An evaporation crystallization device for recycling waste power lithium batteries

Abstract

The invention discloses an evaporation crystallization device for recycling waste power lithium batteries, and relates to the technical field of evaporation crystallization equipment. The device comprises a preheating tank for heating a dissolving liquid for the first time; an evaporation crystallizer performs a second heating by steam heating and gradually evaporates the dissolving liquid; a steam condenser condenses the evaporated gas into a liquid state and stores it; a vacuum pump reduces the air pressure in the evaporation crystallizer and reduces the boiling point of the dissolving liquid; a waste heat heat exchange mechanism comprises a compressor, a steam-fluorine heat exchanger, a heat exchanger and a first evaporator, recovers the waste heat of the evaporation crystallizer and the steam condenser, and realizes heating of the preheating tank and cooling of the steam condenser; through the waste heat recovery and reuse of the waste heat of the waste heat heat exchange mechanism, the heating and cooling compensation of the preheating tank and the steam condenser are realized, so as to realize reduced energy consumption, improved energy efficiency and efficient recovery of valuable metals in waste lithium batteries; and the problem of low energy efficiency of the existing evaporation crystallization device for recycling lithium battery liquid due to insufficient or wasteful energy utilization is solved.

Description

Technical Field

[0001] The invention relates to the technical field of evaporation crystallization equipment, and in particular to an evaporation crystallization device for recycling waste power lithium batteries. Background Art

[0002] Waste power lithium battery recycling refers to the process of recycling, processing and reusing used power lithium batteries. With the popularity of electric vehicles and other electric equipment, the number of waste power lithium batteries continues to increase; and power lithium batteries contain a large amount of valuable metals (such as lithium, cobalt, nickel, etc.) and harmful substances (such as heavy metals). Recycling and processing these waste batteries can promote resource recycling, effectively reduce environmental pollution, save resources; and promote the sustainable development of the new energy industry.

[0003] At present, the technical links of decomposition and extraction of waste power lithium batteries mainly include: classification and collection according to the type of lithium battery (such as lithium-ion battery, lithium iron phosphate battery, ternary lithium battery, etc.), discharge and disassembly, mechanical crushing, screening (preliminary separation of metal and non-metal), physical separation (magnetic separation and density separation), chemical treatment (hydrometallurgy: acid hydrolysis), precipitation separation or electrolytic deposition to obtain the target compound or solution.

[0004] The products recovered are usually: electrolyte, dissolving solution (acid hydrolysis forms a solution containing metal ions such as lithium, cobalt, nickel, and manganese), precipitate (such as nickel hydroxide, cobalt hydroxide, etc.), by-products and waste liquid (such as insoluble impurities, acidic waste liquid and waste liquid containing a small amount of heavy metals). Among them, the waste liquid generated is more polluting to the environment and needs to be treated to meet environmental emission standards before it can be discharged.

[0005] Through these steps and treatments, valuable metals in waste power lithium batteries can be effectively recovered, environmental pollution can be reduced, and resource recycling can be achieved. However, the solution obtained by hydrometallurgy needs to be added with replacement materials to obtain the precipitate of the target product. The material input is large and the cost is high. In addition, the corresponding acidic waste liquid or replacement by-products will be produced, and the cost of pollutant treatment is also high; thus, the recycling and treatment cost is high, so technical improvements and scale effects are needed to reduce the cost.

[0006] The most commonly used product separation method at present is to extract the product in the acid hydrolysis solution by evaporation and crystallization, that is, to heat the solution to be extracted by thermal means to evaporate the water or acid solution therein, increase the solution concentration, and precipitate the product, thereby obtaining crystals, water and acid hydrolysis liquid during evaporation. This method does not require the input of materials to replace the precipitate, thereby controlling the cost of product recovery. However, in the existing evaporation and crystallization device using steam heating, the steam is directly discharged, and the condenser is directly cooled by a refrigerator, resulting in waste of heat and electricity, insufficient or wasteful energy utilization, and low energy efficiency.

[0007] In summary, it is found that the prior art has at least the following technical problems:

[0008] The existing evaporation and crystallization devices for lithium battery recovery liquid have the problem of low energy efficiency due to insufficient or wasteful energy utilization. Summary of the invention

[0009] The purpose of the present invention is to provide an evaporation crystallization device for recycling waste power lithium batteries, so as to solve the problem of low energy efficiency due to insufficient or wasteful energy utilization in existing evaporation crystallization devices for lithium battery recovery liquid.

[0010] The various technical effects that can be produced by the preferred technical solutions among the various technical solutions provided by the present invention are described in detail below.

[0011] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0012] The present invention provides an evaporation crystallization device for recycling waste power lithium batteries, comprising a preheating tank, the preheating tank being connected to a liquid inlet pipe; the liquid inlet pipe being used to introduce a dissolved solution, and the dissolved solution is heated for the first time through the preheating tank; and an evaporation crystallizer, the solution inlet of the evaporation crystallizer being connected to the solution outlet of the preheating tank; the steam inlet of the evaporation crystallizer being heated by steam, so as to increase the temperature of the dissolved solution entering for the second time and to evaporate the dissolved solution step by step; and a steam condenser, the evaporation gas inlet of the steam condenser being connected to the evaporation gas outlet of the evaporation crystallizer, the liquid discharge port of the steam condenser being connected to a liquid storage tank, and the exhaust port of the steam condenser being connected to a vacuum pump; the vacuum pump extracts the gas in the evaporation crystallizer to reduce the air pressure in the evaporation crystallizer, so as to reduce the boiling point of the dissolved solution in the evaporation crystallizer; and A waste heat heat exchanging mechanism, the waste heat heat exchanging mechanism comprises a compressor, a steam-fluorine heat exchanger, a heat exchanger arranged on the preheating tank and a first evaporator arranged on the steam condenser; the compressor is connected to the heat exchanger; the coolant channel of the steam-fluorine heat exchanger connects the heat exchanger and the compressor, the first evaporator connects the heat exchanger and the compressor, the coolant channel of the steam-fluorine heat exchanger and the first evaporator are connected in parallel to the copper tubes of the heat exchanger and the compressor; the steam channel of the steam-fluorine heat exchanger is connected to the steam outlet of the evaporator crystallizer; the waste heat heat exchanging mechanism collects the steam heat discharged from the evaporator crystallizer and the heat in the steam condenser respectively through the steam-fluorine heat exchanger and the first evaporator connected in parallel, and the collected heat is transferred to the heat exchanger for heating the preheating tank and cooling the steam condenser.

