A denitrification sewage treatment pool

Abstract

The invention discloses a denitrification sewage treatment pool, which relates to the technical field of denitrification sewage treatment pools, and comprises a filter tank, an anaerobic tank, an anoxic tank and an aerobic tank which are connected in sequence, wherein the filter tank is connected to one end of a sewage inlet pipe, the aerobic tank is connected to a drainage pipe and one end of a return pipe, and the other end of the return pipe is connected back to the anoxic tank, a grille assembly seat is arranged in the filter tank, an adjustable-spacing grille is installed on the grille assembly seat, the adjustable-spacing grille comprises a fixed grille and a movable grille, the fixed grille is connected to the grille assembly seat, the movable grille comprises a horizontal outer frame, a vertical outer frame, an inner grille and a positioning plate, the horizontal outer frame and the vertical outer frame are connected to form a frame structure, the angle and the spacing of the grille can be adjusted in real time according to different needs, a three-gear setting is adopted, and switching between a coarse grille, a medium grille and a fine grille can be performed without affecting the filtering impurity range of the grille, the filtering effect of the grille is ensured, and the denitrification efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of denitrification sewage treatment tanks, and in particular to a denitrification sewage treatment tank. Background Art

[0002] When treating sewage in a sewage treatment plant, it is usually necessary to carry out multi-step process treatment, among which sewage denitrification is of great significance in its treatment process. Sewage denitrification technology is mainly a technical measure to remove nitrogen from wastewater to prevent eutrophication of water bodies, mainly including biological denitrification, ion exchange, air stripping and other methods. Biological denitrification is the main technology in sewage treatment. Its denitrification principle is to convert nitrogen elements in sewage into harmless nitrogen gas through aerobic nitrification and anoxic denitrification, which is generally carried out inside a biological denitrification tank.

[0003] Before the sewage is denitrified, it needs to pass through the screen pool to intercept the larger suspended solids and easily precipitated objects in the water to avoid clogging the pump and pipes. Pollutants in sewage generally exist in three forms: suspended (including floating), colloid and dissolved. The objects of physical treatment of sewage are mainly suspended solids and some colloids that may clog the impeller of the pump and the valve of the pipeline and increase the load of the subsequent treatment unit. Therefore, the physical treatment of sewage is generally called solid-liquid separation treatment of wastewater. In principle, solid-liquid separation of wastewater is mainly divided into two categories: one is that the wastewater is subject to certain restrictions, and the suspended solids flow in the water and are removed; the other is that the suspended solids are subject to certain restrictions, and the wastewater flows and discards the suspended solids. The screen belongs to the latter. The screen is the most important auxiliary equipment in the sewage pumping station. The screen is generally composed of a group of parallel bars, which are placed obliquely at the inlet of the pump station sump.

[0004] The determination of the existing grid spacing depends on its application scenario and purpose. The current grid bar spacing is fixed or can only be adjusted to two positions. In the existing wastewater treatment system, the grid can be divided into coarse grid, medium grid and fine grid according to the distance between the bars. The coarse grid is mainly used to filter larger suspended matter and floating objects in the sewage, such as leaves, plastic bags, etc.; the medium grid bars intercept most of the screen residue; the fine grid bars are used to intercept fine and soft screen residue to prevent entanglement from passing through;

[0005] Some fixed grids need to prepare coarse grids, medium grids and fine grids, and select grids with corresponding hole spacing according to different sewage filtration standards. The grids with two adjustable gears, such as the Chinese utility model patent with application number 2019204572506, disclose a sewage treatment grid with adjustable grid holes. By switching to achieve two aperture adjustments, the range of impurities that can be filtered by the sewage treatment grid is reduced, greatly limiting the role of the sewage treatment grid. Summary of the invention

[0006] The object of the present invention is to provide a denitrification sewage treatment tank to solve the above problems.

[0007] To achieve the above object, the present invention provides the following technical solution: A denitrification sewage treatment tank includes a filtering tank, an anaerobic tank, an anoxic tank, and an aerobic tank connected in sequence. One end of the filtering tank is connected to an influent pipe, and one end of the aerobic tank is connected to a drain pipe and a reflux pipe. The other end of the reflux pipe is connected back to the anoxic tank. A grille assembly seat is arranged in the filtering tank, and an adjustable-spacing grille is installed on the grille assembly seat.

