Modular filter material filling structure and autotrophic denitrification reactor

Abstract

The invention discloses a modular filter material filling structure and an autotrophic denitrification reactor, and relates to the technical field of autotrophic denitrification reactors, the modular filter material filling structure comprises a filter material filling structure, the filter material filling structure comprises a rigid support net formed by steel wire supports arranged in a criss-cross manner, the periphery of the hard supporting net is fixedly connected with a cylindrical filter material box body, a plurality of connecting hanging holes are formed in the periphery, close to the side wall of the hard supporting net, of the bottom of the filter material box body, a plurality of adjusting supports which are distributed in a staggered mode are detachably installed at the connecting hanging holes, and the filter material box body is filled with autotrophic denitrification filler; according to the modular filter material filling structure, drawer type design is adopted, so that filler replacement is simple and rapid, and mechanical excavation or manual cleaning is not needed. And the filler can be easily replaced or supplemented by screwing out the filler drawer, so that the manpower, material resources and time cost are greatly saved.

Description

Technical Field

[0001] The present invention relates to the technical field of autotrophic denitrification reactors, and particularly relates to a modular filter media filling structure and an autotrophic denitrification reactor. Background Art

[0002] This technology is developed based on the common packing methods of denitrification filters in the market. The existing packing method is to mechanically hoist and pack denitrification filter media, and the packing depth is basically higher than 2m. After packing, it is very troublesome to replace and unload the filter media, and it requires a combination of mechanical excavation and manual excavation for operation. For large-scale civil filters, the packing method of mechanically hoisting filter media is more reasonable, but the packing of filter media for integrated equipment needs to be carried out in the same way, and the operability and flexibility are restricted. It is difficult to check and analyze the denitrification reaction status of filter media at each depth after packing. Usually, problems need to accumulate to a certain extent, and finally, the problems of filter media can be reflected only when the effluent water quality does not meet the standards. At this time, it is necessary to excavate and check the filter media in the entire reactor.

[0003] In autotrophic denitrification equipment, the packing of filter media is mostly a one-time packing, that is, the filter media package is hoisted above the reactor by a crane, the bottom zipper of the filter media package is opened, and the filter media is unloaded into the reactor. The packing height of the filter media is generally 1.5 - 3m. If the filter media needs to be replaced, it is necessary to mechanically excavate the original filter media and then hoist and replace the new filter media. The operation is complex, requires a lot of mechanical equipment, and is time-consuming and laborious. Summary of the Invention

[0004] The purpose of the present invention is to provide a modular filter media filling structure and an autotrophic denitrification reactor. The modular rotatable drawer-type design makes the replacement of filter media simple and fast, without mechanical excavation, and has stronger controllability for the filter media in a certain area, so as to solve the above technical problems.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] A modular filter media filling structure includes a filter media filling structure. The filter media filling structure includes a rigid support net composed of criss-crossed steel wires. The outer periphery of the rigid support net is fixedly connected with a cylindrical filter media box. A plurality of connecting hanging holes are opened around the side wall of the bottom of the filter media box close to the rigid support net. A plurality of staggered adjustment supports are detachably installed at the connecting hanging holes. Autotrophic denitrification filter media is filled in the filter media box.

[0007] Preferably, the adjustment supports are arranged in a criss-cross manner and a plurality of them are arranged between adjacent parallel steel wires.

[0008] Preferably, the adjustment supports are arranged in a staggered manner with the steel wires.

[0009] Preferably, the adjusting support is a spiral spring structure, a hard iron wire structure or a combined structure of a spiral spring and a hard iron wire.

[0010] Preferably, the adjusting supports are arranged at intervals above and below the rigid support net.

