Cyclic utilization device for recycling, finely-steaming and purifying NMP in coating process of lithium ion battery

Abstract

The invention relates to a cyclic utilization device for recycling, finely-steaming and purifying NMP in coating process of a lithium ion battery. The cyclic utilization device comprises a coating machine, a heat exchanger, a rotating wheel, finely-steaming and purifying equipment, a waste liquid tank, automatic liquid feeding equipment and an NMP solution storage tank. The device is characterized in that the heat exchanger comprises a heat exchanger high-temperature inlet, a heat exchanger low-temperature inlet, a heat exchanger dry air inlet and a heat exchanger dry air outlet; and a coating machine head and a coating machine tail are arranged on the left and right sides of the coating machine, respectively, an exhaust pipeline is arranged above the coating machine and is connected with an exhaust fan, the exhaust fan is connected with the heat exchanger high-temperature inlet through the exhaust pipeline, and an air supply pipeline is arranged below the coating machine. The cyclic utilization device is used for adsorbing NMP exhaust gas exhausted in a coating production process of the lithium ion battery and converting NMP in the exhaust gas into liquid to be recycled by virtue of a condenser so as to realize recycle and reuse, the concentration of NMP is high, and the purifying rate is high; and the automation degree of the device is high, and the recycling rate of liquid is high.

Description

technical field [0001] The invention relates to the technical field of waste gas recovery, in particular to an NMP recovery, refining, steaming, purifying and recycling device in the lithium ion battery coating process. Background technique [0002] N-Methylpyrrolidone (NMP) is a colorless transparent liquid with a boiling point of 202°C and a flash point of 95°C. It is miscible with water and soluble in ether, acetone and various organic solvents. It has a slight ammonia smell and stable chemical properties. Carbon steel and aluminum do not corrode, but are slightly corrosive to copper. It has the advantages of low viscosity, good chemical stability and thermal stability, high polarity, low volatility, infinite miscibility with water and many organic solvents, etc. [0003] In the field of lithium battery production, the positive electrode slurry generally uses NMP liquid solvent, and its utilization rate is the top priority of every battery manufacturer. When a batch of p...

AI Technical Summary

Problems solved by technology

NMP is lost in the form of gas, a large amount of NMP solvent is consumed in the whole process, and the NMP solvent evaporated by gas is also wasted

At the same time, it is extremely unfavorable for energy saving and environmental protection

[0004] At present, in the process of refining and purifying NMP solvents, a heating tube is generally used to mix the liquid to be recovered. After the temperature rises, the NMP gas and water vapor will volatilize together, so that the loss of NMP is large, the concentration is low, and the loss of steam is large.

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