Cooling water circulation system for hot rolled strip steel

Abstract

The utility model provides a hot-rolled strip steel cooling water circulation system, which relates to the technical field of steel hot rolling, and comprises a water collecting tank, a filter tank, a heat exchange tank and a water storage tank, the water collecting tank is arranged below a cooling device, the lower end of the water collecting tank is communicated with the lower end of the filter tank, and the heat exchange tank is communicated with the water storage tank. The upper end of the filter tank is communicated with the upper end of the heat exchange tank, and the lower end of the heat exchange tank is communicated with the lower end of the water storage tank. The water collecting tank is used for collecting used cooling water in the cooling device and preliminarily settling the cooling water, the filtering tank is used for filtering the preliminarily settled cooling water, and the heat exchange tank is used for cooling the filtered cooling water; and the water storage tank is used for storing the cooled cooling water. The hot-rolled strip steel cooling water circulation system has the effect of reducing the energy consumption and investment of the existing hot-rolled strip steel cooling water circulation system.

Description

A cooling water circulation system for hot-rolled strip steel Technical Field

[0001] This utility model relates to the technical field of hot rolling of steel, and more specifically, to a cooling water circulation system for hot-rolled strip steel. Background Technology

[0002] The laminar flow cooling technology for hot-rolled strip steel includes a laminar flow cooling device and a laminar flow cooling water circulation system. The laminar flow cooling device is used to cool the strip steel with low-pressure laminar flow columnar water, while the laminar flow cooling water circulation system is mainly used to treat the used cooling water and provide the cooling circulating water required for strip steel cooling.

[0003] Currently, as shown in Figure 1, a conventional cooling water circulation system includes equipment such as a hot water tank 11, a filter 12, a cooling tower 13, a cold water tank 14, and an iron sheet slag flushing ditch 15. The specific circulation process is as follows: iron oxide scale flows into the iron sheet slag flushing ditch 15 with the cooling water flow, and then enters the hot water tank 11. 50% of the cooling water in the hot water tank 11 is directly pumped to the cold water tank 14 by a laminar flow lift pump group, and the other 50% of the cooling water is pumped to the filter 12 and the cooling tower 13 by a side filter pump group. After filtration and cooling treatment, the water is mixed in the cold water tank 14. Finally, the cooling water in the cold water tank 14 is pumped to the high-level water tank 10 by a lift pump group 9, or to the side spray pipe by a side spray pump group for use by the cooling device 6.

[0004] The aforementioned circulation system mainly involves two pump pressurization processes: the first lifts water from the hot water tank to the cold water tank, and the second pressurizes the water from the cold water tank and sends it to the elevated water tank. These two pressurization processes consume significant energy and only filter and cool 50% of the cooling water. Furthermore, current cooling water circulation systems are primarily located outside the strip steel cooling plant, meaning they deliver cooling water to areas outside the production line via pipes and pumps, thus occupying a considerable amount of additional space. Therefore, how to configure an energy-efficient and rationally planned cooling water circulation system is a pressing issue that needs to be addressed in existing technologies. Summary of the Invention

[0005] To reduce the energy consumption and investment of current hot-rolled strip cooling water circulation systems, this utility model provides a hot-rolled strip cooling water circulation system, which includes a water collection tank, a filter tank, a heat exchange tank, and a water storage tank. The water collection tank is located below the cooling device, and the lower end of the water collection tank is connected to the lower end of the filter tank. The upper end of the filter tank is connected to the upper end of the heat exchange tank, and the lower end of the heat exchange tank is connected to the lower end of the water storage tank. The filter tank is used to filter the cooling water, and the heat exchange tank is used to cool the filtered cooling water.

[0006] Optionally, the hot-rolled strip cooling water circulation system further includes a booster pump set, which is used to boost the cooling water in the water storage tank to a high-level water tank to supply water to the cooling device.

[0007] Optionally, the water collection tank, filtration tank, heat exchange tank, and water storage tank are arranged in parallel and extend along the length of the cooling device.

[0008] Optionally, a sludge hopper is provided below the filtration tank.

[0009] Optionally, the bottom of the water collection tank and the filter tank has a slope that slopes downward toward the sludge hopper.

[0010] Optionally, the filter pool is provided with multiple filter layers from bottom to top, and each filter layer is filled with filter media.

[0011] Optionally, the pore size of the plurality of filter layers decreases sequentially from bottom to top.

[0012] Optionally, the filter medium includes one or more of quartz sand, anthracite, and polymeric fibrous materials.

[0013] Optionally, the upper end of the filter layer is provided with a backwashing device, which is used to rinse the filter layer.

