Cold capacity and water resource comprehensive utilization system in production process of secondary battery positive electrode material precursor

Abstract

The utility model discloses a cold energy and water resource comprehensive utilization system in the production process of a secondary battery positive electrode material precursor, relates to the field of secondary battery positive electrode material precursor material production, aims to solve the problem of high energy consumption in the prior art, and adopts the technical scheme that waste water is recycled after being neutralized, cooled, filtered and purified. According to the cooling part, nitrogen is provided for a follow-up shielding gas and / or replacement gas supply pipeline for cooling, so that cold energy recovery is achieved, purified water can be reused in the centrifugal washing process, and recycling of water is achieved. The cooling capacity of the liquid nitrogen for supplying nitrogen to the follow-up shielding gas and / or replacement gas supply pipeline is used for cooling the waste water, an existing water cooling tower is replaced, and energy consumption can be reduced by recycling the cooling capacity.

Description

Technical Field

[0001] The utility model relates to the technical field of secondary battery positive electrode material precursor production, in particular to a cold and water resource comprehensive utilization system in the secondary battery positive electrode material precursor production process. Background Art

[0002] At present, the centrifugal washing process in the production process of secondary battery positive electrode material precursors consumes a large amount of pure water. After washing, high-temperature and high-alkaline wastewater is produced, which is difficult to treat. It enters the industrial wastewater evaporator MVR for treatment, which has high energy consumption and is very unfavorable for the company's energy conservation and emission reduction. Utility Model Content

[0003] The technical problem to be solved by the utility model is to overcome the existing defects and provide a system for comprehensive utilization of cold and water resources in the production process of secondary battery positive electrode material precursors, which can effectively solve the problems in the background technology.

[0004] In order to achieve the above-mentioned purpose, the utility model discloses a system for comprehensive utilization of cold and water resources in the production process of a positive electrode material precursor for a secondary battery. The technical scheme adopted is as follows: the system comprises a centrifugal washing device, the wastewater outlet of the centrifugal washing device is connected to a washing water discharge pipe, the wastewater outlet of the centrifugal washing device is connected to one port of a three-way solenoid valve, the other two ports of the three-way solenoid valve are respectively connected to the washing water discharge pipe and the washing water recovery pipe, a conductivity detector is connected between the rear end of the wastewater outlet and the three-way solenoid valve, and the conductivity of the wastewater is detected by detecting the conductivity of the wastewater to detect the high conductivity wastewater. Water waste treatment, recycling wastewater with conductivity within the recyclable range, the wash water recovery pipeline is connected to a pH adjustment device, which can neutralize the wastewater, the wash water recovery pipeline is connected to a cold recovery device, and then connected to a water treatment filter, the rear end of the water treatment filter is connected to a reverse osmosis device, the rear end of the reverse osmosis device is connected to a qualified water recovery pipeline, and qualified water is recycled; the cold recovery device is also connected to a liquid nitrogen storage tank; and also includes a control device, which is electrically connected to the conductivity detector, the three-way solenoid valve, and the pH adjustment device.

[0005] As an optimal technical solution of the utility model, the pH adjusting device includes an acid storage tank, in which acid is stored, and a solenoid valve is installed at the outlet. A three-way pipe fitting is provided on the wash water recovery pipeline, and the branch pipe outlet of the three-way pipe fitting is connected to the outlet of the solenoid valve through a pipeline; a pH meter is connected to the main pipe of the three-way pipe fitting, and the solenoid valve and the pH meter are electrically connected to the control device. The control device opens and closes the solenoid valve according to the pH condition of the wastewater to neutralize the wastewater.

[0006] As a preferred technical solution of the utility model, the cold recovery device is a shell and tube heat exchanger, including a tube side and a shell side, the tube side is covered with a sleeve, the tube side is connected to the liquid nitrogen storage tank, the shell side is connected to the wash water recovery pipeline and the water treatment filter, and there is a refrigerant in the sleeve. Since the temperature of liquid nitrogen is too low, if it is directly exchanged with wastewater, it will cause the wastewater to cool down and freeze rapidly, increase its volume, and cause the pipeline to expand, rupture, and block, and it cannot operate. Therefore, a refrigerant is used for cold transfer, and the refrigerant can be selected from R1150, R14, etc.

[0007] As a preferred technical solution of the utility model, the pipe side inlet is a liquid nitrogen inlet, the pipe side outlet is a nitrogen outlet, the liquid nitrogen inlet is connected to the liquid nitrogen storage tank, and the nitrogen outlet is connected to the subsequent protective gas and / or replacement gas supply pipeline to provide protective gas or replacement gas for the reactor, centrifugal process, oven, kiln, etc. The cold energy generated during the evaporation of liquid nitrogen is used for cooling the wastewater, achieving the effect of cold recovery and realizing energy saving.

[0008] As a preferred technical solution of the utility model, the sleeve is provided with an inlet and an outlet, a circulation pipeline is connected between the inlet and the outlet, the circulation pipeline contains the refrigerant and is connected to a circulation pump, thereby realizing the circulation of the refrigerant and achieving a better cold transfer effect.

