Integrated device for pretreatment of coking wastewater for water reuse

Abstract

This invention relates to the technical field of industrial wastewater treatment equipment, specifically an integrated pretreatment device for coking wastewater reuse. It includes an integrated housing, internally divided into a hardening reaction zone, a coagulation and flocculation zone, an inclined tube sedimentation zone, and a COD deep removal zone. The hardening reaction zone is equipped with a first-stage cyclone mixer and a lime slurry dosing loop to achieve hydraulic mixing and hardening removal. The coagulation and flocculation zone features alternating downflow and upflow baffles, working in conjunction with polyaluminum chloride and polyacrylamide dosing loops to complete baffled coagulation. The inclined tube sedimentation zone contains hexagonal honeycomb inclined tubes and a sawtooth overflow weir. The COD deep removal zone is filled with a granular activated carbon packing layer, with a perforated air distribution pipe at the bottom. Each reaction zone has a pyramidal sludge collection hopper and a pneumatically controlled sludge discharge pipeline at the bottom. This invention features high integration, eliminates the need for an electric agitator, utilizes hydraulic mixing and baffles to extend the reaction path, allows for activated carbon regeneration via air washing, and ensures reliable operation.

Description

Technical Field

[0001] This invention relates to the technical field of industrial wastewater treatment equipment, specifically an integrated pretreatment device for coking wastewater reuse. Background Technology

[0002] Coking wastewater is a highly concentrated toxic organic wastewater generated during the coal-to-coke and coal-to-gas processes. It contains high concentrations of ammonia nitrogen, phenols, cyanides, polycyclic aromatic hydrocarbons, and high-hardness ions. In coking wastewater reuse systems, pretreatment is a crucial step. Its main purpose is to remove hardness, suspended solids, and some COD to protect subsequent membrane systems (such as reverse osmosis) and ensure the quality of reused water.

[0003] Existing pretreatment units typically employ a split design, with the hardening reactor, coagulation sedimentation tank, and activated carbon filter operating independently. This results in a large footprint, complex piping connections, and inconvenient operation and maintenance. Furthermore, traditional units heavily rely on electronic equipment such as electric agitators, metering pumps, and online sensors, leading to a high failure rate in the high-humidity, corrosive, and explosion-proof environments of coking plants. In addition, existing units have shortcomings in areas such as reagent mixing uniformity, hydraulic conditions in the sedimentation zone, and ease of activated carbon regeneration, resulting in high operating costs and unstable treatment effects.

[0004] Therefore, developing a compact, stir-free, low-electronic, high-efficiency, and low-consumption integrated pretreatment device for coking wastewater reuse has significant engineering practical value. Summary of the Invention

[0005] The purpose of this invention is to provide an integrated pretreatment device for coking wastewater reuse, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution: An integrated pretreatment device for coking wastewater reuse includes: An integrated box is a rectangular horizontal sealed container, which is divided into a hardness removal reaction zone, a coagulation and flocculation zone, an inclined tube sedimentation zone and a COD deep removal zone along the water flow direction. The hardening reaction zone is located at the left end inside the integrated box and is directly connected to the water inlet pipe located on the upper left side wall of the integrated box. The hardening reaction zone is equipped with a first-stage vortex mixer and a lime slurry dosing ring pipe installed at the top of the hardening reaction zone. The coagulation and flocculation zone is located to the right of the hardening reaction zone, and the two are separated by a first longitudinal baffle. A water passage gap is left between the top of the first longitudinal baffle and the top wall of the integrated box. Downflow baffles and upflow baffles are alternately arranged along the height direction in the coagulation and flocculation zone. Polyaluminum chloride dosing ring pipe and polyacrylamide dosing ring pipe are installed on the top of the coagulation and flocculation zone. The inclined tube sedimentation zone is located to the right of the coagulation and flocculation zone, and the two are separated by a second longitudinal partition. The second longitudinal partition is welded and sealed to the top wall of the integrated box, and a rectangular water passage hole is opened at its lower part. The interior of the inclined tube sedimentation zone includes, from bottom to top, a bottom flow stabilizing layer, a middle inclined tube packing layer and an upper water collection layer. A sawtooth overflow weir is installed at the top of the inclined tube sedimentation zone. The COD deep removal zone is located to the right of the inclined tube sedimentation zone, and the two are separated by a third longitudinal partition. A water passage is left between the top of the third longitudinal partition and the top wall of the integrated box. The COD deep removal zone is filled with a granular activated carbon packing layer. A porous support plate is set below the granular activated carbon packing layer and a pressure plate grid is set above it. An outlet collection tank is installed at the top of the COD deep removal zone near the right side wall. The right side wall of the outlet collection tank is shared with the right side wall of the integrated box, and an outlet pipe is opened on the shared wall. The mud collection hopper and mud discharge pipe are located at the bottom of the integrated box; And a cleaning component installed at the bottom of the COD deep removal zone.

