Causticized liquid heat exchange system
The combined use of a freezing crystallization device and a heat exchanger solves the problems of crystallization and high energy consumption of the causticized liquid in the pipeline, achieves temperature increase and energy consumption reduction, and ensures production stability and economy.
Patent Information
- Application Number
- CN202422818310.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-19
- Publication Date
- 2025-09-23
- Estimated Expiration
- 2034-11-19
AI Technical Summary
The causticized liquid is prone to crystallization and precipitation in the pipeline, leading to pipeline blockage and increased energy consumption.
A freezing crystallization device and a heat exchanger are used to exchange heat between condensed water and the causticized liquid, thereby increasing the temperature of the causticized liquid, avoiding premature precipitation of lithium hydroxide and reducing the latent heat of evaporation.
It effectively avoids the premature precipitation of lithium hydroxide in the subsequent treatment process, reduces the latent heat demand for evaporation, and improves the economy and stability of production.
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Figure CN223376428U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of heat exchange systems, and more specifically relates to a causticized liquid heat exchange system. Background Art
[0002] In current lithium salt plants, the production process for lithium hydroxide primarily relies on the causticization reaction between lithium sulfate and sodium hydroxide, converting it into two products: lithium hydroxide and sodium sulfate. The resulting sodium sulfate undergoes a series of physical treatment steps to separate it from the lithium hydroxide solution. Specifically, this separation process involves two stages: primary freeze crystallization and secondary freeze crystallization. By gradually lowering the solution temperature, the sodium sulfate forms a stable crystal structure and precipitates from the solution, leaving the remaining lithium hydroxide solution, the post-causticization solution.
[0003] In practice, the temperature of the causticized liquid drops significantly after undergoing two stages of freeze crystallization. While this low temperature facilitates the crystallization and separation of sodium sulfate, excessively low temperatures can cause the lithium hydroxide component in the liquid to crystallize and precipitate within the piping system, forming a so-called "scab." Over time, these crystalline deposits accumulate and thicken, reducing the effective flow area of the pipeline and potentially completely blocking it, severely disrupting the continuous and stable operation of the production line and even causing production interruptions.
[0004] Furthermore, directing the cool causticized solution to the lithium hydroxide workshop for evaporation and crystallization presents energy consumption challenges. Due to the low solution temperature, the evaporation process requires additional heat input to overcome the high latent heat of vaporization, which undoubtedly increases energy consumption throughout the production process and reduces production economics. Utility Model Content
[0005] The purpose of the embodiments of the present application is to provide a causticized liquid heat exchange system to solve the technical problems existing in the prior art that the causticized liquid is prone to crystallization and precipitation in the pipeline and has a large latent heat of evaporation.
[0006] To achieve the above objectives, the technical solution adopted in this application is:
[0007] Provided is a causticized liquid heat exchange system, comprising:
[0008] A freezing crystallization device having a condensate water pipeline;
[0009] Causticized liquid pipeline;
[0010] The heat exchanger includes a hot stream and a cold stream; the condensed water in the condensed water pipe flows through the hot stream of the heat exchanger, and the causticized liquid in the causticized liquid pipe flows through the cold stream of the heat exchanger, and the condensed water and the causticized liquid exchange heat in the heat exchanger.
[0011] As a further improvement of the above technical solution:
[0012] Optionally, the freezing crystallization device includes a primary freezing crystallization device and a secondary freezing crystallization device; the primary freezing crystallization device has a primary condensed water pipeline; the secondary freezing crystallization device has a secondary condensed water pipeline; the heat exchanger includes a first heat exchanger and a second heat exchanger;
[0013] The secondary condensate in the secondary condensate pipe flows through the hot stream of the second heat exchanger, and the causticized liquid in the causticized liquid pipe flows through the cold stream of the second heat exchanger, and the secondary condensate and the causticized liquid undergo a first heat exchange in the second heat exchanger;
[0014] The primary condensate in the primary condensate pipe flows through the hot stream of the first heat exchanger, and the causticized liquid after the first heat exchange flows through the cold stream of the first heat exchanger. The primary condensate and the causticized liquid undergo a second heat exchange in the first heat exchanger.
