Hot-dip galvanizing post-plating air-cooling heat energy recovery device

Abstract

This utility model discloses a post-hot-dip galvanizing air-cooled heat recovery device, relating to the field of hot-dip galvanizing technology for steel strips. The device includes an air-cooled heat recovery unit comprising a steel strip, a left and right blower box, a circulating fan, a working fluid evaporator, a hot water / thermal oil circulating pump, a working fluid condenser, a working fluid expansion valve and a working fluid compressor, and a cooler. This post-hot-dip galvanizing air-cooled heat recovery device can cool down the gas that rises after cooling the steel strip, facilitating its recycling. The significant cooling effect of the cooling air improves the cooling efficiency of the steel strip. The heat transferred to the refrigerant is transferred to the hot water / thermal oil via the working fluid compressor and condenser, and then output to the production line for reuse. This avoids the thermal pollution problems caused by existing open-type jet cooling equipment that uses ambient gas to cool the steel strip, resulting in the escape of heated gas into the working environment, while achieving the effect of heat recovery and utilization.

Description

Technical Field

[0001] This utility model relates to the field of steel strip zinc plating technology, specifically to a hot-dip galvanized post-plating air-cooled heat recovery device. Background Technology

[0002] The hot-dip galvanizing process for steel strip mainly includes three stages: pretreatment, galvanizing, and post-treatment.

[0003] Pretreatment: Cleaning: Use a degreasing agent to remove dust and grease from the surface of the strip steel to ensure the substrate is clean and improve the adhesion of the coating; Annealing: The strip steel is recrystallized and annealed in a reducing atmosphere to obtain an active metal surface, reduce the interfacial tension of the zinc liquid, avoid coating peeling, and restore the processing performance of the strip steel.

[0004] Hot-dip galvanizing: Pretreated steel strip is immersed in molten zinc (temperature usually 450-460℃). Iron and zinc react to form an Fe-Zn alloy layer (such as FeZn7), which is then covered with a pure zinc layer. The coating thickness can be adjusted by air knife blowing.

[0005] Post-treatment: After hot-dip galvanizing, the strip steel is cooled and then enters the post-treatment stage, which includes tension leveling, finishing, passivation (such as chromate treatment), oiling or alloying (high-temperature diffusion to form Fe-Zn alloy) to improve corrosion resistance and processing performance.

[0006] Currently, open-type air-blowing cooling equipment is used to cool strip steel. However, during use, this equipment draws in ambient air and uses it to cool the strip steel, causing the heated air to escape into the working environment and creating a thermal pollution problem. Utility Model Content

[0007] To address the shortcomings of existing technologies, this utility model provides a post-hot-dip galvanizing air-cooled heat recovery device, which solves the problems mentioned in the background art.

[0008] To achieve the above objectives, this utility model provides the following technical solution: a hot-dip galvanized post-galvanizing air-cooled heat recovery device, comprising an air-cooled heat recovery unit, which includes a strip steel, a left blower box, a right blower box, a circulating fan, a working fluid evaporator, a hot water / thermal oil circulating pump, a working fluid condenser, a working fluid expansion valve, a working fluid compressor, and a cooler. The air-cooled heat recovery unit internally houses the left and right blower boxes, which together form a cooling system. The evaporator has a circulating fan fixedly connected to its air outlet. One end of the circulating fan is fixedly connected to the main air inlet duct. The air inlets of the left and right spray air boxes are each equipped with a branch air inlet duct. The branch air inlet ducts are all internally connected to the main air inlet duct. After the cooling air is sprayed onto the strip, it enters the left and right return air ducts through the left and right spray air boxes respectively, and then merges into the branch return air ducts and finally into the main return air duct. The air outlet of the main return air duct is connected to the air inlet of the evaporator.

[0009] Preferably, the air-cooled heat recovery equipment includes a refrigerant heat transfer system consisting of a working fluid evaporator, a working fluid condenser, a working fluid compressor, a cooler, and a working fluid expansion valve, which transfers the heat entering the system to hot water or heat transfer oil.

[0010] Preferably, the outlet of the water / heat transfer oil used for cooling in the working fluid condenser is connected to the pumping end of the hot water / heat transfer oil circulation pump, and the hot water or heat transfer oil in the working fluid condenser is transported out through the hot water / heat transfer oil circulation pump.

[0011] Preferably, a closed channel for cooling the strip is formed between the left and right blower boxes.

[0012] This utility model provides a post-hot-dip galvanizing air-cooled heat recovery device, which has the following beneficial effects:

[0013] 1. This hot-dip galvanizing post-galvanizing air-cooled heat recovery device, by setting up a left blower box, a right blower box and an evaporator, can recover and circulate the gas used to cool the strip steel for reuse. This avoids the problem of existing open-type air-blowing cooling equipment drawing in ambient gas and using ambient gas to cool the strip steel, causing the heated gas to escape into the working environment and causing thermal pollution.

