Steelmaking wastewater recovery treatment circulating system for steel plant

Abstract

The invention discloses a steelmaking wastewater recovery treatment circulation system for a steel plant, which comprises a liquid recovery module, a gas recovery module, a cooling circulation module, a coarse filtration module and a flocculent precipitation module, and the liquid recovery module comprises a liquid pump, and the invention relates to the technical field of steelmaking. According to the steelmaking wastewater recycling and treating circulating system for the steel plant, the liquid recycling module, the gas recycling module, the cooling circulating module, the coarse filtering module and the flocculent precipitation module are arranged, and the different modules can respectively form an indirect cooling water circulating system and a direct cooling water and washing wastewater circulating system; cooling water or washing water which is generated in different procedures and contains various different impurities is fully purified through the two systems respectively, it is guaranteed that the cooling water or the washing water can be put into the circulating system after meeting the discharge requirement, the multiple modules act jointly, waste water in the different procedures is treated respectively, and the waste water treatment efficiency is improved. And the waste of resources is reduced while the treatment effect is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of steelmaking, and particularly to a steelmaking wastewater recycling and treatment circulation system for a steel mill. Background Art

[0002] Ironmaking is a process of extracting metallic iron from iron-containing minerals (mainly iron oxides), mainly including the blast furnace method, direct reduction method, smelting reduction method, and plasma method. From a metallurgical perspective, ironmaking is the reverse behavior of iron rusting and gradual mineralization. Simply put, it is to reduce pure iron from iron-containing compounds.

[0003] During the process of steelmaking, cooling water is required for cooling in multiple steps. In some processes, the cooling water flows in pipelines and has no direct contact with the heat source. This part of the cooling water is indirect cooling water. There is also some cooling water directly sprayed on the surface of steel billets or equipment, and this part of the cooling water is direct cooling water. In addition to cooling water, pickling and ordinary cleaning are also required during steelmaking, and a large amount of water is used in these processes. The wastewater generated in different processes often requires different treatment methods, while the existing wastewater treatment circulation systems often have only one treatment and circulation structure, which cannot meet the treatment needs of steelmaking wastewater. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the present invention provides a steelmaking wastewater recycling and treatment circulation system for a steel mill, which solves the problem that the wastewater generated in different processes of steelmaking often requires different treatment methods, while the existing wastewater treatment circulation systems often have only one treatment and circulation structure and cannot meet the treatment needs of steelmaking wastewater.

[0005] To achieve the above objectives, the present invention is realized through the following technical solutions: A steelmaking wastewater recycling and treatment circulation system for a steel mill includes a liquid recovery module, a gas recovery module, a cooling circulation module, a coarse filtration module, and a flocculation precipitation module;

[0006] The liquid recovery module includes a liquid pump, and a suction pipe and a delivery pipe are respectively connected to the inlet and outlet of the liquid pump;

[0007] The gas recovery module includes a condensation box. A plurality of connecting frames are fixedly connected inside the condensation box. The bottom ends of the plurality of connecting frames are fixedly connected with a bent condensation pipe. Both ends of the condensation pipe penetrate through the top end of the condensation box and extend outward. A gas collecting pipe is horizontally connected to one side surface of the condensation box. The other end of the gas collecting pipe bends downward and expands to form a gas collecting hopper. An exhaust fan is fixedly connected inside the gas collecting hopper. A drain port is vertically penetrated and opened in the middle of the bottom end of the condensation box. A water tank with an open top is arranged at the bottom end of the condensation box. A water outlet pipe is horizontally connected to the bottom end of one side surface of the water tank.

[0008] Further, the cooling cycle module includes a circulation tank with a hollow interior. At the top and bottom of the middle part of the inner cavity of the circulation tank, a plurality of upper partitions and a plurality of lower partitions are respectively vertically and fixedly connected. The plurality of upper partitions and the plurality of lower partitions are arranged at intervals. Both ends inside the circulation tank are fixedly connected with hollow frames with a hollow interior through connection blocks. Horizontally communicated with a plurality of connecting pipes inside one of the hollow frames. The other ends of the plurality of connecting pipes penetrate through the plurality of upper partitions and the plurality of lower partitions and communicate with the other hollow frame. Vertically communicated with inlet and outlet pipes at the top of both hollow frames. The top ends of the two inlet and outlet pipes penetrate through the upper surface of the circulation tank and extend upward. Liquid inlet and outlet openings are respectively penetrated and opened at both ends of the circulation tank.