[0015] Optionally, the causticized liquid heat exchange system further includes a mixing water tank, which is connected to the evaporative cooler, and the primary condensed water flows into the mixing water tank after heat exchange with the causticized liquid.
[0016] Compared with the prior art, the beneficial effects of the present invention are:
[0017] The causticized liquid heat exchange system provided in the present application includes a freezing crystallization device, a causticized liquid pipeline and a heat exchanger. Among them, the freezing crystallization device is responsible for cooling the causticized liquid so that the sodium sulfate in the causticized liquid forms crystals and precipitates. During the operation of the freezing crystallization device, condensed water is produced. Since the heat in the causticized liquid is transferred to the condensed water, the condensed water temperature is relatively high and is then discharged through the condensed water pipeline. The causticized liquid pipeline is used to guide the causticized liquid to flow along a specified path. The heat exchanger specifically includes two independent channels, a hot stream and a cold stream. The high-temperature condensed water in the condensed water pipeline is guided to flow in the hot stream, while the causticized liquid to be treated in the causticized liquid pipeline flows through the cold stream. Under the action of the heat exchanger, the heat released by the condensed water is absorbed by the causticized liquid, thereby realizing effective heat transfer. On the one hand, the temperature of the causticized liquid is increased, thereby increasing the solubility of lithium hydroxide therein, effectively avoiding the premature precipitation of lithium hydroxide in the subsequent treatment process. At the same time, it also reduces the latent heat of evaporation that the causticized liquid needs to overcome during the evaporation stage, which is beneficial to energy conservation and consumption reduction. On the other hand, the temperature of the condensed water is significantly reduced, providing more favorable conditions for subsequent water resource recycling or cooling treatment. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.
[0019] Figure 1 It is a schematic diagram of the structural layout of the causticized liquid heat exchange system of this application.
[0020] Among them, the reference numerals in the figures are:
[0021] 1. Primary freezing crystallization device; 2. Secondary freezing crystallization device;
[0022] 3. Primary condensate water pipeline; 4. Secondary condensate water pipeline;
[0023] 5. First heat exchanger; 6. Second heat exchanger;
[0024] 7. Mixing water tank. DETAILED DESCRIPTION
[0025] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application more clearly understood, this application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.
[0026] It should be noted that when an element is referred to as being “fixed on” or “disposed on” another element, it may be directly on the other element or indirectly on the other element. When an element is referred to as being “connected to” another element, it may be directly connected to the other element or indirectly connected to the other element.
[0027] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.
[0028] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. Throughout the description of this application, "plurality" means two or more, unless otherwise specifically defined.
[0029] Unless otherwise defined, all technical terms used hereinafter have the same meanings as those generally understood by those skilled in the art. The technical terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention.
[0030] like Figure 1 As shown, the present application provides a causticized liquid heat exchange system, including a freezing crystallization device, a causticized liquid pipeline and a heat exchanger.
[0031] The freeze crystallization unit is responsible for cooling the causticized liquid, causing the sodium sulfate in the liquid to form crystals and precipitate. During the operation of the freeze crystallization unit, condensate is produced. Heat from the causticized liquid is transferred to the condensate, resulting in a higher temperature. This condensate is then discharged through a condensate pipe. The causticized liquid pipe guides the liquid along a designated path. The heat exchanger specifically includes two independent channels: a hot stream and a cold stream. High-temperature condensate in the condensate pipe is directed into the hot stream, while untreated causticized liquid in the causticized liquid pipe flows through the cold stream. The heat released by the condensate is absorbed by the causticized liquid through the heat exchanger, achieving efficient heat transfer. This increases the temperature of the causticized liquid, thereby increasing the solubility of lithium hydroxide, effectively preventing premature precipitation of lithium hydroxide during subsequent processing. It also reduces the latent heat of evaporation required during the evaporation phase, contributing to energy conservation and cost reduction. Furthermore, the condensate temperature is significantly lowered, providing more favorable conditions for subsequent water recycling or cooling treatment.
