Experience of modification of thermo-compressors in multiple effects desalination plants in Assaluyeh in IRAN

Nowadays multiple effect desalination plants are used widely in water treatment processes. They utilize thermal vapor compressors instead of mechanical ones. One of the major complexities about thermo-compressors is related to its unstable operational mode. An experimental malfunctioning occurred in a desalination unit established in south pars gas field phases 9&10 with 1718 cubic meter per day capacity. Some modifications on the thermo-compressor design were applied and well tested.In the current study a numerical investigation was performed on a malfunctioning thermo-compressor and the source of the problem was observed via a numerical simulation. Afterwards, the modifications were conducted on the numerical models and then a perfect analyzed and verified model was selected to manufacture and install. The test results were shown a better performance of thermo-compressor which yields an increase in entrainment ratio and extend the stable region of thermo-compressor working. It is shown that the entrainment ratio is very sensitive to the geometrical parameters of mixing area zone and throat section of thermo-compressor.

► Thermo-compressor should be designed in double choking mode in the worst case.
► Thermo-compressor maximum discharge pressure is very sensitive to the mixing angle.
► Low mixing angle causes to increase the mixing efficiency of thermo-compressors.