of filtered water. At the same time, this multi-level interception design not only enhances the interception effect, but also effectively prevents channel blockage and extends the service life of the device.

[0024] Optionally, the secondary particle retention assembly also includes a threaded water pipe arranged on one side of the outer water cylinder and a threaded fastener screwed on the threaded water pipe, and the threaded water pipe passes through the outer water cylinder, the middle water cylinder and the inner water cylinder in sequence and is connected to the secondary retention inner cavity.

[0025] By adopting the above technical solution, the combination of the threaded water pipe and the threaded fastener not only enhances the structural stability of the particle secondary interception assembly, but also facilitates the installation and maintenance of the assembly. The threaded water pipe passes through the outer water cylinder, the middle water cylinder and the inner water cylinder in sequence, ensuring the smooth passage of water flow. At the same time, the fixing of the threaded fastener makes the entire assembly more stable and reliable.

[0026] Optionally, both ends of the bottom plate, the first side plate and the second side plate are fixedly provided with air-water distribution end sealing plates, wherein at least one of the air-water distribution end sealing plates is provided with a water distribution branch pipe for communicating with the primary backwash water distribution chamber and an air distribution branch pipe for communicating with the secondary backwash gas distribution chamber.

[0027] By adopting the above technical solution, the end sealing plate of the air-water distribution closes the end of the backwash water-distribution air-distribution filter brick, ensuring the closure of each chamber, and ensuring the effectiveness and uniformity of the air-water distribution. The water distribution branch pipe and the air distribution branch pipe set on the end sealing plate of the air-water distribution not only simplify the installation and maintenance of the filter tank, but also improve the reliability and stability of the system. The reasonable layout of the water distribution branch pipe and the air distribution branch pipe enables the backwash water and backwash gas to be evenly distributed to each filter brick, avoiding the problem of excessive or low local backwash intensity, thereby ensuring the efficient backwashing of the sulfur autotrophic filter material and reducing the maintenance frequency of the filter tank.

[0028] In the second aspect, the backwash water and air distribution device of the sulfur autotrophic denitrification filter provided in the present application adopts the following technical solution:

[0029] A backwashing water and air distribution device for a sulfur autotrophic denitrification filter tank, comprising a plurality of the above-mentioned backwashing water and air distribution filter bricks, wherein the plurality of the backwashing water and air distribution filter bricks are sequentially laid in an array at the bottom of the filter tank, the length direction of the backwashing water and air distribution filter bricks is consistent with the length direction of the filter tank, the ends of the backwashing water and air distribution filter bricks in the same row are butt-jointed and connected, and the ends of the outermost backwashing water and air distribution filter bricks are welded and blocked by a blocking plate; the bottom plates of all the backwashing water and air distribution filter bricks are abutted against the bottom surface of the filter tank and all the backwashing water and air distribution filter bricks are Assembled together by welding; a channel is opened at the bottom of the filter tank along the width direction, and the backwash water and air distribution filter bricks above the channel are opened on the bottom plate with a total cleaning water inlet hole connected to the backwash water primary distribution chamber and an air cleaning inlet hole connected to the backwash gas primary distribution chamber, and the bottom plates of the remaining backwash water and air distribution filter bricks are completely closed; the channel is connected to the total cleaning water inlet hole, an air backwash main pipe is arranged in the channel, and an air backwash branch pipe connected to the air cleaning inlet hole is arranged on the air backwash main pipe.

[0030] By adopting the above technical scheme, the structure of the filter brick itself in the present application can intercept the fine particulate matter slowly released by the consumable filter material, reduce the consumption of sulfur autotrophic filter material, and also reduce the structural depth of the filter tank due to the support layer structure. At the same time, through the design of the secondary particle interception component, the fine particles in the filtered water are effectively intercepted, the purity of the water quality is ensured, the loss of fine particles is reduced, and the stability of the system is improved. The suspended matter remaining in the filtered water is also difficult to block the water and air distribution holes, ensuring the long-term stable operation of the entire device. In addition, the water distribution and air distribution in the present application are more uniform, which improves the backwashing effect. The air and water use independent distribution units respectively, which reduces the requirements for the flatness of the filter tank during the installation of the filter brick, avoids the compression of the residual air in the filter brick due to the combined backwashing of air and water after sharing a chamber, thereby avoiding the high-intensity flushing of the combined backwashing of air and water at the tail of the filter tank, which causes the filter material on the surface of the filter tank to escape.

[0031] In the third aspect, the backwash water and air distribution device of another sulfur autotrophic denitrification filter provided by the present application adopts the following technical solution:

[0032] A backwash water and air distribution device for a sulfur autotrophic denitrification filter tank comprises a plurality of the above-mentioned backwash water and air distribution filter bricks, the bottom plates of all the backwash water and air distribution filter bricks are completely closed, both ends of each of the backwash water and air distribution filter bricks are fixedly provided with air and water distribution end sealing plates, at least one of the air and water distribution end sealing plates is provided with a water distribution branch pipe for communicating with a primary distribution chamber of backwash water and an air distribution branch pipe for communicating with a secondary distribution chamber of backwash gas.

[0033] The backwash water and air distribution device in the present application is suitable for application scenarios when the filter tank length is ≤18m. By adopting the above-mentioned technical solution, the end of a single backwash water and air distribution filter brick is connected to the external unit of the filter tank through a water distribution branch pipe and an air distribution branch pipe, which makes the installation more flexible and the use more convenient and reliable.

