The application of MEMS flash in reuse of alkalinous waste water

Abstract The waste water of mercerization in dying industry contains about 4.75% NaOH. It is required to be concentrated to 23.7% for reuse. The MEMS flash has been used to treat this waste water in a plant for six years. The unit consists of two effects and fifteen stages. It is much more simpler in construction and less likely to deposit scale on the heating surface than conventional multi-effect evaporation. In comparison with the common MSF, it gives the advantages of higher concentration ratio and thermal efficiency into full play. The performance ratio is about 3.8. Not only alkali, but also desalination water can be reused. By the end of the first year of operation, the plant had recovered the capital invested. In this paper, the application of MEMS flash for treatment of alkalinous waste water is described. We have recommended the optimum stage number and the distribution of stages in two effects, which can serve as a reliable basis for successful design.