[0014] 2. This hot-dip galvanizing post-galvanizing air-cooled heat recovery device is equipped with an evaporator, a working fluid compressor, and a working fluid condenser. When the air is cooled by the evaporator, the refrigerant in the refrigeration pipes inside the evaporator vaporizes. The vaporized refrigerant is then compressed by the working fluid compressor, making the gas high-temperature and high-pressure. It then enters the heat transfer pipes inside the working fluid condenser to heat the heat transfer medium (water / heat transfer oil) inside the condenser, making the working fluid gas low-temperature and high-pressure. When the working fluid gas continues to pass through the working fluid expansion valve, the gas becomes low-pressure, cooling the gas into a gas-liquid mixture or low-temperature liquid. It then re-enters the refrigeration pipes inside the evaporator to further cool the strip steel cooling gas. The heat transfer medium, such as water or heat transfer oil, inside the working fluid condenser is extracted by a hot water / heat transfer oil circulation pump for reuse. This allows for the recovery and utilization of the heat energy in the heated gas after cooling the strip steel. Attached Figure Description

[0015] Figure 1 This is a diagram of the galvanized steel strip production line of this utility model;

[0016] Figure 2 This is a schematic diagram of the structure of the hot-dip galvanized post-galvanizing air-cooled heat recovery device of this utility model;

[0017] Figure 3 This is a schematic diagram of the circulating air cooling structure in the hot-dip galvanizing post-galvanizing air-cooled heat energy recovery device of this utility model;

[0018] Figure 4 This is a schematic diagram of the cross-sectional structure of the circulating air-cooled jet in the air-cooled heat recovery device of this utility model;

[0019] Figure 5 A schematic diagram of the open-type air-cooled equipment structure replaced by this utility model.

[0020] In the diagram: 1. Working fluid condenser; 2. Strip steel; 3. Branch return air duct; 4. Branch inlet air duct; 5. Right jet blower box; 6. Left jet blower box; 8. Main inlet air duct; 9. Main return air duct; 10. Evaporator; 11. Circulating fan; 12. Working fluid pipeline; 13. Working fluid compressor; 14. Working fluid expansion valve; 15. Hot water / thermal oil circulating pump; 17. High-temperature water / oil supply pipeline; 18. Air-cooled heat recovery equipment; 19. Cooling tower; 20. Quenching water cooling system; 21. Centering machine; 22. Galvanizing machine; 23. Annealing furnace; 24. Hot tension roller; 25. Hot air blower; 26. Steering roller; 27. Low-temperature water / oil return pipeline; 28. Cooler. Detailed Implementation

[0021] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0022] Example 1

[0023] Please see Figures 2 to 4 This utility model provides a technical solution: a hot-dip galvanized post-galvanizing air-cooled heat recovery device, including an air-cooled heat recovery unit 18. The air-cooled heat recovery unit 18 consists of a strip steel 2, a left blower box 6, a right blower box 5, a circulating fan 11, a working fluid evaporator 10, a hot water / thermal oil circulating pump 15, a working fluid condenser 1, a working fluid expansion valve 14, a working fluid compressor 13, and a cooler 28. The air-cooled heat recovery unit 18 has the left blower box 6 and the right blower box 5 installed inside, and the left blower box 6 and the right blower box 5 together form a cooling system. The air outlet of the evaporator 10 is fixedly connected to a circulating fan 11. One end of the circulating fan 11 is fixedly connected to a main air inlet duct 8. The air inlets of the left and right air inlets 6 and 5 are each equipped with a branch air inlet duct 4. The branch air inlet ducts 4 are all connected to the inside of the main air inlet duct 8. After the cooling air is sprayed onto the strip 2, it enters the left and right return air ducts through the left and right air inlets 6 and 5 respectively, and then flows into the branch return air duct 3, and then into the main return air duct 9. The outlet of the main return air duct 9 is connected to the air inlet of the evaporator 10.

[0024] The air-cooled heat recovery equipment 18 includes a working fluid evaporator 10, a working fluid condenser 1, a working fluid compressor 13, a cooler 28, and a working fluid expansion valve 14, forming a refrigerant working fluid heat transfer system that transfers the heat entering the system to hot water or heat transfer oil.

[0025] The liquid outlet of the working fluid condenser 1 is connected to the liquid extraction end of the hot water / heat transfer oil circulation pump 15, and the hot water or heat transfer oil in the working fluid condenser 1 is transported out through the hot water / heat transfer oil circulation pump 15.