[0007] As a further embodiment of the present invention: the first-stage cyclone mixer comprises, from bottom to top, a bottom inlet cone, a middle guide cylinder, and a top diffuser cone. The bottom inlet cone is a frustum shape, wider at the top and narrower at the bottom, and its lower edge is sealed to the inner wall of the inlet pipe via a flange. The middle guide cylinder is a cylindrical shell, and its lower edge is welded to the upper edge of the bottom inlet cone. The top diffuser cone is a frustum shape, narrower at the top and wider at the bottom, and its lower edge is welded to the upper edge of the middle guide cylinder. The upper opening of the top diffuser cone serves as the outlet. A turbulence cone is fixedly installed at the center of the bottom inlet cone via a cross bracket. This turbulence cone is a cone with its tip pointing downwards and its bottom surface pointing upwards.

[0008] As a further embodiment of the present invention: the lime slurry dosing ring pipe 22 is an annular circular pipe, placed horizontally, and fixed to the inner side of the top wall of the integrated housing 1 by a hanger 221. The inner side of the lime slurry dosing ring pipe 22 has 6 to 8 dosing holes 222 evenly opened, and the dosing holes 222 face the central axis of the top diffusion cone 213. The lime slurry dosing ring pipe 22 is connected to an external lime slurry storage tank through the top wall of the integrated housing 1 via an external lime slurry dosing pipe 223. The structure and fixing method of the polyaluminum chloride dosing ring pipe 34 and the polyacrylamide dosing ring pipe 35 are the same as those of the lime slurry dosing ring pipe 22, and they are respectively installed in the first half and the second half of the coagulation and flocculation zone 3.

[0009] As a further embodiment of the present invention: the downstream baffle 32 is a rectangular flat plate, which is vertically welded to the inner side of the top wall of the integrated housing 1, and its lower edge is 300-400 mm away from the flat bottom structure 13 of the integrated housing 1; the upstream baffle 33 is a rectangular flat plate, which is vertically welded to the inner bottom wall of the integrated housing 1, and its upper edge is 300-400 mm away from the inner side of the top wall; the downstream baffle 32 and the upstream baffle 33 are alternately arranged along the water flow direction, and a total of 3-5 sets are arranged.

[0010] As a further embodiment of the present invention: the central inclined tube packing layer is composed of several groups of hexagonal honeycomb inclined tubes made of polypropylene. The length of the hexagonal honeycomb inclined tube is 1000 mm, the inclination angle is 60 degrees, and the lower end faces the water inlet direction; the sawtooth overflow weir is formed by bending stainless steel plate, with a cross-section in the shape of continuous isosceles triangular teeth, a tooth height of 50 mm, and a tooth base width of 100 mm. The sawtooth overflow weir is welded and fixed horizontally between the front and rear inner walls of the integrated box, and its top edge is horizontal and located at the same elevation.

[0011] As a further aspect of the present invention: the bottom of the integrated box is a flat-bottom structure, and several sludge discharge ports are provided along the length of the flat-bottom structure; the sludge collection hopper includes a first pyramidal sludge collection hopper, a second pyramidal sludge collection hopper, and a third pyramidal sludge collection hopper respectively provided at the bottom of the hardening reaction zone, the coagulation and flocculation zone, and the inclined tube sedimentation zone. Each pyramidal sludge collection hopper is a four-sided pyramidal shell that is larger at the top and smaller at the bottom. Its upper opening is welded to the sludge discharge port on the flat-bottom structure, and its lower tip is provided with a sludge outlet.

[0012] As a further embodiment of the present invention: the sludge discharge pipeline includes sludge discharge branch pipes connected to each sludge outlet, a sludge discharge main pipe that connects all the sludge discharge branch pipes, and a manual gate valve and a sludge discharge outlet installed at the end of the sludge discharge main pipe; each sludge discharge branch pipe is equipped with a diaphragm sludge discharge valve, and the control air pipes of all the diaphragm sludge discharge valves are connected in parallel to a centralized air control box, which is installed on the outer wall of the integrated box body.

[0013] As a further embodiment of the present invention: the granular activated carbon filler layer is composed of stacked columnar activated carbon with a particle size of 3-5 mm and a thickness of 800-1200 mm; the porous support plate is a steel plate with a thickness of 8 mm, and the plate is uniformly provided with round holes with a diameter of 10 mm, with an opening rate of 30%. The porous support plate is welded to the inner side of the four walls of the COD deep removal zone, and is 300 mm away from the flat bottom structure 13; the pressure plate grid is a stainless steel wire woven mesh with a mesh size of 2 mm × 2 mm. The pressure plate grid is fixed to the inner side of the four walls of the COD deep removal zone by the surrounding angle steel frame, and is 400 mm away from the top wall.

