A combined form evaporator system

Abstract

The utility model belongs to lithium concentration technical field, concretely relates to a combined form evaporator system. Including series' MVR falling film concentration unit, primary forced circulation evaporation concentration unit, secondary forced circulation evaporation concentration unit and vacuum unit, the material outlet of MVR falling film concentration unit is connected to primary forced circulation evaporation concentration unit through falling film discharge pump, then is connected to secondary forced circulation evaporation concentration unit through material transfer pump, and material carries on concentration evaporation in turn through MVR falling film concentration unit, primary forced circulation evaporation concentration unit and secondary forced circulation evaporation concentration unit, vacuum unit, including condenser and vacuum pump group. The utility model discloses through the collaborative design of MVR falling film concentration unit and two stage forced circulation evaporation unit, realizes the efficient stage -by -stage concentration of lithium salt, also significantly reduces energy consumption and operating cost.

Description

Technical Field

[0001] This utility model belongs to the field of lithium concentration technology, specifically relating to a combined evaporator system. Background Technology

[0002] With the rapid development of the global new energy vehicle and energy storage industries, the demand for lithium batteries continues to rise, making the efficient extraction and concentration of lithium resources a key link in the industrial chain. In the preparation of lithium salts (such as lithium carbonate and lithium hydroxide), evaporation and concentration are one of the core processes, and their efficiency and energy consumption directly affect production costs and product quality. With the development of the lithium battery industry, the demand for evaporators in the lithium extraction industry is also increasing year by year.

[0003] Currently, the lithium battery industry commonly uses multi-effect evaporation or single evaporator concentration processes, which have the following prominent problems: 1. Inaccurate control of the concentration endpoint: When the concentration is too high, lithium salts are prone to crystallization, resulting in raw material waste and equipment blockage; when the concentration is too low, the lithium content is insufficient and cannot meet the requirements of subsequent lithium precipitation processes, requiring repeated evaporation and extending the production cycle. 2. High energy consumption: Traditional processes rely on external steam heating, resulting in low thermal energy utilization, with overall energy consumption accounting for more than 60% of the total cost. 3. Ineffective recovery of condensate and secondary steam, leading to significant waste of water resources and thermal energy.

[0004] Therefore, there is an urgent need for a low-energy-consumption, high-yield lithium concentration and evaporation system to solve the above problems. Utility Model Content

[0005] This invention addresses the technical problems existing in the prior art by providing a combined evaporator system. Through the coordinated design of an MVR falling film concentration unit and a two-stage forced circulation evaporation unit, it achieves efficient and phased concentration of lithium salts, while significantly reducing energy consumption and operating costs, providing a reliable solution for the lithium battery industry.

[0006] The technical solution of this utility model to solve the above-mentioned technical problems is as follows:

[0007] The MVR falling film concentration unit includes a falling film evaporator, a falling film separator, and a steam compressor;

[0008] A primary forced circulation evaporation and concentration unit includes a primary forced evaporator, a primary forced separator, and a primary forced circulation pump; the material outlet of the primary forced evaporator is connected to the material inlet of the primary forced separator via a first pipeline; the material outlet of the MVR falling film concentration unit is connected to the material inlet of the primary forced evaporator.

[0009] The two-stage forced circulation evaporation and concentration unit includes a two-stage forced evaporator, a two-stage forced separator, and a two-stage forced circulation pump; the material outlet of the two-stage forced evaporator is connected to the material inlet of the two-stage forced separator via a second pipeline; the material outlet of the one-stage forced separator is connected to the material inlet of the two-stage forced evaporator.

[0010] The steam inlet of the primary forced evaporator is connected to the first steam pipe; the steam outlet of the primary forced separator is connected to the steam inlet of the secondary forced evaporator via the second steam pipe.

[0011] Vacuum unit, including condenser and vacuum pump assembly;

[0012] The steam inlet of the condenser shell side is connected to the steam outlet of the secondary forced separator via a third steam pipe; the non-condensable gas outlet of the condenser shell side is connected to the air inlet of the vacuum pump unit; a drain port is provided at the lower end of the condenser shell side; and the condenser tube side is connected to a circulating cooling water pipe.

[0013] Based on the above technical solution, the present invention can be further improved as follows.

