Cold trap system for lithium battery cell baking area vacuum device

Abstract

The utility model discloses a cold trap system for a vacuum device in a lithium battery cell baking area in the technical field of lithium battery production, and aims to solve the problem of low defrosting efficiency of a liquid nitrogen cold trap in the prior art. The system comprises a cold trap, a recovery tank, a circulating pump and a spraying assembly, the cold trap, the recovery tank, the circulating pump and the spraying assembly are in closed-loop connection through pipelines, the recovery tank comprises a second heat exchange pipe, the recovery tank heats condensed NMP and water through the second heat exchange pipe by means of waste heat of an air compressor, and the heated NMP and water are conveyed to the spraying assembly through the circulating pump and sprayed into the cold trap through the spraying assembly. NMP exchanges heat with frost blocks in the cold trap, quick defrosting is achieved, and condensed NMP and water flow into the recovery tank. According to the system, NMP and liquid nitrogen can be captured and recycled, rapid defrosting is achieved, and the system is economical and environmentally friendly.

Description

Technical Field

[0001] The utility model relates to a cold trap system for a vacuum device in a lithium battery core baking area, belonging to the technical field of lithium battery production. Background Art

[0002] In the lithium battery cell baking section, in order to quickly bake the battery cells, the oven needs to be evacuated to 10~50 Pa. In the existing production line, an oil-filled rotary vacuum pump is generally used as a front-stage pump to pre-evacuate to about -96 kPa, and then the Roots pump is started to evacuate to the required vacuum degree of the oven.

[0003] With the continuous improvement of battery production technology, the NMP (N-methylpyrrolidone) content in the positive electrode sheets of the newly built production lines has seriously exceeded the standard. When the battery cells are baked in the oven, the vacuum pump extracts a large amount of NMP and water vapor. NMP is a solvent. After dissolving in oil, the vacuum pump oil deteriorates, and the sealing ring and rotor are severely corroded. These all lead to insufficient sealing of the oil rotor vacuum pump, thereby affecting the vacuum degree of the vacuum system, causing great trouble to battery production.

[0004] In the prior art, liquid nitrogen cold traps are used as capture devices to capture NMP vapor and water vapor by condensation. Although the influence of NMP and water vapor can be eliminated from the source, the following problems will arise: 1. When production time is tight, the efficiency of defrosting will directly affect the production efficiency of the workshop; 2. Accelerating defrosting must consume heat sources, increasing operating costs. Utility Model Content

[0005] The technical problem to be solved by the utility model is to overcome the defects of the prior art and provide a cold trap system for a vacuum device in a lithium battery cell baking area, which can capture and recycle NMP and liquid nitrogen, and can quickly defrost, and is economical and environmentally friendly.

[0006] In order to solve the above technical problems, the utility model is implemented by adopting the following technical solutions:

[0007] The utility model provides a cold trap system for a vacuum device in a lithium battery cell baking area, comprising a cold trap, a recovery tank, a circulation pump and a spray assembly, wherein the cold trap, the recovery tank, the circulation pump and the spray assembly are connected through a pipeline to form a closed loop; the circulation pump and the spray assembly are used to spray the condensate in the recovery tank into the cold trap to melt the frost blocks; the utility model is characterized in that it also comprises a heat recovery assembly;

[0008] The recovery tank has a second heat exchange tube built in, and the second heat exchange tube is connected to the heat recovery component to form a closed loop; the heat recovery component is used to provide heat medium to the second heat exchange tube to heat the condensate in the recovery tank.

[0009] Preferably, the cold trap has a built-in first heat exchange tube, and the cold trap is provided with an air inlet, an air outlet, a condensate outlet, a liquid nitrogen inlet and a nitrogen exhaust port;

[0010] The air inlet, the air outlet and the condensate outlet are all arranged outside the cold trap housing, and the condensate outlet is connected to the recovery tank;

[0011] The liquid nitrogen inlet and the nitrogen exhaust port are arranged on the top of the cold trap cover; the nitrogen exhaust port is connected to the production workshop; one end of the first spiral heat exchange tube is connected to the liquid nitrogen inlet, and the other end is connected to the nitrogen exhaust port.

