FILTRATION METHOD USING CROSS-FLOW FILM AND PRODUCING METHOD OF ACRYLAMIDE USING THE SAME

摘要

A filtration method using a cross-flow film has a storage vessel and a circulation pump that are used for circulating and feeding a raw material liquid or a concentrate liquid that is obtained by concentrating the raw material liquid. The method has a step of continuously filtering the raw material liquid or the concentrate liquid by the cross-flow film while additionally feeding the raw material liquid into the storage vessel so as to maintain the level of the liquid in the vessel constant, a step of concentrating a liquid while further continuing the filtration to lower the liquid level with the additional feeding of the raw material liquid to the storage vessel stopped, and a step of discharging a remaining concentrate liquid after the concentration step.