[0011] An autotrophic denitrification reactor includes the above modular filter media loading structure, and also includes a water inlet tank, a reactor tank body and a water outlet tank. The reactor tank body includes a lower fixed tank, an upper end of the lower fixed tank is fixedly connected with a side-opening tank, an upper end of the side-opening tank is fixedly connected with an upper fixed tank, a connecting rotating shaft is fixedly arranged on the side-opening tank, and a side-opening door for closing the side-opening tank is rotatably installed at the connecting rotating shaft. A water stop sealing ring for preventing water leakage is installed on the outer periphery of the side-opening door, and a plurality of filter media loading structures are rotatably installed on the connecting rotating shaft from bottom to top;

[0012] A water inlet is arranged at a side end of the lower fixed tank, a drain pipe for discharging sewage in the lower fixed tank is communicated with a lower part of the lower fixed tank, the water inlet tank is connected with a water inlet pump through a water inlet pipe, and a water outlet of the water inlet pump is communicated with the water inlet through a pipeline. The water inlet pump is used for pumping sewage in the water inlet tank into the lower fixed tank;

[0013] An outlet pipe is connected to the upper fixed tank, and a water outlet end of the outlet pipe is connected with the water outlet tank.

[0014] Preferably, a water inlet nitrate nitrogen detector is installed on the water inlet pipe, and a water outlet nitrate nitrogen detector is installed on the outlet pipe.

[0015] Preferably, it further includes a backwashing water pump and a backwashing air blower. The lower part of the water outlet tank is communicated with the inside of the lower fixed tank through a backwashing connecting pipe. A water inlet pump is arranged on the backwashing connecting pipe for pumping clear water in the water outlet tank into the lower fixed tank. The backwashing air blower is used for supplying air into the lower fixed tank to wash the filter media in the reactor through the backwashing connecting pipe.

[0016] Preferably, a filter media supporting plate is arranged at a connection part between the lower fixed tank and the side-opening tank. A plurality of water distribution round holes are uniformly arranged on the filter media supporting plate, and a plurality of supporting legs for supporting the filter media supporting plate are fixedly installed at a lower end of the filter media supporting plate.

[0017] Preferably, a plurality of sampling pipes are installed on the reactor tank body. The number of the sampling pipes is equal to that of the filter media loading structures and is located at an upper end of the filter media loading structures. Sampling valves for controlling on-off are installed on the sampling pipes.

[0018] Advantages of the present invention:

[0019] (1) The modular filter media loading structure of the present invention adopts a rotatable drawer - type design, making the replacement of the packing simple and fast, without the need for mechanical excavation or manual cleaning. By rotating out the packing drawer, the replacement or supplement of the packing can be easily carried out, greatly saving labor, material and time costs.

[0020] (2) The adjusting supports inside the filter media loading structure adopt a spiral spring structure, a hard steel wire structure or a combined structure, and can be flexibly arranged at the upper or lower end of the rigid support net. By adjusting the number and arrangement mode of the adjusting supports, the aperture of the packing drawer can be changed to meet the packing loading requirements of different particle sizes and types, and realize the layered loading or one - time loading mode.

[0021] (3) By combining the sampling pipe to detect the water quality of the water outlets at various heights, the denitrification efficiency of the packing in a certain depth interval can be comprehensively analyzed, and abnormal situations such as the decline of denitrification efficiency, blockage and short - circuit flow of the packing in a certain depth can be processed in time. Each layer of the filter media loading structure can be rotated out, which is convenient for observing and sampling the consumption situation and particle size change of the packing at each depth, and is also convenient for sampling and analyzing the activity and flora structure of the autotrophic denitrifying bacteria attached to the packing at each depth position.

[0022] (4) The reactor tank adopts an upward - flow water inlet mode. Combined with the water distribution round holes on the filter media support plate, the uniform distribution of the influent water can be realized, and the denitrification efficiency of the reactor can be improved. At the same time, by installing an influent nitrate nitrogen detector and an effluent nitrate nitrogen detector, the water quality of the influent and effluent of the reactor can be monitored in real time, providing important data support for the operation and maintenance of the reactor. Brief Description of the Drawings

[0023] The following further explains the present invention with reference to the drawings.

[0024] Figure 1 is a schematic diagram of a modular filter media loading structure of the present invention;

[0025] Figure 2 is a schematic diagram of the installation structure of the adjusting support of a modular filter media loading structure of the present invention;

[0026] Figure 3 is a schematic diagram of the structure of an autotrophic denitrification reactor of the present invention;

[0027] Figure 4 is a schematic diagram of the reactor tank structure of an autotrophic denitrification reactor of the present invention;

[0028] Figure 5 is a schematic diagram of the filter media support plate structure of an autotrophic denitrification reactor of the present invention.