[0009] Compared with the prior art, the utility model has the following beneficial effects: the utility model determines the recycling value of wastewater by testing its conductivity, neutralizes the recyclable wastewater, and uses liquid nitrogen that provides protective nitrogen to the subsequent protective gas and / or replacement gas supply pipeline to cool it down, thereby realizing cold recovery, and then purifies the wastewater after filtration and reverse osmosis. The purified water can be reused in the centrifugal washing process to realize water recycling. The coldness of liquid nitrogen that provides nitrogen to the subsequent protective gas and / or replacement gas supply pipeline is used to cool the wastewater, replacing the existing cooling tower, and can reduce energy consumption by using cold recovery. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a schematic diagram of the structure of the utility model.

[0011] In the figure: 1. Centrifugal washing equipment; 2. Wastewater outlet; 3. Washing water discharge pipe; 4. Conductivity detector; 5. Three-way solenoid valve; 6. pH adjustment device; 7. Washing water recovery pipe; 8. Liquid nitrogen storage tank; 9. Liquid nitrogen inlet; 10. Nitrogen outlet; 11. Coolant; 12. Cold recovery device; 13. Water treatment filter; 14. Reverse osmosis device; 15. Qualified water recovery pipe. DETAILED DESCRIPTION

[0012] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model. Example 1

[0013] like Figure 1 As shown, the utility model discloses a system for comprehensive utilization of cold and water resources in the production process of a precursor of anode materials for secondary batteries. The technical scheme adopted is that waste water in a centrifugal washing device 1 is discharged through a waste water outlet 2. In order to determine the recoverable value of the waste water, a conductivity detector 4 is used at the waste water outlet 2 to detect the conductivity. In order to recycle water with qualified conductivity, a three-way solenoid valve 5 is connected behind the conductivity test point of the waste water outlet 2, and the other two ports of the three-way solenoid valve 5 are respectively connected to a washing water discharge pipe 3 and a washing water recovery pipe 7. Since the wastewater is high-temperature and high-alkali wastewater, it is necessary to cool and neutralize the wastewater before recycling. A three-way pipe fitting is provided on the washing water recovery pipeline 7, and the washing water recovery pipeline 7 is connected to the main pipe of the three-way pipe fitting, and a pH meter is installed in front of the main pipe. The branch pipe of the three-way pipe fitting is connected to the pH adjusting device 6, and the pH adjusting device 6 is an acid storage tank, which stores concentrated sulfuric acid solution. The outlet of the acid storage tank has a solenoid valve and an acid metering pump, and the rear end of the solenoid valve is connected to the branch pipe of the three-way pipe fitting. A liquid level sensor is installed on the acid storage tank to detect the remaining amount of concentrated sulfuric acid.

[0014] In order to cool the wastewater, a cold recovery device 12 is introduced. The main body of the cold recovery device 12 is a shell and tube heat exchanger, which includes a tube side and a shell side. The shell side inlet is connected to the wash water recovery pipeline 7, and the shell side outlet is connected to the water treatment filter 13. The tube side inlet is the liquid nitrogen inlet 9, which is connected to the liquid nitrogen storage tank 8. The tube side outlet is the nitrogen outlet 10, which is connected to the rear-end nitrogen delivery pipeline to provide nitrogen as a protector or replacement gas for subsequent equipment. Considering that the temperature of liquid nitrogen is too low, if liquid nitrogen is directly used for heat exchange with wastewater, the temperature of the wastewater will drop suddenly to freezing, which will not only cause pipeline blockage, but also may cause pipeline rupture due to volume expansion. Therefore, a sleeve is set outside the heat exchange tube, and a refrigerant 11 is set inside the sleeve. The refrigerant 11 uses R1150. By using the refrigerant 11 as a cold transfer medium, the refrigerant 11 is first cooled by liquid nitrogen, and then the wastewater is cooled by the refrigerant 11. The purpose of using the cold of liquid nitrogen to cool the wastewater can be achieved while avoiding the problem of freezing of wastewater due to too low temperature. In order to make the cold transfer of the refrigerant 11 more uniform, an inlet and outlet are set on the sleeve, and a circulating pump is set outside the shell and tube heat exchanger. The inlet and outlet of the sleeve are connected to the circulating pipeline, and the circulating pipeline is connected to the circulating pump and the buffer tank. The refrigerant 11 is in a flowing state through the circulating pump, and the flowing refrigerant 11 is buffered by the buffer tank to ensure the stable flow of the refrigerant 11 in the circulating pipeline. Temperature sensors and solenoid valves are installed at the tube inlet and outlet and the shell inlet and outlet.

[0015] The rear end of the water treatment filter 13 is connected to a reverse osmosis device 14 to perform reverse osmosis treatment on the wastewater to obtain pure water, which is then passed into a pure water temporary storage tank through a qualified water recovery pipeline 15 for temporary storage, and then supplied to the centrifugal washing device 1 for use.

