Mechanism for treating mixed sewage of pickling line

Abstract

This invention provides a mixed wastewater treatment mechanism for a pickling line, comprising a circulating water tank, a water supply pipe, a return water trench, a spraying mechanism, a cooling circulation pipe, a cooling tower, an overflow pipe, a collection water tank, and a wastewater treatment unit. The spraying mechanism is connected to the circulating water tank via the water supply pipe and sprays cooling water from the circulating water tank onto the steel coils to be cooled in the coil stacking tank. The return water trench connects the steel coil stacking tank and the circulating water tank, and returns the sprayed cooling water collected in the steel coil stacking tank to the circulating water tank. The first end of the cooling circulation pipe is connected to the cooling circulation pipe, flows through the cooling tower, and returns to the circulating water tank through the second end. The cooling tower cools the cooling water in the circulating water tank. After being cooled by the cooling water in the cooling tower, the water returns to the circulating water tank. The cooling water is recycled within the system, significantly reducing the volume of mixed wastewater, lowering the load on the treated mixed wastewater, and reducing treatment costs.

Description

Technical Field

[0001] This utility model relates to the field of hot-rolled coil cooling, and more particularly to a mixed wastewater treatment mechanism for pickling lines. Background Technology

[0002] During the production of hot-rolled steel sheets, the coils need to be cooled before pickling. To accelerate the cooling process, some steel mills use large amounts of cooling water, which is then directly discharged into storm drains. Inevitably, seepage occurs in the pickling pits, and this acidic seepage also flows into the storm drains. Furthermore, seepage from the pits corresponding to the acid regeneration stations, along with reddish-brown iron oxide powder, as well as clean water from the storage areas and rainwater, also flows into the storm drains. These various types of water, when discharged into the storm drains, create a large volume of mixed wastewater. Direct discharge of this mixed wastewater has adverse environmental impacts; it can cause rivers to turn red and result in pollution incidents that are difficult to treat. Additionally, the large volume of mixed wastewater leads to high treatment costs. Utility Model Content

[0003] The main purpose of this utility model is to provide a mixed wastewater treatment mechanism for pickling lines to solve the technical problem of high cost of direct treatment of mixed wastewater.

[0004] To achieve the above objectives, this utility model provides a mixed wastewater treatment mechanism for an acid pickling line, including a circulating water tank, a water supply pipeline, a return water trench, a spraying mechanism, a cooling circulation pipeline, a cooling tower, an overflow pipe, a collection water tank, and a wastewater treatment mechanism.

[0005] The spraying mechanism is connected to the circulating water pool through the water supply pipe, and is used to spray the cooling water of the circulating water pool onto the steel coils to be cooled in the steel coil stacking pool.

[0006] The return water trench connects the steel coil stacking pool and the circulating water pool, and is used to return the sprayed cooling water collected in the steel coil stacking pool to the circulating water pool.

[0007] The first end of the cooling circulation pipeline is connected to the cooling circulation pipeline, and after flowing through the cooling tower, it returns to the circulating water pool through the second end. The cooling tower is used to cool and lower the temperature of the cooling water in the circulating water pool.

[0008] The overflow pipe connects the circulating water tank to the external rainwater ditch; the sewage treatment unit is connected to the rainwater ditch through the collection water tank.

[0009] According to the embodiments of this application, the wastewater treatment facility is an acid-base wastewater treatment facility, which includes a primary neutralization tank, a secondary neutralization tank, and an acid-base clarification tank.

[0010] According to an embodiment of this application, a regulating pump is provided between the water collection tank and the sewage treatment mechanism.

[0011] According to an embodiment of this application, the spraying mechanism includes multiple spray pipes arranged at equal intervals, and the spray pipes are provided with multiple sets of spray nozzles arranged at equal intervals along the axial direction.

[0012] According to an embodiment of this application, each set of spray nozzles includes a plurality of spray nozzles distributed at different angles along the circumference of the spray pipe.

[0013] According to an embodiment of this application, the cooling tower is designed to have a cooling capacity of 0.4-0.8 times the spray water volume of the spraying mechanism.

[0014] According to an embodiment of this application, the cooling tower is a counter-flow cooling tower.

[0015] According to an embodiment of this application, it further includes a level gauge and a water replenishment mechanism. The circulating water tank is connected to an external water storage tank or water replenishment pipeline through the water replenishment mechanism. The level gauge is installed in the circulating water tank and controls the start and stop of the water replenishment mechanism.

