미세기포를 이용한 직접접촉식 막증류 공정의 성능평가

Abstract

Most of previous studies on direct contact membrane distillation (DCMD) process have been focused on the effect of operating conditions (i.e., temperature, flow rate and concentration) on the DCMD permeate flux. In this study, DCMD experiments are conducted to examine an influence of microbubble on the DCMD performance. A flat-sheet membrane module with an effective membrane area of 0.01 m² is adopted in the DCMD process with a composite membrane, which comprises of an active layer of polytetrafluoroethylene (PTFE) and a support layer of polypropylene (PP). The net-type PP spacers are employed at both feed and permeate channels as a membrane support and turbulence promoter. It is found that with an implementation of microbubble the heat and mass transfers across the membrane are greatly enhanced, resulting in a significant improvement in the DCMD permeate flux.