[0008] The adjustable-spacing grille includes a fixed grille and a movable grille. The fixed grille is connected to the grille assembly seat. The movable grille includes a horizontal outer frame, a vertical outer frame, an inner grille, and a positioning plate. The horizontal outer frame and the vertical outer frame are connected to form a frame structure. The inner grille is fixed inside the frame structure. A through horizontal channel is provided in the horizontal grid bars of the inner grille, and a through vertical channel is provided in the vertical grid bars of the inner grille.

[0009] Horizontal guide grooves and vertical guide grooves are respectively arranged on the horizontal outer frame and the vertical outer frame. Both ends of a horizontal guide rod passing through the horizontal channel are respectively inserted into the vertical guide grooves of the two vertical outer frames. One end of a vertical guide rod passing through the vertical channel passes through the horizontal guide groove of the horizontal outer frame, and the other end of the vertical guide rod is connected to the positioning plate.

[0010] The top of the inner grille is connected to a grille driving assembly on the grille assembly seat.

[0011] Further, the horizontal channels and the vertical channels are arranged in a staggered manner and the axes of the horizontal channels and the vertical channels are perpendicular. The horizontal guide rod and the vertical guide rod are made of steel structures, and the horizontal guide rod and the vertical guide rod slide in the horizontal channels and the vertical channels.

[0012] Further, one horizontal outer frame is provided, and two vertical outer frames are provided. The horizontal outer frame and the vertical outer frames are connected to form a "冂" shape. The horizontal outer frame and the vertical outer frames cover three outer walls of the fixed grille, and the horizontal outer frame and the vertical outer frames are fixed to the fixed grille by bolts.

[0013] The positioning plate contacts the bottom horizontal grid bar of the fixed grille.

[0014] Further, the grille assembly seat includes a first retaining strip, a second retaining strip, a reinforcing rod, a rotating shaft, and a cylinder. Both ends of the reinforcing rod are fixed to the tops of the first retaining strip and the second retaining strip. Both ends of the rotating shaft respectively pass through the bottoms of the first retaining strip and the second retaining strip and are movably connected to the two side walls of the filtering tank. The cylinder is installed on the support frame of the filtering tank, and the cylinder rod connected to the piston of the cylinder is movably connected to the reinforcing rod.

[0015] The two outermost vertical grid bars of the fixed grille are assembled on the first retaining strip and the second retaining strip by bolts, and the bottom edge of the fixed grille contacts the bottom of the filtering tank.

[0016] Furthermore, the grille drive assembly is provided with two groups and is installed on the bracket at the top of the fixed grille. The two groups of the grille drive assembly are also connected to the top of the inner grille and are used to drive the inner grille to move back and forth in an "L" shape to change the grille spacing after the fixed grille and the movable grille are stacked.

[0017] Furthermore, each group of the grille driving components includes a hydraulic cylinder, a cylinder telescopic rod and a limit assembly. The hydraulic cylinder is assembled on a bracket, one end of the cylinder telescopic rod is connected to the piston of the hydraulic cylinder, and the other end of the cylinder telescopic rod is fixed to the inner grille through the limit assembly.

[0018] Furthermore, the limit assembly includes a limit seat, a first supporting plate, a second supporting plate, a first rotating shaft group, a second rotating shaft group and a connecting rod. The limit seat is also fixed on the bracket. An "L"-shaped channel is arranged inside the limit seat, and a strip groove connected to the "L"-shaped channel is opened at the bottom of the limit seat. The first rotating shaft group is movably connected to the first supporting plate, and the bent rod fixed on the bottom surface of the first supporting plate is fixed on the inner grille. The second rotating shaft group is movably connected to the second supporting plate. The first rotating shaft group is movably connected to the second rotating shaft group through a connecting rod, and the first rotating shaft group is also provided with a ring fixed to the auxiliary rod.

[0019] Furthermore, the first rotating shaft group and the second rotating shaft group are each composed of two shafts, and two connecting rods are provided to be sleeved on the shafts corresponding to the first rotating shaft group and the second rotating shaft group.