[0014] Furthermore, the upper tube box inlet of the falling film evaporator is connected to the material feed pipe, and the lower tube box outlet is connected to the upper end head return pipe through a falling film circulation pump;

[0015] The inlet of the falling film separator is connected to the falling film evaporator, and the outlet is connected to the falling film discharge pump.

[0016] The inlet of the steam compressor is connected to the steam outlet of the falling film separator, and the outlet is connected to the falling film evaporator.

[0017] Furthermore, the material feed pipe is equipped with a falling film feed regulating valve.

[0018] Furthermore, the pipeline between the steam compressor and the falling film evaporator is equipped with an expansion joint and an anti-surge valve.

[0019] Furthermore, the material inlet of the first-stage forced evaporator is connected to the first-stage forced separator through a first circulation pipe, and the first-stage forced circulation pump is installed on the pipe; the material outlet of the MVR falling film concentration unit is connected to the first circulation pipe through a falling film discharge pump, and is also connected to the material inlet of the first-stage forced evaporator through the pipe.

[0020] The material inlet of the secondary forced evaporator is connected to the liquid phase outlet of the secondary forced separator through a second circulation pipe, and the secondary forced circulation pump is installed on the second circulation pipe. The material outlet of the primary forced separator is connected to the second circulation pipe through a transfer pump, and is also connected to the material inlet of the secondary forced evaporator through the second circulation pipe.

[0021] The material outlet of the secondary forced separator is equipped with a forced discharge pump.

[0022] Furthermore, the secondary forced separator is equipped with a level transmitter and a liquid phase temperature transmitter.

[0023] Furthermore, the steam inlet of the first-stage forced evaporator is connected to an external live steam pipe through the first steam pipe.

[0024] Furthermore, the live steam pipe is connected to the falling film evaporator via a fourth steam pipe to provide it with initial steam.

[0025] Furthermore, the drain outlet is connected to an external condensate recovery pipe.

[0026] Furthermore, the exhaust pipe of the vacuum pump unit is connected to the atmosphere.

[0027] The beneficial effects of this utility model are:

[0028] This invention achieves staged concentration by combining an MVR falling film concentration unit, primary and secondary forced circulation evaporation units, and a vacuum unit. Initial concentration is achieved through MVR, saving energy for subsequent concentrations. Then, dual-effect forced circulation concentration addresses the problems of low lithium concentration and high energy consumption in traditional evaporation processes. Simultaneously, the system controls evaporation parameters during operation to adjust the concentration of the evaporated material, preventing excessively high concentrations. This ensures a suitable concentration, avoiding both excessively high and low concentrations. The entire system optimizes thermal energy and material flow paths through a series design, reducing energy consumption and achieving highly efficient lithium concentration. Attached Figure Description

[0029] Figure 1 This is a flowchart of the combined evaporator system described in an embodiment of the present invention;

[0030] The attached diagram lists the components represented by each number as follows:

[0031] 1. Steam compressor; 2. Expansion joint; 3. Anti-surge valve; 4. Falling film evaporator; 5. Falling film separator; 6. Primary forced evaporator; 7. Primary forced separator; 8. Secondary forced evaporator; 9. Secondary forced separator; 10. Falling film circulating pump; 11. Falling film discharge pump; 12. Primary forced circulating pump; 13. Transfer pump; 14. Secondary forced circulating pump; 15. Forced discharge pump; 16. Falling film feed regulating valve; 17. Condenser; 18. Vacuum pump set; 19. First pipeline; 20. Second pipeline; 21. First circulating pipeline; 22. Second circulating pipeline; 23. First steam pipeline; 24. Second steam pipeline; 25. Third steam pipeline; 26. Fourth steam pipeline; 27. Live steam pipeline; 28. Drain outlet; 29. ​​First condensate outlet; 30. Second condensate outlet; 31. Circulating cooling water pipeline. Detailed Implementation

[0032] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0033] In the description of this application, 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 indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0034] In the description of this application, the term "for example" is used to mean "used as an example, illustration, or description." Any embodiment described as "for example" in this application is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is provided to enable any person skilled in the art to implement and use the present invention. Details are set forth in the following description for purposes of explanation. It should be understood that those skilled in the art will recognize that the present invention can be implemented without using these specific details. In other instances, well-known structures and processes will not be described in detail to avoid obscuring the description of the present invention with unnecessary detail. Therefore, the present invention is not intended to be limited to the embodiments shown, but is consistent with the broadest scope of the principles and features disclosed in this application.