[0013] In one embodiment, a vapor-liquid separator is connected between the exhaust port of the steam condenser and the vacuum pump.

[0014] In one of the embodiments, a throttle valve is provided between the heat exchanger and a node where the coolant channel of the steam-fluorine heat exchanger and the first evaporator are connected in parallel.

[0015] In one of the embodiments, the evaporation crystallizer is provided with an evaporation tank body, the evaporation tank body is provided with a steam inlet chamber and an evaporation chamber in sequence along the length direction, the steam inlet chamber and the evaporation chamber are sealed and isolated from each other; and a steam heat exchange mechanism installed in the evaporation tank body, the steam heat exchange tube mechanism includes a plurality of heat exchange tubes, and a total reversing chamber connected to the tail ends of the plurality of heat exchange tubes; the heat exchange tubes and the total reversing chamber are arranged in the evaporation chamber, and the heads of the heat exchange tubes are connected to the steam inlet chamber; the solution inlet and the evaporation gas outlet of the evaporation crystallizer are arranged at the evaporation chamber, and the steam inlet and the steam outlet of the evaporation crystallizer are arranged at the steam inlet chamber; a steam inlet baffle is provided in the steam inlet chamber, and a reversing baffle is provided in the total reversing chamber, and the steam inlet baffle and the reversing baffle are used to constrain and guide the flow direction of steam from the steam inlet to the steam outlet.

[0016] In one embodiment, there are three steam inlet baffles, which divide the space of the steam inlet chamber into four sub-steam inlet chambers; wherein, only one group of the heat exchange tubes is arranged in two of the sub-steam inlet chambers, and are respectively connected to the steam inlet and the steam outlet; two groups of the heat exchange tubes are respectively arranged in the other two sub-steam inlet chambers; there are two reversing baffles, which divide the space of the total reversing chamber into three sub-reversing chambers; wherein, two groups of the heat exchange tubes are respectively arranged in the three sub-reversing chambers; steam enters from the sub-steam inlet chamber corresponding to the steam inlet, and then enters the corresponding sub-reversing chamber, and then circulates in the multiple sub-steam inlet chambers and the sub-reversing chambers, and finally returns to the sub-steam inlet chamber corresponding to the steam outlet, and flows out from the steam outlet.

[0017] In one of the embodiments, the evaporation tank body is placed horizontally; two openable crystal outlets are provided at the evaporation chamber, the two crystal outlets are arranged at the bottom of the evaporation chamber in the vertical direction, and the two crystal outlets are respectively arranged adjacent to the middle and tail of the evaporation chamber in the length direction; the solution inlet is arranged at the bottom of the head of the evaporation chamber in the vertical direction; the evaporated gas outlet is arranged at the top of the middle of the evaporation chamber in the vertical direction.

[0018] In one of the embodiments, a driving motor and a special screw are arranged near the bottom position of the evaporation tank body in the vertical direction; an end plate is arranged at the tail of the evaporation chamber; the special screw passes through the steam inlet chamber from the head of the evaporation tank body and passes through the end plate of the evaporation chamber; one end of the special screw is exposed outside the head of the evaporation tank body and is connected to the driving motor by transmission; one end of the special screw is rotatably mounted on the end plate; two arc-shaped push plates are arranged in the evaporation tank, and both of the two arc-shaped push plates are connected to the special screw by transmission; the two arc-shaped push plates are respectively arranged in the head to middle section of the evaporation chamber and the evaporation chamber. The evaporation chamber is provided with an intermediate bearing plate in the middle; the special screw rod passes through the lower part of the intermediate bearing plate and is rotatably connected to the intermediate bearing plate; the intermediate bearing plate separates the two arc-shaped push plates; when the evaporation chamber ends evaporation and starts to discharge crystals, the two crystal outlets at the bottom are opened, and the driving motor is started to drive the special screw rod to rotate, and the arc-shaped push plate pushes the crystals at the bottom of the evaporation chamber to the crystal outlet; the special screw rod and the arc-shaped push plate are both made of a mixture of modified PP and glass fiber to resist the corrosive solution introduced into the evaporation chamber and the high-temperature evaporation environment.

[0019] In one of the embodiments, the upper portion of the intermediate bearing plate allows the plurality of heat exchange tubes to pass through, and provides bearing capacity for the plurality of heat exchange tubes.