[0014] Optionally, the heat exchange pool is provided with a heat exchange tube bundle arranged in a vertical direction, and a cooling medium flows through the heat exchange tube bundle.

[0015] The advantages of this utility model compared to the prior art are:

[0016] In this invention, the cooling water after use flows directly into the collection tank under gravity. As the water level in the collection tank gradually rises, the cooling water flows upward into the filtration tank, where it undergoes filtration from bottom to top. The filtered cooling water then overflows from the top of the filtration tank into the heat exchange tank, where it is cooled. After heat exchange, the cooling water finally enters the storage tank for storage. The cooling water in the storage tank is then supplied to the cooling system, thus achieving constant water level self-circulating cooling. In this invention, the cooling water flows continuously between the collection tank, filtration tank, heat exchange tank, and storage tank through gravity, the principle of communicating vessels, and overflow, eliminating the need for additional booster pumps and pipelines. This significantly reduces energy consumption and construction costs associated with installing additional pumps and laying pipelines. Furthermore, as the water level increases, the filtration and heat exchange processes automatically begin based on the principle of communicating vessels, requiring no manual control and further reducing labor costs. Furthermore, in actual deployment, the circulation system in this invention makes reasonable use of the area below the production line floor (cooling device) without occupying additional space, which greatly reduces construction costs. Attached Figure Description

[0017] Figure 1 is a schematic diagram of the structure of a cooling water circulation system in the prior art;

[0018] Figure 2 is a structural schematic diagram of the cooling water circulation system from a first-view perspective in an embodiment of this utility model;

[0019] Figure 3 is a structural schematic diagram of the cooling water circulation system from a second perspective in an embodiment of this utility model;

[0020] Explanation of reference numerals in the attached figures:

[0021] 1. Water collection tank; 2. Filtration tank; 3. Heat exchange tank; 4. Water storage tank; 5. Sludge hopper; 6. Cooling device; 7. Filter layer; 8. Heat exchange tube bundle; 9. Booster pump set; 10. High-level water tank; 11. Hot water tank; 12. Filter; 13. Cooling tower; 14. Cold water tank; 15. Slag flushing ditch; 16. Slope. Detailed Implementation

[0022] To make the above-mentioned objects, features, and advantages of this utility model more apparent and understandable, specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Although some embodiments of this utility model are shown in the drawings, it should be understood that this utility model can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of this utility model. It should be understood that the drawings and embodiments of this utility model are for illustrative purposes only and are not intended to limit the scope of protection of this utility model.

[0023] The term "comprising" and its variations as used herein are open-ended, meaning "including but not limited to"; the term "based on" means "at least partially based on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments"; and the term "optionally" means "optional embodiments". Definitions of other terms will be given in the following description. It should be noted that the concepts of "first," "second," etc., mentioned in this utility model are only used to distinguish different devices, modules, or units, and are not used to limit the order of functions performed by these devices, modules, or units or their interdependencies.

[0024] It should be noted that the terms "one" and "multiple" used in this utility model are illustrative rather than restrictive. Those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0025] Improving the performance of rolled products through post-rolling controlled cooling technology is an effective approach and an important part of hot-rolled strip steel production lines. Generally speaking, the cooling devices in hot-rolled strip steel cooling technology include laminar flow cooling devices, ultra-fast cooling devices, water curtain cooling devices, and high-pressure water spray cooling devices. Since the cooling water absorbs heat from the strip steel during the cooling process, the hot-rolled strip steel cooling water circulation system in this utility model can be used to filter and cool the cooling water that has been heated after the above-mentioned cooling devices have been used. Taking the laminar flow cooling device as an example, according to the requirements of the laminar flow cooling process of the 1000-2300mm hot-rolled wide strip steel production line, the laminar flow cooling water mainly has the following characteristics: (1) large flow rate, generally between 4000 and 18000 m³ / h. 3 / h; (2) Low pressure, the pressure required at the laminar flow manifold is generally 0.07MPa, and the pressure is required to be stable; (3) Low water quality requirements, the iron oxide scale contained in the laminar flow cooling water has fine particle size and low oil content; (4) Large water volume variation, the water consumption varies with the type of rolled steel plate. For ease of understanding, the embodiments of this utility model specifically introduce the application scenario of the hot-rolled strip cooling water circulation system in the laminar flow cooling device. It should be understood that the protection scope of this utility model is not limited to this specific application scenario.

