High-temperature steam recycling device

Abstract

The utility model discloses a high-temperature steam recycling device which comprises a direct heat exchange steam pipeline, an indirect heat exchange steam pipeline, a heat exchange condenser a and a cold medium pipeline, the direct heat exchange steam pipeline is communicated with a fine filter box, and a microporous membrane is arranged in the fine filter box. Steam output by the fine filter box is communicated with the mixing tank through an output pipeline and an indirect heat exchange steam pipeline, and the mixing tank is communicated with the heat exchange condenser a through a condensation pipeline. According to the high-temperature steam recycling device, alumina particles with the particle diameter larger than that of water vapor drop particles or aluminum hydroxide suspended solids which are not completely decomposed in steam are filtered and separated in a microporous filtering mode, the temperature of the alumina particles or the aluminum hydroxide suspended solids is increased in a compression mode, and the alumina particles or the aluminum hydroxide suspended solids are recycled through heat exchange and then enter the next condenser to be released, so that the temperature of the alumina particles or the aluminum hydroxide suspended solids is reduced; therefore, heat energy can be recycled, meanwhile, the recycling efficiency of condensate water can be improved, and waste of water resources and heat energy is avoided.

Description

Technical Field

[0001] This utility model relates to the field of aluminum production technology, specifically a high-temperature steam recycling device for cooling high-temperature aluminum. Background Technology

[0002] Electrolytic aluminum is a process for producing primary aluminum through electrolysis. It is the core production method of the modern aluminum industry and is characterized by large scale and high efficiency. Electrolytic aluminum adopts the cryolite-alumina molten salt electrolysis method. In the electrolytic cell, carbon is used as the anode and aluminum liquid is used as the cathode. After a strong direct current is passed through, at a high temperature of 950℃-970℃, alumina is reduced to liquid aluminum at the cathode. This is high-temperature aluminum. The liquid aluminum is periodically extracted from the cell through a vacuum ladle and sent to the foundry.

[0003] Cooling high-temperature molten aluminum (liquid aluminum, typically above 660℃) requires selecting a suitable cooling method based on production process requirements, equipment conditions, and the final product form. Water cooling is commonly used, including direct and indirect cooling. In direct cooling, the molten aluminum comes into direct contact with water, rapidly dissipating heat through vaporization (evaporation) and heat conduction. The molten aluminum is poured into a metal mold (such as a copper or steel mold), and heat is carried away from the outside of the mold by circulating water or a coolant (such as water with a corrosion inhibitor). The water vapor generated by indirect cooling can be directly recovered. However, the water vapor generated by direct cooling may contain alumina particles or incompletely decomposed aluminum hydroxide solids, which cannot be effectively recovered. After condensation, it is sent directly for treatment, resulting in both heat and water waste. Therefore, this application is proposed. Utility Model Content

[0004] The purpose of this invention is to provide a high-temperature steam recycling device to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution:

[0006] A high-temperature steam recycling device includes a direct heat exchange steam pipeline, an indirect heat exchange steam pipeline, a heat exchange condenser a, and a cold medium pipeline. The direct heat exchange steam pipeline is connected to a fine filter box, which is equipped with a microporous membrane. The steam output from the fine filter box is connected to a mixing tank through both the output pipeline and the indirect heat exchange steam pipeline. The mixing tank is connected to the heat exchange condenser a through a condensation pipeline.

[0007] As a further embodiment of this utility model: a pressure relief valve is provided at the steam output end of the heat exchange condenser a, an air pump is provided on the condensation pipeline, the cold medium pipeline is connected to the medium cavity of the heat exchange condenser a, and a heat recovery pipeline is connected to the output end of the medium cavity.

[0008] As a further embodiment of this utility model: the output end of the pressure relief valve is connected to a heat exchange condenser b via a pipeline, the cold medium pipeline is connected to the medium cavity of the heat exchange condenser b, the output end of the medium cavity is connected to a medium recovery pipeline, and a gas output pipeline is provided at the top of the heat exchange condenser b.

[0009] As a further improvement of this utility model: the bottoms of the heat exchange condenser a, heat exchange condenser b and mixing tank are all connected to the condensate output pipeline, and the fine filter box is connected to the condensate output end and is connected to the condensate output pipeline.

[0010] As a further embodiment of this utility model: the interior of the fine filter box is divided into three chambers by two microporous membranes, with an isolation chamber between the two microporous membranes and purification chambers on both sides of the microporous membranes. The purification chambers are connected to the condensate output end, and the bottom of the isolation chambers is connected to the concentrate pipeline.