[0012] Preferably, the recovery tank is provided with a drain port, a circulation pump port, a condensate inlet, a water inlet, a heat medium inlet and a heat medium outlet;

[0013] The liquid discharge port and the circulation pump port are arranged outside the recovery tank housing, the circulation pump port is connected to the circulation pump; the liquid discharge port is connected to an external waste liquid tank;

[0014] The condensate inlet, water inlet, heat medium inlet and heat medium outlet are all arranged on the top of the recovery tank cover; the condensate inlet is connected to the condensate outlet of the cold trap;

[0015] One end of the second heat exchange tube is connected to the heat medium inlet, and the other end is connected to the heat medium outlet;

[0016] The heat medium outlet, the heat recovery component, the second heat exchange tube and the heat medium inlet form a closed loop.

[0017] Preferably, the heat recovery component includes a centrifugal air compressor, a waste heat recovery device and a heat recovery water pump;

[0018] The heat medium outlet heat recovery water pump, the water side pipeline of the waste heat recovery device and the heat medium inlet are connected to form a closed loop;

[0019] The compressed air generated by the centrifugal air compressor passes through the shell side pipeline of the waste heat recovery device and then returns to the centrifugal air compressor, and is then transported to the workshop for air supply through the centrifugal air compressor;

[0020] The heat medium is medium water that absorbs the residual heat of compressed air.

[0021] Preferably, the heat recovery component includes an oil-injected screw air compressor and a heat recovery oil pump;

[0022] The heat medium outlet, the heat recovery oil pump, the oil side pipeline of the oil injection screw air compressor and the heat medium inlet are connected to form a closed loop;

[0023] The heat medium is medium oil that absorbs the residual heat of compressed air.

[0024] Preferably, the first heat exchange tube and the second heat exchange tube are both spiral heat exchange tubes.

[0025] Preferably, the cold trap further comprises a spray port,

[0026] The spray port is arranged at the center position of the top of the cold trap cover or at the side of the cold trap shell; the spray port is connected to the circulation pump and the spray assembly.

[0027] Compared with the prior art, the utility model has the following beneficial effects:

[0028] 1. The utility model provides a cold trap system for a vacuum device in a lithium battery cell baking area. The system replaces a heat pipe in a recovery tank and connects the second heat exchange pipe to a heat recovery component to form a closed loop. The heat recovery component provides heat medium to the heat exchange pipe to heat the condensate collected in the recovery tank, which is then sprayed into the cold trap by a circulation pump and a spray component to melt frost blocks, thereby achieving rapid defrosting and recycling of NMP, which is economical and environmentally friendly.

[0029] 2. The cold trap system for the vacuum device in the lithium battery cell baking area provided by the utility model can not only be used as a liquid nitrogen gasification and recycling device, but also can condense and capture NMP to prevent corrosion of the vacuum pump.

[0030] 3. In the cold trap system of the vacuum device for the lithium battery cell baking area provided by the utility model, the recovery tank can also be used as an air compressor waste heat recovery device to achieve energy reuse and save operating costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 A schematic diagram of a cold trap system for a vacuum device in a lithium battery cell baking area provided in Example 2 of the utility model;

[0032] Figure 2 This is a schematic diagram of a cold trap system for a vacuum device in a lithium battery cell baking area provided in Example 3 of the utility model. DETAILED DESCRIPTION

[0033] The specific implementation of the utility model will be further described in detail below in conjunction with the accompanying drawings and embodiments. The embodiments described below with reference to the accompanying drawings are illustrative and intended to be used to explain the utility model, and should not be understood as limiting the utility model.

[0034] In the description of the present invention, it should be noted that the terms "upper", "lower", "front", "rear", "end", "bottom", "side", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0035] In the present invention, unless otherwise specified or limited, the terms "connection" and "installation" should be understood in a broad sense, for example, it can be a fixed connection, a direct connection, or a connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] Secondly, the term "one embodiment" or "embodiment" as used in the present invention refers to a specific feature, structure or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0037] The following embodiments of the present invention are described in further detail in conjunction with the accompanying drawings. The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0038] Example 1, reference Figure 1 , which is the first embodiment of the utility model, provides a cold trap system for a vacuum device in a lithium battery cell baking area, including a cold trap 1, a recovery tank 2, a heat recovery component, a circulation pump 3 and a spray component 4.

[0039] In this embodiment, the cold trap 1, the recovery tank 2, the circulation pump 3 and the spray assembly 4 are connected through pipelines to form a closed loop.