[0009] Further, the coarse filtration module includes a main pipeline. The middle part of the main pipeline expands outward to form a spherical shape. Vertically communicated with a riser pipe with a closed top at the top of the middle part of the main pipeline. Vertically fixedly connected with a filter screen cylinder inside the riser pipe. Fixedly connected with a connecting ring at the front end inside the main pipe. The rear end surface of the connecting ring is fixedly connected with a filter screen pipe. The other end of the filter screen pipe communicates with the inside of the filter screen cylinder.

[0010] Further, a screw conveyor located inside the filter screen cylinder and coaxial and adapted to it is vertically rotatably connected to the bottom inside the riser pipe. Vertically fixedly connected with a plurality of support rods at the outer edge of the top of the riser pipe. Horizontally fixedly connected with a top plate at the top of the plurality of support rods. Fixedly connected with a first motor at the top of the top plate. The output shaft of the first motor rotatably penetrates through the top plate and the top of the riser pipe and is fixedly connected with the top end of the rotating shaft of the screw conveyor.

[0011] Further, the flocculation and sedimentation module includes a flocculation tank. Horizontally fixedly connected with a plurality of zigzag plates at the top and bottom inside the flocculation tank. Horizontally fixedly connected with a plurality of second motors on one side surface of the flocculation tank. The output shafts of the plurality of second motors rotatably penetrate through the side surface of the flocculation tank and extend into it. Horizontally fixedly connected with rotating shafts at the outer ends of the output shafts of the plurality of second motors. The other ends of the plurality of rotating shafts rotatably penetrate through the plurality of zigzag plates and extend to the other end of the flocculation tank. Stirring blades are fixedly connected on the outer surfaces of the plurality of rotating shafts and between every two adjacent zigzag plates.

[0012] Further, a sedimentation tank with an open top is fixedly connected to the rear end of the flocculation tank. Horizontally penetrated and opened at the lower part of the rear end surface of the flocculation tank with a communication port communicating with the sedimentation tank.

[0013] Further, the liquid recovery module and the cooling cycle module are combined to form an indirect cooling water circulation system.

[0014] Furthermore, the liquid recovery module, the gaseous recovery module, the coarse filtration module, and the flocculation sedimentation module are combined to form a direct cooling water and washing wastewater circulation system.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows. In the steelmaking wastewater recovery and treatment circulation system for steel mills, by setting up a liquid recovery module, a gaseous recovery module, a cooling circulation module, a coarse filtration module, and a flocculation sedimentation module, the liquid recovery module and the cooling circulation module form a circulation system for indirect cooling water. The indirect cooling water is sent to the cooling circulation module through the liquid recovery module for heat exchange and cooling, and then directly returns to the circulation system. This not only has high efficiency but also consumes less resources. The liquid recovery module, the gaseous recovery module, the coarse filtration module, and the flocculation sedimentation module can form a circulation system for direct cooling water. Through the coarse filtration of the coarse filtration module and the flocculation and sedimentation of the flocculation sedimentation module, the cooling water or washing water containing various impurities generated in different processes can be fully purified to ensure that they can meet the discharge requirements before being put into the circulation system. The multiple modules work together to separately treat the wastewater from different processes, reducing resource waste while ensuring the treatment effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the system of the present invention;

[0017] Figure 2 It is a schematic structural diagram of the indirect cooling water circulation system of the present invention;

[0018] Figure 3 It is a schematic structural diagram of the direct cooling water and washing wastewater circulation system of the present invention;

[0019] Figure 4 It is a schematic structural diagram of the liquid recovery module of the present invention;

[0020] Figure 5 It is a schematic structural diagram of the cooling circulation module of the present invention;

[0021] Figure 6 It is a schematic structural diagram of the gaseous circulation module of the present invention;

[0022] Figure 7 It is a schematic structural diagram of the coarse filtration module of the present invention;

[0023] Figure 8 It is a schematic structural diagram of the flocculation sedimentation module of the present invention.

