Research On Liquid Film Evaporation And Concentration Technology Of Concentrate In Vertical Tube With Industrial Waste Heat As Heat Source

In industrial water treatment and seawater desalination treatment,a large number of concentrate will be produced.Concentrate has high salinity and its main component is soluble inorganic salt,which should be concentrated and reduced,and treated and disposed of as resources.Industrial discharged concentrate needs to be concentrated before entering the crystallization salt separation process to meet the crystallization requirements,and various commonly used thermal concentration processing methods are restricted by high energy consumption.In steel,metallurgy,chemical and other industries,the utilization rate of waste heat is low,low temperature waste heat is often waste heat of enterprises,which causes the waste of energy and high energy consumption of enterprises.In this paper,a process method and device of using industrial waste heat as heat source to concentrate concentrated brine was explored.Combining the utilization of low temperature waste heat with concentrated brine concentration,a process method of using water film evaporation to concentrate concentrated brine by blast furnace slag water was constructed,which realized bidirectional utilization and double cost reduction.At first,this paper starts with the basic requirements of strong brine concentration,looking for the right of industrial waste heat as heat source,to the use of industrial waste heat sources of heat matching to explore,to analyze the applicability of the blast furnace cinder flushing water,according to the heat transfer process of water both,construct a blast furnace cinder flushing water as a heat source in the heat exchange tube internal flow,strong brine on the vertical pipe set uniform,The process of membrane flow down the outer wall of a tube.And then to build the vertical pipe water film evaporation system operating conditions studied,studied the vertical pipe flow direction,both inside and outside the strong brine flow rate and strong brine,and the effects of initial temperature on heat transfer,through the measured vertical pipe in and out of the water inside and outside temperature and evaporation capacity assessment system,the effect of heat transfer in concentrated brine initial water temperature is higher,the tube inside and outside fluid for upstream,When the flow of concentrated brine outside the tube is 50L/h,the heat transfer effect is the best,and the evaporation amount of concentrated brine is the largest.Then,the heat transfer coefficient of the water film evaporation system of the vertical tube is calculated according to the parameters measured in the experiment,so as to evaluate the heat transfer effect of the system.The calculation results show that the heat transfer coefficient is 1.3 times that of the common heat exchanger by using the latent heat of evaporation of the liquid film.Finally,this article analyzes the steam condensate and strong brine evaporation residual concentrate,the quality of the water evaporation in the different phases and different evaporation temperature experiment were analyzed,and the condensate as the evaporation process for pollutants content increases,and with the evaporation temperature,evaporation rate faster,concentrate the enrichment degree of increase,concentrate the contaminants will increase,In the process of evaporation,only a small amount of microbial metabolites with relatively small molecular weight and humic acid,fulvic acid will be evaporated,but the more stable protein organic matter will not be evaporated.