[0034] In summary, the present application includes at least one of the following beneficial technical effects:

[0035] 1. In the present application, the backwash water and air filter bricks are arranged at the bottom of the filter tank, and the filter tank can be directly filled with sulfur autotrophic denitrification filter material without the need for a pebble supporting layer, thereby reducing the structural depth of the filter tank due to the use of a supporting layer structure.

[0036] 2. In this application, the backwashing water and air filter bricks can intercept the fine filter material particles slowly released in the filtered water, reduce the consumption of sulfur autotrophic filter material, and save costs.

[0037] 3. In this application, the optimized design of the secondary particle retention component and the first through hole effectively intercepts the fine particles in the filtered water, ensures the purity of the water quality, reduces the loss of fine particles, improves the stability of the system, and the suspended matter remaining in the filtered water is difficult to clog the water distribution and air distribution holes, ensuring the long-term stable operation of the entire device.

[0038] 4. In this application, the water and air distribution is more uniform, which improves the backwashing effect.

[0039] 5. In the present application, air and water are distributed in separate units, which reduces the requirement for the flatness of the filter bed during the installation of the filter bricks, avoids the compression of residual air in the filter bricks due to the combined backwashing of air and water after sharing a chamber, and thus avoids the phenomenon of filter material escaping from the filter bed due to the high-intensity flushing at the initial stage of the combined backwashing of air and water at the tail of the filter bed. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a three-dimensional structural schematic diagram of the backwash water and air distribution filter brick in this application.

[0041] Figure 2 It is a schematic diagram of the explosion structure of the backwash water and air distribution filter brick in this application.

[0042] Figure 3 It is a cross-sectional view of the backwash water and air distribution filter brick in this application.

[0043] Figure 4 It is the first longitudinal cross-sectional view of the backwash water and air distribution filter brick in Example 1 of the present application.

[0044] Figure 5 It is the second longitudinal cross-sectional view of the backwash water and air distribution filter brick in Example 1 of the present application.

[0045] Figure 6 It is a schematic diagram of the three-dimensional structure of the particle secondary interception component in this application.

[0046] Figure 7 It is a schematic diagram of the partial cross-sectional structure of the particle secondary interception component in this application.

[0047] Figure 8 It is a schematic diagram of the explosion structure of the backwash water and air distribution filter brick in Example 2 of the present application.

[0048] Fig. 9 It is a schematic diagram of the three-dimensional structure of the backwash water and air distribution device in Example 4 of the present application.

[0049] Fig.10 It is a schematic diagram of the partial explosion structure of the backwash water and air distribution device in Example 4 of the present application.

[0050] In the figure:

[0051] 10. Bottom plate; 11. Main inlet hole for washing water; 12. Inlet hole for air washing; 13. Gas distribution channel plate; 131. Primary distribution chamber for backwash gas; 132. Top plate; 133. Side plate;

[0052] 20. first side plate; 21. first through hole; 22. second through hole; 23. strip through hole; 24. arc-shaped shielding portion; 241. first barb protrusion; 25. second barb protrusion; 26. primary interception channel;

[0053] 30. Second side plate; 31. Air distribution rectifier grid;

[0054] 40. Secondary particle interception assembly; 41. Secondary interception inner cavity; 42. Secondary interception water hole; 43. Outer water cylinder; 44. Middle water cylinder; 45. Inner water cylinder; 46. End plate; 47. Secondary interception outer cavity; 48. Secondary interception middle cavity; 49. Threaded water pipe; 491. Threaded fastener;

[0055] 50. Gas-water distribution end plugging plate; 51. Water distribution branch pipe; 52. Gas distribution branch pipe;

[0056] 60. Channel;

[0057] 70. Gas backwash main pipe; 71. Gas backwash branch pipe;

[0058] 80. Cover plate; 81. Opening;

[0059] 90. Partition;

[0060] 100. Backwash water primary distribution chamber; 200. Backwash water secondary distribution chamber; 300. Backwash gas secondary distribution chamber. DETAILED DESCRIPTION

[0061] The following will be combined with the attached Figure 1 -Attached Fig.10 , the technical solutions in the embodiments of the present invention are clearly and completely described. The described embodiments are only possible technical implementations of the present invention, not all possible implementations. Those skilled in the art can completely combine the embodiments of the present invention to obtain other embodiments without creative work, and these embodiments are also within the scope of protection of the present invention.

[0062] Example 1

[0063] Reference Figure 1 and Figure 2As shown, the backwash water and air filter brick of the sulfur autotrophic denitrification filter tank in the embodiment of the present application includes a bottom plate 10, a first side plate 20 fixedly arranged on the bottom plate 10, and a second side plate 30 fixedly arranged on the bottom plate 10. The bottom plate 10 is a long rectangular flat plate. The bottom plate 10, the first side plate 20 and the second side plate 30 can all be made of stainless steel. There are two first side plates 20 and two second side plates 30. The two first side plates 20 are symmetrically arranged on the bottom plate 10, and the two second side plates 30 are also symmetrically arranged on the bottom plate 10. The two first side plates 20 are distributed on the outside of the two second side plates 30; the two first side plates 20 and the two second side plates 30 are formed by bending a whole plate from the middle and then being arranged in an inverted V shape on the bottom plate. 10 is formed, the lower sides of the two first side plates 20 and the two second side plates 30 are fixed on the bottom plate 10 at intervals, the lower sides of the two first side plates 20 and the two second side plates 30 have skirts and are spot welded to the bottom plate 10 through the skirts, the upper sides of the two first side plates 20 and the two second side plates 30 are fixed together and the inclination angle of the first side plate 20 on the bottom plate 10 is smaller than the inclination angle of the second side plate 30 on the bottom plate 10, the inclination angle of the first side plate 20 on the bottom plate 10 is 55°~60°, preferably 60°; the inclination angle of the second side plate 30 on the bottom plate 10 is 70°~80°, preferably 75°, so that the cross-section of the entire backwashing water-cloth air filter brick is triangular.