[0026] A closed channel for cooling the strip steel 2 is formed between the left blower box 6 and the right blower box 5.

[0027] Example 2

[0028] Please see Figure 1 This utility model provides a technical solution: a galvanized steel strip production line consists of a hot air blowing machine 25, an annealing furnace 23, a hot tension roller 24, a galvanizing machine 22, a quenching water cooling system 20, a centering machine 21, a cooling tower 19, an air-cooled heat recovery device 18, and a steering roller 26.

[0029] The hot-dip galvanized post-galvanizing air-cooled heat recovery device is used as follows: gas cooled by the evaporator 10 is sprayed out through the right blower box 5 and the left blower box 6 to cool the strip steel 2, cooling the high-temperature strip steel 2 that enters the air-cooled heat recovery device 18 into a low-temperature strip steel 2 that exits to the outside of the air-cooled heat recovery device 18. The gas used to cool the strip steel 2 becomes hot and enters the branch return air pipeline 3 through the return air end of the left blower box 6 and the right blower box 5. Then it enters the evaporator 10 through the main return air pipeline 9 for further cooling, thus cooling the strip steel 2.

[0030] When air is cooled by evaporator 10, the refrigerant in the refrigeration pipes inside evaporator 10 vaporizes. The vaporized refrigerant is then compressed by working fluid compressor 13, making the gas high temperature and high pressure. It then enters the heat transfer pipes inside working fluid condenser 1 through working fluid compressor 13, making the gas low temperature and high pressure. This heats the heat transfer medium inside working fluid condenser 1, cooling the gas in the heat transfer pipes inside working fluid condenser 1. This completes the heating of the heat transfer medium (water / heat transfer oil) inside working fluid condenser 1, making the working fluid gas low temperature and high pressure. As the gas continues to pass through the working fluid expansion valve 14, the gas becomes low-pressure, which cools the gas, turning it into a gas-liquid mixture or a low-temperature liquid. Then, it re-enters the refrigeration pipe inside the evaporator 10 through the working fluid pipe 12 to further cool the gas cooling the strip 2. The heat transfer medium, such as water or heat transfer oil, inside the working fluid condenser 1 is extracted by the hot water / heat transfer oil circulation pump 15 and utilized through the high-temperature water / oil supply pipe 17. The heat transfer medium is discharged into the working fluid condenser 1 through the low-temperature water / oil return pipe 27 to continue heating.

[0031] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A hot-dip galvanized post-galvanizing air-cooled heat recovery device, characterized in that: The device includes an air-cooled heat recovery unit (18), which comprises a strip steel (2), a left jet air box (6), a right jet air box (5), a circulating fan (11), a working fluid evaporator (10), a hot water / thermal oil circulating pump (15), a working fluid condenser (1), a working fluid expansion valve (14), a working fluid compressor (13), and a cooler (28). The air-cooled heat recovery unit (18) is internally equipped with a left jet air box (6) and a right jet air box (5), which together form a cooling air box. The air outlet of the evaporator (10) is... A circulating fan (11) is fixedly connected to one end of the circulating fan (11), and a main air inlet pipeline (8) is fixedly connected to one end of the circulating fan (11). A branch air inlet pipeline (4) is installed at the air inlet end of the left blower box (6) and the right blower box (5). The branch air inlet pipeline (4) is connected to the inside of the main air inlet pipeline (8). After the cooling air is blown onto the strip steel (2), it enters the left and right return air pipelines through the left blower box (6) and the right blower box (5) respectively, and flows into the branch return air pipeline (3), and then into the main return air pipeline (9). The air outlet end of the main return air pipeline (9) is connected to the air inlet end of the working fluid evaporator (10).

2. The hot-dip galvanizing post-galvanizing air-cooled heat recovery device according to claim 1, characterized in that: The air-cooled heat recovery equipment (18) includes a working fluid evaporator (10), a working fluid condenser (1), a working fluid compressor (13), a cooler (28), and a working fluid expansion valve (14), which together form a refrigerant working fluid heat transfer system to transfer the heat entering the system to hot water or heat transfer oil.

3. The hot-dip galvanizing post-galvanizing air-cooled heat recovery device according to claim 1, characterized in that: The cooling medium water / heat transfer oil outlet of the working fluid condenser (1) is connected to the liquid extraction end of the hot water / heat transfer oil circulation pump (15), and the water or heat transfer oil in the working fluid condenser (1) is recycled on the production line through the hot water / heat transfer oil circulation pump (15).

4. The hot-dip galvanizing post-galvanizing air-cooled heat recovery device according to claim 1, characterized in that: The left blower box (6) and the right blower box (5) form a closed channel for cooling the strip (2).

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