[0011] As a further improvement of this utility model, valves are provided for the connection between the condensate output pipeline and the heat exchange condenser a, heat exchange condenser b and the mixing tank.

[0012] Compared with the prior art, the beneficial effects of this utility model are:

[0013] This high-temperature steam recycling device separates alumina particles or incompletely decomposed aluminum hydroxide solid suspensions in steam by microfiltration, which are larger than the diameter of water vapor droplets. The steam temperature is increased by compression and then recovered through heat exchange before entering the next condenser to release the steam at a lower temperature for secondary heat exchange and condensation. This not only recovers heat energy but also improves the recovery efficiency of condensate, avoiding the waste of water resources and heat energy. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of a high-temperature steam recycling device.

[0015] In the diagram: 1. Direct heat exchange steam pipeline; 2. Indirect heat exchange steam pipeline; 3. Heat exchange condenser a; 4. Heat exchange condenser b; 5. Fine filter box; 6. Microporous membrane; 7. Condensate outlet; 8. Condensate outlet pipeline; 9. Concentrate pipeline; 10. Outlet pipeline; 11. Medium recovery pipeline; 12. Condensate pipeline; 13. Gas outlet pipeline; 14. Cold medium pipeline; 15. Mixing tank; 16. Air pump; 17. Heat recovery pipeline; 18. Pressure relief valve. Detailed Implementation

[0016] Please see Figure 1In this embodiment of the invention, the high-temperature steam recycling device includes a direct heat exchange steam pipeline 1, an indirect heat exchange steam pipeline 2, a heat exchange condenser a3, and a cold medium pipeline 14. The direct heat exchange steam pipeline 1 is connected to a fine filter box 5. A microporous membrane 6 is installed inside the fine filter box 5. The steam output from the fine filter box 5 is connected to a mixing tank 15 via an output pipeline 10 and an indirect heat exchange steam pipeline 2. The mixing tank 15 is connected to the heat exchange condenser a3 via a condensation pipeline 12. The microporous membrane 6 is a ceramic membrane filter or a metal membrane filter. The device utilizes the properties of the microporous membrane 6... The sieving process traps nanoscale particles. The water vapor from the direct heat exchange steam line 1 is recycled and enters the fine filter box 5. After being filtered by the microporous membrane 6, it enters the mixing tank 15 together with the steam from the indirect heat exchange steam line 2. In the mixing tank 15, the microporous membrane 6 removes alumina particles or incompletely decomposed aluminum hydroxide solids that may be entrained in the water vapor, thus purifying the water vapor. The water vapor is then sent to the heat exchange condenser a3 for unified condensation and recovery. The water vapor generated from directly cooling high-temperature aluminum is also recovered, saving water resources and reducing waste.

[0017] In a preferred embodiment, a pressure relief valve 18 is provided at the steam output end of the heat exchange condenser a3, an air pump 16 is provided on the condensation pipeline 12, the cold medium pipeline 14 is connected to the medium cavity of the heat exchange condenser a3, and the output end of the medium cavity is connected to the heat recovery pipeline 17. The steam in direct and indirect heat exchange has a large amount of heat energy, and its temperature is further increased by steam compression. It has two functions: first, it can better enable the heat exchange condenser b4 to recover condensate, and second, it can recover heat to a greater extent. The medium can be gas or cooling water, and its heat is recovered through heat exchange.

[0018] In a preferred embodiment, the output end of the pressure relief valve 18 is connected to the heat exchange condenser b4 via a pipeline. The cold medium pipeline 14 is connected to the medium cavity of the heat exchange condenser b4. The output end of the medium cavity is connected to the medium recovery pipeline 11. A gas output pipeline 13 is provided at the top of the heat exchange condenser b4. The steam inside the heat exchange condenser a3 is cooled down after heat exchange. After passing through the pressure relief valve 18, the pressure is released, the temperature is further reduced, and then further cooled by the medium to recover the remaining condensate.

[0019] In a preferred embodiment, the bottoms of heat exchange condenser a3, heat exchange condenser b4, and mixing tank 15 are all connected to the condensate output line 8. Fine filter box 5 is connected to condensate output end 7 and is also connected to condensate output line 8. Mixing tank 15 not only has a mixing function but also a function of separating condensate. Since liquids are incompressible, it is necessary to avoid condensate from entering air pump 16 as much as possible to prevent damage to air pump 16.