[0024] In the figure: 1 - Liquid recovery module, 11 - Liquid pump, 12 - Suction pipe, 13 - Water supply pipe, 2 - Gas recovery module, 21 - Condensation box, 22 - Condensation pipe, 23 - Gas collecting pipe, 24 - Gas collecting hopper, 25 - Exhaust fan, 26 - Water tank, 27 - Outlet pipe, 3 - Cooling circulation module, 31 - Circulation box, 32 - Upper partition board, 33 - Lower partition board, 34 - Connecting pipe, 35 - Hollow frame, 36 - Inlet and outlet pipe, 37 - Liquid inlet, 38 - Liquid outlet, 4 - Coarse filtration module, 41 - Main pipeline, 42 - Vertical pipe, 43 - Filter screen cylinder, 44 - Connecting ring, 45 - Filter screen pipe, 46 - Sewage outlet, 47 - Support rod, 48 - Top plate, 49 - First motor, 410 - Auger, 5 - Flocculation and precipitation module, 51 - Flocculation tank, 52 - Zigzag plate, 53 - Second motor, 54 - Rotating shaft, 55 - Stirring blade, 56 - Sedimentation tank, 57 - Connecting port. Detailed implementation manners

[0025] 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 creative efforts shall fall within the protection scope of the present invention.

[0026] Please refer to Figure 1-8 , the present invention provides a technical solution: a steelmaking wastewater recycling and treatment circulation system for a steel mill, including a liquid recovery module 1, a gas recovery module 2, a cooling circulation module 3, a coarse filtration module 4, and a flocculation and precipitation module 5;

[0027] The liquid recovery module 1 and the cooling circulation module 3 are combined to form an indirect cooling water circulation system.

[0028] The liquid recovery module 1 includes a liquid pump 11, and the water inlet and outlet of the liquid pump 11 are respectively communicated with a suction pipe 12 and a water supply pipe 13;

[0029] The cooling circulation module 3 includes a circulation box 31 with a hollow interior. At the top and bottom of the middle cavity of the circulation box 31, a plurality of upper partition boards 32 and a plurality of lower partition boards 33 are respectively vertically fixedly connected. The plurality of upper partition boards 32 and the plurality of lower partition boards 33 are arranged at intervals. Both ends inside the circulation box 31 are fixedly connected with a hollow frame 35 with a hollow interior through a connecting block. The inside of one hollow frame 35 is horizontally communicated with a plurality of connecting pipes 34, and the other ends of the plurality of connecting pipes 34 penetrate through the plurality of upper partition boards 32 and the plurality of lower partition boards 33 and are communicated with the other hollow frame 35. The tops of both hollow frames 35 are vertically communicated with an inlet and outlet pipe 36, and the tops of both inlet and outlet pipes 36 penetrate through the upper surface of the circulation box 31 and extend upward. The two ends of the circulation box 31 are respectively penetrated and provided with a liquid inlet 37 and a liquid outlet 38.

[0030] The indirect cooling water used in the steelmaking process does not come into direct contact with the surface of the steel billet or other structures. After use, this part of the cooling water does not contain other substances, and it can be directly cooled during treatment. This system pumps this part of the cooling water into the circulation tank 31 of the cooling circulation module 3 through the liquid pump 11. At the same time, the heat exchange fluid is sent into the hollow frame 35 inside the circulation tank 31 through the inlet and outlet pipes 36. The cooling water entering the circulation tank 31 will exchange heat with the heat exchange fluid in the multiple connecting pipes 34 inside it. While cooling the cooling water, this part of the heat can also be transported out through heat exchange, reducing resource waste.

[0031] The liquid recovery module 1, the gas recovery module 2, the coarse filtration module 4, and the flocculation and precipitation module 5 are combined to form a direct cooling water and washing wastewater circulation system.

[0032] The gas recovery module 2 includes a condensation box 21. Inside the condensation box 21, a plurality of connecting frames are fixedly connected. The bottom ends of the plurality of connecting frames are fixedly connected with a bent condensation pipe 22. Both ends of the condensation pipe 22 penetrate through the top end of the condensation box 21 and extend outward. A gas collecting pipe 23 is horizontally communicated with one side surface of the condensation box 21. The other end of the gas collecting pipe 23 bends downward and expands to form a gas collecting hopper 24. Inside the gas collecting hopper 24, an exhaust fan 25 is fixedly connected. A drain port is vertically penetrated and opened in the middle of the bottom end of the condensation box 21. A water tank 26 with an open top is arranged at the bottom end of the condensation box 21. A water outlet pipe 27 is horizontally communicated with the bottom end of one side surface of the water tank 26.

[0033] The coarse filtration module 4 includes a main pipe 41. The middle part of the main pipe 41 expands to form a spherical shape. A vertically closed riser 42 is vertically communicated with the top end of the middle part of the main pipe 41. Inside the riser 42, a filter screen cylinder 43 is vertically fixedly connected. A connecting ring 44 is fixedly connected to the front end inside the main pipe 41. The rear end surface of the connecting ring 44 is fixedly connected with a filter screen pipe 45. The other end of the filter screen pipe 45 is communicated with the inside of the filter screen cylinder 43.