[0040] Specifically, the recovery tank 2 has a built-in second spiral heat exchange tube 206, which is connected to the heat recovery component to form a closed loop. The heat recovery component is used to provide heat medium to the second spiral heat exchange tube 206 to heat the condensed NMP and water in the recovery tank 2. The heated NMP and water are then sprayed into the cold trap 1 by the circulation pump 3 and the spray component 4 to melt the frost.

[0041] In this embodiment, the cold trap 1 has a first spiral heat exchange tube 105 built therein, and is provided with an air inlet 107 , an air outlet 104 , a condensate outlet 106 , a liquid nitrogen inlet 101 and a nitrogen exhaust port 103 .

[0042] Specifically, the air inlet 107, the air outlet 104 and the condensate outlet 106 are all arranged outside the cold trap housing, and the condensate outlet 106 is connected to the recovery tank 2;

[0043] The liquid nitrogen inlet 101 and the nitrogen exhaust port 103 are arranged on the top of the cold trap cover; the nitrogen exhaust port 103 is connected to the production workshop;

[0044] One end of the first spiral heat exchange tube 105 is connected to the liquid nitrogen inlet 101 , and the other end is connected to the nitrogen exhaust port 103 .

[0045] In this embodiment, the recovery tank 2 is provided with a liquid discharge port 207 , a circulation pump port 205 , a condensate inlet 202 , a water inlet 204 , a heat medium inlet 203 and a heat medium outlet 201 .

[0046] Specifically, the drain port 207 and the circulation pump port 205 are arranged outside the shell of the recovery tank 2, and the circulation pump port 205 is connected to the circulation pump 3; the drain port 207 is connected to the external waste liquid tank;

[0047] The condensate inlet 202, the water inlet 204, the heat medium inlet 203 and the heat medium outlet 201 are all arranged on the top of the tank cover of the recovery tank 2; the condensate inlet 202 is connected to the condensate outlet 106 of the cold trap;

[0048] One end of the second spiral heat exchange tube 206 is connected to the heat medium inlet 203, and the other end is connected to the heat medium outlet 201. The heat medium outlet 201, the heat recovery component, the second spiral heat exchange tube 206 and the heat medium inlet 203 form a closed loop.

[0049] Preferably, the cold trap 1 further comprises a spray port 102 , which is arranged at the center of the top of the cold trap cover or at the side of the cold trap housing. The spray port 102 is used to connect the circulation pump 3 and the spray assembly 4 .

[0050] Embodiment 2 is the second embodiment of the present utility model. In this embodiment, the heat recovery component includes a centrifugal air compressor 7, a waste heat recovery device 6 and a heat recovery water pump 5;

[0051] In this embodiment, the heat medium outlet 201, the heat recovery water pump 5, the water side pipeline of the waste heat recovery device 6 and the heat medium inlet 203 are connected to form a closed loop;

[0052] The compressed air generated by the centrifugal air compressor 7 passes through the shell side pipeline of the waste heat recovery device 6 and then returns to the centrifugal air compressor 7, and is then processed inside the centrifugal air compressor 7 and transported to the workshop for air supply.

[0053] The rest of the structure is the same as that of Example 1.

[0054] When using, refer to Figure 1, liquid nitrogen first enters the first spiral heat exchange tube 105 from the liquid nitrogen inlet 101, and then the mixed gas in the oven cavity enters the cold trap 1 from the air inlet 107, and stably exchanges heat with the liquid nitrogen from the bottom of the first spiral heat exchange tube 105 from bottom to top. The NMP and water vapor in the mixed gas condense into frost, and the liquid nitrogen is converted into nitrogen and transported to the workshop for reuse through the nitrogen outlet 103. When the vacuum pumping stops, if the water volume in the recovery tank is insufficient, pure water is injected to 1 / 3 of the tank through the water inlet 202 of the recovery tank 2. The water in the recovery tank is transported to the spray port 102 by the circulating pump 3, and sprayed into the cold trap 1 by the spray assembly 4, and heat is exchanged with the frost blocks on the first spiral heat exchange tube 105 in the cold trap 1. The condensed NMP and water flow into the recovery tank 2 through the condensate outlet 106 and the condensate inlet 202. At the same time, the medium water in the second spiral heat exchange tube 206 in the recovery tank 2 circulates in the water side pipeline and the second spiral heat exchange tube 206 in the waste heat recovery device 5 through the heat recovery water pump 5. Through the waste heat recovery device 6, the medium water in the pipeline first absorbs the waste heat of the compressed air and then flows to the second spiral heat exchange 206 to heat the liquid in the recovery tank 2. After heating, the liquid is sprayed into the cold trap 1 by the circulation pump 3 and the spray assembly 4 to melt the frost. In this way, the cold trap 1 can be defrosted quickly without affecting production, and the waste heat of the air compressor is fully utilized to save costs. When the liquid concentration in the recovery tank 2 reaches a certain concentration, it enters the NMP waste liquid tank through the drain port to recover NMP. The compressed air generated by the centrifugal air compressor returns to the centrifugal air compressor after passing through the shell side pipeline of the waste heat recovery device, and is then transported to the workshop air supply after being processed internally by the centrifugal air compressor.