[0020] In a preferred embodiment, the interior of the fine filter box 5 is divided into three chambers by two microporous membranes 6. The space between the two microporous membranes 6 is an isolation chamber, and the two sides of the microporous membranes 6 are purification chambers. The purification chambers are connected to the condensate outlet 7, and the bottom of the isolation chamber is connected to the concentrate pipeline 9. The microporous membranes 6 filter alumina particles or incompletely decomposed aluminum hydroxide solids suspended in the water vapor into the isolation chamber. The water vapor passes through the microporous membranes 6 into the purification chamber. The liquid with increased impurities accumulated in the isolation chamber is called the concentrate, which needs to be periodically discharged. The purification chamber is also connected to a pulse backflush pipeline. The pulse backflush pipeline is existing technology, commonly used in bag filters. The microporous membrane 6 has extremely high filtration accuracy, achieving complete particle retention, but the membrane is prone to clogging, requiring frequent cleaning or replacement, resulting in high costs. It is only used in high-value-added applications. Therefore, a pulse backflush pipeline is designed. The droplet size in the water vapor is not fixed, typically ranging from 0.01 micrometers to 10 micrometers. The pore size is between micrometers, while the alumina particles or incompletely decomposed aluminum hydroxide solid suspensions carried in water vapor are usually larger than 8 micrometers. The filtration pore size of the microporous membrane 6 can be set according to the actual situation.

[0021] In a preferred embodiment, valves are installed in the connection between the condensate outlet pipeline 8 and the heat exchange condenser a3, heat exchange condenser b4 and mixing tank 15. The valves control the recovery of condensate and prevent gas from entering. Water level sensors can be installed inside the heat exchange condenser a3, heat exchange condenser b4 and mixing tank 15 to detect the amount of condensate stored. When the water level reaches the high critical point, the condensate is discharged and the discharge stops when it reaches the low critical point.

[0022] It should be noted that all the above embodiments belong to the same utility model concept, and the descriptions of each embodiment have different focuses. Where the description in a particular embodiment is not detailed, please refer to the description in other embodiments.

[0023] The embodiments described above merely illustrate the implementation of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A high-temperature steam recycling device, comprising a direct heat exchange steam pipeline (1), an indirect heat exchange steam pipeline (2), a heat exchange condenser a (3), and a cold medium pipeline (14), characterized in that, The direct heat exchange steam pipeline (1) is connected to the fine filter box (5). The fine filter box (5) is equipped with a microporous membrane (6). The steam output from the fine filter box (5) is connected to the mixing tank (15) through the output pipeline (10) and the indirect heat exchange steam pipeline (2). The mixing tank (15) is connected to the heat exchange condenser a (3) through the condensation pipeline (12).

2. The high-temperature steam recycling device according to claim 1, characterized in that, The heat exchange condenser a (3) is equipped with a pressure relief valve (18) at the steam output end, and a gas pump (16) is installed on the condensation pipeline (12). The cold medium pipeline (14) is connected to the medium cavity of the heat exchange condenser a (3), and the output end of the medium cavity is connected to a heat recovery pipeline (17).

3. The high-temperature steam recycling device according to claim 2, characterized in that, The output end of the pressure relief valve (18) is connected to the heat exchange condenser b (4) through a pipeline. The cold medium pipeline (14) is connected to the medium cavity of the heat exchange condenser b (4). The output end of the medium cavity is connected to the medium recovery pipeline (11). A gas output pipeline (13) is provided at the top of the heat exchange condenser b (4).

4. The high-temperature steam recycling device according to claim 3, characterized in that, The bottoms of the heat exchange condenser a (3), heat exchange condenser b (4) and mixing tank (15) are all connected to the condensate output pipeline (8), and the fine filter box (5) is connected to the condensate output end (7) and is connected to the condensate output pipeline (8).

5. The high-temperature steam recycling device according to claim 4, characterized in that, The interior of the fine filter box (5) is divided into three chambers by two microporous membranes (6). The space between the two microporous membranes (6) is an isolation chamber, and the two sides of the microporous membranes (6) are purification chambers. The purification chamber is connected to the condensate output end (7), and the bottom of the isolation chamber is connected to the concentrate pipeline (9).

6. The high-temperature steam recycling device according to claim 4, characterized in that, Valves are provided for the connection between the condensate output pipeline (8) and the heat exchange condenser a (3), heat exchange condenser b (4) and mixing tank (15).

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