[0014] As a further embodiment of the present invention: the cleaning component includes an air distribution perforated pipe installed at the bottom of the COD deep removal zone. The air distribution perforated pipe is a horizontally arranged rectangular annular pipe. The four corners of the rectangular annular pipe are fixed to the lower surface of the porous support plate by U-shaped clamps. The lower side of the rectangular annular pipe is evenly provided with air distribution holes 93 with a diameter of 3 mm and a hole spacing of 50 mm. The air distribution perforated pipe is connected to an external fan through an air inlet pipe passing through the side wall of the integrated housing.

[0015] As a further embodiment of the present invention: the integrated housing has a length of 8-12 meters, a width of 2.5-4 meters, and a height of 2-3 meters; the water passage gap 311 at the top of the first longitudinal partition is 150-250 mm; the bottom edge of the rectangular water passage hole at the bottom of the second longitudinal partition is 400-500 mm from the flat bottom structure; the water passage at the top of the third longitudinal partition is 200-300 mm; the height of the bottom flow stabilizing layer is 500-600 mm, and the height of the upper water collection layer is 300-400 mm.

[0016] The present invention has the following advantages: 1. Highly integrated and compact structure: The four functional units of hardening removal, coagulation, sedimentation and adsorption are integrated into the same box, reducing the floor space by more than 50% compared with traditional split-type devices. It also adopts a fully enclosed structure, with no volatile pollutants escaping.

[0017] 2. Enhanced hydraulic mixing without the need for a stirring motor: Except for the hard reaction zone which adopts a pure hydraulic vortex structure of “cone + turbulence cone”, the wastewater is accelerated when passing through the bottom inlet cone (211) and forms strong turbulence after impacting the turbulence cone (215), which fully mixes with the lime slurry. No additional electric stirrer is needed, which is energy-saving and maintenance-free.

[0018] 3. Baffled coagulation with high reagent utilization: The coagulation and flocculation zone adopts an alternating upper and lower baffle design, and the wastewater flows in an "S" shape along the baffle channel, extending the reaction path by more than 1.5 times. At the same time, it is combined with point-by-point dosing (polyaluminum chloride first, polyacrylamide later) to ensure that the reagents are in full contact with the wastewater, reducing the reagent dosage by 15% to 20%.

[0019] 4. Excellent hydraulic conditions in the sedimentation zone: The combination of inclined tube sedimentation and sawtooth overflow weir is adopted. The hexagonal honeycomb inclined tube (431) improves the sedimentation efficiency and the surface load can reach 2.5~3.5 m³ / (m²·h); the sawtooth overflow weir (45) can collect the supernatant evenly, avoid short-circuiting and foam carry-out, and ensure that the suspended solids in the sedimentation effluent are less than 20 mg / L.

[0020] 5. Integrated COD deep removal and regeneration: The granular activated carbon packing layer (52) is used to adsorb residual COD. At the same time, the bottom gas distribution perforated pipe (91) can periodically introduce compressed air or water vapor to regenerate the activated carbon, extending the replacement cycle by 3 to 5 times and reducing operating costs.

[0021] 6. Reliable pneumatic control of the sludge discharge system: The diaphragm sludge discharge valve (75) is centrally pneumatically controlled to avoid the risk of electrical failure of the electric valve. It is suitable for the high humidity and corrosive environment of the coking plant. Each pyramidal sludge collection hopper (61, 62, 63) discharges sludge independently and can be emptied in sections at regular intervals to prevent sludge from decaying and floating.

[0022] 7. Fully mechanical structure with very few electronic components: Except for the addition of a level gauge when necessary, the core reaction unit operates by gravity flow and fluid kinetic energy. There are no pumps, no agitators, and no online sensors, resulting in a low failure rate. It is especially suitable for coking plants with high explosion-proof requirements. Attached Figure Description

[0023] Figure 1 This is a front view of the overall internal structure of an embodiment of the present invention.

[0024] Figure 2 This is a schematic diagram of the internal structure of the first-stage cyclone mixer in an embodiment of the present invention.

[0025] Figure 3 This is a schematic diagram of the lime slurry dosing ring pipe in an embodiment of the present invention.

[0026] Figure 4 This is a schematic diagram of the inclined tube packing layer in an embodiment of the present invention.

