Decomposing tank structure
By designing the decomposition tank structure during the alumina production process, using sodium aluminate solution to cool down and exchange heat with the denominator liquid to increase its temperature, the problem of high energy consumption in the alumina process is solved, and energy consumption is reduced and Reduced circulating water usage.
Patent Information
- Application Number
- CN202323412975.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-14
- Publication Date
- 2024-12-17
- Estimated Expiration
- 2033-12-14
AI Technical Summary
During the alumina production process, the sodium aluminate solution in the decomposition tank cools down and the returned denominator liquid is heated and concentrated, and the energy consumption is high, and the circulating water consumption of the wide plate heat exchanger is large, resulting in an increase in production energy consumption.
A decomposed tank structure is designed, including a tank body, a wide plate heat exchanger and a plurality of heat exchange coils, connecting the wide plate heat exchanger and the groove body through the first and second pipelines, and a heat exchange plate is provided in the tank body The tube is heat exchanged with the denominator solution after cooling with the sodium aluminate solution, and then heat is increased, and then sent to the evaporation process for concentration to reduce the circulating water consumption of the wide plate heat exchanger.
Effectively reduces the energy consumption of the evaporation process, increases the temperature of the denominator liquid, reduces the circulating water consumption of the wide plate heat exchanger, reduces the production energy consumption, and simplifies the installation and processing of the heat exchange coil, reducing costs. .
Smart Images
Figure CN222181833U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the field of aluminum oxide production, in particular to a decomposition tank structure. Background Art
[0002] In the Bayer process of producing alumina by chemical companies, the sodium aluminate solution separated from the red mud is sent to multiple decomposition tanks connected in series. After step-by-step stirring and cooling, aluminum hydroxide is separated and precipitated to obtain a mother liquor containing a large amount of aluminum hydroxide. After filtration, the separated filter cake is used for roasting and dehydration to obtain an alumina product. The separated seed mother liquor is evaporated and concentrated and then returned for the refining process.
[0003] The sodium aluminate solution in the decomposition tank needs to be cooled, while the seed liquor returned to the evaporation process needs to be heated and concentrated, which consumes a lot of energy.
[0004] Therefore, how to make full use of this heat to reduce the production energy consumption of the alumina process is an urgent problem to be solved by technicians in this field. Summary of the invention
[0005] The purpose of the utility model is to provide a decomposition tank structure in view of the deficiencies in the prior art. The structure is simple and the modification cost is low. The sodium aluminate solution in the decomposition tank can be used to increase the temperature of the seed liquor and reduce the energy consumption of the subsequent evaporation process. The amount of circulating water used in the wide plate heat exchanger of the decomposition tank can also be reduced, thereby reducing production energy consumption.
[0006] The technical solution of the present invention is: a decomposition tank structure, including a tank body and a wide plate heat exchanger, the bottom of the tank body is connected to the process medium inlet of the wide plate heat exchanger through a first pipeline, the process medium outlet of the wide plate heat exchanger is connected to the top of the tank body through a second pipeline, a circulating pump is arranged on the second pipeline, and a heat exchange coil is also arranged in the tank body, the upstream end of the heat exchange coil is used to be connected to the seed denominator liquid source, and the downstream end of the heat exchange coil is used to feed the evaporation process.
[0007] The upstream end of the heat exchange coil is located at the top of the tank body, and the downstream end is located at the bottom of the tank body.
[0008] There are multiple heat exchange coils arranged along the height direction of the tank body. The upstream ends of the heat exchange coils are connected in parallel to the seed denominator liquid source, and the downstream ends of the heat exchange coils are connected in parallel to supply materials to the evaporation process.
[0009] The above technical solution has the following beneficial effects:
[0010] 1. The decomposition tank structure includes a tank body and a wide plate heat exchanger. The bottom of the tank body is connected to the process medium inlet of the wide plate heat exchanger through a first pipeline, and the process medium outlet of the wide plate heat exchanger is connected to the top of the tank body through a second pipeline. A circulation pump is arranged on the second pipeline. The sodium aluminate solution in the tank body is cooled by the wide plate heat exchanger and then returns to the tank body to form a cycle. A heat exchange coil is also arranged in the tank body. The upstream end of the heat exchange coil is used to be connected to the seed and denominator liquid source, and the downstream end of the heat exchange coil is used to feed the evaporation process. The seed and denominator liquid for separating aluminum hydroxide is first heated by the heat exchange coil and heated by the high-temperature sodium aluminate solution in the tank body, and then sent to the evaporation process to continue heating, evaporation and concentration. In this way, the energy consumption of the evaporation process can be reduced. After heat exchange, the temperature of the high-temperature sodium aluminate solution in the tank body drops, which can reduce the amount of circulating water used in the matching wide plate heat exchanger.