[0016] According to an embodiment of this application, the circulating water tank is provided with a step for the lowest water level, and the level gauge is installed on the step.

[0017] According to an embodiment of this application, the first end of the cooling circulation pipeline includes two parallel branch pipes, each branch pipe having a corresponding circulation pump.

[0018] In the aforementioned pickling line mixed wastewater treatment system, cooling water is supplied through a water supply pipe and sprayed by a spray mechanism to cool the steel coils. Afterward, the cooling water returns to the circulating water tank via a return pipe trench. Following this process, the temperature of the cooling water increases, and it is then transported through a cooling circulation pipeline to a cooling tower for further cooling before returning to the circulating water tank. Thus, the combined effect of the spray mechanism and the cooling tower achieves highly efficient cooling. The cooling water is recycled within the system, significantly reducing the amount of cooling water discharged into the rainwater ditch, thereby greatly reducing the volume of mixed wastewater, lowering the load on the mixed wastewater treatment system, and reducing treatment costs. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0020] Figure 1This is a schematic diagram of the usage status of the acid pickling line mixed wastewater treatment mechanism according to one embodiment of this application.

[0021] Figure 2 This is a schematic diagram of the wastewater treatment facility in use according to one embodiment of this application.

[0022] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the implementation methods and with reference to the accompanying drawings. Attached image description:

[0024] 100. Circulating water tank; 200. Water supply pipeline; 300. Return water trench; 400. Spraying mechanism; 500. Cooling circulation pipeline; 600. Cooling tower; 510. Circulating pump; 700. Overflow pipe; 800. Collection tank; 900. Sewage treatment mechanism; 520. Water replenishment mechanism; 910. Primary neutralization tank; 920. Secondary neutralization tank; 930. Acid-base clarification tank. Detailed Implementation

[0025] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] It should be noted that all directional indicators (such as up, down, etc.) in the embodiments of this utility model are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0027] Furthermore, in this utility model, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features.

[0028] Furthermore, the technical solutions of the various embodiments of this utility model can be combined with each other, but only if they are based on the ability of a person skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0029] See Figure 1This utility model provides a mixed wastewater treatment mechanism for a pickling line, including a circulating water tank 100, a water supply pipe 200, a return water trench 300, a spraying mechanism 400, a cooling circulation pipe 500, a cooling tower 600, an overflow pipe 700, a collection water tank 800, and a wastewater treatment mechanism 900. The spraying mechanism 400 is connected to the circulating water tank 100 via the water supply pipe 200, and is used to spray cooling water from the circulating water tank 100 onto the steel coils to be cooled in the steel coil stacking pool. The return water trench 300 connects the steel coil stacking pool and the circulating water tank 100, and is used to return the sprayed cooling water collected in the steel coil stacking pool to the circulating water tank 100. The first end of the cooling circulation pipe 500 is connected to the cooling circulation pipe 500, flows through the cooling tower 600, and then returns to the circulating water tank 100 through the second end. The cooling tower 600 is used to cool and lower the temperature of the cooling water in the circulating water tank 100. The overflow pipe 700 is connected to the circulating water tank 100 and the external rainwater ditch; the sewage treatment unit 900 is connected to the rainwater ditch through the collection tank 800.

[0030] Steel coils are placed in the raw material storage area, i.e., the steel coil stacking pool. A spray system 400 is arranged in the steel coil stacking pool. A water supply pipe 200 connects to a circulating water pool 100 to supply water to the spray system 400. A water pump is installed on the water supply pipe 200 to regulate the supply of cooling water. The cooling water sprayed by the spray system 400 cools the steel coils. The cooled water collects on the ground of the steel coil stacking pool and returns to the circulating water pool 100 through the return water trench 300.

[0031] The spray system 400 continuously sprays cooling water, which not only acts on the surface of the steel coil but also penetrates into the gaps between the layers inside the coil for cooling. This comprehensive cooling method significantly improves the cooling efficiency of the steel coil. Taking the cold rolling and pickling line as an example, its original design capacity was 1.53 million tons / year. Thanks to the efficient cooling of the spray system 400, the actual output soared to 2.5 million tons / year in 2024, achieving a significant improvement in production efficiency.