[0026] This utility model embodiment provides a cooling water circulation system for hot-rolled strip steel. Referring to Figures 2 and 3, the system includes a water collection tank 1, a filter tank 2, a heat exchange tank 3, and a water storage tank 4. The water collection tank 1 is located below the cooling device 6. The lower end of the water collection tank 1 is connected to the lower end of the filter tank 2, the upper end of the filter tank 2 is connected to the upper end of the heat exchange tank 3, and the lower end of the heat exchange tank 3 is connected to the lower end of the water storage tank 4. The filter tank 2 is used to filter the cooling water; the heat exchange tank 3 is used to cool the filtered cooling water.

[0027] Specifically, the cooling device 6 mainly consists of an upper manifold and a lower manifold, located on the upper and lower surfaces of the strip steel, respectively. Cooling of the strip steel is achieved by spraying a laminar flow cooling medium (such as water). In actual installation, the water collection tank 1 is located below the outlet pipe assembly of the cooling device 6 and the finished product conveyor rollers, specifically corresponding to the outlet of the cooling device 6. The cooling water used by the cooling device 6 flows into the water collection tank 1 under gravity. As the water level in the water collection tank 1 gradually rises, the cooling water flows upward through the filter layer of the filter tank 2. The filtered cooling water then overflows from the upper end of the filter tank 2 into the heat exchange tank 3, where it is cooled. After heat exchange, the cooling water finally enters the storage tank 4 for temporary storage, thus achieving constant water level self-circulating cooling.

[0028] In this invention, cooling water flows continuously between the collection tank 1, the filter tank 2, the heat exchange tank 3, and the storage tank 4 using the principle of communicating vessels and overflow. There is no need to set up facilities such as slag flushing ditches, inlet and outlet water corridors, or laminar flow stations. By utilizing gravity and the principle of communicating vessel structure, the collection, purification, and cooling of cooling water can be continuously processed. Moreover, the cooling water after being used by the cooling device 6 can directly flow into the collection tank 1 under the action of gravity, without the need to set up other pump sets, thus reducing the energy consumption and construction investment caused by setting up pump sets and laying pipelines.

[0029] As an optional further reference, as shown in Figures 2 and 3, the water collection tank 1, the filter tank 2, the heat exchange tank 3 and the water storage tank 4 are arranged in parallel and extend along the length of the cooling device 6.

[0030] Specifically, the water collection tank 1, filter tank 2, heat exchange tank 3, and water storage tank 4 are arranged parallel to each other along the rolling centerline to the mill drive side. The length of each of these tanks extends from the rear section of the finishing F7 roll to the front section of the coiler DC1. This invention, by adopting the above arrangement, rationally utilizes the underground space of the production line, saving on the project's land area.

[0031] Furthermore, in some optional embodiments, the hot-rolled strip cooling water circulation system also includes a booster pump set 9, which is used to lift the cooling water in the storage tank 4 to supply water to the cooling device 6. Specifically, the cooling water in the storage tank 4 is first transported to the elevated water tank 10 by the booster pump set 9. The elevated water tank 10 is usually located above the cooling device 6, and provides a stable water pressure to the system through gravity, ensuring that the cooling water can be smoothly supplied to the cooling device 6, thereby providing the cooling device 6 with cooled water. Therefore, this utility model only needs to set up one set of booster pump set 9 to lift the cooling water from the storage tank 4 to the elevated water tank 10, which can achieve 100% filtration and cooling of the cooling circulating water, without the need to set up other pump sets.

[0032] In some optional embodiments, referring to Figures 2 and 3, the bottom of the filter tank 2 is provided with a sludge hopper 5, which is used to collect settled impurities in the cooling water. The bottom of the water collection tank 1 has a slope 16, which slopes downward toward the sludge hopper 5. The slope 16 allows the directly collected cooling water to fully release energy and initially settle some impurity particles in the water. The sludge hopper 5 further collects the initially settled iron oxide scale, a small amount of floating oil, and other impurities, as well as impurities dropped off during the backwashing of the filter tank 2. The sludge hopper 5 can be periodically discharged with a sewage pump. Furthermore, referring to Figure 3, a slope 16 can also be provided between the sludge hopper 5 and the inner wall of the filter tank 2, so that the impurities dropped off from the filter tank 2 can fully settle into the sludge hopper 5.

[0033] In some optional embodiments, referring to FIG3, a plurality of filter layers 7 are arranged from bottom to top in the filter tank 2, each filter layer 7 being filled with filter media. Specifically, the pore size of the plurality of filter layers 7 decreases sequentially from bottom to top, and the filter media may include any one or more of quartz sand, anthracite, and polymer fibrous materials. Through the particle size distribution of larger particles at the bottom and smaller particles at the top, as the water level in the filter tank 2 gradually increases, the filter layers 7 can first adsorb larger particles of impurities, and then adsorb smaller particles of impurities. This can significantly reduce the burden on each filter layer 7, while ensuring that fine iron oxide particles and floating oil and other impurities in the water can be fully removed and adsorbed in the filter tank 2.