[0064] Reference Figure 1 and Figure 3 As shown, a partition 90 is fixedly arranged between the adjacent first side plate 20 and the second side plate 30 above the bottom plate 10; the partition 90 is arranged obliquely, and the partition 90 is arranged obliquely upward from the first side plate 20 to the second side plate 30, and the angle between the partition 90 and the bottom plate 10 is not less than 10°, for example, it can be 12°, 15°, or 20°, etc. The partition 90 can also be made of stainless steel. Both sides of the partition 90 also have downwardly bent skirts for abutting against the inner side surface of the first side plate 20 and the outer side surface of the second side plate 30 to facilitate spot welding connection. The inner sides of the two second side plates 30 and the bottom plate 10 together form a primary backwash water distribution chamber 100, the inner side of the first side plate 20, the outer side of the second side plate 30 and the partition plate 90 together form a secondary backwash water distribution chamber 200, the inner side of the first side plate 20, the outer side of the second side plate 30, the partition plate 90 and the bottom plate 10 together form a secondary backwash gas distribution chamber 300, and the secondary backwash water distribution chamber 200 is located above the secondary backwash gas distribution chamber 300; in this way, two symmetrical secondary backwash water distribution chambers 200 and two symmetrical secondary backwash gas distribution chambers 300 are formed.

[0065] Reference Figure 2 and Figure 3As shown, the outer side of the first side plate 20 is provided with a plurality of first through holes 21 connected to the secondary backwash water distribution chamber 200 and a plurality of second through holes 22 connected to the secondary backwash gas distribution chamber 300; the outer side of the first side plate 20 is also provided with a plurality of strip through holes 23 connected to the secondary backwash water distribution chamber 200, and the strip through holes 23 are designed as elongated holes with a width of 1 mm to 2 mm and a length of 80 mm to 120 mm; the length direction of the strip through holes 23 is along the length direction of the bottom plate 10 The strip-shaped through holes 23 are arranged in a direction and all the strip-shaped through holes 23 are arranged at intervals along the length direction of the bottom plate 10; the strip-shaped through holes 23 are arranged at a position of the first side plate 20 close to the partition 90; the first through holes 21, the strip-shaped through holes 23 and the second through holes 22 on each first side plate 20 are arranged in sequence from top to bottom, the first through holes 21, the second through holes 22 and the strip-shaped through holes 23 on the first side plate 20 are all stamped and formed, and the first through holes 21, the second through holes 22 and the strip-shaped through holes 23 on the two first side plates 20 are symmetrically arranged. In this embodiment, as a preferred solution, the first through holes 21 are designed as three rows, the second through holes 22 and the strip-shaped through holes 23 are designed as a single row, and the first through holes 21, the second through holes 22 and the strip-shaped through holes 23 are arranged at equal intervals. When the length of the filter tank is long, the number and spacing of the first through holes 21, the second through holes 22 and the strip-shaped through holes 23 can be designed according to the length of the filter tank.

[0066] Reference Figure 3 As shown, the first side plate 20 is provided with an arc-shaped shielding portion 24 on the outer side of the first through hole 21 and the second through hole 22; the arc-shaped shielding portion 24 is formed by the first side plate 20 protruding outward from the upper side edges of the first through hole 21 and the second through hole 22 and extending downward, and the lower side of the arc-shaped shielding portion 24 is lower than the lower side edges of the corresponding first through hole 21 and the second through hole 22; the inner side and the outer side of the arc-shaped shielding portion 24 both have an arc-shaped guide surface; the lower side of the arc-shaped shielding portion 24 has a first barbed protrusion 241 facing the outer side surface of the first side plate 20, and the first through hole 21 and the second through hole 22 are The lower side has a second barb protrusion 25 facing the inner side of the arc-shaped shielding portion 24, and the first barb protrusion 241 and the upper side of the first barb protrusion 241 both have arc-shaped chamfers; the first barb protrusion 241 and the second barb protrusion 25 are staggered and form a primary retention channel 26 between the two; from the perspective of oblique upward along the outer side of the first side plate 20, the orthographic projections of the first barb protrusion 241 and the second barb protrusion 25 partially overlap, so that the water flow needs to bend multiple times when passing through the primary retention channel 26. In the present application, the gap of the primary retention channel 26 is controlled at 1 mm.