[0020] A waste heat recovery evaporation crystallization method is also provided, comprising the following steps:

[0021] S1: The dissolved liquid is passed into the preheating tank, but not into the evaporation crystallizer; the vacuum pump is started to discharge the air in the evaporation crystallizer and reach the set air pressure value;

[0022] S2: Steam is introduced into the evaporation crystallizer for preheating. At this time, the waste heat heat exchange mechanism is started and operates at 60% of the heat exchange power. The heat of the steam discharged from the evaporation crystallizer and the heat of the steam condenser are absorbed through the steam-fluorine heat exchanger and the first evaporator. The compressor transfers the heat to the heat exchanger through the coolant in the copper tube. The heat exchanger releases heat to the preheating tank to heat the preheating tank;

[0023] S3: The preheating temperature of the evaporator crystallizer reaches the set value; the temperature of the dissolved liquid in the preheating tank reaches the set value;

[0024] S4: The preheating tank is opened to pass the dissolved liquid in the tank into the evaporation crystallizer;

[0025] S5: After the liquid level of the dissolved liquid in the evaporation crystallizer reaches the set value, the steam introduction amount is increased to increase the temperature in the evaporation crystallizer and increase the evaporation crystallization speed of the evaporation crystallizer;

[0026] S6: The waste heat exchange mechanism operates at full power to increase the heat absorption of the steam-fluorine heat exchanger and the first evaporator, increase the heat release of the heat exchanger to the preheating tank, and maintain the temperature in the preheating tank stable when the dissolved liquid is continuously introduced;

[0027] S7: An ultrasonic sensor is arranged on the evaporation crystallizer to monitor the amount of crystals in the evaporation crystallizer.

[0028] S8: When the amount of crystals in the evaporation crystallizer reaches a preset value, the preheating tank is closed to stop feeding the dissolving liquid into the evaporation crystallizer, the steam is stopped from feeding into the evaporation crystallizer, the steam-fluorine heat exchanger is closed, the first evaporator keeps running to continue absorbing heat to assist the cooling of the evaporation crystallizer, and the vacuum pump is closed; after the evaporation crystallizer is completely cooled, the crystal outlet of the evaporation chamber is opened to take out the crystals.

[0029] The beneficial effects of the present invention are as follows:

[0030] The evaporation crystallization device for recycling waste power lithium batteries achieves efficient and environmentally friendly recycling of waste lithium batteries through the coordinated work of key components such as preheating tank, evaporation crystallizer, steam condenser, vacuum pump, liquid storage tank and waste heat exchange mechanism.

[0031] (1) Efficient energy utilization: The device has multiple components such as preheating tank, evaporation crystallizer and steam condenser, and through reasonable energy utilization and distribution, it greatly improves the overall efficiency of the system. The preheating tank heats up the dissolved liquid for the first time, so that the dissolved liquid reaches a higher temperature before entering the evaporation crystallizer, shortening the heating time of the dissolved liquid after entering the evaporation crystallizer, and also reducing the heat consumption of the evaporation crystallizer. The evaporation crystallizer heats up the liquid for the second time through steam heating, further increasing the temperature of the dissolved liquid, allowing it to evaporate quickly, and greatly improving the speed of the heating process before evaporation.

[0032] (2) Efficient evaporation and crystallization: The design of the evaporator crystallizer can ensure that the dissolved liquid can evaporate quickly at a relatively low temperature. The air pressure in the evaporator crystallizer is reduced by a vacuum pump, thereby reducing the boiling point of the dissolved liquid, allowing it to evaporate at a relatively low temperature. This not only improves the evaporation efficiency, but also reduces energy consumption, which helps to save energy and reduce operating costs.

[0033] (3) Waste heat recovery and reuse: A waste heat heat exchange mechanism is specially designed in the device. Through the coordinated work of components such as the compressor, the steam-fluorine heat exchanger, the first evaporator and the heat exchanger, waste heat recovery and reuse are achieved. The steam-fluorine heat exchanger and the first evaporator respectively collect the steam heat discharged from the evaporation crystallizer and the heat in the steam condenser, and transfer this heat to the heat exchanger for heating the preheating tank. The waste heat heat exchange mechanism not only realizes the recycling of heat and reduces the demand for external heating energy, such as reducing the consumption of fuel or electricity used for heating, but also effectively improves the thermal efficiency of the entire device system.

[0034] (4) Cost control and economic benefits: Through the above-mentioned functions such as efficient energy utilization, efficient evaporation and crystallization, and waste heat recovery and reuse, the device not only reduces energy consumption and improves efficiency, but also significantly reduces operating costs. Valuable metals in waste lithium batteries can be efficiently recovered and reused at a lower cost, bringing considerable economic benefits.

[0035] In summary, with the rapid development of industries such as electric vehicles, the recycling market for used power lithium batteries has broad prospects. The application of this device will further promote the development of the used power lithium battery industry. The evaporation crystallization device for recycling used power lithium batteries has significant advantages in improving evaporation efficiency, improving device energy efficiency and controlling recycling costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solution of the present invention, the drawings required for use in the implementation mode will be briefly introduced below. Obviously, the drawings described below are only some implementation modes of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0037] Figure 1 It is a structural schematic diagram of the first embodiment of the evaporation crystallization device of the present invention;

[0038] Figure 2 It is an axonometric diagram of a first embodiment of the evaporation crystallization device of the present invention;

[0039] Figure 3 It is a cross-sectional schematic diagram of the steam inlet chamber of the first embodiment of the evaporation crystallization device of the present invention;

[0040] Figure 4 It is a cross-sectional schematic diagram of the total reversing chamber of the first embodiment of the evaporation crystallization device of the present invention;

[0041] Figure 5 It is a cross-sectional schematic diagram of an evaporation crystallizer of a second embodiment of the evaporation crystallization device of the present invention;

[0042] Figure 6It is a cross-sectional schematic diagram of the total reversing chamber of the second embodiment of the evaporation crystallization device of the present invention.