[0027] In the picture: 1. Integrated housing; 11. Water inlet; 12. Water outlet; 13. Flat bottom structure; 14. Sludge discharge port; 2. Hard reaction zone; 21. First-stage cyclone mixer; 211. Bottom inlet cone; 212. Middle guide tube; 213. Top diffuser cone; 214. Cross support; 215. Turbulence cone; 22. Lime slurry dosing ring; 221. Hanger; 222. Dosing port; 223. Lime slurry dosing pipe; 3. Coagulation and flocculation zone; 31. First longitudinal baffle; 311. Water passage gap; 32. Downflow baffle; 33. Upflow baffle; 34. Polyaluminum chloride dosing loop; 35. Polyacrylamide dosing loop; 4. Inclined tube sedimentation zone; 41. Second longitudinal baffle; 411. Rectangular water passage hole; 42. Bottom flow stabilizing layer; 43. Inclined tube packing layer; 431. Hexagonal honeycomb inclined tube; 44. Upper water collection layer; 45. Sawtooth overflow weir; 5. COD deep removal zone; 51. Third longitudinal baffle; 511. Water passage; 52. Granular activated carbon packing layer; 521. Columnar activated carbon; 53. Porous support plate; 531. Circular holes; 54. Pressure plate grid; 541. Angle steel frame; 6. Mud collection hopper; 61. First pyramidal mud collection hopper; 62. Second pyramidal mud collection hopper; 63. Third pyramidal mud collection hopper; 611. Mud outlet; 7. Sludge discharge pipeline; 71. Sludge discharge branch pipe; 72. Sludge discharge main pipe; 73. Manual gate valve; 74. Sludge discharge outlet; 75. Diaphragm sludge discharge valve; 76. Control air pipe; 77. Centralized air control box; 8. Water collection tank; 9. Cleaning components; 91. Air distribution perforated pipe; 92. U-shaped clamp; 93. Air distribution hole; 94. Air inlet pipe. Detailed Implementation

[0028] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0029] The technical solution of the present invention will be further described in detail below with reference to specific embodiments.

[0030] Example 1: Please refer to Figures 1 to 4 An integrated pretreatment device for coking wastewater reuse includes: An integrated box 1 is a rectangular horizontal sealed container, which is divided into hardness removal reaction zone 2, coagulation and flocculation zone 3, inclined tube sedimentation zone 4 and COD deep removal zone 5 along the water flow direction. The hardening reaction zone 2 is located inside the left end of the integrated box 1 and is directly connected to the water inlet 11 located on the upper left side wall of the integrated box 1. The hardening reaction zone 2 is equipped with a first-stage vortex mixer 21 and a lime slurry dosing ring pipe 22 installed at the top of the hardening reaction zone 2. The coagulation and flocculation zone 3 is located to the right of the hardening reaction zone 2, and the two are separated by a first longitudinal baffle 31. A water passage gap 311 is left between the top of the first longitudinal baffle 31 and the top wall of the integrated box 1. Downflow baffles 32 and upflow baffles 33 are alternately arranged along the height direction in the coagulation and flocculation zone 3. Polyaluminum chloride dosing ring pipe 34 and polyacrylamide dosing ring pipe 35 are installed on the top of the coagulation and flocculation zone 3. The inclined tube sedimentation zone 4 is located to the right of the coagulation and flocculation zone 3, and the two are separated by a second longitudinal partition 41. The second longitudinal partition 41 is welded and sealed to the top wall of the integrated box 1, and a rectangular water passage hole 411 is provided at its lower part. The interior of the inclined tube sedimentation zone 4 includes, from bottom to top, a bottom flow stabilizing layer 42, a middle inclined tube packing layer 43, and an upper water collection layer 44. A sawtooth overflow weir 45 is installed at the top of the inclined tube sedimentation zone 4. The COD deep removal zone 5 is located to the right of the inclined tube sedimentation zone 4, and the two are separated by a third longitudinal partition 51. A water passage 511 is left between the top of the third longitudinal partition 51 and the top wall of the integrated box 1. The COD deep removal zone 5 is filled with a granular activated carbon packing layer 52. A porous support plate 53 is provided below the granular activated carbon packing layer 52, and a pressure plate grid 54 is provided above it. An outlet collection tank 8 is installed at the top of the COD deep removal zone 5 near the right side wall. The right side wall of the outlet collection tank 8 is shared with the right side wall of the integrated box 1, and an outlet pipe 12 is opened on the shared wall. The mud collection hopper 6 and mud discharge pipe 7 are located at the bottom of the integrated box 1; And the cleaning component 9 installed at the bottom of the COD deep removal zone 5.

[0031] The first-stage cyclone mixer 21 comprises, from bottom to top, a bottom inlet cone 211, a middle guide tube 212, and a top diffuser cone 213. The bottom inlet cone 211 is a frustum shape with a larger top and a smaller bottom, and its lower edge is sealed to the inner wall of the inlet pipe 11 by a flange. The middle guide tube 212 is a cylindrical shell, and its lower edge is welded to the upper edge of the bottom inlet cone 211. The top diffuser cone 213 is a frustum shape with a smaller top and a larger bottom, and its lower edge is welded to the upper edge of the middle guide tube 212. The upper edge opening of the top diffuser cone 213 serves as the water outlet. A turbulence cone 215 is fixedly installed at the center of the bottom inlet cone 211 by a cross bracket 214. The turbulence cone 215 is a cone with its tip pointing downwards and its bottom surface pointing upwards. The cross bracket 214 is made of three or four flat steel bars welded radially, with its outer end welded to the inner wall of the bottom water inlet cone 211 and its inner end welded to the center of the bottom surface of the turbulence cone 215.

