MASS TRANSFER MODEL OF AIR GAP MEMBRANE DISTILLATION BASED ON STEFAN LAW

摘要

The membrane distillation is a new membrane separation technique. Its advantages are that it can operate in lower temperature and pressure and can use low grade energy as driven force to desalinate the brackish water. In order to improve the permeate flux, a new high flux air gap membrane distillation module was designed and manufactured. The mechanism of mass transfer in air gap membrane distillation (AGMD) is studied in this paper. A simple model based on the Stefan law for our air gap membrane distillation is proposed. This model can be calculated directly by hot solution temperature and cooling water temperature that can be measured in experiment. This model is simple, the parameter of this model is easy to measure and compute except for big error in some points. It is a good engineering prediction model.