[0055] Example 3, see Figure 2 , which is the third embodiment of the utility model, in this embodiment, the heat recovery component includes an oil-injected screw air compressor 9 and a heat recovery oil pump 8;

[0056] In this embodiment, the heat medium outlet 201, the heat recovery oil pump 8, the oil side pipeline of the oil injection screw air compressor 9 and the heat medium inlet 203 are connected to form a closed loop.

[0057] When in use, liquid nitrogen first enters the first spiral heat exchange tube 105 from the liquid nitrogen inlet 101, and then the mixed gas in the oven cavity enters the cold trap 1 from the air inlet 107, and stably exchanges heat with the liquid nitrogen from the bottom of the first spiral heat exchange tube 105 from bottom to top, and the NMP and water vapor in the mixed gas condense into frost, and the liquid nitrogen is converted into nitrogen and transported to the workshop for reuse. When the vacuum pumping is stopped, if the water volume of the recovery tank 2 is insufficient, pure water is injected to the 1 / 3 position of the tank through the water inlet 204 of the recovery tank 2. The water in the recovery tank 2 is transported to the spray port 102 by the circulating pump 3, and sprayed into the cold trap 1 by the spray assembly 4, and heat is exchanged with the frost blocks on the first spiral heat exchange tube 105 in the cold trap 1, and the condensed NMP and water flow into the recovery tank. At the same time, the medium oil in the second spiral heat exchange tube 206 in the recovery tank 2 circulates in the oil side pipeline of the oil injection screw air compressor 9 and the second spiral heat exchange tube 206 through the action of the heat recovery oil pump 8. When passing through the oil side pipeline of the oil-injected screw air compressor 9, the medium oil first absorbs the waste heat of the compressed air and then flows into the second spiral heat exchange tube 206 to heat the liquid in the recovery tank. The heated liquid is then sprayed into the cold trap 1 by the circulating pump 3 and the spray assembly 4 to melt the frost. In this way, the cold trap can be defrosted quickly without affecting production, and the waste heat of the air compressor is fully utilized to save costs. When the liquid concentration in the recovery tank reaches a certain concentration, it enters the NMP waste liquid tank through the drain port to recover NMP.

[0058] Importantly, it should be noted that the construction and arrangement of the present application shown in a number of different exemplary embodiments are only exemplary. Although only a few embodiments are described in detail in this disclosure, it should be readily understood by those who refer to this disclosure that many modifications are possible (e.g., the size, scale, structure, shape and proportion of various elements, and parameter values ​​(e.g., temperature, pressure, etc.), mounting arrangements, use of materials, color, directional changes, etc.) without substantially departing from the novel teachings and advantages of the subject matter described in the application. For example, an element shown as integrally formed may be composed of multiple parts or elements, the position of the element may be inverted or otherwise changed, and the nature or number or position of the discrete element may be altered or changed. Therefore, all such modifications are intended to be included within the scope of the present invention. The order or sequence of any process or method steps may be changed or reordered according to alternative embodiments. In the claims, any "device plus function" clause is intended to cover the structure that performs the function described in the present utility model, and is not only structurally equivalent but also an equivalent structure. Without departing from the scope of the present invention, other substitutions, modifications, changes and omissions may be made in the design, operating conditions and arrangement of the exemplary embodiments. Therefore, the present invention is not limited to a specific embodiment, but extends to various modifications that still fall within the scope of the appended claims.

[0059] Additionally, in order to provide a concise description of example embodiments, all features of an actual embodiment may not be described (ie, those features that are not relevant to the best mode presently contemplated for carrying out the invention or those that are not relevant to implementing the invention).

[0060] It will be appreciated that in the development of any actual implementation, as in any engineering or design project, numerous implementation-specific decisions may be made. Such a development effort may be complex and time-consuming, but will be a routine task of design, fabrication, and production for those of ordinary skill having the benefit of this disclosure without undue experimentation.