[0067] Reference Figure 4 and Figure 5As shown, a total inlet hole 11 for washing water connected to the primary distribution chamber 100 for backwash water is provided on the bottom plate 10; an air distribution channel plate 13 is fixedly provided on the bottom plate 10 in the primary distribution chamber 100 for backwash water, and the air distribution channel plate 13 is located in the middle position of the bottom plate 10, and the air distribution channel plate 13 includes a top plate portion 132 and side plate portions 133 located at both ends of the top plate portion 132. The entire air distribution channel plate 13 is integrally stamped from a whole plate, and the lower sides of the two side plate portions 133 are fixedly connected to the bottom plate 10, and the top plate portion 132 and the two side edges of the two side plate portions 133 are respectively sealed and fixedly connected to the inner sides of the two second side plates 30. On the surface, the air distribution channel plate 13, the second side plate 30 and the bottom plate 10 are together enclosed to form a backwash gas primary distribution chamber 131, and an air cleaning inlet hole 12 connected to the backwash gas primary distribution chamber 131 is opened on the bottom plate 10, and the air cleaning inlet hole 12 is located directly below the air distribution channel plate 13; the total cleaning water inlet hole 11 can be set to two and are arranged on both sides of the air cleaning inlet hole 12, and the second side plate 30 is provided with an air distribution rectifier grid 31 for connecting the backwash gas primary distribution chamber 131 and the backwash gas secondary distribution chamber 300, and a plurality of through grooves in the middle of the air distribution rectifier grid 31 are used for airflow to pass through.

[0068] Reference Figure 4 , Figure 6 and Figure 7As shown, the outer side of the second side plate 30 is located in the backwash water secondary distribution chamber 200 and is fixed with a plurality of particle secondary retention components 40, which can be made of plastic or stainless steel; the particle secondary retention component 40 includes an outer water cylinder 43, a middle water cylinder 44 and an inner water cylinder 45 which are coaxially spaced from the outside to the inside; both ends of the outer water cylinder 43, the middle water cylinder 44 and the inner water cylinder 45 are sealed and fixedly connected by an end plate 46; the inner water cylinder 45 has a secondary retention inner cavity 41 inside, a secondary retention outer cavity is formed between the outer water cylinder 43 and the middle water cylinder 44, and a secondary retention middle cavity 48 is formed between the middle water cylinder 44 and the inner water cylinder 45; the outer water cylinder 43, The outer circumferential surfaces of the middle water cylinder 44 and the inner water cylinder 45 are both provided with a plurality of secondary interception water holes 42, and the secondary interception water holes 42 are thin slits with a width of 1 mm and a length of 5 mm to 10 mm; in the present application, the secondary interception water holes 42 on the outer water cylinder 43 are distributed in 8 rows along its circumference, the secondary interception water holes 42 on the middle water cylinder 44 are distributed in 4 rows along its circumference, and the secondary interception water holes 42 on the inner water cylinder 45 are distributed in 4 rows along its circumference; the secondary interception water holes 42 on the outer water cylinder 43 are staggered with the secondary interception water holes 42 on the middle water cylinder 44, and the secondary interception water holes 42 on the middle water cylinder 44 are staggered with the secondary interception water holes 42 on the inner water cylinder 45. The second side plate 30 is provided with mounting holes corresponding to the secondary particle retention components 40 one by one, and a threaded water pipe 49 and a threaded fastener 491 screwed on the threaded water pipe 49 are provided on one side of the outer water cylinder 43. One end of the threaded water pipe 49 passes through the outer water cylinder 43, the middle water cylinder 44 and the inner water cylinder 45 in sequence to be connected with the secondary retention inner cavity 41, and the other end of the threaded water pipe 49 passes through the mounting hole to be connected with the backwash water primary distribution cavity 100; the threaded water pipe 49 is screwed on the second side plate 30 and can be locked by the threaded fastener 491.

[0069] In the present application, the secondary particle retention components 40 are arranged in a row, and the secondary particle retention components 40 are installed above the partition 90 and can be flush with the first through holes 21 in the bottom row.

[0070] The implementation principle is as follows: in the filtering mode, water flows through the first through hole 21 on the first side plate 20 into the secondary distribution chamber 200 of backwash water, and then enters the primary distribution chamber 100 of backwash water through the secondary particle interception assembly 40, and is finally discharged through the channel 60 of the filter tank or a special pipe. In the present application, the first particle interception is performed by the specially designed first through hole 21 and the arc-shaped shielding part 24, and the second particle interception is performed by the secondary particle interception assembly 40, and the particles are finally precipitated above the partition 90 in the secondary distribution chamber 200 of backwash water, and do not flow out with the filtered water. After two physical interceptions, the slow-release free particles are not easy to be lost, which reduces the consumption of sulfur autotrophic filter material and saves costs.

[0071] In the present application, the gap of the first through hole 21 is 1mm, which can successfully intercept particles larger than 1mm; for particles smaller than 1mm, the arc-shaped shielding portion 24 and related structures can be used for interception. Specifically, the first through hole 21 is arranged on the first side plate 20 with an inclination angle of 60°, and the arc-shaped shielding portion 24 is a raised arc-shaped structure. The arc-shaped shielding portion 24 drains the filtered water, and the fine particles mixed in the filtered water collide with the outer side of the arc-shaped shielding portion 24 for the first time. After the collision, some of the particles change their movement trajectory, peel off the filtered water, and settle to the bottom of the filter tank; then the remaining particles carried by the filtered water form a second collision with the first barb protrusion 241, Then, it collides with the second barb protrusion 25 for the third time. After the collision, the particles that deviate from the motion trajectory slide along the outer side of the first side plate 20 to the bottom of the filter tank; then the remaining particles collide with the inner side of the arc-shaped shielding portion 24 for the fourth time. At the same time, because the gap of the primary retention channel 26 is much smaller than the secondary distribution chamber 200 of backwash water, the filtered water decelerates in the secondary distribution chamber 200 of backwash water, and the secondary distribution chamber 200 of backwash water is a triangular structure. The closer to the partition 90, the smaller the movement speed. At this time, there are sufficient conditions to cause the particles in the filtered water to settle in this area, and finally the particles accumulate on the partition 90. The above process completes the primary particle interception function.