[0016] It also includes a control device, which has a microprocessor and a control panel. The microprocessor and the control panel, the conductivity detector 4, the three-way solenoid valve 5, the solenoid valve, the pH meter, the liquid level sensor, the acid metering pump, the temperature sensor, and the circulation pump are electrically connected.

[0017] The working principle of the utility model is as follows: the high-temperature and high-alkali wastewater in the centrifugal washing equipment 1 is discharged through the wastewater outlet 2, and the conductivity is detected by the conductivity detector 4. If the conductivity is not less than 10000 μs / cm, the control device controls the three-way solenoid valve 5 to connect the wastewater outlet 2 and the washing water discharge pipe 3 to discharge the washing water; if the conductivity is less than 10000 μs / cm, the control device controls the three-way solenoid valve 5 to connect the wastewater outlet 2 and the washing water recovery pipe 7, and the wastewater enters the washing water recovery pipe 7.

[0018] The control device detects the pH value of the wastewater in the washing water recovery pipe 7 through the pH meter at the front end of the three-way pipe fitting, and controls the opening and closing of the solenoid valve of the pH adjustment device 6 and the stroke of the acid metering pump according to the pH value to neutralize the wastewater.

[0019] The neutralized wastewater enters the shell side of the shell and tube heat exchanger of the cold recovery device 12, and the liquid nitrogen in the liquid nitrogen storage tank 8 enters the tube side. The circulating pump drives the refrigerant 11 to circulate, and the liquid nitrogen absorbs heat in the tube side, so that the refrigerant 11 is cooled. The refrigerant 11 cools the wastewater. The cooled wastewater enters the water treatment filter 13 for filtration, and then is purified by the reverse osmosis device 14 to obtain pure water. It enters the temporary storage tank through the qualified water recovery pipeline 15 for use by the centrifugal washing equipment 1. The liquid nitrogen evaporates into nitrogen after absorbing heat in the tube side, and enters the subsequent nitrogen supply pipeline to supply nitrogen to the subsequent equipment as a protective gas or a replacement gas.

[0020] The circuits and mechanical connections involved in the present utility model are conventional means used by those skilled in the art, and technical inspiration can be obtained through a limited number of experiments, which belong to common knowledge.

[0021] Components not described in detail herein are prior art.

[0022] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A system for comprehensive utilization of cold and water resources in the production process of a positive electrode material precursor for a secondary battery, comprising a centrifugal washing device (1), wherein a wastewater outlet (2) of the centrifugal washing device (1) is connected to a washing water discharge pipeline (3), and characterized in that: The wastewater outlet (2) of the centrifugal washing device (1) is connected to one port of a three-way solenoid valve (5), and the other two ports of the three-way solenoid valve (5) are respectively connected to the wash water discharge pipe (3) and the wash water recovery pipe (7); a conductivity detector (4) is connected between the wastewater outlet (2) and the three-way solenoid valve (5); the wash water recovery pipe (7) is connected to a pH adjustment device (6); the wash water recovery pipe (7) is connected to a cold recovery device (12) and then to a water treatment filter (13); the rear end of the water treatment filter (13) is connected to a reverse osmosis device (14); the rear end of the reverse osmosis device (14) is connected to a qualified water recovery pipe (15); the cold recovery device (12) is also connected to a liquid nitrogen storage tank (8); and the device further comprises a control device, which is electrically connected to the conductivity detector (4), the three-way solenoid valve (5), and the pH adjustment device (6).

2. The system for comprehensive utilization of cold and water resources in the production process of secondary battery positive electrode material precursor according to claim 1, characterized in that: The pH adjusting device (6) comprises an acid storage tank, in which acid is stored, and an electromagnetic valve is installed at the outlet. A three-way pipe fitting is provided on the wash water recovery pipeline (7), and the branch pipe opening of the three-way pipe fitting is connected to the outlet of the electromagnetic valve through a pipeline; a pH meter is connected to the main pipe of the three-way pipe fitting, and the electromagnetic valve and the pH meter are both electrically connected to the control device.

3. The system for comprehensive utilization of cold and water resources in the production process of secondary battery positive electrode material precursor according to claim 1, characterized in that: The cold recovery device (12) is a shell and tube heat exchanger, comprising a tube side and a shell side, the tube side being provided with a casing, the tube side being connected to the liquid nitrogen storage tank (8), the shell side being connected to the wash water recovery pipeline (7) and the water treatment filter (13), and the casing containing a refrigerant (11).

4. The system for comprehensive utilization of cold and water resources in the production process of secondary battery positive electrode material precursor according to claim 3, characterized in that: The pipe-side inlet is a liquid nitrogen inlet (9), and the pipe-side outlet is a nitrogen outlet (10). The liquid nitrogen inlet (9) is connected to the liquid nitrogen storage tank (8), and the nitrogen outlet (10) is connected to a subsequent protective gas and / or replacement gas supply pipeline.

5. The system for comprehensive utilization of cold and water resources in the production process of secondary battery positive electrode material precursor according to claim 3, characterized in that: The sleeve has an inlet and an outlet, a circulation pipeline is connected between the inlet and the outlet, the circulation pipeline contains the coolant (11) and is connected to a circulation pump.

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