[0034] At the bottom of the inside of the riser 42, a screw conveyor 410 located inside the filter screen cylinder 43 and coaxial with and adapted to it is vertically rotatably connected. A plurality of support rods 47 are vertically fixedly connected to the outer edge of the top end of the riser 42. The top ends of the plurality of support rods 47 are horizontally fixedly connected with a top plate 48. A first motor 49 is fixedly connected to the top end of the top plate 48. The output shaft of the first motor 49 rotatably penetrates through the top plate 48 and the top end of the riser 42 and is fixedly connected to the top end of the rotating shaft of the screw conveyor 410.

[0035] The cooling water that directly contacts the billet is called direct cooling water. This cooling water will turn into steam after contacting the billet. At this time, it can be recovered by the gaseous recovery module 2. The exhaust fan 25 in the gaseous recovery module 2 continuously operates to absorb the steam into the gas collecting hopper 24, and then enters the inside of the condensation box 21 through the gas collecting pipe 23. A low-temperature fluid continuously flows in the condensation pipe 22 in the condensation box 21, and the steam can condense on the condensation pipe 22 and finally drip into the inside of the water tank 26.

[0036] There is also some washing wastewater, which includes a large amount of slag blocks and impurities. Both it and the direct cooling water need to be filtered through the coarse filtration module 4. After entering the coarse filtration module 4, the impurities in the wastewater will be blocked by the filter screen cylinder 43 and the filter screen pipe 45 and cannot move backward continuously. At the same time, the auger 410 continuously rotates under the drive of the first motor 49, and its rotation can drive the impurities gathered inside the filter screen cylinder 43 to move upward. A plurality of sewage outlets 46 are opened at the top of the riser pipe 42, and these large impurities filtered out can be discharged through the sewage outlets 46.

[0037] After the wastewater passes through the coarse filtration module 4, it will enter the flocculation and precipitation module 5. After entering it, the wastewater will first flow irregularly under the action of a plurality of zigzag plates 52 to ensure its full fusion with the flocculant. And a plurality of second motors 53 continuously operate. Driven by the rotation of the stirring blades 55 they drive, the fluidity of the wastewater in the flocculation tank 51 becomes better, and it can also ensure the effect of its fusion with the flocculant. After passing through the flocculation tank 51, the wastewater will enter the sedimentation tank 56 for sedimentation. A vacuum sewage discharge device is arranged outside the sedimentation tank 56, which can suck away the sedimented sludge.

[0038] In this device, the liquid recovery module 1 and the cooling circulation module 3 form a circulation system for indirect cooling water. The indirect cooling water is sent to the cooling circulation module 3 through the liquid recovery module 1 for heat exchange and cooling, and then directly returns to the circulation system. It has high efficiency and consumes less resources. While the liquid recovery module 1, the gaseous recovery module 2, the coarse filtration module 4 and the flocculation and precipitation module 5 can form a circulation system for direct cooling water. Through the coarse filtration of the coarse filtration module and the flocculation and precipitation of the flocculation and precipitation module, the cooling water or washing water containing various impurities generated in different processes can be fully purified to ensure that they can all meet the discharge requirements before being put into the circulation system. The multiple modules work together to separately treat the wastewater in different processes, reducing the waste of resources while ensuring the treatment effect.

[0039] It should be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprising", "including" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or elements inherent to such process, method, article or device.

[0040] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A steelmaking wastewater recycling and treatment circulation system for a steelmaking plant, characterized in that: It comprises a liquid recovery module (1), a gas recovery module (2), a cooling circulation module (3), a coarse filtration module (4) and a flocculation sedimentation module (5); The liquid recovery module (1) comprises a liquid pump (11), and a water inlet and a water outlet of the liquid pump (11) are respectively connected to a water pumping pipe (12) and a water supply pipe (13); The gas recovery module (2) comprises a condensation box (21), the interior of which is fixedly connected with a plurality of connecting frames, the bottom ends of the plurality of connecting frames being fixedly connected with a bent condensation pipe (22), both ends of the condensation pipe (22) passing through the top end of the condensation box (21) and extending outwards, a side surface of the condensation box (21) being laterally connected with an air collecting pipe (23), the other end of the air collecting pipe (23) being bent downward and expanded outwards to form an air collecting hopper (24), an exhaust fan (25) being fixedly connected inside the air collecting hopper (24), a drainage outlet being vertically penetrated in the middle of the bottom end of the condensation box (21), a water tank (26) with an open top end being provided at the bottom end of the condensation box (21), and a water outlet pipe (27) being laterally connected at the bottom end of a side surface of the water tank (26).