[0032] The lime slurry dosing ring pipe 22 is a horizontally placed annular circular pipe, fixed to the inner side of the top wall of the integrated housing 1 by a hanger 221. The inner side of the lime slurry dosing ring pipe 22 has 6-8 dosing holes 222 evenly distributed, with the dosing holes 222 facing the central axis of the top diffusion cone 213. The lime slurry dosing ring pipe 22 is connected to an external lime slurry storage tank through an external lime slurry dosing pipe 223 passing through the top wall of the integrated housing 1. The polyaluminum chloride dosing ring pipe 34 and the polyacrylamide dosing ring pipe 35 have the same structure and fixing method as the lime slurry dosing ring pipe 22, and are installed in the front and rear halves of the coagulation and flocculation zone 3, respectively. All dosing ring pipes are made of corrosion-resistant polypropylene (PP) or polyvinyl chloride (PVC), and the hanger 221 is made of stainless steel.

[0033] The downstream baffle 32 is a rectangular flat plate, vertically welded to the inner side of the top wall of the integrated housing 1, with its lower edge 300-400 mm from the flat bottom structure 13 of the integrated housing 1. The upstream baffle 33 is a rectangular flat plate, vertically welded to the flat bottom structure 13 of the integrated housing 1, with its upper edge 300-400 mm from the inner side of the top wall. The downstream baffle 32 and the upstream baffle 33 are alternately arranged along the water flow direction, with a total of 3-5 sets. The width of all baffles is the same as the internal width of the integrated housing 1, and the two sides of the baffles are welded and sealed to the front and rear inner walls of the housing to prevent short circuits in the water flow.

[0034] The central inclined tube packing layer 43 is composed of several sets of hexagonal honeycomb inclined tubes 431 made of polypropylene. The length of each hexagonal honeycomb inclined tube 431 is 1000 mm, the inclination angle is 60 degrees, and the lower end faces the water inlet direction. The sawtooth overflow weir 45 is formed by bending stainless steel plate, with a cross-section of continuous isosceles triangular teeth, a tooth height of 50 mm, and a tooth base width of 100 mm. The sawtooth overflow weir 45 is welded and fixed horizontally between the front and rear inner walls of the integrated housing 1, with its top edge horizontal and at the same elevation. The installation height of the sawtooth overflow weir 45 is 200-300 mm higher than the upper end face of the hexagonal honeycomb inclined tubes 431.

[0035] The integrated housing 1 has a flat bottom structure 13 with several sludge discharge ports 14 along its length. The sludge collection hopper 6 includes a first pyramidal sludge collection hopper 61, a second pyramidal sludge collection hopper 62, and a third pyramidal sludge collection hopper 63, respectively located at the bottom of the hardening reaction zone 2, the coagulation and flocculation zone 3, and the inclined tube sedimentation zone 4. Each pyramidal sludge collection hopper is a four-sided pyramid shell that is larger at the top and smaller at the bottom. Its upper opening is welded to the sludge discharge ports 14 on the flat bottom structure 13, and its lower tip has a sludge outlet 611. The angle between the four side edges of each pyramidal sludge collection hopper and the horizontal plane is not less than 55 degrees to ensure that the sludge can smoothly slide down to the sludge outlet 611 by gravity.

[0036] The sludge discharge pipeline 7 includes sludge discharge branch pipes 71 connected to each sludge outlet 611, a main sludge discharge pipe 72 connecting all the sludge discharge branch pipes 71, and a manual gate valve 73 and a sludge discharge outlet 74 installed at the end of the main sludge discharge pipe 72. Each sludge discharge branch pipe 71 is equipped with a diaphragm sludge discharge valve 75. The control air pipes 76 of all the diaphragm sludge discharge valves 75 are connected in parallel and then connected to a centralized air control box 77, which is installed on the outer wall of the integrated housing 1. The centralized air control box 77 has a main air inlet and a number of branch valves equal to the number of diaphragm sludge discharge valves 75, for independent or sequential control of each diaphragm sludge discharge valve 75.