[0043] The reference numerals are as follows:

[0044] 1. Preheating tank; 11. Solution outlet; 12. Liquid inlet pipe;

[0045] 2. Evaporation crystallizer;

[0046] 3. Evaporation tank; 31. Steam inlet chamber; 311. Steam inlet; 312. Steam outlet; 313. Steam inlet baffle; 314. Sub-steam inlet chamber; 32. Evaporation chamber; 321. Solution inlet; 322. Evaporation gas outlet; 323. Crystal outlet;

[0047] 4. Steam heat exchange mechanism; 41. Heat exchange tube; 42. Main reversing chamber; 421. Reversing baffle; 422. Sub-reversing chamber;

[0048] 5. Steam condenser; 51. Evaporation gas inlet; 52. Liquid discharge port; 53. Exhaust port; 54. Vapor-liquid separator;

[0049] 6. Liquid storage tank;

[0050] 7. Vacuum pump;

[0051] 8. Waste heat exchange mechanism; 81. Compressor; 82. Steam-fluorine heat exchanger; 83. Heat exchanger; 84. First evaporator; 85. Throttle valve;

[0052] 9. Driving motor; 91. Special screw rod; 92. End plate; 93. Arc push plate; 94. Intermediate bearing plate; 95. Bushing; 96. Limit plate. DETAILED DESCRIPTION

[0053] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0054] Obviously, the described embodiments are only some embodiments of the device, not all embodiments. Based on the embodiments of the device, all other implementation methods obtained by ordinary technicians in this field without creative work are within the scope of protection of the device.

[0055] In a specific embodiment, an evaporation crystallization device for recycling waste power lithium batteries is provided. Through the waste heat recovery and reuse of the waste heat exchange mechanism, the heating and cooling compensation of the preheating tank and the steam condenser, the temperature of the dissolved liquid entering the evaporation crystallizer is rapidly increased, the evaporation efficiency is improved, and energy consumption is reduced, energy efficiency is improved, and valuable metals in waste lithium batteries are efficiently recovered; it effectively solves the problem of low energy efficiency due to insufficient or wasteful energy utilization in the existing evaporation crystallization devices for lithium battery recovery liquid.

[0056] Hereinafter, embodiments will be described with reference to the drawings. Note that all contents of the configurations shown in the following embodiments are not necessarily required as the solution to the invention described in the claims.

[0057] The first embodiment of the evaporation crystallization device is as follows Figures 1 to 4 As shown, it includes a preheating tank 1, which is connected to a liquid inlet pipe 12; the liquid inlet pipe 12 is used to introduce a dissolved liquid and to heat the dissolved liquid for the first time through the preheating tank 1; and an evaporation crystallizer 2, the solution inlet 321 of the evaporation crystallizer 2 is connected to the solution outlet 11 of the preheating tank 1; the steam inlet 311 of the evaporation crystallizer 2 is heated by steam to increase the temperature of the dissolved liquid entering for the second time and to gradually evaporate the dissolved liquid; and a steam condenser 5, the evaporation gas inlet 51 of the steam condenser 5 is connected to the evaporation gas outlet 322 of the evaporation crystallizer 2, the discharge port 52 of the steam condenser 5 is connected to a liquid storage tank 6, and the exhaust port 53 of the steam condenser 5 is connected to a vacuum pump 7; the vacuum pump 7 extracts the gas in the evaporation crystallizer 2 to reduce the air pressure in the evaporation crystallizer 2, so as to reduce the boiling point of the dissolved liquid in the evaporation crystallizer 2; and a waste heat exchange mechanism 8 The waste heat exchange mechanism 8 includes a compressor 81, a steam-fluorine heat exchanger 82, a heat exchanger 83 arranged on the preheating tank 1 and a first evaporator 84 arranged on the steam condenser 5; the compressor 81 is connected to the heat exchanger 83; the coolant channel of the steam-fluorine heat exchanger 82 is connected to the heat exchanger 83 and the compressor 81, the first evaporator 84 is connected to the heat exchanger 83 and the compressor 81, the coolant channel of the steam-fluorine heat exchanger 82 and the first evaporator 84 are connected in parallel to the copper tubes of the heat exchanger 83 and the compressor 81; the steam channel of the steam-fluorine heat exchanger 82 is connected to the steam outlet 312 of the evaporator crystallizer 2; the waste heat exchange mechanism 8 collects the steam heat discharged from the evaporator crystallizer 2 and the heat in the steam condenser 5 through the parallel steam-fluorine heat exchanger 82 and the first evaporator 84, and the collected heat is transferred to the heat exchanger 83 for heating the preheating tank 1 and cooling the steam condenser 5.

[0058] The device realizes efficient and environmentally friendly recycling of waste lithium batteries through the coordinated work of key components such as preheating tank 1, evaporation crystallizer 2, steam condenser 5, vacuum pump 7, liquid storage tank 6 and waste heat exchange mechanism 8, and achieves the following four functions and effects:

[0059] (1) Efficient energy utilization: The device has multiple components such as preheating tank 1, evaporation crystallizer 2 and steam condenser 5, and through reasonable energy utilization and distribution, the overall efficiency of the system is greatly improved. The preheating tank 1 heats the dissolved liquid for the first time, so that the dissolved liquid reaches a higher temperature before entering the evaporation crystallizer 2, shortening the heating time of the dissolved liquid after entering the evaporation crystallizer 2, and also reducing the heat consumption of the evaporation crystallizer 2. The evaporation crystallizer 2 heats up for the second time through steam heating, further increasing the temperature of the dissolved liquid, allowing it to evaporate quickly, and greatly improving the speed of the heating process before evaporation.

[0060] (2) Efficient evaporation and crystallization: The design of the evaporator crystallizer 2 can ensure that the dissolved liquid can be evaporated quickly at a relatively low temperature. The air pressure in the evaporator crystallizer 2 is reduced by the vacuum pump 7, thereby reducing the boiling point of the dissolved liquid, so that it can evaporate at a relatively low temperature. This not only improves the evaporation efficiency, but also reduces energy consumption, which helps to save energy and reduce operating costs.

[0061] (3) Waste heat recovery and reuse: A waste heat heat exchange mechanism 8 is specially designed in the device. Through the coordinated work of components such as the compressor 81, the steam-fluorine heat exchanger 82, the first evaporator 84 and the heat exchanger 83, the waste heat recovery and reuse are realized; the steam-fluorine heat exchanger 82 and the first evaporator 84 respectively collect the steam heat discharged from the evaporation crystallizer 2 and the heat in the steam condenser 5, and transfer this heat to the heat exchanger 83 for heating the preheating tank 1; the waste heat heat exchange mechanism 8 not only realizes the recycling of heat and reduces the demand for external heating energy, such as reducing the consumption of fuel or electricity used for heating, but also effectively improves the thermal efficiency of the entire device system.