2. The steelmaking wastewater recycling and treatment circulation system for a steelmaking plant according to claim 1, characterized in that: The cooling circulation module (3) comprises an internally hollow circulation box (31), wherein the top and bottom ends of the middle part of the inner cavity of the circulation box (31) are respectively vertically fixedly connected with a plurality of upper plates (32) and a plurality of lower partitions (33), wherein the plurality of upper partitions (32) and the plurality of lower partitions (33) are arranged at intervals from each other, and both ends of the inner part of the circulation box (31) are fixedly connected with an internally hollow hollow frame (35) through a connecting block, and the inner side of one of the hollow frames (35) is horizontally connected with a plurality of connecting blocks. The other ends of the connecting pipes (34) penetrate through the upper partitions (32) and the lower partitions (33) and are connected to another hollow frame (35). The top ends of the two hollow frames (35) are vertically connected with inlet and outlet pipes (36). The top ends of the two inlet and outlet pipes (36) penetrate through the upper surface of the circulation box (31) and extend upward. The two ends of the circulation box (31) are respectively provided with a liquid inlet (37) and a liquid outlet (38).

3. The steelmaking wastewater recycling and treatment circulation system for a steelmaking plant according to claim 1, characterized in that: The coarse filtering module (4) comprises a main pipe (41), the middle part of the main pipe (41) is expanded outward to form a spherical shape, the top end of the middle part of the main pipe (41) is vertically connected to a standpipe (42) with a closed top end, the inside of the standpipe (42) is vertically fixedly connected to a filter cylinder (43), the front end of the inside of the main pipe (41) is fixedly connected to a connecting ring (44), the rear end surface of the connecting ring (44) is fixedly connected to a filter pipe (45), and the other end of the filter pipe (45) is connected to the inside of the filter cylinder (43).

4. The steelmaking wastewater recycling and treatment circulation system for a steelmaking plant according to claim 3 is characterized by: The bottom of the vertical pipe (42) is vertically rotatably connected to an auger (410) located inside the filter cylinder (43) and coaxial with the filter cylinder (43) and adapted thereto; the outer edge of the top end of the vertical pipe (42) is vertically fixedly connected to a plurality of support rods (47); the top ends of the plurality of support rods (47) are laterally fixedly connected to a top plate (48); the top end of the top plate (48) is fixedly connected to a first motor (49); the output shaft of the first motor (49) rotatably passes through the top plate (48) and the top end of the vertical pipe (42) and is fixedly connected to the top end of the rotating shaft of the auger (410).

5. The steelmaking wastewater recycling and treatment circulation system for steelmaking plants according to claim 4, characterized in that: The flocculation sedimentation module (5) comprises a flocculation tank (51), wherein the top and bottom of the flocculation tank (51) are laterally fixedly connected with a plurality of zigzag plates (52), a side surface of the flocculation tank (51) is laterally fixedly connected with a plurality of second motors (53), the output shafts of the plurality of second motors (53) are rotatably passed through the side surface of the flocculation tank (51) and extend into the interior thereof, the outer ends of the output shafts of the plurality of second motors (53) are laterally fixedly connected with a rotating shaft (54), the other ends of the plurality of rotating shafts (54) are rotatably passed through the plurality of zigzag plates (52) and extend to the other end of the flocculation tank (51), and a stirring blade (55) is fixedly connected to the outer surfaces of the plurality of rotating shafts (54) and located between every two adjacent zigzag plates (52).

6. The steelmaking wastewater recycling and treatment circulation system for a steelmaking plant according to claim 5, characterized in that: The rear end of the flocculation tank (51) is fixedly connected to a sedimentation tank (56) with an open top, and a communication port (57) is transversely penetrated through the lower part of the rear end surface of the flocculation tank (51) and communicated with the sedimentation tank (56).

7. The steelmaking wastewater recycling and treatment circulation system for a steelmaking plant according to claim 3, characterized in that: The liquid recovery module (1) and the cooling circulation module (3) are combined to form an indirect cooling water circulation system.

8. The steelmaking wastewater recycling and treatment circulation system for a steelmaking plant according to claim 6, characterized in that: The liquid recovery module (1), the gas recovery module (2), the coarse filtration module (4) and the flocculation sedimentation module (5) are combined to form a direct cooling water and washing wastewater circulation system.

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