Abstract: The conventional multi-effect evaporator,a high-tech device to process salty wastewater,was modified with the self-developed "Venturi-effect pump" and by reusing the 1^st-stage high-speed exhaust steam.The original work was the jet-nozzle inside a T-junction.The flow field in T-junction was mathematically modeled theoretically analyzed,numerically simulated and experimentally evaluated.The influence of the injection steam pressure and nozzle diameter on the water production ratio was investigated for design optimization.The results show that when it comes to low-pressure generation,the lab-built "Venturi-effect pump" works well.Specifically,as a substitute for the 1^st-stage vacuum pump,it increases the injection pressure and decreases the increase-rate of water-production ratio,resulting in reduction of energy consumption by 47%.We suggest that the self-developed "Venturi-effect pump" be of some technological interest in design optimization of multi-effect evaporator for salty sewage processing.