[0037] The granular activated carbon packing layer 52 is composed of stacked columnar activated carbon 521 with a particle size of 3-5 mm, and has a thickness of 800-1200 mm. The porous support plate 53 is an 8 mm thick steel plate with uniformly distributed circular holes 531 with a diameter of 10 mm, resulting in an opening rate of 30%. This porous support plate 53 is welded to the inner sides of the four walls of the COD deep removal zone 5, 300 mm away from the flat bottom structure 13. The pressure plate grid 54 is a stainless steel wire woven mesh with a mesh size of 2 mm × 2 mm. This pressure plate grid 54 is fixed to the inner sides of the four walls of the COD deep removal zone 5 by angle steel frames 541 around it, 400 mm away from the top wall. The upper surface of the porous support plate 53 is also covered with a layer of stainless steel filter screen with a pore size of 0.5 mm (not shown in the figure) to prevent the columnar activated carbon 521 from leaking out of the circular holes 531.

[0038] The cleaning component 9 includes an air distribution perforated pipe 91 installed at the bottom of the COD deep removal zone 5. The air distribution perforated pipe 91 is a horizontally arranged rectangular annular pipe. The four corners of the rectangular annular pipe are fixed to the lower surface of the porous support plate 53 by U-shaped clamps 92. Air distribution holes 93 with a diameter of 3 mm are evenly opened on the lower side of the rectangular annular pipe, with a hole spacing of 50 mm. The air distribution perforated pipe 91 is connected to an external fan through an air inlet pipe 94 passing through the side wall of the integrated housing 1. A manually adjustable valve (not shown in the figure) is installed on the air inlet pipe 94 to control the air intake.

[0039] Example 2: Based on Example 1, the integrated housing 1 has a length of 8-12 meters, a width of 2.5-4 meters, and a height of 2-3 meters; the water passage gap 311 at the top of the first longitudinal partition 31 is 150-250 mm; the bottom edge of the rectangular water passage hole 411 at the bottom of the second longitudinal partition 41 is 400-500 mm from the flat bottom structure 13; the water passage 511 at the top of the third longitudinal partition 51 is 200-300 mm; the height of the bottom flow stabilizing layer 42 is 500-600 mm, and the height of the upper water collection layer 44 is 300-400 mm.

[0040] Working principle: Coking wastewater enters the hardening reaction zone 2 from the inlet pipe 11 via a booster pump at a flow rate of 0.5~0.8 m / s. The water first enters the bottom inlet cone 211, where the flow velocity increases to 1.5~2.0 m / s as the cone's cross-section gradually narrows. The high-speed water flow impacts the tip of the turbulence cone 215 and then spreads outwards, forming a strong turbulence zone. Simultaneously, lime slurry from the external lime slurry storage tank is fed into the lime slurry dosing ring pipe 22 through the lime slurry dosing pipe 223, and is sprayed radially into the center of the turbulence zone from the dosing holes 222, instantly mixing evenly with the wastewater. The mixture continues upwards, flowing out through the central guide tube 212 and the top diffusion cone 213 before being decelerated, and enters the coagulation and flocculation zone 3. During this process, calcium ions react with bicarbonate ions in the wastewater to form calcium carbonate precipitate, reducing hardness.

[0041] Wastewater enters the coagulation and flocculation zone 3 through the water passage gap 311 at the top of the first longitudinal baffle 31. Coaluminum chloride dosing loop 34 and polyacrylamide dosing loop 35 are used to add coagulant and coagulant aid, respectively. The wastewater flows in a "down-up-down" path in the baffle channel, undergoing a change in flow direction and velocity redistribution after each set of baffles. The total residence time is 15-20 minutes, ensuring sufficient floc growth.

[0042] The coagulated effluent enters the inclined tube sedimentation zone 4 through the rectangular water passage 411 at the bottom of the second longitudinal baffle 41. It first enters the bottom stabilizing layer 42 for energy dissipation, and then rises into the hexagonal honeycomb inclined tube 431. The flocs settle to the bottom in the inclined tube by gravity and slide into the third pyramidal sludge collection hopper 63. The clear water continues to rise and overflows evenly through the sawtooth overflow weir 45, entering the COD deep removal zone 5.

[0043] The effluent from the sedimentation process enters the COD deep removal zone 5 through the water passage 511 at the top of the third longitudinal baffle 51. It flows from top to bottom through the granular activated carbon packing layer 52, where the residual COD is adsorbed by the activated carbon. The effluent is then discharged from the outlet 12 through the effluent collection tank 8 and enters the subsequent greywater reuse system (such as a reverse osmosis system).

[0044] Every 4-8 hours, operate the centralized air control box 77 to sequentially open each diaphragm sludge discharge valve 75, discharging the sludge from the first pyramidal sludge collection hopper 61, the second pyramidal sludge collection hopper 62, and the third pyramidal sludge collection hopper 63 through the sludge discharge branch pipe 71 and the sludge discharge main pipe 72. When the granular activated carbon packing layer 52 is saturated (usually 3-6 months), close the outlet valve and introduce compressed air at 0.2-0.3 MPa through the air inlet pipe 94. The air evenly impacts the activated carbon layer through the air distribution holes 93 of the air distribution perforated pipe 91, flushing down the trapped suspended solids and some organic matter, which are then discharged with the backwash water, achieving simple regeneration of the activated carbon. During backwashing, the backwash wastewater is discharged from the outlet pipe 12 or a separately installed backwash drain pipe (not shown in the figure).