[0032] The leap in production efficiency allowed for the rational division of the original compact pickling and rolling combined production line's raw material storage area, creating separate storage areas for the pickling line and the pickling and rolling combined production line. This transformation did not require additional expansion of the storage area, nor did it necessitate the expansion of the hot rolling mill's storage area, thus achieving highly efficient utilization of space resources.

[0033] The efficient cooling system enables steel coils from the hot rolling mill to be rapidly cooled to the required production temperature, significantly reducing the waiting time before cold rolling. This not only improves the continuity of the production process but also significantly reduces inventory capital, minimizes the capital costs tied up in stockpiled steel coils, and enhances the company's capital turnover efficiency.

[0034] The pickling line's mixed wastewater treatment system achieves a closed-loop cooling water circulation system. After spraying and cooling the steel coils, the cooling water is collected in the circulating water tank 100, cooled by the cooling tower 600, and then reused, achieving efficient water resource recycling. In addition, a large amount of high-temperature cooling water forms a loop with the steel coil stacking area for circulating cooling of the steel coils. The continuous heating of this large amount of high-temperature cooling water reduces its cooling efficiency; water exceeding 50°C cannot cool the steel coils below 50°C. Furthermore, the higher the temperature of the cooling water sprayed onto the steel coils, the more easily water vapor is generated, causing water mist to permeate the entire storage area, affecting the working environment. More importantly, because crane operators cannot see the steel coils on the ground, it is extremely easy for the crane to be unable to lift the steel coils, potentially causing them to fall from a height and leading to a major safety accident. This process not only maintains high efficiency in cooling the steel coils but also reduces the amount of water replenished to the circulating water tank 100. It effectively reduced the phenomenon of water overflow into rainwater ditches, reduced potential environmental pollution, demonstrated good environmental protection benefits, ensured the on-site working environment, and avoided major safety risks.

[0035] In some related technologies, using fire-fighting water or circulating water for production and equipment cooling within a plant as cooling water, and then directly discharging it after use, will cause at least the following problems:

[0036] 1. Direct discharge after use results in a large amount of fire-fighting water being discharged into the factory's rainwater ditch, wasting a significant amount of fresh water.

[0037] 2. The fire pumps are overloaded; and the fire water pipe network has been under low pressure due to water pressure release in the raw material storage area, posing a threat to fire safety in other areas.

[0038] 3. If water quality stabilizers are added to fire-fighting water or circulating water used for production and equipment cooling within the plant, the large-scale discharge will cause an imbalance between scale inhibition and corrosion inhibition in the pipelines, resulting in a large amount of rust formation in the pipelines, which will seriously threaten the normal operation of equipment and pipelines of other units.

[0039] In terms of wastewater treatment, the technical solution of this application achieves the recycling and reuse of rainwater and sewage through the installation of a collection tank 800 and a sewage treatment unit 900, thereby improving the utilization rate of water resources. The mixed water can be reused in the cooling system after treatment, reducing environmental pollution and demonstrating significant environmental benefits.

[0040] In this application, the amount of cooling water discharged into the rainwater ditch is significantly reduced (approximately 1 / 20 of the volume of cooling water directly discharged in the prior art). As a result, the water entering the rainwater ditch is only water that has been cleaned by iron oxide powder scattered on the ground or seepage water from the pit. The water volume is small, and the collected water is pumped into the acid and alkali wastewater treatment process of the cold rolling wastewater station for treatment. This results in a small increase in the amount of wastewater treated, a small increase in the load, and the wastewater is under control, achieving true separation of rainwater and sewage.

[0041] In the aforementioned pickling line mixed wastewater treatment unit 900, cooling water is supplied via the water supply pipe 200 and sprayed by the spray mechanism 400 to cool the steel coils before returning to the circulating water tank 100 through the return pipe trench. After this process, the temperature of the cooling water increases, and it is then transported through the cooling circulation pipe 500 to the cooling tower 600 for further cooling before returning to the circulating water tank 100. Thus, the coordinated operation of the spray mechanism 400 and the cooling tower 600 achieves a highly efficient cooling effect. The cooling water is recycled within the system, significantly reducing the amount of water discharged into the rainwater ditch, greatly decreasing the volume of mixed wastewater, reducing the load on the mixed wastewater treatment system, and lowering treatment costs.

[0042] In some embodiments, see Figure 2 The wastewater treatment unit 900 is an acid and alkali wastewater treatment unit, which includes a primary neutralization tank 910, a secondary neutralization tank 920, and an acid and alkali clarification tank 930.