[0020] Furthermore, the "L"-shaped channel opening of the limit seat is respectively set as an upper opening and a side opening, the auxiliary rod passes through the upper opening, and the side opening is for the first supporting plate to pass through.

[0021] Technical effects and advantages of the present invention:

[0022] The inner grille moves to the upper left corner, at which point the inner grille and the fixed grille overlap, and the fixed grille and the movable grille form a coarse grille. The inner grille moves downward, the inner grille and the fixed grille interlace, and the area enclosed by the grille bars is reduced by half, forming a medium grille. The inner grille moves to the right, at which point the inner grille and the fixed grille continue to interlace, and the area enclosed by the grille bars continues to be reduced by half, forming a fine grille. The angle and spacing of the fixed grille and the movable grille can be adjusted in real time according to different needs. A three-gear setting is adopted, and switching between the coarse grille, the medium grille and the fine grille can be performed without affecting the range of impurities filtered by the grille, thereby ensuring the filtering effect of the grille and improving the denitrification efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is the overall structure diagram of the present invention;

[0024] Figure 2This is a structural diagram of the adjustable spacing grid inside the filter tank of the present invention;

[0025] Figure 3 An exploded view of the adjustable spacing grid of the present invention;

[0026] Figure 4 The fixed grille and the movable grille of the present invention are adjusted to a coarse grille state diagram;

[0027] Figure 5 The fixed grille and the movable grille of the present invention are adjusted to the middle grille state;

[0028] Figure 6 The fixed grille and the movable grille of the present invention are adjusted to a fine grille state diagram;

[0029] Figure 7 This is a structural diagram of the grille assembly seat inside the filter tank according to the second embodiment of the present invention;

[0030] Figure 8 A connection diagram of a grille driving assembly and an adjustable-pitch grille according to a third embodiment of the present invention;

[0031] Fig. 9 A diagram showing the connection between the fixed grille and the movable grille of the present invention and the grille driving assembly when the fixed grille and the movable grille are adjusted to the middle grille;

[0032] Fig.10 A partial cross-sectional view of a grille drive assembly of the present invention;

[0033] Fig.11 This is a diagram showing the internal structure of the grille drive assembly of the present invention.

[0034] In the figure:

[0035] 1. Filter tank; 2. Anaerobic tank; 3. Anoxic tank; 4. Grille assembly seat; 41. First stop bar; 42. Second stop bar; 43. Reinforcement rod; 44. Rotating shaft; 45. Cylinder; 5. Fixed grille; 6. Movable grille; 61. Horizontal outer frame; 611. Horizontal guide rod; 62. Vertical outer frame; 621. Vertical guide rod; 63. Inner grille; 64. Positioning plate; 7. Grille drive assembly; 71. Hydraulic cylinder; 72. Cylinder telescopic rod; 731. Limit seat; 732. First supporting plate; 733. Second supporting plate; 734. First rotating shaft group; 735. Second rotating shaft group; 736. Connecting rod; 737. Strip groove; 8. Aerobic tank. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] Embodiment 1, refer to Figure 1-Figure 6 , which is the first embodiment of the present invention, provides a denitrification sewage treatment pool, comprising a filter tank 1, an anaerobic tank 2, an anoxic tank 3, and an aerobic tank 8 connected in sequence, the filter tank 1 is connected to one end of a sewage inlet pipe, the aerobic tank 8 is connected to a drain pipe and one end of a return pipe, and the other end of the return pipe is connected back to the anaerobic tank 2, a grille assembly seat 4 is provided in the filter tank 1, and an adjustable spacing grille is installed on the grille assembly seat 4, the sewage is filtered after passing through the adjustable spacing grille of the filter tank 1, and then flows into the anaerobic tank 2, the anoxic tank 3 and the aerobic tank 8 in sequence;

[0038] However, in the prior art, when intercepting sewage in the same section, different sizes of suspended matter are carried at different stages or under different external runoff conditions. The use of fixed-size and two adjustable-size screens cannot further screen and isolate the suspended matter at different stages, which will cause certain damage to subsequent supporting facilities such as water pumps or shorten the normal service life of subsequent main equipment. The adjustable-pitch screen used in this technology is different from the screens in the prior art. The adjustable-pitch screen can be adjusted to a coarse screen, a medium screen or a fine screen according to needs, and is adapted to filter suspended matter of different sizes brought by different stages or different external runoffs to avoid loss of subsequent equipment.