[0029] In the figure: 10, water inlet tank; 11, water inlet pipe; 12, water inlet pump; 13, inlet nitrate nitrogen detector; 20, reactor tank body; 21, lower fixed tank; 22, side opening and closing tank; 23, upper fixed tank; 24, connecting rotating shaft; 25, opening and closing side door; 251, water stop sealing ring; 26, filter material supporting plate; 261, water distribution round hole; 27, support leg of the plate; 28, water inlet; 29, drain pipe; 30, filter material filling structure; 31, rigid support net; 32, filter material box; 33, connecting hanging hole; 34, adjusting support; 40, water outlet tank; 41, water outlet pipe; 42, outlet nitrate nitrogen detector; 43, backwashing connecting pipe; 44, backwashing pump; 50, backwashing fan; 60, sampling pipe; 61, sampling valve. Detailed implementation manners

[0030] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

[0031] In the description of the present invention, it should be understood that the terms "upper", "lower", "left", "right", etc. indicating the orientation or position relationship are based on the orientation or position relationship shown in the accompanying drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, as well as a specific orientation structure and operation. Therefore, it cannot be understood as a limitation to the present invention. In addition, "first" and "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise stated, the meaning of "a plurality" is two or more.

[0032] In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, the terms "installation", "connection", "connection", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0033] Please refer to Figure 1-2As shown in the figure, an embodiment of the first aspect of the present invention provides a modular filter media filling structure, including a filter media filling structure 30. The filter media filling structure 30 includes a rigid support net 31 composed of wire supports arranged in a crisscross pattern. The outer periphery of the rigid support net 31 is fixedly connected to a cylindrical filter media box 32. A plurality of connecting hanging holes 33 are provided around the side wall of the bottom of the filter media box 32 near the rigid support net 31. A plurality of staggered adjustment supports 34 are detachably installed at the connecting hanging holes 33. The filter media box 32 is filled with autotrophic denitrification fillers.

[0034] In an alternative embodiment, the adjustment supports 34 are arranged in a crisscross pattern and a plurality of them are provided between adjacent parallel wire supports.

[0035] It should be noted that the adjustment supports 34 are arranged in a crisscross pattern between the wire supports, enhancing the support force for the fillers, preventing the short-circuit phenomenon caused by uneven accumulation of the filter media, and facilitating the hierarchical adjustment of the pore size.

[0036] In an alternative embodiment, the adjustment supports 34 are arranged in a staggered pattern with the wire supports.

[0037] It should be noted that the adjustment supports 34 are arranged in a staggered pattern with the wire supports, improving the stability of the internal structure of the filter media layer, reducing the displacement of the fillers caused by water flow impact, and being able to adjust the pore mesh numbers of different specifications of the filter media to adapt to different specifications of the fillers.

[0038] In an alternative embodiment, the adjustment support 34 is a spiral spring structure, a hard wire structure, or a combined structure of a spiral spring and a hard wire.

[0039] It should be noted that the adjustment support 34 adopts a spiral spring, a hard wire, or a combined structure thereof, having both flexibility and rigidity, being able to adapt to the change of the filler particle size, providing reliable support, and extending the service life.

[0040] In an alternative embodiment, the adjustment supports 34 are arranged at intervals above and below the rigid support net 31.

[0041] It should be noted that the adjustment supports 34 are arranged at the upper and lower ends of the rigid support net 31 or in a staggered pattern, optimizing the pore size adjustment range and meeting the filling requirements of different fillers.