[0043] Because iron oxide powder, clean water from storage sites, or rainwater drainage contain iron ions, the discharged cooling water also contains a certain amount of iron ions. In existing technologies, the volume of the discharged mixed wastewater is relatively large, resulting in a low concentration of iron ions. In this application, the volume of the discharged mixed wastewater is significantly reduced, approximately one-tenth the volume of the mixed wastewater discharged in existing technologies, thus the concentration of iron ions is more than ten times that of the discharged wastewater in existing technologies.

[0044] Acid and alkali wastewater treatment facilities typically include an acid and alkali wastewater equalization tank, a primary neutralization tank 910, a secondary neutralization tank 920, an acid and alkali clarification tank 930, a final pH adjustment tank, a filter, and an effluent tank.

[0045] Taking the invention patent with publication number CN 119874099 A as an example, the mixed wastewater, after passing through an acid-base wastewater equalization tank, a primary neutralization tank 910, and a secondary neutralization tank 920, reaches an acid-base clarification tank 930. Due to the relatively high concentration of iron ions, a large amount of ferric hydroxide precipitate will form in the acid-base clarification tank 930. The ferric hydroxide precipitate is flocculent and can precipitate other impurities in the mixed wastewater, thus reducing the amount of additional flocculant required and achieving the purpose of treating waste with waste.

[0046] In existing technologies, the large volume of mixed wastewater leads to a low concentration of iron ions, resulting in less iron hydroxide precipitate being generated, making it difficult to achieve the goal of treating waste with waste.

[0047] In some embodiments, a regulating pump is provided between the collection tank and the wastewater treatment unit 900. The regulating pump regulates the flow rate of mixed wastewater entering the wastewater treatment unit 900 from the collection tank to prevent exceeding the treatment load of the wastewater treatment unit 900.

[0048] In some embodiments, see Figure 1 The spraying mechanism 400 includes multiple spray pipes arranged at equal intervals, and the spray pipes are provided with multiple sets of spray nozzles arranged at equal intervals along the axial direction.

[0049] The design of multiple spray pipes and multiple sets of spray nozzles ensures that cooling water can be sprayed evenly onto the steel coils, improving the cooling effect. Moreover, the evenly spaced spray nozzles can fully cover the steel coil stacking pool, ensuring that each steel coil is fully cooled.

[0050] In some embodiments, see Figure 1 Each set of spray nozzles includes multiple nozzles distributed at different angles along the circumference of the spray pipe. For example, spray nozzles distributed at 30°, 45°, 60°, 120°, 135°, and 150° can spray cooling water from multiple angles to ensure all-round cooling of the steel coil.

[0051] In some embodiments, the cooling tower 600 is designed to have a cooling capacity of 0.4-0.8 times the spray water volume of the spray mechanism 400.

[0052] This design ensures that the cooling tower 600 can effectively reduce the temperature of the cooling water to meet the cooling requirements of the steel coils. The optimized cooling capacity design guarantees the overall balance of the cooling system and improves cooling efficiency.

[0053] In some specific embodiments, the cooling tower 600 is a counter-flow cooling tower 600.

[0054] The cooling tower is designed to cool 200 cubic meters per hour at a temperature of 4℃-8℃. A high-efficiency, energy-saving, seal-free self-priming pump is used to supply water to the cooling tower; model number: 50WFB-B3, power 37KW, head 20 meters, flow rate 200 cubic meters per hour.

[0055] The sprinkler system has three units (selectable as two-in-one-standby or one-in-two-standby operation modes depending on production needs). The selected pumps are model ISG200-320, supplying water to the steel coil storage area for the sprinkler system. Each pump has a motor power of 37KW, a head of 38 meters, and a flow rate of 253 cubic meters per hour. The combined flow rate of the two pumps is approximately 500 cubic meters per hour.

[0056] Therefore, the cooling tower is designed to have a cooling capacity of 0.4-0.8 times the spray water volume of the spraying mechanism.

[0057] In some embodiments, the system further includes a level gauge and a water replenishment mechanism 520. The circulating water tank 100 is connected to an external water storage tank or water replenishment pipeline through the water replenishment mechanism 520. The level gauge is installed in the circulating water tank 100 and controls the start and stop of the water replenishment mechanism 520.