[0072] The secondary interception assembly in the present application has at least three functions: first, it is used to intercept the finer water particles mixed in the filtered water in the secondary distribution chamber 200 of the backwash water; second, it is used to intercept the particles that are precipitated on the surface of the partition 90 and float due to disturbance; and third, it is used to intercept the particles mixed in a small part of the filtered water drained by the strip through hole 23. The secondary interception water holes 42 on the outer water cylinder 43, the middle water cylinder 44 and the inner water cylinder 45 of the secondary interception assembly are arranged alternately. The fine suspended particles repeatedly collide in the secondary interception outer cavity, the secondary interception middle cavity 48 and the secondary interception inner cavity 41. Most of the particles will deviate from their water flow trajectory and eventually fall back on the partition 90 in the secondary distribution chamber 200 of the backwash water, where they are precipitated. The filtered water is then discharged in a centralized manner after converging to the primary distribution chamber 100 of the backwash water through the threaded water pipe 49, thereby completing the filtering process.

[0073] In the backwash mode, the present application adopts a two-stage water and air distribution concept to ensure the uniformity of water and air distribution; and the air and water are separate independent channels, which can avoid the problem of a sharp increase in backwashing intensity caused by air compression in the combined backwashing of air and water after air backwashing, and at the same time reduce the horizontal flatness requirements for the installation of the filter bricks; by optimizing the structure of the first through hole 21 and the second through hole 22, the risk of channel blockage can be reduced under the action of backwashing.

[0074] The backwash water process in the present application is opposite to the filtration mode. The backwash water is introduced into the backwash water primary distribution chamber 100 through the channel 60 of the filter tank or a special pipeline. The backwash water in the backwash water primary distribution chamber 100 diffuses reversely to the backwash water secondary distribution chamber 200 through the particle secondary retention component 40. The backwash water in the backwash water secondary distribution chamber 200 is introduced into the filter tank through the first through hole 21 and the strip through hole 23 to backwash the sulfur autotrophic filter material.

[0075] The backwash water in the first-level backwash water distribution chamber 100 enters the second-level particle retention component 40. At this time, the second-level particle retention component 40 completes two functions. One is the primary distribution of backwash water, that is, the backwash water in the first-level backwash water distribution chamber 100 is evenly distributed to the second-level backwash water distribution chamber 200 on both sides of the filter brick. The three-layer structure in the second-level retention component and the staggered second-level retention water holes 42 create multiple "S"-shaped channels, creating certain resistance conditions, so that the first-level uniform distribution of backwash water can be completed; the second is to use the tortuous flow of backwash water in the "S"-shaped channel to effectively remove residual particulate dirt.

[0076] The backwash water in the secondary distribution chamber 200 of backwash water then enters the filter layer through the second through hole 22 of the component. This process is the secondary distribution of backwash water. The second through hole 22 has two functions at this time. First, the microporous structure forms the conditions for secondary distribution. At the same time, it is close to the inner arc surface of the arc-shaped shielding part 24 to form a buffer zone for backwash water, which is more conducive to the uniformity of secondary water distribution and ensures that all water distribution holes maintain a uniform flow rate. Second, this structural design helps to avoid channel blockage, because the arc-shaped shielding part 24 maintains a 60° inclination angle with the first side plate 20, and the arc of the arc-shaped shielding part 24 The arc-shaped design produces diversion, and its first-level retention channel 26 is not on the water-facing surface, which greatly reduces the risk of tiny suspended matter in the filtered water freely settling and blocking on the first-level retention channel 26; on the other hand, the design of the first-level retention channel 26 is conducive to backwashing and water cleaning. The first-level retention channel 26 is a tapered channel, and the flow rate of the backwash water is significantly increased here. Combined with the arc-shaped surface design of the arc-shaped shielding part 24, the backwash water is locally diverted, and the backwash water will form multiple "vortices" here. The formed "vortices" will help to clean the first-level retention channel 26, thereby helping to prevent the channel from being blocked.

[0077] In the present application, the strip through hole 23 is close to the partition 90 and has a width dimension greater than that of the first through hole 21. The fine particle sediment remaining on the partition 90 in the secondary distribution chamber 200 of backwash water is preferentially discharged from the strip through hole 23 under the action of the backwash water in the secondary distribution chamber 200 of backwash water. The inclined structure of the first side plate 20 further enhances the discharge effect of the particulate matter. The rest is discharged from the first through hole 21 to the filter tank, and finally escapes upward in the filter tank. After the backwash is completed, it is deposited on the upper surface of the filter tank to be consumed again in the denitrification filtration mode.

[0078] In the backwash process mode of the present application, the backwash gas is introduced into the backwash gas primary distribution chamber 131 through the air cleaning inlet hole 12 through the pipeline, and the backwash gas primary distribution chamber 131 is then dispersed into the backwash gas secondary distribution chamber 300 through the through groove in the middle of the gas distribution rectifying grid 31, and then diffused into the filter tank through the second through hole 22 for air scrubbing. The backwash gas also completes the secondary distribution process. The backwash gas in the backwash gas primary distribution chamber 131 completes the primary distribution under the action of the gas distribution rectifying grid 31, and is evenly distributed to the backwash gas secondary distribution chamber 300; the gas distribution rectifying grid 31 adopts the grid bar design to rectify and distribute the large flow gas to make it uniform; the gas in the backwash gas secondary distribution chamber 300 is secondarily distributed through the second through hole 22, and the medium flow process is the same as the flow of backwash water in the first through hole 21 described above, which will not be repeated here.

