The Process Parameters Optimization Of Multi-effect Evaporating Equipment For "Three Wastes" Emissions Wastewater Treatment

With the rapid development of polysilicon production industry,a great amount of industrial wastewater which contain high concentrations chloride ions is produced.If the industrial wastewater cannot be treated well and reused,it will cause great waste of water resources and serious pollution to the water body of the whole society.The wastewater containing high concentrations chlorine ion "zero emission" and reuse is a basic requirement of society for polysilicon production.Given a polysilicon company produces a large amount of industrial wastewater,and if the wastewater is discharged into lakes or rivers,it will not only waste water,but also violate the purpose of the company's energy-saving and environment-friendly.The company expected to realize the goal of reuse of the waste water containing high concentration of chloride ions("three wastes" emissions wastewater)by adding a multi-effect evaporating equipment.Which not only can greatly reduce municipal water usage,but also can significantly reduce the discharge wastewater with chlorine.This paper main explore the technical operation conditions of multi-effect evaporating equipment for the "three wastes" emissions wastewater treatment and stepwise optimize operation conditions based on the actual production.And we ultimately identified the most reasonable operation conditions to realize "zero emission".The operation conditions as follows: the negative pressure is-45 KPa ~-35 KPa,and the ischarge temperature in separator bottom is 123.9?~136.2?,and the difference of the ischarge temperature in separator bottom and negative pressure is 168.1 ~ 172.5,and the hydraulic is 10% ~ 55%.In view of the new multi-effect evaporating equipment,we first introduce this new equipment and the process.During the whole process of the equipment test run,the pressure,purge and airtightness requirements of the new device were strictly followed to ensure the stability of the system during operation.The research is carried out by collecting and analyzing the results of the testing data each hour and the crystallization of calcium chloride.According to the series of experiments' results,we finally determine the ideal process parameters for safety production and get the goal of "three wastes" emissions wastewater treatment and reuse.