[0062] (4) Cost control and economic benefits: Through the above-mentioned functions such as efficient energy utilization, efficient evaporation and crystallization, and waste heat recovery and reuse, the device not only reduces energy consumption and improves efficiency, but also significantly reduces operating costs. Valuable metals in waste lithium batteries can be efficiently recovered and reused at a lower cost, bringing considerable economic benefits.

[0063] In summary, with the rapid development of industries such as electric vehicles, the recycling market for used power lithium batteries has broad prospects. The application of this device will further promote the development of the used power lithium battery industry. The evaporation crystallization device for recycling used power lithium batteries has significant advantages in improving evaporation efficiency, improving device energy efficiency and controlling recycling costs.

[0064] As one optional implementation,

[0065] Regarding the structure for ensuring the operation of the vacuum pump 7 during the evaporation process, this embodiment Figure 1 As shown, a vapor-liquid separator 54 is connected between the exhaust port 53 of the steam condenser 5 and the vacuum pump 7 .

[0066] When in use, a vapor-liquid separator 54 is installed on the exhaust pipe of the vacuum pump 7, which can effectively separate the gas and liquid, reduce the operating load of the vacuum pump 7, and enable the vacuum pump 7 to continue to operate stably during the evaporation process.

[0067] The vapor-liquid separator 54 and the liquid storage tank 6 realize the functions of environmental protection and safety. The steam condenser 5 cools the evaporated gas discharged from the evaporation crystallizer 2, condenses it into liquid and collects it in the liquid storage tank 6. Through the action of the vacuum pump 7, the air pressure in the evaporation crystallizer 2 is reduced, making the evaporation process of the dissolved liquid more stable and safe, and reducing the risk of high temperature and high pressure operation.

[0068] At the same time, the exhaust port 53 of the vacuum pump 7 is connected to the waste treatment device on the recycling production line, thereby ensuring the effective treatment of waste gas and avoiding the direct emission of harmful gases, which is of great significance to environmental protection.

[0069] Regarding the specific structure of the waste heat exchange mechanism 8, this embodiment Figure 1 As shown, a throttle valve 85 is provided between the heat exchanger 83 and the node where the coolant channel of the steam-fluorine heat exchanger 82 and the first evaporator 84 are connected in parallel.

[0070] Regarding the specific evaporation structure of the evaporation crystallizer 2, this embodiment Figure 1 As shown, the evaporation crystallizer 2 is provided with an evaporation tank body 3, which is provided with a steam inlet chamber 31 and an evaporation chamber 32 in sequence along the length direction, and the steam inlet chamber 31 and the evaporation chamber 32 are sealed and isolated from each other; and a steam heat exchange mechanism 4 installed in the evaporation tank body 3, the steam heat exchange tube 41 mechanism includes a plurality of heat exchange tubes 41, and a total reversing chamber 42 connected to the tail ends of the plurality of heat exchange tubes 41; the heat exchange tubes 41 and the total reversing chamber 42 are arranged in the evaporation chamber 32, and the head of the heat exchange tube 41 is connected to the steam inlet chamber 31; The solution inlet 321 and the evaporation gas outlet 322 of the evaporation crystallizer 2 are arranged at the evaporation chamber 32, and the steam inlet 311 and the steam outlet 312 of the evaporation crystallizer 2 are arranged at the steam inlet chamber 31; a steam inlet baffle 313 is provided in the steam inlet chamber 31, and a reversing baffle 421 is provided in the total reversing chamber 42, and the steam inlet baffle 313 and the reversing baffle 421 are used to constrain and guide the flow direction of steam from the steam inlet 311 to the steam outlet 312; an openable crystal outlet 323 is provided at the evaporation chamber 32.

[0071] Regarding the specific structure of how to restrict the flow of steam in the steam heat exchange mechanism 4, this embodiment is as follows. Figure 3 and Figure 4As shown, there are three steam inlet baffles 313, which divide the space of the steam inlet chamber 31 into four sub-steam inlet chambers 314; among them, only one group of heat exchange tubes 41 are arranged in two sub-steam inlet chambers 314, and they are respectively connected to the steam inlet 311 and the steam outlet 312; two groups of heat exchange tubes 41 are respectively arranged in the other two sub-steam inlet chambers 314; there are two reversing baffles 421, which divide the space of the total reversing chamber 42 into three sub-reversing chambers 422; among them, two groups of heat exchange tubes 41 are respectively arranged in the three sub-reversing chambers 422; steam enters from the sub-steam inlet chamber 314 corresponding to the steam inlet 311, and then enters the corresponding sub-reversing chamber 422, and then circulates in multiple sub-steam inlet chambers 314 and sub-reversing chambers 422, and finally returns to the sub-steam inlet chamber 314 corresponding to the steam outlet 312, and flows out from the steam outlet 312.

[0072] Specifically, Figure 3 and Figure 4 As shown, in the cross section of the steam inlet chamber 31, in a clockwise direction, the sub-steam inlet chamber 314 connected to the steam inlet 311 is defined as chamber A1, the chamber next to chamber A1 is chamber A2, the chamber connected to the steam outlet 312 is chamber A4, and the chamber next to chamber A4 is chamber A3. Among them, chambers A1 and A4 each have only one set of heat exchange tubes 41, while chambers A2 and A3 each have two sets of heat exchange tubes 41.

[0073] In the cross section of the main reversing chamber 42 , in the ascending direction from bottom to top, the three sub-reversing chambers 422 are respectively B1 , B2 and B3 chambers, each of which has two groups of heat exchange tubes 41 .