[0079] The design in the present application not only makes the water and air distribution more uniform, improves the backwash effect, reduces the consumption of filter media and the risk of clogging, and reduces the structural depth of the filter tank due to the support layer structure, but also greatly improves the working efficiency of the entire device through double-sided filtration.

[0080] Example 2

[0081] This embodiment is substantially the same as Embodiment 1, except that the bottom plate 10 in this embodiment is fully enclosed, and the bottom plate 10 is not provided with a total cleaning water inlet hole 11 connected to the primary backwash water distribution chamber 100, nor is it provided with an air cleaning inlet hole 12 connected to the primary backwash gas distribution chamber 131; at the same time, the gas distribution channel plate 13 is not provided on the bottom plate 10 in the primary backwash water distribution chamber 100, and the gas distribution rectifying grid 31 is not provided on the second side plate 30.

[0082] Example 3

[0083] Reference Figure 8As shown, this embodiment is substantially the same as Embodiment 2, except that in this embodiment, both ends of the bottom plate 10, the first side plate 20 and the second side plate 30 are fixedly provided with air-water distribution end sealing plates 50, wherein at least one of the air-water distribution end sealing plates 50 is provided with a water distribution branch pipe 51 for communicating with the first-level backwash water distribution chamber 100 and an air distribution branch pipe 52 for communicating with the second-level backwash gas distribution chamber 300. The air-water distribution end sealing plates 50 seal the ends of the backwash water and air distribution filter bricks, ensuring the closure of each chamber, and ensuring the effectiveness and uniformity of the air-water distribution. The water distribution branch pipe 51 and the air distribution branch pipe 52 provided on the air-water distribution end sealing plates 50 not only simplify the installation and maintenance of the filter tank, but also improve the reliability and stability of the system. The reasonable layout of the water distribution branch pipe 51 and the gas distribution branch pipe 52 enables the backwash water and backwash gas to be evenly distributed to each filter brick, avoiding the problem of excessive or low local backwash intensity, thereby ensuring efficient backwashing of the sulfur autotrophic filter material, extending the service life of the filter material, and reducing the maintenance frequency of the filter tank.

[0084] Example 4

[0085] Reference Fig. 9 and Fig.10 As shown, the present embodiment provides a backwashing water distribution and air distribution device for a sulfur autotrophic denitrification filter, comprising a plurality of backwashing water distribution and air distribution filter bricks in the above-mentioned embodiment 1 and embodiment 2, wherein the plurality of backwashing water distribution and air distribution filter bricks are sequentially laid in an array at the bottom of the filter, the length direction of the backwashing water distribution and air distribution filter bricks is consistent with the length direction of the filter, the ends of the backwashing water distribution and air distribution filter bricks in the same row are butt-jointed and connected, and the ends of the outermost backwashing water distribution and air distribution filter bricks are welded and blocked by blocking plates; the bottom plates 10 of all the backwashing water distribution and air distribution filter bricks are abutted against the bottom surface of the filter and all the backwashing water distribution and air distribution filter bricks are assembled together by welding; a channel is opened at the bottom of the filter along the width direction Channel 60, the backwash water and air distribution filter bricks above the channel 60 are the backwash water and air distribution filter bricks in the above-mentioned embodiment 1, that is, a total cleaning water inlet hole 11 connected to the backwash water primary distribution chamber 100 and an air cleaning inlet hole 12 connected to the backwash gas primary distribution chamber 131 are opened on the bottom plate 10, and the remaining backwash water and air distribution filter bricks are the backwash water and air distribution filter bricks in the above-mentioned embodiment 2, that is, the bottom plate 10 is completely closed; the channel 60 is connected to the total cleaning water inlet hole 11, and an air backwash main pipe 70 is provided in the channel 60, and an air backwash branch pipe 71 connected to the air cleaning inlet hole 12 is provided on the air backwash main pipe 70.

[0086] Reference Fig.10As shown, in the present application, a cover plate 80 is also provided on the channel 60, and a plurality of openings 81 are provided on the cover plate 80, through which the channel 60 is connected to the total inlet hole 11 for washing water, and the air backwash branch pipe 71 is connected to the air washing inlet hole 12 through the opening 81. The cover plate 80 plays a role of sealing with the bottom plate 10 of the backwash water and air filter brick above it, so as to reduce the outflow of filtered water or backwash water.

[0087] The backwash water and air distribution filter bricks are arranged at the bottom of the filter tank. The filter tank can be directly filled with sulfur autotrophic denitrification filter material without the need for a pebble support layer. The backwash water and air distribution filter bricks can intercept the fine filter material particles slowly released in the filtered water, thereby achieving the purpose of reducing the structural depth of the filter tank. The filter brick structure itself in the present application can intercept the fine particulate matter slowly released by the consumable filter material, reducing the consumption of the sulfur autotrophic filter material; at the same time, through the design of the particle secondary interception component 40, the fine particles in the filtered water are effectively intercepted, ensuring the purity of the water quality, reducing the loss of fine particles, and improving the stability of the system. The suspended matter remaining in the filtered water is also difficult to block the water and air distribution pores, ensuring the long-term stable operation of the entire device. In addition, the water distribution and air distribution in the present application are more uniform, which improves the backwashing effect. Air and water use independent distribution units respectively, which reduces the requirements for the flatness of the filter bed during the installation of the filter bricks, avoids the compression of residual air in the filter bricks due to the combined backwashing of air and water after sharing a chamber, and thus avoids the phenomenon of filter material on the surface of the filter bed escaping due to the high-intensity flushing in the initial stage of the combined backwashing of air and water at the end of the filter bed.