[0035] Example

[0036] A combined evaporator system, comprising:

[0037] The MVR falling film concentration unit has its material outlet connected to the falling film discharge pump 11;

[0038] The primary forced circulation evaporation and concentration unit includes a primary forced evaporator 6, a primary forced separator 7, and a primary forced circulation pump 12;

[0039] The material outlet of the first-stage forced evaporator 6 is connected to the material inlet of the first-stage forced separator 7 via a first pipe 19; the material inlet of the first-stage forced evaporator 6 is connected to the liquid phase outlet of the first-stage forced separator 7 via a first circulation pipe 21, and the first-stage forced circulation pump 12 is installed on the pipe; the material outlet of the MVR falling film concentration unit is connected to the first circulation pipe 21 via a falling film discharge pump 11, and is also connected to the material inlet of the first-stage forced evaporator 6 via the pipe.

[0040] The two-stage forced circulation evaporation and concentration unit includes a two-stage forced evaporator 8, a two-stage forced separator 9, and a two-stage forced circulation pump 14;

[0041] The material outlet of the secondary forced evaporator 8 is connected to the material inlet of the secondary forced separator 9 via a second pipe 20; the material inlet of the secondary forced evaporator 8 is connected to the liquid phase outlet of the secondary forced separator 9 via a second circulation pipe 22, and the secondary forced circulation pump 14 is installed on this pipe; the material outlet of the secondary forced separator 9 is connected to the second circulation pipe 22 via a transfer pump 13, and is also connected to the material inlet of the secondary forced evaporator 8 via this pipe; the material outlet of the secondary forced separator is equipped with a forced discharge pump 15.

[0042] The steam inlet of the first-stage forced evaporator 6 is connected to the first steam pipe 23; the steam outlet of the first-stage forced separator 7 is connected to the steam inlet of the second-stage forced evaporator 8 through the second steam pipe 24.

[0043] The vacuum unit includes a condenser 17 and a vacuum pump assembly 18;

[0044] The steam inlet of the shell side of the condenser 17 is connected to the steam outlet of the secondary forced separator 9 through the third steam pipe 25; the non-condensable gas outlet of the shell side of the condenser 17 is connected to the air inlet of the vacuum pump group 18; the lower end of the shell side of the condenser 17 is provided with a drain port 28; the tube side of the condenser 17 is connected to the circulating cooling water pipe 31.

[0045] The drain port 28 is connected to an external condensate recovery pipe; the exhaust pipe of the vacuum pump unit 18 is connected to the atmosphere.

[0046] In a preferred embodiment, the MVR falling film concentration unit includes:

[0047] The falling film evaporator 4 has a material feed pipe connected to the inlet of the upper tube box, and a falling film feed regulating valve 16 is provided on the material feed pipe. The outlet of the lower tube box is connected to the upper head return pipe through a falling film circulation pump 10.

[0048] The falling film separator 5 has its inlet connected to the falling film evaporator 4 and its outlet connected to the falling film discharge pump 11.

[0049] The steam compressor 1 has its inlet connected to the steam outlet of the falling film separator 5 and its outlet connected to the falling film evaporator 4; the pipeline between the steam compressor 1 and the falling film evaporator 4 is equipped with an expansion joint 2 and an anti-surge valve 3.

[0050] By recovering secondary steam heat energy through steam compressor 1, external steam consumption is reduced, significantly lowering energy consumption. At the same time, falling film feed regulating valve 16 can precisely control the material flow rate entering falling film evaporator 4, improving concentration stability. Expansion joint 2 and anti-surge valve 3 can alleviate pressure fluctuations during steam compression, prevent compressor surge, extend equipment life, and ensure safe system operation.

[0051] In a preferred embodiment, the secondary forced separator 9 is equipped with a level transmitter and a liquid phase temperature transmitter. This allows for real-time monitoring of the concentrate's condition, ensuring precise and controllable process parameters.

[0052] In a preferred embodiment, the steam inlet of the primary forced evaporator 6 is connected to an external live steam pipe 27 via the first steam pipe 23. External live steam is introduced into the primary forced evaporator 6 through the first steam pipe 23, providing an initial heat source for the primary forced circulation evaporation. The waste heat from the live steam is then used to drive the secondary evaporation unit, achieving cascaded utilization of thermal energy.