[0042] Please refer to Figures 3-5As shown in the figure, an embodiment of the second aspect of the present invention provides an autotrophic denitrification reactor, which includes the modular filter media filling structure as described above, and further includes a water inlet tank 10, a reactor tank body 20, and a water outlet tank 40. The reactor tank body 20 includes a lower fixed tank 21. The upper end of the lower fixed tank 21 is fixedly connected to a side-opening tank 22. The upper end of the side-opening tank 22 is fixedly connected to an upper fixed tank 23. A connecting rotating shaft 24 is fixedly arranged on the side-opening tank 22. A side-opening door 25 for closing the side-opening tank 22 is rotatably installed at the connecting rotating shaft 24. A water stop sealing ring 251 for preventing water leakage is installed on the outer periphery of the side-opening door 25. A plurality of filter media filling structures 30 are rotatably installed on the connecting rotating shaft 24 from bottom to top;

[0043] A water inlet 28 is arranged at the side end of the lower fixed tank 21. A drain pipe 29 for discharging the sewage in the lower fixed tank 21 is communicated with the lower part of the lower fixed tank 21. The water inlet tank 10 is connected to a water inlet pump 12 through a water inlet pipe 11. The water outlet of the water inlet pump 12 is communicated with the water inlet 28 through a pipeline. The water inlet pump 12 is used to pump the sewage in the water inlet tank 10 into the lower fixed tank 21;

[0044] An outlet pipe 41 is connected to the upper fixed tank 23. The water outlet end of the outlet pipe 41 is connected to the water outlet tank 40.

[0045] In an optional embodiment, a water inlet nitrate nitrogen detector 13 is installed on the water inlet pipe 11, and a water outlet nitrate nitrogen detector 42 is installed on the outlet pipe 41.

[0046] It should be noted that by installing the water inlet nitrate nitrogen detector 13 and the water outlet nitrate nitrogen detector 42 to monitor the denitrification efficiency in real time, the water quality of the reactor inlet and outlet can be monitored in real time, providing important data support for the operation and maintenance of the reactor.

[0047] In an optional embodiment, it further includes a backwashing water pump 44 and a backwashing air blower 50. The lower part of the water outlet tank 40 is communicated with the inside of the lower fixed tank 21 through a backwashing connecting pipe 43. The backwashing water pump 44 is arranged on the backwashing connecting pipe 43 to pump the clear water in the water outlet tank 40 into the lower fixed tank 21. The backwashing air blower 50 is used to supply air into the lower fixed tank 21, and the filter media in the reactor is washed through the backwashing connecting pipe 43.

[0048] It should be noted that the design of the backwashing connecting pipe 43 and the backwashing air blower 50 can regularly backwash the filter media layer, prevent the filter media from being blocked and polluted, extend the service life of the filter media, and improve the operation stability and treatment efficiency of the reactor.

[0049] In an alternative embodiment, a filter media support plate 26 is provided at the connection between the lower fixed tank 21 and the side-opening tank 22. A number of water distribution round holes 261 are evenly arranged on the filter media support plate 26. A number of support legs 27 for supporting the filter media support plate 26 are fixedly installed at the lower end of the filter media support plate 26.

[0050] It should be noted that the water distribution round holes 261 on the filter media support plate 26 ensure uniform distribution of water flow, and the support legs 27 enhance the stability of the support plate and prevent the collapse of the filter media layer.

[0051] In an alternative embodiment, a plurality of sampling tubes 60 are installed on the reactor tank body 20. The number of the sampling tubes 60 is equal to that of the filter media filling structure 30 and is located at the upper end of the filter media filling structure 30. A sampling valve 61 for controlling on-off is installed on the sampling tube 60.

[0052] It should be noted that the sampling tubes 60 correspond one-to-one with the filter media filling structure 30, which is convenient for sampling and analyzing each layer of packing, and accurately evaluating the microbial activity and denitrification effect.