[0039] The sewage undergoes nitrification in the aerobic tank 8, where the ammonia nitrogen is oxidized into nitrite nitrogen and nitrate nitrogen by the action of autotrophic microorganisms nitrite bacteria and nitrate bacteria, and then flows back to the anaerobic tank 2 through the return pipe. Under anoxic conditions, denitrification reaction occurs. Due to the action of facultative denitrifying bacteria (denitrifying bacteria), NO 2 - and NO 3 - Reduction to N 2 process, thereby achieving the purpose of denitrification.

[0040] The adjustable spacing grille includes a fixed grille 5 and a movable grille 6. The fixed grille 5 is connected to the grille assembly seat 4. The movable grille 6 includes a horizontal outer frame 61, a vertical outer frame 62, an inner grille 63 and a positioning plate 64. The horizontal outer frame 61 and the vertical outer frame 62 are connected to form a frame structure. The inner grille 63 is fixed in the frame structure. A through-going horizontal channel is provided in the horizontal bars of the inner grille 63, and a through-going vertical channel is provided in the vertical bars of the inner grille 63.

[0041] The horizontal outer frame 61 and the vertical outer frame 62 are respectively provided with a horizontal guiding groove and a vertical guiding groove. Both ends of the horizontal guiding rod 611 penetrating through the horizontal channel are respectively inserted into the vertical guiding grooves of the two vertical outer frames 62. One end of the vertical guiding rod 621 penetrating through the vertical channel passes through the horizontal guiding groove of the horizontal outer frame 61, and the other end of the vertical guiding rod 621 is connected to the positioning plate 64.

[0042] There is one horizontal outer frame 61 and two vertical outer frames 62. The horizontal outer frame 61 and the vertical outer frames 62 are connected to form a "冂" shape. The horizontal outer frame 61 and the vertical outer frames 62 cover three outer walls of the fixed grille 5, and the horizontal outer frame 61 and the vertical outer frames 62 are fixed to the fixed grille 5 by bolts; the positioning plate 64 contacts the horizontal grid bars at the lowermost end of the fixed grille 5. A groove is formed on the positioning plate 64, and a convex block is fixed on the fixed grille 5. The convex block is snapped into the groove, so that the positioning plate 64 can only slide along the horizontal grid bars of the fixed grille 5.

[0043] The position of the fixed grille 5 in the filtering tank 1 is in a limited state. After the horizontal outer frame 61 and the vertical outer frames 62 are fixed to the fixed grille 5, a frame structure is formed, achieving the purpose of stability and firmness. The inner grille 63 can move along the vertical guiding rod 621 and the horizontal guiding rod 611, thereby changing the position of the inner grille 63 in the frame structure. The grid bar spacing between the inner grille 63 and the fixed grille 5 is set to be the same. Through the above settings, the inner grille 63 can be moved to achieve the purpose of switching between a coarse grille, a medium grille, and a fine grille;

[0044] The horizontal channels and the vertical channels are arranged in an alternating manner and the axes of the horizontal channels and the vertical channels are perpendicular to each other. The horizontal guiding rod 611 and the vertical guiding rod 621 are made of a steel structure, and the horizontal guiding rod 611 and the vertical guiding rod 621 slide in the horizontal channels and the vertical channels.

[0045] As Figure 4 shown, when the inner grille 63 moves to the upper left corner, at this time, the grids of the inner grille 63 and the fixed grille 5 overlap, and this is the coarse grille at this time. The inner grille 63 moves downward to the position as shown in Figure 5 shown. At this time, the inner grille 63 and the fixed grille 5 are staggered, Figure 4 and the area enclosed by the grid bars is reduced by half. At this time, a medium grille is formed. The inner grille 63 moves to the right to the position as shown in Figure 6 shown. At this time, the inner grille 63 and the fixed grille 5 continue to be staggered, Figure 5 and the area enclosed by the grid bars continues to be reduced by half. At this time, a fine grille is formed. The provided horizontal guiding rod 611 and vertical guiding rod 621 provide guidance for the movement of the inner grille 63. At the same time, the horizontal guiding rod 611 and the vertical guiding rod 621 can also function as grid bars.