[0053] The live steam pipe 27 is connected to the falling film evaporator 4 via the fourth steam pipe 26 to provide it with initial steam.

[0054] The material flow path in this embodiment is as follows:

[0055] 1. MVR Falling Film Concentration Unit: The raw material liquid enters the falling film evaporator 4 through the material feed pipe. Driven by the falling film circulation pump 10, the liquid is pumped from the lower tube box outlet to the upper end cap of the falling film evaporator 4, forming a uniform liquid film that flows downward along the heating tube wall. The liquid film is heated and evaporated during the flow, resulting in preliminary concentration. The evaporated mixture (gas and liquid phases) enters the falling film separator 5 for gas-liquid separation: the liquid phase (concentrated liquid) is transported to the first-stage forced circulation evaporation unit through the falling film discharge pump 11; the gas phase (secondary steam) enters the steam compressor 1.

[0056] 2. First-stage forced circulation concentration:

[0057] The concentrate enters the first circulation pipe 21 from the falling film separator 5 via the falling film discharge pump 11 and then enters the first-stage forced evaporator 6 through the pipe. Driven by the first-stage forced circulation pump 12, the concentrate circulates at high speed between the first-stage forced evaporator 6 and the first-stage forced separator 7.

[0058] The concentrate is heated by steam in the first-stage forced evaporator 6. The mixture of the heated and evaporated concentrate and steam enters the first-stage forced separator 7 through the first pipe 19 for gas-liquid separation to obtain the first-stage concentrate.

[0059] 3. Two-stage forced circulation concentration:

[0060] The primary concentrate is transferred to the secondary forced evaporator 8 via the transfer pump 13. Driven by the secondary forced circulation pump 14, the material circulates between the secondary forced evaporator 8 and the secondary forced separator 9.

[0061] In this stage, the mixture of primary concentrate and steam enters the secondary forced separator 9 through the second pipeline 20. At this time, the vacuum pump group 18 is started to reduce the system pressure, thereby lowering the boiling point of the material and achieving low-temperature evaporation. The liquid phase is further concentrated to obtain secondary concentrate, which is discharged from the system by the forced discharge pump 15.

[0062] The steam and heat energy cycle in this embodiment is as follows:

[0063] 1. MVR Falling Film Concentration Unit:

[0064] Steam compressor 1 provides steam to falling film evaporator 4. The secondary steam generated by falling film separator 5 enters steam compressor 1, is compressed and heated, and then returns to falling film evaporator 4 as a heat source, forming a closed-loop heat energy cycle and reducing external steam consumption.

[0065] 2. Dual-effect forced circulation unit:

[0066] First-stage forced evaporator 6: External live steam enters the first-stage forced evaporator 6 through the first steam pipe 23 to heat the concentrate. The condensate generated in this stage is discharged from the first condensate outlet 29 at the lower end of the first-stage forced evaporator 6.

[0067] The concentrated liquid after heating and evaporation is mixed with steam and enters the first-stage forced separator 7 through the first pipe 19 for gas-liquid separation: the separated waste heat steam is transported to the second-stage forced evaporator 8 through the second steam pipe 24.

[0068] Secondary forced evaporator 8: The waste heat steam from the primary separator is used to heat the primary concentrate. However, since the primary concentrate is obtained after the material and steam have undergone one heat exchange, its temperature is close to that of the waste heat steam, resulting in low heat exchange efficiency. The condensate generated in this stage is discharged from the second condensate outlet 30 at the lower end of the secondary forced evaporator 8.

[0069] The heated primary concentrate and steam mixture enter the secondary forced separator 9 through the second pipe 20 for final gas-liquid separation. The vacuum pump group 18 is started to reduce the system pressure, thereby lowering the boiling point of the material and achieving low-temperature evaporation. The liquid phase from the gas-liquid separation is further concentrated to obtain the secondary concentrate, which is discharged from the system by the forced discharge pump 15. The gas phase enters the shell side of the condenser 17 through the third steam pipe 25, where it exchanges heat with the circulating cooling water in the tube side and condenses into liquid water before being discharged. The uncondensed gas (non-condensable gas) is extracted from the system by the vacuum pump group 18.

