Study On Simulation And Optimization Of Ammonia Distillation Process And Performances Of An Anti-shock Leakage Device Of Tray

Various forms of trays with downcomers are often used as working internals in distillation columns and absorption towers of industry.However,liquid leakage and mist entrainment on the tray are almost inevitable,and liquids will inevitably have back mixing on the plate surface.Due to the short circuit of the liquid,the liquid leakage from the tray will leak down without passing through the tray mass transfer,which will reduce the tray mass transfer efficiency,especially the liquid leakage near the tray inlet,a small amount of liquid leakage can cause the serious decrease of the pedal efficiency.In addition,excessive liquid leakage will affect the stability of the tray operation and reduce the tray efficiency.In order to reduce the negative impact of the tray caused by the impact leakage,the 600 mm diameter tower was used to test the impact leakage rate,and the multi-structured bubble element was selected to replace the previous two-way oblique hole structure.This multi-structured element has the function of reducing the impact leakage of the suspended downcomer tray.Based on the 25 m³/h wastewater produced by a lithium power plant,the ammonia distillation process consumes too much energy.In this paper,combined with the on-site situation of the ammonia distillation process,and the feed position and operating pressure,Reflux ratio and other aspects,using Aspen plus software to simulate and optimize,and perform energy and economic calculations on the simulated process,so as to determine the best plan,so that the waste water removal content reaches the standard,the discharge and the ammonia concentration meet the recycling requirements,and energy saving is achieved.The purpose of the row.A glass tower with a diameter of 600 mm was used to test the hydrodynamic performance of three anti-impact and liquid leakage structures to assist the process.For the three anti-impact leakage devices with two-way oblique holes,strip-shaped fixed valves and round fixed valves as the main components,the selected material systems are air and water,and the trend of the impact leakage rate with the F factor is tested.The experimental results show that the leakage rate of three kinds of anti-dumping unit decreases with the increase of F factor of gas.In general,when the f factor is about0.5 m·s^-1(kg·m^-3)^0.5,the circular fixed valve has more advantages than the strip fixed valve,which is 1.5-2 times higher.Analyzing the current simulation process and on-site data,the ammonia nitrogen concentration reached 21%,and the ammonia nitrogen content in the bottom of the tower was less than 15 ppm to meet the requirements of the process;the separation of the ammonia nitrogen in the raw material liquid was realized to meet the needs of environmental protection;it was found through simulation The consumption of saturated steam has dropped by 24.04%,and the consumption of condensed circulating water has dropped by about 39.63%,which provides a reference for future optimization of the ammonia distillation system.