[0034] In some optional embodiments, a backwashing device (not shown in the figure) is also provided at the upper end of the filter layer 7. The backwashing device is used to apply a downward water flow to the filter layer 7 for backwashing. Specifically, the backwashing device can be a flushing water pipe arranged horizontally above the filter layer 7, with multiple high-pressure nozzles spaced apart on the flushing water pipe. The high-pressure nozzles spray high-pressure water onto the filter layer 7 to flush it. The washed-off impurities then enter the sludge hopper 5 along the bottom of the inclined filter tank 2.

[0035] In some optional embodiments, referring to Figure 3, the heat exchange tank 3 is provided with a heat exchange tube bundle 8 arranged vertically, and a cooling medium flows through the heat exchange tube bundle 8. Alternatively, in other embodiments, the heat exchange tank 3 is provided with multiple vertical heat exchange plates, which are spaced apart horizontally, and a cooling medium flows through the vertical heat exchange plates. Specifically, the cooling medium can be water, liquid nitrogen, etc. The cooling water exchanges heat with the heat exchange medium in the heat exchange tube bundle 8 or the heat exchange plates, and then collects, stores, and utilizes this heat. In other embodiments, this collected and stored heat can be used as a power heat source for the lithium bromide refrigeration unit.

[0036] In some optional embodiments, at 12000m 3 Taking a cooling circulating water volume of / h as an example, the design calculation of the layout height of each area is as follows: In the actual layout process, it is necessary to avoid the various detection instruments on the production line. Assuming the ground elevation is 0.00m, in this embodiment, the highest water level elevation of the water collection tank 1, filter tank 2, heat exchange tank 3, and water storage tank 4 is approximately -1.00m; the bottom elevation of heat exchange tank 3 and water storage tank 4 is approximately -9.00 to -10.00m; the length of water collection tank 1, filter tank 2, heat exchange tank 3, and water storage tank 4 is approximately 100m; the cross-sectional width ratio of water collection tank 1, filter tank 2, heat exchange tank 3, and water storage tank 4 along the rolling mill drive side is 1:2:2:1. In other embodiments, the dimensions of each functional area can also be reasonably adjusted according to the cooling circulating water volume.

Claims

1. A cooling water circulation system for hot-rolled strip steel, characterized in that, The device includes a water collection tank (1), a filter tank (2), a heat exchange tank (3), and a water storage tank (4). The water collection tank (1) is located below the cooling device (6). The lower end of the water collection tank (1) is connected to the lower end of the filter tank (2). The upper end of the filter tank (2) is connected to the upper end of the heat exchange tank (3). The lower end of the heat exchange tank (3) is connected to the lower end of the water storage tank (4). The filter tank (2) is used to filter the cooling water, and the heat exchange tank (3) is used to cool the filtered cooling water.

2. The hot-rolled strip cooling water circulation system according to claim 1, characterized in that, The hot-rolled strip cooling water circulation system also includes a booster pump set (9), which is used to boost the cooling water in the water storage tank (4) to the high-level water tank (10) to supply water to the cooling device (6).

3. The hot-rolled strip cooling water circulation system according to claim 1, characterized in that, The water collection tank (1), filter tank (2), heat exchange tank (3) and water storage tank (4) are arranged in parallel and extend along the length of the cooling device (6).

4. The hot-rolled strip cooling water circulation system according to claim 1, characterized in that, The filtration tank (2) is provided with a sludge hopper (5) below it.

5. The hot-rolled strip cooling water circulation system according to claim 4, characterized in that, The bottom of the water collection tank (1) and the filter tank (2) has a slope (16) that slopes downward toward the sludge hopper (5).

6. The hot-rolled strip cooling water circulation system according to claim 1, characterized in that, The filter pool (2) is provided with multiple filter layers (7) from bottom to top, and each filter layer (7) is filled with filter media.

7. The hot-rolled strip cooling water circulation system according to claim 6, characterized in that, The pore size of the plurality of filter layers (7) decreases sequentially from bottom to top.

8. The hot strip cooling water circulation system according to claim 6, wherein The filter medium includes any one or more of quartz sand, anthracite, and high molecular weight fibrous materials.

9. The hot strip cooling water circulation system of claim 6, wherein, The filter layer (7) is provided with a backwashing device at its upper end, which is used to rinse the filter layer (7).

10. The hot-rolled strip cooling water circulation system according to claim 1, characterized in that, The heat exchange pool (3) is provided with a heat exchange tube bundle (8) arranged in a vertical direction, and a cooling medium flows through the heat exchange tube bundle (8).

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