[0070] While embodiments or examples of this disclosure have been described with reference to the accompanying drawings, it should be understood that the methods, systems, and devices described above are merely exemplary embodiments or examples, and the scope of this utility model is not limited by these embodiments or examples, but only by the granted claims and their equivalents. Various elements in the embodiments or examples may be omitted or replaced by their equivalents. Furthermore, the steps may be performed in a different order than that described in this disclosure. Further, various elements in the embodiments or examples may be combined in various ways. Importantly, as technology evolves, many elements described herein can be replaced by equivalents that appear after this disclosure.

Claims

1. A combined evaporator system, characterized in that, include: The MVR falling film concentration unit includes a falling film evaporator, a falling film separator, and a steam compressor; A primary forced circulation evaporation and concentration unit includes a primary forced evaporator, a primary forced separator, and a primary forced circulation pump; the material outlet of the primary forced evaporator is connected to the material inlet of the primary forced separator via a first pipeline; the material outlet of the MVR falling film concentration unit is connected to the material inlet of the primary forced evaporator. The two-stage forced circulation evaporation and concentration unit includes a two-stage forced evaporator, a two-stage forced separator, and a two-stage forced circulation pump; the material outlet of the two-stage forced evaporator is connected to the material inlet of the two-stage forced separator via a second pipeline; the material outlet of the one-stage forced separator is connected to the material inlet of the two-stage forced evaporator. The steam inlet of the primary forced evaporator is connected to the first steam pipe; the steam outlet of the primary forced separator is connected to the steam inlet of the secondary forced evaporator via the second steam pipe. Vacuum unit, including condenser and vacuum pump assembly; The steam inlet of the condenser shell side is connected to the steam outlet of the secondary forced separator via a third steam pipe; the non-condensable gas outlet of the condenser shell side is connected to the air inlet of the vacuum pump unit; a drain port is provided at the lower end of the condenser shell side; and the condenser tube side is connected to a circulating cooling water pipe.

2. The combined evaporator system according to claim 1, characterized in that, The upper tube box of the falling film evaporator is connected to the material feed pipe at the inlet, and the lower tube box outlet is connected to the upper head return pipe through the falling film circulation pump. The inlet of the falling film separator is connected to the falling film evaporator, and the outlet is connected to the falling film discharge pump. The inlet of the steam compressor is connected to the steam outlet of the falling film separator, and the outlet is connected to the falling film evaporator.

3. The combined evaporator system according to claim 2, characterized in that, The material feed pipe is equipped with a falling film feed regulating valve.

4. The combined evaporator system according to claim 2, characterized in that, The pipeline between the steam compressor and the falling film evaporator is equipped with an expansion joint and an anti-surge valve.

5. The combined evaporator system according to claim 1, characterized in that, The material inlet of the first-stage forced evaporator is connected to the first-stage forced separator through a first circulation pipe, and the first-stage forced circulation pump is installed on the pipe; the material outlet of the MVR falling film concentration unit is connected to the first circulation pipe through a falling film discharge pump, and is also connected to the material inlet of the first-stage forced evaporator through the pipe. The material inlet of the secondary forced evaporator is connected to the liquid phase outlet of the secondary forced separator through a second circulation pipe, and the secondary forced circulation pump is installed on the second circulation pipe. The material outlet of the primary forced separator is connected to the second circulation pipe through a transfer pump, and is also connected to the material inlet of the secondary forced evaporator through the second circulation pipe. The material outlet of the secondary forced separator is equipped with a forced discharge pump.

6. The combined evaporator system according to claim 1, characterized in that, The secondary forced separator is equipped with a level transmitter and a liquid phase temperature transmitter.

7. The combined evaporator system according to claim 1, characterized in that, The steam inlet of the first-stage forced evaporator is connected to an external raw steam pipe through the first steam pipe.

8. The combined evaporator system according to claim 7, characterized in that, The live steam pipe is connected to the falling film evaporator via the fourth steam pipe, providing it with initial steam.

9. The combined evaporator system according to claim 1, characterized in that, The drain outlet is connected to an external condensate recovery pipeline.

10. The combined evaporator system according to claim 1, characterized in that, The exhaust pipe of the vacuum pump unit is connected to the atmosphere.

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