Claims

1. An integrated pretreatment device for coking wastewater reuse, characterized in that, include: An integrated box (1) is a rectangular horizontal sealed container, which is divided into a hardness removal reaction zone (2), a coagulation and flocculation zone (3), an inclined tube sedimentation zone (4) and a COD deep removal zone (5) in sequence along the water flow direction. The hardening reaction zone (2) is located at the left end inside the integrated box (1) and is directly connected to the water inlet (11) opened on the upper part of the left side wall of the integrated box (1). The hardening reaction zone (2) is equipped with a first-stage vortex mixer (21) and a lime milk dosing ring pipe (22) installed on the top of the hardening reaction zone (2). The coagulation and flocculation zone (3) is located to the right of the hardening reaction zone (2), and the two are separated by a first longitudinal baffle (31). A water passage gap (311) is left between the top of the first longitudinal baffle (31) and the top wall of the integrated box (1). Downflow baffles (32) and upflow baffles (33) are alternately arranged along the height direction in the coagulation and flocculation zone (3). A polyaluminum chloride dosing ring pipe (34) and a polyacrylamide dosing ring pipe (35) are installed on the top of the coagulation and flocculation zone (3). The inclined tube sedimentation zone (4) is located on the right side of the coagulation and flocculation zone (3), and the two are separated by a second longitudinal partition (41). The second longitudinal partition (41) is welded and sealed to the top wall of the integrated box (1), and a rectangular water passage hole (411) is provided at its lower part. The interior of the inclined tube sedimentation zone (4) includes, from bottom to top, a bottom flow stabilizing layer (42), a middle inclined tube packing layer (43), and an upper water collection layer (44). A sawtooth overflow weir (45) is installed on the top of the inclined tube sedimentation zone (4). The COD deep removal zone (5) is located to the right of the inclined tube sedimentation zone (4), and the two are separated by a third longitudinal partition (51). A water passage (511) is left between the top of the third longitudinal partition (51) and the top wall of the integrated box (1). The COD deep removal zone (5) is filled with a granular activated carbon packing layer (52). A porous support plate (53) is provided below the granular activated carbon packing layer (52), and a pressure plate grid (54) is provided above it. An outlet collection tank (8) is installed at the top of the COD deep removal zone (5) near the right side wall. The right side wall of the outlet collection tank (8) is shared with the right side wall of the integrated box (1), and an outlet pipe (12) is opened on the shared wall. The mud collection hopper (6) and mud discharge pipe (7) are located at the bottom of the integrated box (1). And a cleaning component (9) installed at the bottom of the COD deep removal zone (5).

2. The integrated pretreatment device for coking wastewater reuse according to claim 1, characterized in that, The first-stage vortex mixer (21) includes, from bottom to top, a bottom inlet cone (211), a middle guide cylinder (212), and a top diffuser cone (213). The bottom inlet cone (211) is a frustum shape with a larger top and a smaller bottom. Its lower edge is sealed to the inner wall of the inlet pipe (11) by a flange. The middle guide cylinder (212) is a cylindrical shell. Its lower edge is welded to the upper edge of the bottom inlet cone (211). The top diffuser cone (213) is a frustum shape with a smaller top and a larger bottom. Its lower edge is welded to the upper edge of the middle guide cylinder (212). The upper edge opening of the top diffuser cone (213) serves as the outlet. A turbulence cone (215) is fixedly installed in the center of the bottom inlet cone (211) by a cross bracket (214). The turbulence cone (215) is a cone with its tip pointing downwards and its bottom surface pointing upwards.

3. The integrated pretreatment device for coking wastewater reuse according to claim 1, characterized in that, The lime slurry dosing ring pipe (22) is a ring-shaped circular pipe, placed horizontally, and fixed to the inner side of the top wall of the integrated box (1) by a hanger (221). The inner side of the lime slurry dosing ring pipe (22) is evenly provided with 6 to 8 dosing holes (222), and the dosing holes (222) face the central axis of the top diffusion cone (213). The lime slurry dosing ring pipe (22) is connected to the external lime slurry storage tank through the top wall of the integrated box (1) via an external lime slurry dosing pipe (223). The structure and fixing method of the polyaluminum chloride dosing ring pipe (34) and polyacrylamide dosing ring pipe (35) are the same as those of the lime slurry dosing ring pipe (22), and they are installed in the first half and the second half of the coagulation and flocculation zone (3), respectively.

