Mathematical modeling of membrane distiller with liquid gap

One of the basic tasks of any separation process is the creation of an installation with minimal power inputs. This work examines three possible schemes of the liquid gap membrane distiller with small productivity consisting of a membrane module assembled from separate liquid gap membrane cells, a heater and a heat exchanger. The heat exchanger can also consist of separate heat transfer cells. For estimation of power inputs for a membrane module it is necessary to consider the features of heat transport in each separate element included in a membrane distiller. Possible membrane distiller schemes consisting of a liquid-gap membrane module and heat exchanger have been studied. The analysis of power inputs during the production of pure water has been carried out and the equations for the evaluation have been derived. It has been shown that in all cases of MD-modules assembly, the value of power inputs increases directly proportional to the product of volume stream rate and the temperature difference of the streams at the entry to the membrane module. One of the three analyzed schemes of the membrane distiller with optimal power inputs has been chosen. The numerical simulation of the MD process in an optimal membrane distiller has shown that productivity Q decreases with the growth of a membrane surface.