[0046] Example 2, referring to Figure 7, which is the second embodiment of the present invention, and this embodiment is different from the first embodiment. The grille assembly seat 4 includes a first baffle 41, a second baffle 42, a reinforcing rod 43, a rotating shaft 44 and a cylinder 45. The two ends of the reinforcing rod 43 are fixed on the top of the first baffle 41 and the second baffle 42, and the two ends of the rotating shaft 44 pass through the bottom ends of the first baffle 41 and the second baffle 42 and are movably connected to the two side walls of the filter tank 1. The cylinder 45 is installed on the support frame of the filter tank 1, and the cylinder rod connected by the piston of the cylinder 45 is movably connected to the reinforcing rod 43.

[0047] The two outermost vertical bars of the fixed grille 5 are assembled on the first stop bar 41 and the second stop bar 42 by bolts, and the bottom edge of the fixed grille 5 is in contact with the bottom of the filter tank 1 .

[0048] The cylinder 45 drives the cylinder rod to extend and retract to push the first baffle 41, the second baffle 42 and the reinforcing rod 43 to rotate around the rotating shaft 44, thereby changing the angle of the first baffle 41 and the second baffle 42. The fixed grille 5 and the movable grille 6 are installed on the first baffle 41 and the second baffle 42, and the angle of the fixed grille 5 and the movable grille 6 can also be changed. The angle of the fixed grille 5 and the movable grille 6 can be adjusted in real time according to different needs. The existing manual adjustment of the grille angle causes the treatment pool to stop using, affecting denitrification. The present device adjusts the grille angle mechanically to shorten the equipment adjustment time, reduce the downtime of the treatment pool, and improve the denitrification efficiency.

[0049] Example 3, refer to Figure 8-Figure 11 , which is the third embodiment of the present invention. This embodiment is different from the second embodiment. The top of the inner grille 63 is connected to the grille driving assembly 7 on the grille assembly seat 4. The grille driving assembly 7 is provided with two groups and is installed on the bracket on the top of the fixed grille 5. The two groups of grille driving assemblies 7 are also connected to the top of the inner grille 63, and are used to drive the inner grille 63 to move back and forth in the "L" shape direction to change the grille spacing after the fixed grille 5 and the movable grille 6 are stacked.

[0050] The movable grille 6 is driven to move by the grille driving assembly 7 to achieve the purpose of adjusting the grille spacing between the fixed grille 5 and the movable grille 6 .

[0051] Each grille driving assembly 7 includes a hydraulic cylinder 71, a cylinder telescopic rod 72 and a limit assembly. The hydraulic cylinder 71 is assembled on the bracket, one end of the cylinder telescopic rod 72 is connected to the piston of the hydraulic cylinder 71, and the other end of the cylinder telescopic rod 72 is fixed to the inner grille 63 through the limit assembly.

[0052] The hydraulic cylinder 71 is the power source. The hydraulic cylinder 71 drives the cylinder telescopic rod 72 to extend and retract, and then drives the limit assembly to move synchronously. The grille driving assembly 7 is provided with two groups, which are respectively connected to the top two end corners of the inner grille 63, providing high support for the inner grille 63, allowing it to move stably.

[0053] The limiting assembly includes a limiting seat 731, a first supporting plate 732, a second supporting plate 733, a first rotating shaft group 734, a second rotating shaft group 735 and a connecting rod 736. The limiting seat 731 is also fixed on the bracket. An "L"-shaped channel is arranged inside the limiting seat 731, and a strip groove 737 connected to the "L"-shaped channel is opened at the bottom of the limiting seat 731. The first rotating shaft group 734 is movably connected to the first supporting plate 732. The bent rod fixed on the bottom surface of the first supporting plate 732 passes through the strip groove 737 and is fixed on the inner grille 63. The second rotating shaft group 735 is movably connected to the second supporting plate 733. The first rotating shaft group 734 is movably connected to the second rotating shaft group 735 through the connecting rod 736. The second rotating shaft group 735 is also covered with a ring fixed to the cylinder telescopic rod 72.

