| The treatment of acrylon production waste water is one of the problem of acrylon production enterprises.Propylene ammmoxidation process is the current widely used acrylon production process,1.5 tons of waste water would be produced when getting 1 ton of acrylon in this process.There is a variety of acrylon waste water treatment processes according to current literature,however the environmental friendly and economic reasonable process is still not founded.Generally large acrylon production enterprises adopt four effect evaporation when processing waste water,however continuous supplement of steam is needed,the energy consumption is still high and the enterprise burden is very heavy.Energy saving of mechanical vapor recompression is obvious,and it's widely used in the yield of evaporation in recent years.Acrylon waste water dealt with MVR technology is studied in this paper.Simulation of single effect,two effect,triple effect,four effect and MVR technology has been carried on to deal with acrylon waste water by Aspen plus.Also comparison of energy consumption and process parameters has been made,especially the influence of operating parameters like compress ratio,operating pressure on performance parameters like COP,heat transfer area,compressor energy consumption and water supplement was analyzed in this paper.Gas-liquid separator is one of the key equipment in MVR system.Gas liquid column cyclone was chosen after comparison and analysis.After structure design analysis of the internal flow field by Fluent was made.And made summary and study of internal fluent field and influence of structure size on separation effect.The main results of this paper are included below:(1)COP is inversely proportional to compression ratio and operating pressure.Temperature of steam after compression increases when compression ratio increases.At the same time more water supplement is needed and increase of heat transfer temperature difference decreases heat exchange area,also the construction cost of MVR system decreases,but operating cost increases.(2)Higher temperature of raw material liquid,it contains more heat.And it's more likely to evaporate more secondary steam.Heat transfer area needed is smaller when evaporation amount is larger.(3)There are inside and outside two swirls inside the separator fluent field.Gas exit velocity is affected by overflow pipe and rate of gas content in liquid is decided by under flow pipe.And separation process with two inlets is more steady compared to separator with one inlet.(4)When separator body height is certain appropriate increase of separation diameter could decrease the pressure drop,shorten the transition zone between pure liquid phase zone and the gas phase area,improve the separation effect.Based on simulation data of MVR system,referring to relevant standard and manual,preliminary exploration of engineering design method of MVR system has been carried on in this paper and made balance calculation of materials and energy,also provided equipment parameters like circulating pump,vapor compressor,storage tank.Complete the preliminary engineering design. |
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