[0053] Working principle of the present invention: The reactor tank body 20 is a cylindrical tank body as the main body. The water inlet mode of the reactor tank body 20 is an upward flow mode, with water inlet from the bottom of the equipment and water outlet from the upper part. Above the water inlet 28 at the bottom of the tank body, there is a filter media support plate 26. The upper part of the tank body above the filter media support plate 26 can be opened and closed laterally to facilitate the replacement of the packing layer. There is a water stop sealing ring 251 around the opening and closing side door 25 to prevent water from seeping out from the side after closing in the reactor tank body 20. The internal packing area is a multi-layer modular filter media loading structure 30. A single modular filter media loading structure 30 is a short cylindrical drawer layer, and vertical holes are opened on the side of each layer of filter media loading structure 30 to pass through the longitudinal connecting rotating shaft 24. Each layer of packing layer can be rotated out around the vertical connecting rotating shaft 24 to facilitate the replacement of autotrophic denitrification packing, without the need to excavate and replace the entire packing layer according to the traditional mode. The bottom of each layer of filter media loading structure 30 is formed into a rigid support net 31 by staggered arrangement of steel wires. There are steel wire supports in both the warp and weft directions, and adjustable supports 34 can be hung between the rigid supports. The steel wire support is a fixed support, welded on the filter media box 32, with a relatively large spacing, and it is the main load-bearing structure of the filter media loading structure 30. Both ends of the adjustable support 34 have hooks, which can be hung at the connecting hanging holes 33 of the filter media box 32 to assist the fixed support in supporting the filter media. The adjustable support 34 adopts a spiral spring, a hard iron wire or a combined structure thereof, with both flexibility and rigidity, which can not only adapt to the change of the packing particle size but also provide reliable support. Multiple spiral spring supports can be hung between every two steel wire supports to reduce the aperture of the filter media drawer, and the adjustable range of the aperture is 2 - 40 mm. The combined use of the fixed support and the detachable adjustable support 34, while meeting the basic requirements of filter media support, increases the aperture adjustment function, convenient loading and unloading function of the filter media loading structure 30. By increasing or decreasing the number of adjustable supports 34, the aperture of the filter media loading structure 30 can be flexibly adjusted to meet the packing requirements of different particle sizes and types. When the same kind of packing needs to be loaded, reduce the number of adjustable supports 34 in the upper drawer bed layer and increase the number of adjustable supports 34 in the bottom bed layer, and adjust the bed layer aperture of the filter media loading structure 30 from top to bottom to gradually decrease, so as to facilitate the one-time loading of autotrophic denitrification filter media from top to bottom, and it is also convenient for the packing particle size to automatically supplement to the bottom during the consumption process of the packing. When loading different types of packing, adjust the aperture of each layer of packing layer according to the packing particle size for layered loading. The consumption rates of different types of autotrophic denitrification packing are different, and layered loading is convenient for timely supplementing the packing with a faster consumption rate to ensure the consistency of the packing composition ratio during the reaction process. If analyzing and comparing the denitrification effects of different composition packings, the layered loading mode is convenient for replacing the packing types in the equipment at any time without hoisting and excavation.

[0054] When packing the packing material, open the opening and closing side door 25 of the tank body, screw out the filter material packing structure 30 outward, increase or decrease the number of adjusting supports 34 to adjust the aperture of the rigid support net 31, and then pack the autotrophic denitrification filter material into the filter material box body 32. After the packing is completed, screw the filter material packing structure 30 back inward to carry out the packing of the next packing layer. After the packing of the packing layer is completed, close the opening and closing side door 25 of the tank body to complete the packing of the packing material. When there is no need for layered packing, do not hang in the adjusting support 34, the fixed support spacing is relatively large, and the packing material is hoisted and filled into the tank from the upper part of the reactor tank body 20 for one-time packing. The two packing methods can be selected according to the specific requirements of the project operation. During the operation of the reactor tank body 20, when packing replacement or supplement is required, it is necessary to close the water inlet of the reactor tank body 20 and then empty the water level in the reactor tank body 20 below the filter material supporting plate 26, and then open the opening and closing side door 25 of the tank body to carry out packing or replacement of the packing material. When discharging, remove the spring support, increase the aperture of the bed layer, and the autotrophic denitrification packing material can quickly leak out of the filter material packing structure 30 without mechanical excavation.

[0055] The above has described an embodiment of the present invention in detail, but the content described is only the preferred embodiment of the present invention and cannot be considered as limiting the scope of implementation of the present invention. All equivalent changes and improvements made according to the scope of the application of the present invention should still fall within the scope covered by the patent of the present invention.