[0074] When the steam heat exchange mechanism 4 is in operation, steam enters chamber A1 from the steam inlet 311, enters chamber B1 through the first group of heat exchange tubes 41 (the single group of heat exchange tubes 41 in chamber A1 is equivalent to the first group of heat exchange tubes 41 in chamber B1), and returns to chamber A2 through the second group of heat exchange tubes 41 in chamber B1 (the second group of heat exchange tubes 41 in chamber B1 is relative to the first group of heat exchange tubes 41 in chamber A2); enters chamber B2 through the second group of heat exchange tubes 41 in chamber A2; the introduced steam flows in chambers A1, B1, A2, B2, A3, B3 and A4 in this order, and finally flows out at the steam outlet 312 in chamber A4; the outflowing steam enters the steam channel of the steam-fluorine heat exchanger 82 to realize heat recovery of waste heat; so that when the steam flows through the evaporation chamber 32, it efficiently heats and evaporates the dissolved liquid in the evaporation chamber 32, realizes efficient evaporation and crystal recovery, and realizes waste heat recovery at the same time, and the recovered heat is applied to the preheating tank 1 again, reducing energy waste and improving the energy efficiency of the device.

[0075] Among them, the evaporation tank body 3 is placed horizontally; two openable crystal outlets 323 are provided at the evaporation chamber 32, and the two crystal outlets 323 are arranged at the bottom of the evaporation chamber 32 in the vertical direction, and the two crystal outlets 323 are respectively arranged adjacent to the middle and tail of the evaporation chamber 32 in the length direction; the solution inlet 321 is arranged at the bottom of the head of the evaporation chamber 32 in the vertical direction; the evaporated gas outlet 322 is arranged at the top of the middle of the evaporation chamber 32 in the vertical direction; the steam inlet 311 is arranged in the horizontal direction of the steam inlet chamber 31, and the steam outlet 312 is arranged in the vertical direction of the steam inlet chamber 31.

[0076] The second embodiment of the evaporation crystallization device is as follows Figure 5 and Figure 6 As shown, the difference between this embodiment and the first embodiment is that a driving motor 9 and a special screw 91 are arranged near the bottom position of the evaporation tank body 3 in the vertical direction; an end plate 92 is arranged at the tail of the evaporation chamber 32; the special screw 91 passes through the steam inlet chamber 31 from the head of the evaporation tank body 3 and passes through the end plate 92 of the evaporation chamber 32; one end of the special screw 91 is exposed outside the head of the evaporation tank body 3 and is transmission-connected to the driving motor 9; one end of the special screw 91 is rotatably mounted on the end plate 92; two arc-shaped push plates 93 are arranged in the evaporation tank body, and the two arc-shaped push plates 93 are transmission-connected to the special screw 91; the two arc-shaped push plates 93 are respectively arranged in the head to middle section of the evaporation chamber 32, and the evaporation chamber 32 is connected to the evaporation chamber 32. The middle to tail section of the evaporation chamber 32; an intermediate bearing plate 94 is arranged in the middle of the evaporation chamber 32; the special screw 91 passes through the lower part of the intermediate bearing plate 94 and is rotatably connected to the intermediate bearing plate 94; the intermediate bearing plate 94 separates the two arc-shaped push plates 93; when the evaporation chamber 32 ends evaporation and starts to discharge the crystals, the two crystal outlets 323 at the bottom are opened, and the drive motor 9 is started to drive the special screw 91 to rotate, and the arc-shaped push plate 93 pushes the crystals at the bottom of the evaporation chamber 32 to be discharged to the crystal outlet 323; the special screw 91 and the arc-shaped push plate 93 are both made of a mixture of modified PP and glass fiber, which are used to resist the corrosive solution and high-temperature evaporation environment introduced into the evaporation chamber 32.

[0077] The upper portion of the middle bearing plate 94 allows the plurality of heat exchange tubes 41 to pass through, and provides bearing capacity for the plurality of heat exchange tubes 41 .

[0078] A shaft sleeve 95 is arranged at the head of the evaporation tank body 3, and the shaft sleeve 95 is rotatably connected to the special screw rod 91; the special screw rod 91 is provided with a bare rod section at the position where it needs to be rotatably installed, so as to facilitate the rotation mechanism, such as bearing, shaft sleeve 95, bearing shell, to realize rotation connection with the characteristic screw rod.

[0079] like Figure 5As shown, in order to limit the movement of the arc-shaped push plate 93, the arc edge shape of the arc-shaped push plate 93 corresponds to the inner profile of the evaporation chamber 32, so as to limit the rotational freedom and realize the function of the driving motor 9 to drive the arc-shaped push plate 93 to move linearly; a limit plate 96 is provided on the side of the shaft sleeve 95 of the head of the evaporation tank body 3 and the side of the middle bearing plate 94, so as to provide limit and buffer for the return reset of the arc-shaped push plate 93.

[0080] Based on the above embodiment of the evaporation crystallization device for recycling waste power lithium batteries, a waste heat recovery evaporation crystallization method is provided, comprising the following steps: S1: the dissolved liquid is passed into the preheating tank, but not into the evaporation crystallizer; the vacuum pump is started to discharge the air in the evaporation crystallizer and reach the set air pressure value;

[0081] S2: Steam is introduced into the evaporation crystallizer for preheating. At this time, the waste heat heat exchange mechanism is started and operates at 60% of the heat exchange power. The heat of the steam discharged from the evaporation crystallizer and the heat of the steam condenser are absorbed through the steam-fluorine heat exchanger and the first evaporator. The compressor transfers the heat to the heat exchanger through the coolant in the copper tube. The heat exchanger releases heat to the preheating tank to heat the preheating tank;

[0082] S3: The preheating temperature of the evaporator crystallizer reaches the set value; the temperature of the dissolved liquid in the preheating tank reaches the set value;

[0083] S4: The preheating tank is opened to pass the dissolved liquid in the tank into the evaporation crystallizer;

[0084] S5: After the liquid level of the dissolved liquid in the evaporation crystallizer reaches the set value, the steam introduction amount is increased to increase the temperature in the evaporation crystallizer and increase the evaporation crystallization speed of the evaporation crystallizer;

[0085] S6: The waste heat exchange mechanism operates at full power to increase the heat absorption of the steam-fluorine heat exchanger and the first evaporator, increase the heat release of the heat exchanger to the preheating tank, and maintain the temperature in the preheating tank stable when the dissolved liquid is continuously introduced;

[0086] S7: An ultrasonic sensor is arranged on the evaporation crystallizer to monitor the amount of crystals in the evaporation crystallizer.