[0061] It should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Although the utility model has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the technical solution of the utility model can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the utility model, which should be included in the scope of the claims of the utility model.

Claims

1. A cold trap system for a vacuum device in a lithium battery cell baking area, comprising a cold trap (1), a recovery tank (2), a circulation pump (3) and a spray assembly (4), wherein the cold trap (1), the recovery tank (2), the circulation pump (3) and the spray assembly (4) are connected via a pipeline to form a closed loop; the circulation pump (3) and the spray assembly (4) are used to spray condensate in the recovery tank (2) into the cold trap (1) to melt frost blocks; characterized in that: Also included are heat recovery components; The recovery tank (2) has a second heat exchange tube built in, and the second heat exchange tube is connected to the heat recovery component to form a closed loop; the heat recovery component is used to provide heat medium to the second heat exchange tube to heat the condensate in the recovery tank (2).

2. A cold trap system for a vacuum device in a lithium battery cell baking area according to claim 1, characterized in that: The cold trap (1) has a first heat exchange tube built in, and the cold trap (1) is provided with an air inlet (107), an air outlet (104), a condensate outlet (106), a liquid nitrogen inlet (101) and a nitrogen exhaust port (103); The air inlet (107), the air outlet (104) and the condensate outlet (106) are all arranged outside the cold trap shell, and the condensate outlet (106) is connected to the recovery tank (2); The liquid nitrogen inlet (101) and the nitrogen exhaust port (103) are arranged on the top of the cold trap cover; the nitrogen exhaust port (103) is connected to the production workshop; one end of the first heat exchange tube is connected to the liquid nitrogen inlet (101), and the other end is connected to the nitrogen exhaust port (103).

3. A cold trap system for a vacuum device in a lithium battery cell baking area according to claim 2, characterized in that: The recovery tank (2) is provided with a liquid discharge port (207), a circulation pump port (205), a condensate inlet (202), a water inlet (204), a heat medium inlet (203) and a heat medium outlet (201); The liquid discharge port (207) and the circulation pump port (205) are arranged outside the shell of the recovery tank (2); the circulation pump port (205) is connected to the circulation pump (3); the liquid discharge port (207) is connected to an external waste liquid tank; The condensate inlet (202), the water inlet (204), the heat medium inlet (203) and the heat medium outlet (201) are all arranged on the top of the tank cover of the recovery tank (2); the condensate inlet (202) is connected to the condensate outlet (106) of the cold trap (1); One end of the second heat exchange tube is in communication with the heat medium inlet (203), and the other end is in communication with the heat medium outlet (201); The heat medium outlet (201), the heat recovery component, the second heat exchange tube and the heat medium inlet (203) form a closed loop.

4. A cold trap system for a vacuum device in a lithium battery cell baking area according to claim 3, characterized in that: The heat recovery component comprises a centrifugal air compressor (7), a waste heat recovery device (6) and a heat recovery water pump (5); The heat medium outlet (201), the heat recovery water pump (5), the water side pipeline of the waste heat recovery device (6) and the heat medium inlet (203) are connected to form a closed loop; The compressed air generated by the centrifugal air compressor (7) passes through the shell side pipeline of the waste heat recovery device (6) and then returns to the centrifugal air compressor (7), and is then transported to the workshop for air supply through the centrifugal air compressor (7); The heat medium is medium water that absorbs the residual heat of compressed air.

5. A cold trap system for a vacuum device in a lithium battery cell baking area according to claim 3, characterized in that: The heat recovery component comprises an oil-injected screw air compressor (9) and a heat recovery oil pump (8); The heat medium outlet (201), the heat recovery oil pump (8), the oil side pipeline of the oil injection screw air compressor (9) and the heat medium inlet (203) are connected to form a closed loop; The heat medium is medium oil that absorbs the residual heat of compressed air.

6. A cold trap system for a vacuum device in a lithium battery cell baking area according to claim 2, characterized in that: The first heat exchange tube and the second heat exchange tube are both spiral heat exchange tubes.

7. A cold trap system for a vacuum device in a lithium battery cell baking area according to claim 1, characterized in that: The cold trap (1) further comprises a spray port (102). The spray port (102) is arranged at the center of the top of the cold trap cover or at the side of the cold trap shell; the spray port (102) is connected to the circulation pump (3) and the spray assembly (4).

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