[0054] The first rotating shaft group 734 and the second rotating shaft group 735 are each composed of two shafts, and two connecting rods 736 are provided to be sleeved on the shafts corresponding to the first rotating shaft group 734 and the second rotating shaft group 735 .

[0055] The "L"-shaped channel opening of the limiting seat 731 is respectively set as an upper opening and a side opening, and the cylinder telescopic rod 72 passes through the upper opening, and the side opening is for the first supporting plate 732 to pass through.

[0056] Since the limiting seat 731 is provided with an "L"-shaped channel inside, and the first supporting plate 732 and the second supporting plate 733 are supported by the connecting rod 736, when the fixed grille 5 and the movable grille 6 are adjusted to the coarse grille, the first supporting plate 732 contacts the guide plate on the inner wall of the "L"-shaped channel, and the first supporting plate 732 moves along the guide plate toward the upper opening direction of the "L"-shaped channel, and the connecting rod 736 is in a tilted state at this time;

[0057] When it is necessary to adjust from the coarse grille to the medium grille, the hydraulic cylinder 71 pushes the cylinder telescopic rods 72 on both sides to descend, and the cylinder telescopic rods 72 push the first supporting plate 732, the connecting rod 736 and the second supporting plate 733 to slowly slide along the "L"-shaped channel with the upper opening toward the strip groove 737. After the first supporting plate 732 hits the inner wall of the limit seat 731 locked by the strip groove 737, a pressure sensor is provided on the inner wall of the limit seat 731. After the side of the first supporting plate 732 hits the pressure sensor of the limit seat 731, the pressure data is fed back to the control center to drive the hydraulic cylinder 71 to stop working. At this time, the inner grille 63 moves downward to reduce the grille spacing to half, completing the switching of the medium grille.

[0058] When the middle grille needs to be adjusted to a fine grille, the hydraulic cylinder 71 continues to push the cylinder telescopic rod 72 to move downward. At this time, since the bottom surface of the limit seat 731 is against the first supporting plate 732, and the limit seat 731 on the side of the first supporting plate 732 is provided with a side opening, the second supporting plate 733 continues to descend to push the connecting rod 736 and the first supporting plate 732 toward the side opening, thereby realizing the horizontal rightward movement of the inner grille 63 until the second supporting plate 733 also touches the bottom surface of the limit seat 731. Then the hydraulic cylinder 71 stops working and the inner grille 63 moves to the far right distance, thereby achieving the purpose of switching the middle grille to the fine grille.

[0059] It adopts a three-speed setting, which can switch between coarse grid, medium grid and fine grid without affecting the filtering impurity range of the grid, thus ensuring the filtering effect of the grid.