[0087] S8: When the amount of crystals in the evaporation crystallizer reaches a preset value, the preheating tank is closed to stop feeding the dissolving liquid into the evaporation crystallizer, the steam is stopped from feeding into the evaporation crystallizer, the steam-fluorine heat exchanger is closed, the first evaporator keeps running to continue absorbing heat to assist the cooling of the evaporation crystallizer, and the vacuum pump is closed; after the evaporation crystallizer is completely cooled, the crystal outlet of the evaporation chamber is opened to take out the crystals.

[0088] The preheating tank, evaporation crystallizer and steam condenser are all equipped with temperature sensors to detect the temperature of the corresponding structures. The corresponding temperature data is used for the waste heat exchange mechanism to adjust the operating power and control the amount of steam entering the evaporation crystallizer;

[0089] Through the coordinated operation of multiple steps, efficient and energy-saving recycling of waste power lithium batteries is achieved. During the evaporation process, the power of the waste heat exchange mechanism is dynamically adjusted, so that the device system can flexibly adjust the heat transfer efficiency according to the temperature changes of the solution and the evaporation crystallizer, ensuring the temperature stability in the preheating tank and the evaporation crystallizer. At the same time, the ultrasonic sensor monitors the amount of crystallization in the evaporation crystallizer in real time to ensure precise control of the crystallization process. When the amount of crystallization reaches the preset value, the system automatically stops the introduction of the solution and steam and enters the cooling stage. The first evaporator continuously absorbs heat to assist the smooth cooling of the evaporation crystallizer. The collected heat is used by the heat exchanger to heat the preheating tank, avoiding heat waste.

[0090] In summary, this waste heat recovery evaporation crystallization method has significant improvements and advantages in reducing energy consumption in the evaporation crystallization process, improving the efficiency of evaporation crystallization, the safety of evaporation device operation, and realizing waste heat recovery and reuse, which significantly improves the economy and environmental benefits of the waste power lithium battery recycling process.

[0091] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described.

[0092] The above is a preferred embodiment of the device. It should be noted that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the device, and these improvements and modifications are also considered as the protection scope of the device. Therefore, the protection scope of the device should be based on the protection scope of the claims.

Claims

1. An evaporation crystallization device for recycling waste power lithium batteries, characterized in that: It includes a preheating tank, which is connected to a liquid inlet pipe; the liquid inlet pipe is used to introduce the dissolved liquid and perform the first temperature increase of the dissolved liquid through the preheating tank; and an evaporation crystallizer, wherein the solution inlet of the evaporation crystallizer is connected to the solution outlet of the preheating tank; the steam inlet of the evaporation crystallizer is heated by steam to increase the temperature of the incoming solution for the second time and gradually evaporate the solution; and a steam condenser, wherein the evaporation gas inlet of the steam condenser is connected to the evaporation gas outlet of the evaporation crystallizer, the liquid discharge port of the steam condenser is connected to a liquid storage tank, and the exhaust port of the steam condenser is connected to a vacuum pump; the vacuum pump extracts the gas in the evaporation crystallizer to reduce the air pressure in the evaporation crystallizer, so as to reduce the boiling point of the dissolved liquid in the evaporation crystallizer; and a waste heat exchange mechanism, the waste heat exchange mechanism comprising a compressor, a steam-fluorine heat exchanger, a heat exchanger arranged on the preheating tank and a first evaporator arranged on the steam condenser; the compressor is connected to the heat exchanger; The coolant channel of the steam-fluorine heat exchanger connects the heat exchanger and the compressor, the first evaporator connects the heat exchanger and the compressor, and the coolant channel of the steam-fluorine heat exchanger and the first evaporator are connected in parallel to the copper tubes of the heat exchanger and the compressor; The steam channel of the steam-fluorine heat exchanger is connected to the steam outlet of the evaporation crystallizer; The waste heat exchange mechanism collects the steam heat discharged from the evaporation crystallizer and the heat in the steam condenser through the steam-fluorine heat exchanger and the first evaporator in parallel, and the collected heat is transferred to the heat exchanger to heat the preheating tank and cool the steam condenser.

2. The evaporation crystallization device according to claim 1, characterized in that: A vapor-liquid separator is connected between the exhaust port of the steam condenser and the vacuum pump.

3. The evaporation crystallization device according to claim 2, characterized in that: A throttle valve is provided between the heat exchanger and the node where the coolant channel of the steam-fluorine heat exchanger and the first evaporator are connected in parallel.