[0088] Example 5

[0089] The present embodiment provides another backwash water and air distribution device for a sulfur autotrophic denitrification filter tank, which includes a number of backwash water and air distribution filter bricks of the above-mentioned embodiment 3, the bottom plates 10 of all the backwash water and air distribution filter bricks are completely closed, and both ends of each backwash water and air distribution filter brick are fixedly provided with air-water distribution end sealing plates 50, wherein at least one air-water distribution end sealing plate 50 is provided with a water distribution branch pipe 51 for connecting with the first-level distribution chamber 100 of backwash water and an air distribution branch pipe 52 for connecting with the second-level distribution chamber 300 of backwash gas.

[0090] The backwash water and air distribution device in the present application is suitable for application scenarios when the filter tank length is ≤18m. The end of a single backwash water and air distribution filter brick is connected to the external unit of the filter tank through a water distribution branch pipe 51 and an air distribution branch pipe 52, which makes installation more flexible and use more convenient and reliable.

[0091] The embodiments of this specific implementation are all preferred embodiments of the present application, and are not intended to limit the protection scope of the present application. The same components are represented by the same figure marks. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A backwash water and air filter brick for a sulfur autotrophic denitrification filter, characterized in that: The backwashing water and air distribution filter brick comprises a bottom plate (10), a first side plate (20) fixedly arranged obliquely on the bottom plate (10), and a second side plate (30) fixedly arranged obliquely on the bottom plate (10); A partition plate (90) is fixedly arranged between the first side plate (20) and the second side plate (30); a primary backwash water distribution chamber (100) is provided between the inner side of the second side plate (30) and the bottom plate (10); the inner side of the first side plate (20), the outer side of the second side plate (30) and the partition plate (90) together form a secondary backwash water distribution chamber (200); the inner side of the first side plate (20), the outer side of the second side plate (30), the partition plate (90) and the bottom plate (10) together form a secondary backwash gas distribution chamber (300); the secondary backwash water distribution chamber (200) is located above the secondary backwash gas distribution chamber (300); A plurality of first through holes (21) connected to the backwash water secondary distribution chamber (200) and a plurality of second through holes (22) connected to the backwash gas secondary distribution chamber (300) are provided on the outer side of the first side plate (20); arc-shaped shielding portions (24) are provided on the outer sides of the first through holes (21) and the second through holes (22); The outer side of the second side plate (30) is located in the backwash water secondary distribution chamber (200) and is fixed with a plurality of particle secondary retention components (40); the particle secondary retention component (40) has a secondary retention inner cavity (41) inside, and the outer peripheral surface of the particle secondary retention component (40) has a plurality of secondary retention water holes (42) connected to the secondary retention inner cavity (41); the secondary retention inner cavity (41) of the particle secondary retention component (40) is connected to the backwash water primary distribution chamber (100).

2. The backwash water and air distribution filter brick of the sulfur autotrophic denitrification filter according to claim 1, characterized in that: There are two first side plates (20) and two second side plates (30), the two first side plates (20) are symmetrically arranged on the bottom plate (10), the two second side plates (30) are also symmetrically arranged on the bottom plate (10), and the two first side plates (20) are distributed on the outer sides of the two second side plates (30); the upper sides of the two first side plates (20) and the two second side plates (30) are fixedly connected together, the inclination angle of the first side plate (20) on the bottom plate (10) is smaller than the inclination angle of the second side plate (30) on the bottom plate (10), and the two second side plates (30) and the bottom plate (10) are enclosed to form the backwash water primary distribution chamber (100).

3. The backwash water and air distribution filter brick of the sulfur autotrophic denitrification filter according to claim 1 or 2, characterized in that: The arc-shaped shielding portion (24) is formed by the first side plate (20) protruding outward from the upper side edges of the first through hole (21) and the second through hole (22) and extending downward, and the lower side of the arc-shaped shielding portion (24) is lower than the lower side edges of the corresponding first through hole (21) and the second through hole (22); the inner side and the outer side edges of the arc-shaped shielding portion (24) both have arc-shaped guide surfaces; the lower side of the arc-shaped shielding portion (24) has a first barb protrusion (241) facing the outer side edge of the first side plate (20), and the lower side edges of the first through hole (21) and the second through hole (22) have a second barb protrusion (25) facing the inner side edge of the arc-shaped shielding portion (24); the first barb protrusion (241) and the second barb protrusion (25) are staggered and a primary interception channel (26) is formed between the two.

4. The backwash water and air distribution filter brick of the sulfur autotrophic denitrification filter according to claim 3, characterized in that: The first side plate (20) is also provided with a plurality of strip-shaped through holes (23) connected to the backwash water secondary distribution chamber (200); the length direction of the strip-shaped through holes (23) is arranged along the length direction of the bottom plate (10), and all the strip-shaped through holes (23) are arranged at intervals along the length direction of the bottom plate (10); the strip-shaped through holes (23) are located between the first through holes (21) and the second through holes (22), and the strip-shaped through holes (23) are arranged at a position of the first side plate (20) close to the partition (90).

