The Analysis of Influence Factors on Sprinkle Density of Falling Film in Horizontal Tube Evaporator for Seawater Desalination

The technology of horizontal-tube falling film evaporation is widely used in low temperature multi-effect distillation evaporators. The heat transfer coefficient of it depends on many factors, such as steam velocity, sprinkle density, evaporation temperature, etc. In the engineering design of evaporator, much smaller sprinkle density may led to "dry points on tube", while much bigger sprinkle density may destroy thin film evaporation. Both reduce the heat transfer coefficient and do great harm to the safety of heat transfer at the worst condition. So, appropriate value of sprinkle density is very important to guarantee the heat transfer coefficient. Many influence factors on sprinkle density is analyzed based on low temperature multi-effect desalination system with parallel flow pattern, and the conclusion of which has great guiding significance to the engineering practice.