[0058] The level gauge and water replenishment mechanism 520 enable automatic water replenishment, ensuring a stable water level in the circulating water tank 100. Automatic water replenishment reduces unnecessary water waste and improves water conservation.

[0059] For example, the water replenishment mechanism 520 includes a water replenishment pump and a water replenishment pipeline. The water replenishment pipeline replenishes the circulating water tank 100 with water through a water storage tank or a water replenishment pipeline.

[0060] In some embodiments, the circulating water tank 100 is provided with a step for the lowest water level, and the level gauge is disposed on the step.

[0061] The level gauge is installed on the step at the lowest water level, allowing for more precise water level control and preventing the water level from being too low and affecting the cooling effect. When the water level falls below the minimum level, water is added. This ensures the safe operation of the cooling system and prevents equipment damage due to insufficient water level.

[0062] In some embodiments, see Figure 1 The first end of the cooling circulation pipe 500 includes two parallel branch pipes, each with a corresponding circulation pump 510. Normally, the circulation pumps operate in a one-on-one standby mode. The two parallel branch pipes and circulation pumps 510 provide redundancy, improving system reliability. Furthermore, the cooling water flow rate can be flexibly adjusted according to actual needs, improving cooling efficiency.

[0063] The above technical solutions of this utility model are merely preferred embodiments and do not limit the patent scope of this utility model. All equivalent structural transformations made under the technical concept of this utility model using the contents of this utility model specification and drawings, or direct / indirect applications in other related technical fields, are included in the patent protection scope of this utility model.

Claims

1. An acid pickling line mixed sewage treatment mechanism characterized by comprising: It includes a circulating water tank, water supply pipelines, return water trenches, spraying system, cooling circulation pipelines, cooling tower, overflow pipe, collection water tank, and sewage treatment system; The spraying mechanism is connected to the circulating water pool through the water supply pipe, and is used to spray the cooling water of the circulating water pool onto the steel coils to be cooled in the steel coil stacking pool. The return water trench connects the steel coil stacking pool and the circulating water pool, and is used to return the sprayed cooling water collected in the steel coil stacking pool to the circulating water pool. The first end of the cooling circulation pipeline is connected to the cooling circulation pipeline, and after flowing through the cooling tower, it returns to the circulating water pool through the second end. The cooling tower is used to cool and lower the temperature of the cooling water in the circulating water pool. The overflow pipe connects the circulating water tank to the external rainwater ditch; the sewage treatment unit is connected to the rainwater ditch through the collection water tank.

2. The acid pickling line mixed wastewater treatment mechanism according to claim 1, characterized in that, The wastewater treatment facility is an acid-base wastewater treatment facility, which includes a primary neutralization tank, a secondary neutralization tank, and an acid-base clarification tank.

3. The acid pickling line mixed wastewater treatment mechanism according to claim 2, characterized in that, A regulating pump is provided between the collection tank and the sewage treatment unit.

4. The acid pickling line mixed wastewater treatment mechanism according to claim 1, characterized in that, The spraying mechanism includes multiple spray pipes arranged at equal intervals, and the spray pipes are provided with multiple sets of spray nozzles arranged at equal intervals along the axial direction.

5. The acid pickling line mixed wastewater treatment mechanism according to claim 4, characterized in that, Each set of spray nozzles includes multiple spray nozzles distributed at different angles along the circumference of the spray pipe.

6. The acid pickling line mixed wastewater treatment mechanism according to claim 1, characterized in that, The cooling tower is designed to have a cooling capacity of 0.4-0.8 times the spray water volume of the spraying mechanism.

7. The pickling line mixed wastewater treatment mechanism according to claim 1, characterized in that, The cooling tower is a counter-flow cooling tower.

8. The acid pickling line mixed wastewater treatment mechanism according to claim 1, characterized in that, It also includes a level gauge and a water replenishment mechanism. The circulating water tank is connected to an external water storage tank or water replenishment pipeline through the water replenishment mechanism. The level gauge is installed in the circulating water tank and controls the start and stop of the water replenishment mechanism.

9. The acid pickling line mixed wastewater treatment mechanism according to claim 8, characterized in that, The circulating water tank is equipped with a step for the lowest water level, and the level gauge is installed on the step.

10. The pickling line mixed wastewater treatment mechanism according to any one of claims 1 to 9, characterized in that, The first end of the cooling circulation pipeline includes two parallel branch pipes, each with a corresponding circulation pump.

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