4. The evaporation crystallization device according to claim 3, characterized in that: The evaporation crystallizer comprises an evaporation tank body, wherein the evaporation tank body is provided with a steam inlet chamber and an evaporation chamber in sequence along the length direction, and the steam inlet chamber and the evaporation chamber are sealed and isolated from each other; and a steam heat exchange mechanism installed in the evaporation tank body, the steam heat exchange mechanism comprising a plurality of heat exchange tubes and a main reversing chamber connected to the tail ends of the plurality of heat exchange tubes; The heat exchange tube and the main reversing chamber are arranged in the evaporation chamber, and the head of the heat exchange tube is connected to the steam inlet chamber; The solution inlet and the evaporation gas outlet of the evaporation crystallizer are arranged at the evaporation chamber, and the steam inlet and the steam outlet of the evaporation crystallizer are arranged at the steam inlet chamber; A steam inlet baffle is provided in the steam inlet chamber, and a reversing baffle is provided in the total reversing chamber. The steam inlet baffle and the reversing baffle are used to restrict and guide the flow direction of steam from the steam inlet to the steam outlet.

5. The evaporation crystallization device according to claim 4, characterized in that: There are three steam inlet baffles, which divide the space of the steam inlet chamber into four sub-steam inlet chambers; wherein only one group of the heat exchange tubes is arranged in two of the sub-steam inlet chambers, and they are respectively connected to the steam inlet and the steam outlet; and two groups of the heat exchange tubes are respectively arranged in the other two sub-steam inlet chambers; There are two reversing baffles, and the two reversing baffles divide the space of the main reversing chamber into three sub-reversing chambers; wherein two groups of heat exchange tubes are arranged in each of the three sub-reversing chambers; Steam enters from the sub-steam inlet chamber corresponding to the steam inlet, then enters the corresponding sub-reversing chamber, subsequently circulates in multiple sub-steam inlet chambers and sub-reversing chambers, and finally returns to the sub-steam inlet chamber corresponding to the steam outlet, and flows out from the steam outlet.

6. The evaporation crystallization device according to claim 4, characterized in that: The evaporation tank is placed horizontally; The evaporation chamber is provided with two openable crystal outlets, the two crystal outlets are arranged at the bottom of the evaporation chamber in the vertical direction, and the two crystal outlets are respectively arranged adjacent to the middle and tail of the evaporation chamber in the length direction; The solution inlet is arranged at the bottom of the evaporation chamber head in the vertical direction; The evaporation gas outlet is disposed at a top portion of a middle portion of the evaporation chamber in a vertical direction.

7. The evaporation crystallization device according to claim 6, characterized in that: A driving motor and a special screw are arranged near the bottom of the evaporation tank in the vertical direction; An end plate is provided at the tail portion of the evaporation chamber; The special screw rod passes through the steam inlet chamber from the head of the evaporation tank body and reaches the end plate of the evaporation chamber; one end of the special screw rod is exposed outside the head of the evaporation tank body and is transmission-connected to the drive motor; one end of the special screw rod is rotatably mounted on the end plate; The evaporator is provided with two arc-shaped push plates, and both of the arc-shaped push plates are connected to the special screw in a transmission manner; the two arc-shaped push plates are respectively arranged in the section from the head to the middle of the evaporation chamber, and in the section from the middle to the tail of the evaporation chamber; An intermediate bearing plate is arranged in the middle of the evaporation chamber; the special screw rod passes through the lower part of the intermediate bearing plate and is rotatably connected to the intermediate bearing plate; the intermediate bearing plate separates the two arc-shaped push plates; When the evaporation chamber finishes evaporation and starts to discharge crystals, the two crystal outlets at the bottom are opened, and the drive motor is started to drive the special screw to rotate, and the arc-shaped push plate pushes the crystals at the bottom of the evaporation chamber to be discharged to the crystal outlet; The special screw rod and the arc push plate are both made of a mixture of modified PP and glass fiber, and are used to resist the corrosive solution and high-temperature evaporation environment introduced into the evaporation chamber.

8. The evaporation crystallization device according to claim 7, characterized in that: The upper portion of the middle bearing plate allows the plurality of heat exchange tubes to pass through, and provides bearing capacity for the plurality of heat exchange tubes.

9. A waste heat recovery evaporation crystallization method of the evaporation crystallization device according to claim 3, characterized in that: The following steps are included: S1: The dissolved liquid is passed into the preheating tank, but not into the evaporation crystallizer; the vacuum pump is started to discharge the air in the evaporation crystallizer and reach the set air pressure value; S2: Steam is introduced into the evaporation crystallizer for preheating. At this time, the waste heat heat exchange mechanism is started and operates at 60% of the heat exchange power. The heat of the steam discharged from the evaporation crystallizer and the heat of the steam condenser are absorbed through the steam-fluorine heat exchanger and the first evaporator. The compressor transfers the heat to the heat exchanger through the coolant in the copper tube. The heat exchanger releases heat to the preheating tank to heat the preheating tank. S3: The preheating temperature of the evaporator crystallizer reaches the set value; the temperature of the dissolved liquid in the preheating tank reaches the set value; S4: The preheating tank is opened to pass the dissolved liquid in the tank into the evaporation crystallizer; S5: After the liquid level of the dissolved liquid in the evaporation crystallizer reaches the set value, the steam introduction amount is increased to increase the temperature in the evaporation crystallizer and increase the evaporation crystallization speed of the evaporation crystallizer; S6: The waste heat exchange mechanism operates at full power to increase the heat absorption of the steam-fluorine heat exchanger and the first evaporator, increase the heat release of the heat exchanger to the preheating tank, and maintain the temperature in the preheating tank stable when the dissolved liquid is continuously introduced; S7: An ultrasonic sensor is arranged on the evaporation crystallizer to monitor the amount of crystals in the evaporation crystallizer; S8: When the amount of crystals in the evaporation crystallizer reaches a preset value, the preheating tank is closed and the flow of the dissolving liquid into the evaporation crystallizer is stopped, the flow of steam into the evaporation crystallizer is stopped, the steam-fluorine heat exchanger is closed, the first evaporator keeps running and continues to absorb heat to assist the cooling of the evaporation crystallizer, and the vacuum pump is closed; After the evaporation crystallizer is completely cooled, open the crystal outlet of the evaporation chamber and take out the crystals.

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