Analysis On Model And Dynamic Parameters For Vacuum Evaporation Coking Desulfurization Liquid System

In recent years, HPF desulfurization process using ammonia as alkaline source was developed in domestic. Sulfureted hydrogen and cyanogen hydrogen in gas is removed by HPF as a catalyst. Desulfurization solution contains NH₄SCN and (NH₄)₂S₂O₃. When total content of NH₄SCN and (NH₄)₂S₂O₃ exceed 250g/L, it will seriously affect the effectiveness of the gas desulfurization. So some desulfurization solution should be treated in actual production. At the same time, some fresh solution should be added in order to reduce the content of salt in desulfurization solution. Therefore, looking for a cost-effective method of waste treatment becomes a top priority.In this paper, desulfurization solution of Chongqing Iron & Steel is treated as research object. Quality concentration of NH₄SCN and (NH₄)₂S₂O₃ is measured. Character of NH₄SCN and (NH₄)₂S₂O₃ is analyzed. Viscosity,boiling point and density of desulfurization solution is measured, when quality concentration of NH₄SCN and (NH₄)₂S₂O₃ changes. In addition boiling point and density is regressed into mathematical model. Desulfurization solution is regarded as NH₄SCN- (NH₄)₂S₂O₃-H₂O three phase system. When NH₄SCN,(NH₄)₂S₂O₃ and H₂O exist together, saturation balance point in different temperature is measured. NH₄SCN is removed from desulfurization solution by temperature margin method to deal with desulfurization solution.In this paper, physics model of vacuum evaporation coking desulfurization solution is founded. Mathematics model of evaporator,preheating device and the whole system is founded according as material balance calculation,heat balance calculation and heat transfer rate equation. Linear equation group composed by material balance calculation equation and heat balance calculation equation is solved by Using Gauss elimination algorithm. When NH₄SCN is separated out from cocurrent multieffect evaporation system, the annual total expense-J is treated as optimize objective to found system optimize design model. The system optimize design model is solved by Lagrange multiplier method.Coking desulfurization solution of Chongqing Iron & Steel is treated as research object. Every day runtime is 20h. Every day's disposed capacity is 30t/d。Through solving optimize design model of coking desulfurization solution system, the best economic effect number is one. In this situation, the annual total expense is the least. Vapor pressure,temperature of desulfurization fluid and Velocity of desulfurization fluid impact on total temperature margin,effective total temperature margin,heating steam consumption,gained output ratio and heat transfer area are discussed respectively.