[0032] like Figure 1 As shown, in a specific embodiment of the present application, the freezing crystallization device specifically includes a primary freezing crystallization device 1 and a secondary freezing crystallization device 2. Correspondingly, the primary freezing crystallization device 1 has a primary condensate water pipeline 3; the secondary freezing crystallization device 2 has a secondary condensate water pipeline 4. The heat exchanger specifically includes a first heat exchanger 5 and a second heat exchanger 6.
[0033] During actual operation, the secondary condensate in the secondary condensate pipe 4 flows through the hot stream of the second heat exchanger 6, and the causticized liquid in the causticized liquid pipe flows through the cold stream of the second heat exchanger 6. The secondary condensate and the causticized liquid undergo a first heat exchange in the second heat exchanger 6. The temperature of the causticized liquid can be increased from 12°C to 32°C, and the temperature of the secondary condensate can be cooled from 80°C to 42°C. The cooled secondary condensate can be sent to the leaching workshop for preparation of dilute sulfuric acid.
[0034] The primary condensate in the primary condensate pipe 3 flows through the hot stream of the first heat exchanger 5, and the causticized liquid after the first heat exchange flows through the cold stream of the first heat exchanger 5. The primary condensate and the causticized liquid undergo a second heat exchange within the first heat exchanger 5. After the first heat exchange, the temperature of the causticized liquid rises from 32°C to 65°C, while the temperature of the primary condensate drops from 80°C to 35°C. The cooled primary condensate can be used as a supplemental water source for the evaporative cooler.
[0035] The specific heat exchange data of the first heat exchanger 5 and the second heat exchanger 6 are shown in the following table:
[0036]
[0037] like Figure 1As shown, in a specific embodiment of the present application, the causticized liquid heat exchange system further includes a mixing water tank 7. The mixing water tank 7 is connected to the evaporative cooler. The primary condensate exchanges heat with the causticized liquid and flows into the mixing water tank 7 to serve as a supplementary water source for the evaporative cooler.
[0038] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.
Claims
1. A causticized liquid heat exchange system, characterized in that: include: A freezing crystallization device having a condensate water pipeline; Causticized liquid pipeline; The heat exchanger includes a hot stream and a cold stream; the condensed water in the condensed water pipe flows through the hot stream of the heat exchanger, and the causticized liquid in the causticized liquid pipe flows through the cold stream of the heat exchanger, and the condensed water and the causticized liquid exchange heat in the heat exchanger.
2. The causticized liquid heat exchange system according to claim 1, characterized in that: The freezing crystallization device comprises a primary freezing crystallization device (1) and a secondary freezing crystallization device (2); the primary freezing crystallization device (1) has a primary condensed water pipeline (3); the secondary freezing crystallization device (2) has a secondary condensed water pipeline (4); the heat exchanger comprises a first heat exchanger (5) and a second heat exchanger (6); The secondary condensate in the secondary condensate pipe (4) flows through the hot stream of the second heat exchanger (6), and the causticized liquid in the causticized liquid pipe flows through the cold stream of the second heat exchanger (6), and the secondary condensate and the causticized liquid undergo a first heat exchange in the second heat exchanger (6); The primary condensed water in the primary condensed water pipe (3) flows through the hot stream of the first heat exchanger (5), the causticized liquid after the first heat exchange flows through the cold stream of the first heat exchanger (5), and the primary condensed water and the causticized liquid undergo a second heat exchange in the first heat exchanger (5).
3. The causticized liquid heat exchange system according to claim 2, characterized in that: It also includes a mixing water tank (7), which is connected to the evaporative cooler, and the primary condensed water flows into the mixing water tank (7) after heat exchange with the causticized liquid.