[0060] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A denitrification sewage treatment pool, comprising a filter tank (1), an anaerobic tank (2), an anoxic tank (3), and an aerobic tank (8) connected in sequence, wherein the filter tank (1) is connected to one end of a sewage inlet pipe, the aerobic tank (8) is connected to a drain pipe and one end of a return pipe, and the other end of the return pipe is connected back to the anaerobic tank (2), characterized in that: A grille assembly seat (4) is arranged inside the filtering tank (1), and an adjustable-spacing grille is installed on the grille assembly seat (4); The adjustable-spacing grille includes a fixed grille (5) and a movable grille (6). The fixed grille (5) is connected to the grille assembly seat (4). The movable grille (6) includes a horizontal outer frame (61), a vertical outer frame (62), an inner grille (63) and a positioning plate (64). The horizontal outer frame (61) and the vertical outer frame (62) are connected to form a frame structure. The inner grille (63) is fixed inside the frame structure. A through horizontal channel is provided in the horizontal grid bars of the inner grille (63), and a through vertical channel is provided in the vertical grid bars of the inner grille (63); Horizontal guide grooves and vertical guide grooves are respectively arranged on the horizontal outer frame (61) and the vertical outer frame (62). Both ends of a horizontal guide rod (611) penetrating through the horizontal channel are respectively inserted into the vertical guide grooves of the two vertical outer frames (62). One end of a vertical guide rod (621) penetrating through the vertical channel passes through the horizontal guide groove of the horizontal outer frame (61), and the other end of the vertical guide rod (621) is connected to the positioning plate (64); The horizontal channels and the vertical channels are arranged in a staggered manner and the axes of the horizontal channels and the vertical channels are perpendicular to each other. The horizontal guide rod (611) and the vertical guide rod (621) are made of steel structures, and the horizontal guide rod (611) and the vertical guide rod (621) slide in the horizontal channels and the vertical channels; One horizontal outer frame (61) is provided, and two vertical outer frames (62) are provided. The horizontal outer frame (61) and the vertical outer frames (62) are connected to form a "冂" shape. The horizontal outer frame (61) and the vertical outer frames (62) cover three outer walls of the fixed grille (5), and the horizontal outer frame (61) and the vertical outer frames (62) are fixed to the fixed grille (5) by bolts; The positioning plate (64) contacts the horizontal grid bar at the lowermost end of the fixed grille (5); The top of the inner grille (63) is connected to a grille driving assembly (7) on the grille assembly seat (4); Each group of the grille driving assemblies (7) includes a hydraulic cylinder (71), a cylinder telescopic rod (72) and a limiting assembly. The hydraulic cylinder (71) is assembled on a bracket. One end of the cylinder telescopic rod (72) is connected to the piston of the hydraulic cylinder (71), and the other end of the cylinder telescopic rod (72) is fixed to the inner grille (63) through the limiting assembly; The limiting assembly comprises a limiting seat (731), a first supporting plate (732), a second supporting plate (733), a first rotating shaft group (734), a second rotating shaft group (735) and a connecting rod (736). The limiting seat (731) is also fixed to the bracket. An "L"-shaped channel is provided inside the limiting seat (731), and a strip groove (737) communicating with the "L"-shaped channel is provided at the bottom of the limiting seat (731). The first supporting plate (734) is movably connected to the first supporting plate (732), a bent rod fixed on the bottom surface of the first supporting plate (732) passes through a strip groove (737) and is fixed on the inner grille (63), the second rotating shaft group (735) is movably connected to the second supporting plate (733), the first rotating shaft group (734) is movably connected to the second rotating shaft group (735) through a connecting rod (736), and the second rotating shaft group (735) is also sleeved with a collar fixed to the auxiliary rod (73).

2. A denitrification wastewater treatment pool according to claim 1, characterized in that: The grille assembly seat (4) comprises a first stop bar (41), a second stop bar (42), a reinforcing rod (43), a rotating shaft (44) and a cylinder (45); two ends of the reinforcing rod (43) are fixed to the top ends of the first stop bar (41) and the second stop bar (42); two ends of the rotating shaft (44) respectively pass through the bottom ends of the first stop bar (41) and the second stop bar (42) and are movably connected to the two side walls of the filter tank (1); the cylinder (45) is installed on a support frame of the filter tank (1); and a cylinder rod connected to a piston of the cylinder (45) is movably connected to the reinforcing rod (43); The two outermost vertical bars of the fixed grille (5) are assembled on the first stop bar (41) and the second stop bar (42) by means of bolts, and the bottom edge of the fixed grille (5) contacts the bottom of the filter tank (1).

3. A denitrification wastewater treatment pool according to claim 2, characterized in that: The grille drive components (7) are provided in two groups and are mounted on a bracket at the top of the fixed grille (5). The two groups of grille drive components (7) are also connected to the top of the inner grille (63) and are used to drive the inner grille (63) to move back and forth in an "L"-shaped direction to change the grille spacing after the fixed grille (5) and the movable grille (6) are stacked.

4. A denitrification wastewater treatment pool according to claim 3, characterized in that: The first rotating shaft group (734) and the second rotating shaft group (735) are both composed of two shafts, and the two connecting rods (736) are sleeved on the shafts corresponding to the first rotating shaft group (734) and the second rotating shaft group (735).

5. A denitrification wastewater treatment pool according to claim 4, characterized in that: The "L"-shaped channel opening of the limiting seat (731) is respectively configured as an upper opening and a side opening, the auxiliary rod (73) passes through the upper opening, and the side opening is used for the first supporting plate (732) to pass through.

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