[0011] 2. The upstream end of the heat exchange coil is located at the top of the tank body, and the downstream end is located at the bottom of the tank body. The temperature of the sodium aluminate solution at the bottom of the tank body is higher than that of the sodium aluminate solution at the top. The seed and mother liquor enter from the top with a relatively low temperature and are discharged from the bottom with a relatively high temperature, thereby ensuring the heating effect of the seed and mother liquor for heat exchange.
[0012] 3. There are multiple heat exchange coils arranged along the height direction of the tank body. The upstream ends of the heat exchange coils are connected in parallel and connected to the seed and denominator liquid source. The downstream ends of the heat exchange coils are connected in parallel to supply materials to the evaporation process. Usually, the height of the tank body is relatively high. By designing multiple heat exchange coils to be arranged along the height direction, it can not only ensure the heating effect on the seed and denominator liquid and the cooling effect on the sodium aluminate solution in the tank body, but also reduce the weight of a single heat exchange coil, facilitate installation and disassembly, and reduce the processing cost of the heat exchange coil.
[0013] Further description is given below in conjunction with the accompanying drawings and specific implementation methods. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Figure 1 It is a structural schematic diagram of the utility model.
[0015] In the attached drawings, 1 is a tank body, 2 is a wide plate heat exchanger, 3 is a first pipeline, 4 is a second pipeline, 5 is a circulation pump, and 6 is a heat exchange coil. DETAILED DESCRIPTION
[0016] See also Figure 1, which is a specific embodiment of a decomposition tank structure. The decomposition tank structure includes a tank body 1 and a wide plate heat exchanger 2. The bottom of the tank body 1 is connected to the process medium inlet of the wide plate heat exchanger through a first pipeline 3. The process medium outlet of the wide plate heat exchanger is connected to the top of the tank body through a second pipeline 4. A circulating pump 5 is arranged on the second pipeline 4. The heat exchange medium of the wide plate heat exchanger adopts circulating water, which is used to cool the sodium aluminate solution flowing through the wide plate heat exchanger and promote the decomposition of the sodium aluminate solution into aluminum hydroxide. A heat exchange coil 6 is also provided in the tank body 1, and the upstream end of the heat exchange coil 6 is used to be connected to the seed denominator liquid source, and the downstream end of the heat exchange coil 6 is used to supply material to the evaporation process. In order to improve the heating effect of the seed denominator liquid, the upstream end of the heat exchange coil 6 is located at the top of the tank body 1, and the downstream end is located at the bottom of the tank body 1. Furthermore, in order to reduce the weight and processing cost of a single heat exchange coil and facilitate installation and disassembly, the number of heat exchange coils 6 is multiple, arranged along the height direction of the tank body 1, and the upstream ends of the heat exchange coils 6 are connected in parallel to connect to the seed denominator liquid source, and the downstream ends of the heat exchange coils 6 are connected in parallel to supply material to the evaporation process.
[0017] The working principle of the utility model is as follows: the high-temperature sodium aluminate solution in the tank body is sent to the wide plate heat exchanger through the first pipeline to cool down, and then returns to the tank body through the second pipeline to reduce the temperature. The sodium aluminate solution (seed and denominator solution) from which sodium hydroxide is separated enters through the upstream end of each heat exchange coil, and after heat exchange and temperature increase with the sodium aluminate solution in the tank body, it is discharged from the downstream end of each heat exchange coil and sent to the evaporation process for concentration.
[0018] The applicant's test results show that the temperature of the seed liquid can be increased by 2-5℃, and the circulating water flow rate of the wide plate heat exchanger can be reduced by 300-600m 3 / h.
Claims
1. A decomposition tank structure, comprising a tank body (1) and a wide plate heat exchanger (2), wherein the bottom of the tank body (1) is connected to the process medium inlet of the wide plate heat exchanger through a first pipeline (3), and the process medium outlet of the wide plate heat exchanger is connected to the top of the tank body through a second pipeline (4), and a circulation pump (5) is arranged on the second pipeline (4), characterized in that: A heat exchange coil (6) is also provided in the tank body (1), the upstream end of the heat exchange coil (6) being used to be connected to a seed denominator liquid source, and the downstream end of the heat exchange coil (6) being used to supply material to the evaporation process.
2. The decomposition tank structure according to claim 1, characterized in that: The upstream end of the heat exchange coil (6) is located at the top of the tank body (1), and the downstream end is located at the bottom of the tank body (1).
3. The decomposition tank structure according to claim 1, characterized in that: The heat exchange coils (6) are multiple in number and are arranged along the height direction of the tank body (1). The upstream ends of the heat exchange coils (6) are connected in parallel and connected to the seed denominator liquid source, and the downstream ends of the heat exchange coils (6) are connected in parallel to supply materials to the evaporation process.