Design Of Evaporative Crystallization Process Of High Salt Wastewater And Development Of CAD Software

Environmental pollution and water shortage is an important issue that the society is facing today and zero discharge of industrial wastewater is one of the important technical means to solve the above problems.Evaporation crystallization is a common process for zero discharge treatment of high salinity wastewater as well as evaporation is a typical process with high energy consumption,so reasonable and efficient process design is directly related to equipment investment,energy consumption level and stability of process operation.According to the characteristics of evaporation crystallization of high salinity wastewater,this paper discusses a combined type MVR evaporation optimization process with falling film evaporation and strong circulation evaporation,analyzes the calculation method of system process parameters,and develops a set of CAD software for process design.First,the optimization process and typical equipment of evaporation zero discharge of high salinity wastewater are discussed,and the overall planning of process design is carried out.Comprehensive considering the evaporation efficiency,scaling formation problem and the energy saving of secondary steam reuse,the combined two-effect MVR evaporation process with one-effect falling film and one-effect strong circulation is the most optimized one.The process has remarkable energy-saving effect,is not easy to scale formation,and has strong adaptability.It can be applied to the evaporation crystallization treatment of most high salinity wastewater.Process design is mainly based on the given design conditions and according to the corresponding process calculation model,calculate and determine the main process parameters of system,main equipment parameters and system costs.Second,the system process calculation method is analyzed and summarized.Analyze the theoretical basis of process calculation,determine the system design conditions,process parameters and main equipment parameters,and establish relevant calculation models,including pure process calculation model,coupling calculation model of process parameters to equipment parameters and cost accounting model.Third,CAD software for process design is developed based on VB6.0 softwareenvironment.The software adopts MDI multi-document interface system and adopts parametric design method.It mainly realizes the functions of design conditions input,process parameters calculation,equipment parameters calculation,system cost accounting,file storage,output printing and so on.The application program is based on an independent backstage database system.The related material physical parameters,material fittings parameters and process calculation parameters are saved in the form of Excel data table.And the design output file is formed in text file format.The application program realizes bidirectional data exchange with the database system through a unified data file reading and writing module.Fourth,the design of evaporation crystallization system for a sodium sulfate wastewater is completed.According to the calculation model and CAD software,complete the detailed process design of the system.The application shows that the CAD software is reasonable in design and complete in functions,which can effectively improve the efficiency of system development.