Claims

1. A modular filter media loading structure, characterized in that, It includes a filter media loading structure (30), and the filter media loading structure (30) includes a rigid support mesh (31) composed of wire supports arranged in a crisscross pattern. A cylindrical filter media box body (32) is fixedly connected to the outer periphery of the rigid support mesh (31). A plurality of connecting hanging holes (33) are opened around the side wall of the bottom of the filter media box body (32) close to the rigid support mesh (31). A plurality of staggered adjustment supports (34) are detachably installed at the connecting hanging holes (33). The filter media box body (32) is filled with autotrophic denitrification filler.

2. The modular filter media loading structure according to claim 1, characterized in that, The adjustment supports (34) are arranged in a crisscross pattern and a plurality of them are arranged between adjacent parallel wire supports.

3. The modular filter media loading structure according to claim 1, characterized in that The adjustment supports (34) are arranged in a staggered pattern with the wire supports.

4. A modular filter media filling structure according to claim 2 or 3, characterized in that, The adjustment support (34) is a spiral spring structure, a hard iron wire structure, or a combined structure of a spiral spring and a hard iron wire.

5. The modular filter media loading structure according to claim 4, characterized in that The adjustment supports (34) are arranged at intervals above and below the rigid support mesh (31).

6. An autotrophic denitrification reactor, characterized in that, It includes the modular filter media loading structure as described in claim 5, and also includes a water inlet tank (10), a reactor tank body (20), and a water outlet tank (40). The reactor tank body (20) includes a lower fixed tank (21). An upper side-opening tank (22) is fixedly connected to the upper end of the lower fixed tank (21). An upper fixed tank (23) is fixedly connected to the upper end of the side-opening tank (22). A connecting rotating shaft (24) is fixedly arranged on the side-opening tank (22). A side-opening door (25) for closing the side-opening tank (22) is rotatably installed at the connecting rotating shaft (24). A water stop sealing ring (251) for preventing water leakage is installed on the outer periphery of the side-opening door (25). A plurality of filter media loading structures (30) are arranged from bottom to top in the reactor tank body (20) and are all rotatably installed on the connecting rotating shaft (24); The side end of the lower fixed tank (21) is provided with a water inlet (28). A drain pipe (29) for discharging the sewage in the lower fixed tank (21) is communicated with the lower part of the lower fixed tank (21). The water inlet tank (10) is connected to a water inlet pump (12) through a water inlet pipe (11). The water outlet of the water inlet pump (12) is communicated with the water inlet (28) through a pipeline. The water inlet pump (12) is used to pump the sewage in the water inlet tank (10) into the lower fixed tank (21); An outlet pipe (41) is connected to the upper fixed tank (23), and the water outlet end of the outlet pipe (41) is connected to the water outlet tank (40).

7. The autotrophic denitrification reactor according to claim 6, characterized in that, A water inlet nitrate nitrogen detector (13) is installed on the water inlet pipe (11), and a water outlet nitrate nitrogen detector (42) is installed on the outlet pipe (41).

8. The autotrophic denitrification reactor according to claim 6, characterized in that, It also includes a backwashing water pump (44) and a backwashing air blower (50). The lower part of the water outlet tank (40) is communicated with the inside of the lower fixed tank (21) through a backwashing connecting pipe (43). The backwashing water pump (44) is arranged on the backwashing connecting pipe (43) and is used to pump the clear water in the water outlet tank (40) into the lower fixed tank (21). The backwashing air blower (50) is used to supply air into the lower fixed tank (21) to wash the filter media in the reactor through the backwashing connecting pipe (43).

9. The autotrophic denitrification reactor according to claim 6, wherein A filter media support plate (26) is provided at the connection between the lower fixed tank (21) and the side-opening tank (22). A number of water distribution round holes (261) are evenly arranged on the filter media support plate (26). A number of support legs (27) for supporting the filter media support plate (26) are fixedly installed at the lower end of the filter media support plate (26).

10. The autotrophic denitrification reactor according to claim 6, characterized in that, A plurality of sampling tubes (60) are installed on the reactor tank body (20). The number of the sampling tubes (60) is equal to that of the filter media loading structure (30) and is located at the upper end of the filter media loading structure (30). A sampling valve (61) for controlling on-off is installed on the sampling tube (60).

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