NMP DISTILLING APPARATUS

摘要

Provided is an NMP distilling apparatus used for recovering spent NMP collected from, for example, a process for manufacturing electrodes of lithium-ion secondary batteries, being capable of refining the NMP simply and safely regardless of the water concentration in a material and the variations of a processing amount, and being suitable for automatic operation on site. The NMP distilling apparatus comprises: a first distillation tower (1) for distilling spent NMP that is a liquid to be processed and separating the distilled NMP into a high-concentration NMP and water including low-boiling components; and a second distillation tower (2) for further distilling a bottoms product of the first distillation tower (1) and separating the distilled product into a high-purity NMP and a high-concentration NMP including high-boiling components. In addition, the NMP distilling apparatus is equipped with automatic processing functions including: a start-up function for performing a reduced-pressure operation and a circular operation in the first and second distillation towers (1, 2) to adjust to a steady state and starting a continuous processing operation; and an operation mode switching function for switching to the circular operation again according to the liquid level of a material tank (41) or a product tank (42) in the continuous processing operation.