5. The backwash water and air distribution filter brick of the sulfur autotrophic denitrification filter according to claim 1 or 2, characterized in that: The bottom plate (10) is provided with a cleaning water main inlet hole (11) connected to the backwash water primary distribution chamber (100); the bottom plate (10) is provided with an air distribution channel plate (13) located in the backwash water primary distribution chamber (100); the air distribution channel plate (13), the second side plate (30) and the bottom plate (10) together form a backwash gas primary distribution chamber (131); the bottom plate (10) is provided with an air cleaning inlet hole (12) connected to the backwash gas primary distribution chamber (131); the second side plate (30) is provided with an air distribution rectifying grid (31) for connecting the backwash gas primary distribution chamber (131) with the backwash gas secondary distribution chamber (300).

6. The backwash water and air distribution filter brick of the sulfur autotrophic denitrification filter according to claim 1 or 2, characterized in that: The particle secondary interception assembly (40) comprises an outer water-passing cylinder (43), a middle water-passing cylinder (44) and an inner water-passing cylinder (45) which are coaxially spaced from the outside to the inside; both ends of the outer water-passing cylinder (43), the middle water-passing cylinder (44) and the inner water-passing cylinder (45) are sealed and fixedly connected by an end plate (46); the secondary interception inner cavity (41) is located in the inner water-passing cylinder (45); a secondary interception outer cavity is formed between the outer water-passing cylinder (43) and the middle water-passing cylinder (44); the middle water-passing cylinder (44) and the inner water-passing cylinder (45) are sealed and fixedly connected by an end plate (46); A secondary interception middle cavity (48) is formed between the water cylinders (45); the outer circumferential surfaces of the outer water cylinder (43), the middle water cylinder (44) and the inner water cylinder (45) are all provided with a plurality of secondary interception water holes (42); the secondary interception water holes (42) on the outer water cylinder (43) are staggered with the secondary interception water holes (42) on the middle water cylinder (44), and the secondary interception water holes (42) on the middle water cylinder (44) are staggered with the secondary interception water holes (42) on the inner water cylinder (45).

7. The backwash water and air distribution filter brick of the sulfur autotrophic denitrification filter according to claim 6, characterized in that: The particle secondary retention component (40) also includes a threaded water pipe (49) arranged on one side of the outer water cylinder (43) and a threaded fastener (491) screwed on the threaded water pipe (49), and the threaded water pipe (49) passes through the outer water cylinder (43), the middle water cylinder (44) and the inner water cylinder (45) in sequence to be connected to the secondary retention inner cavity (41).

8. The backwash water and air distribution filter brick of the sulfur autotrophic denitrification filter according to claim 1 or 2, characterized in that: Gas-water distribution end sealing plates (50) are fixedly provided at both ends of the bottom plate (10), the first side plate (20) and the second side plate (30), wherein at least one of the gas-water distribution end sealing plates (50) is provided with a water distribution branch pipe (51) for communicating with the primary backwash water distribution chamber (100) and a gas distribution branch pipe (52) for communicating with the secondary backwash gas distribution chamber (300).

9. A backwash water and air distribution device for a sulfur autotrophic denitrification filter, characterized in that: The invention comprises a plurality of backwashing water-distributing and air-distributing filter bricks as described in any one of claims 1 to 7, wherein the plurality of backwashing water-distributing and air-distributing filter bricks are sequentially laid in an array on the bottom of the filter tank, the length direction of the backwashing water-distributing and air-distributing filter bricks is consistent with the length direction of the filter tank, the ends of the backwashing water-distributing and air-distributing filter bricks in the same row are butt-jointed and connected, and the ends of the outermost backwashing water-distributing and air-distributing filter bricks are welded and blocked by blocking plates; the bottom plates (10) of all the backwashing water-distributing and air-distributing filter bricks are abutted against the bottom surface of the filter tank and all the backwashing water-distributing and air-distributing filter bricks are assembled together by welding; a channel (60) is opened at the bottom of the filter tank along the width direction, and the channel The backwash water and air distribution filter brick (60) above is provided with a cleaning water main inlet hole (11) connected to the backwash water primary distribution chamber (100) and an air cleaning inlet hole (12) connected to the backwash gas primary distribution chamber (131) on the bottom plate (10), and the bottom plates (10) of the other backwash water and air distribution filter bricks are completely closed; the channel (60) is connected to the cleaning water main inlet hole (11), and an air backwash main pipe (70) is provided in the channel (60), and an air backwash branch pipe (71) connected to the air cleaning inlet hole (12) is provided on the air backwash main pipe (70).

10. A backwash water and air distribution device for a sulfur autotrophic denitrification filter, characterized in that: It comprises a plurality of backwash water-distribution and air-distribution filter bricks as described in claim 8 above, the bottom plates (10) of all the backwash water-distribution and air-distribution filter bricks being completely closed, and both ends of each of the backwash water-distribution and air-distribution filter bricks being fixedly provided with air-water distribution end sealing plates (50), wherein at least one of the air-water distribution end sealing plates (50) is provided with a water distribution branch pipe (51) for being connected to a primary distribution chamber (100) of backwash water and an air distribution branch pipe (52) for being connected to a secondary distribution chamber (300) of backwash air.

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