4. The integrated pretreatment device for coking wastewater reuse according to claim 1, characterized in that, The downflow baffle (32) is a rectangular flat plate, which is vertically welded to the inner side of the top wall of the integrated box (1), and its lower edge is 300-400 mm away from the flat bottom structure (13) of the integrated box (1); the upflow baffle (33) is a rectangular flat plate, which is vertically welded to the inner bottom wall of the integrated box (1), and its upper edge is 300-400 mm away from the inner side of the top wall; the downflow baffle (32) and the upflow baffle (33) are alternately arranged along the water flow direction, and a total of 3-5 sets are arranged.

5. The integrated pretreatment device for coking wastewater reuse according to claim 1, characterized in that, The middle inclined tube packing layer (43) is composed of several groups of hexagonal honeycomb inclined tubes (431) made of polypropylene. The length of the hexagonal honeycomb inclined tube (431) is 1000 mm, the inclination angle is 60 degrees, and the lower end faces the water inlet direction. The sawtooth overflow weir (45) is formed by bending stainless steel plate. The cross section is a continuous isosceles triangular tooth shape with a tooth height of 50 mm and a tooth base width of 100 mm. The sawtooth overflow weir (45) is welded and fixed in the horizontal direction between the front and rear inner walls of the integrated box (1). Its top edge is horizontal and located at the same elevation.

6. The integrated pretreatment device for coking wastewater reuse according to claim 1, characterized in that, The bottom of the integrated box (1) is a flat bottom structure (13), and several sludge discharge ports (14) are opened along the length direction of the flat bottom structure (13); the sludge collection hopper (6) includes a first pyramidal sludge collection hopper (61), a second pyramidal sludge collection hopper (62), and a third pyramidal sludge collection hopper (63) respectively corresponding to the bottom of the hardening reaction zone (2), the coagulation and flocculation zone (3) and the inclined tube sedimentation zone (4). Each pyramidal sludge collection hopper is a four-sided pyramid shell with a larger upper part and a smaller lower part. Its upper opening is welded to the sludge discharge port (14) on the flat bottom structure (13), and the lower tip is opened to discharge sludge (611).

7. The integrated pretreatment device for coking wastewater reuse according to claim 6, characterized in that, The sludge discharge pipeline (7) includes a sludge discharge branch pipe (71) connected to each sludge outlet (611), a sludge discharge main pipe (72) that connects all the sludge discharge branch pipes (71), and a manual gate valve (73) and a sludge discharge outlet (74) installed at the end of the sludge discharge main pipe (72); each sludge discharge branch pipe (71) is equipped with a diaphragm sludge discharge valve (75), and the control air pipes (76) of all the diaphragm sludge discharge valves (75) are connected in parallel to a centralized air control box (77), which is installed on the outer wall of the integrated box (1).

8. The integrated pretreatment device for coking wastewater reuse according to claim 1, characterized in that, The granular activated carbon filler layer (52) is made of stacked columnar activated carbon (521) with a particle size of 3-5 mm and a thickness of 800-1200 mm; the porous support plate (53) is a steel plate with a thickness of 8 mm and evenly opened with round holes (531) with a diameter of 10 mm, with an opening rate of 30%. The porous support plate (53) is welded to the inner side of the four walls of the COD deep removal zone (5) and is 300 mm away from the flat bottom structure (13); the pressure plate grid (54) is a stainless steel wire woven mesh with a mesh size of 2 mm × 2 mm. The pressure plate grid (54) is fixed to the inner side of the four walls of the COD deep removal zone (5) by the surrounding angle steel frame (541) and is 400 mm away from the top wall.

9. The integrated pretreatment device for coking wastewater reuse according to claim 1, characterized in that, The cleaning component (9) includes an air distribution perforated pipe (91) installed at the bottom of the COD deep removal zone (5). The air distribution perforated pipe (91) is a horizontally arranged rectangular annular pipe. The four corners of the rectangular annular pipe are fixed to the lower surface of the porous support plate (53) by U-shaped clamps (92). The lower side of the rectangular annular pipe is evenly provided with air distribution holes (93) with a diameter of 3 mm and a hole spacing of 50 mm. The air distribution perforated pipe (91) is connected to an external fan through an air inlet pipe (94) passing through the side wall of the integrated housing (1).

10. The integrated pretreatment device for coking wastewater reuse according to claim 1, characterized in that, The integrated box (1) is 8-12 meters long, 2.5-4 meters wide, and 2-3 meters high; the water passage gap (311) at the top of the first longitudinal partition (31) is 150-250 mm; the bottom edge of the rectangular water passage hole (411) at the bottom of the second longitudinal partition (41) is 400-500 mm from the flat bottom structure (13); the water passage (511) at the top of the third longitudinal partition (51) is 200-300 mm; the bottom flow stabilizing layer (42) is 500-600 mm high, and the upper water collection layer (44) is 300-400 mm high.

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