Study On Spray Drying Process Of Coking Desulphurization Waste Liquid

In view of the current traditional treatment technology of Coking Desulfurization Waste,Such as coal blending,pyrolysis,acid preparation,salt extraction,there are many problems,such as complex process,large energy consumption,serious corrosion of equipment,continuous production,and two pollution.In this paper,the waste liquid of Coking Desulfurization is treated by spray drying technology,and its process is studied.The technology of spray drying for the treatment of Coking Desulfurization Waste Liquor is presented in this paper.It takes the YC-015 type spray dryer as the main equipment and sodium carbonate and ammonia as the source of the desulfurization waste liquid as the research object.According to the theory of airflow spray drying process,the performance of spray dryer is studied,and the dynamic model of spray drying process is built to study the phenomenon of sticky phenomenon and the best process.The main research results are as follows:?1?Airflow spray drying process theory and sticky phenomenon:spray drying process can be divided into two stages:material atomization and droplet drying.The atomization stage of material and liquid determines the quality of final product,which is the core of spray drying.The atomization of the liquid is realized by the relative velocity between the gas and liquid,and the droplets are finer.Spray drying tower due to increase also added auxiliary air,and the air velocity is larger,but the atomization angle is smaller,so how long distance spray droplet injection,wall sticking position compared to the other two lower.?2?Study on the performance of YC-015 spray dryer:By preheating the spray dryer under different conditions,the optimum preheating time is 30min.Under the single factor conditions,the air temperature increases with the increase of the intake temperature,and the air temperature increases linearly with the increase of the volume flow rate;with the increase of material feed,the air outlet temperature is linearly decreased,and the selection of material intake between 400 and 600 m L·h^-1is more suitable;under the inlet pressure of 0.2-0.3Mpa,the inlet pressure has little effect on the outlet temperature.Under the condition of 0.1Mpa and 0.15Mpa,the air compressor is in intermittent operation,resulting in the unstable working state of the atomizer,resulting in the instability of the outlet temperature.The intake volume flow has the greatest influence on the air outlet temperature,followed by the air inlet temperature,and the material feed volume is the smallest.Through the response surface test data analysis,it is concluded that the standard regression model is the outlet temperature=90.80+7.13A+7.25B-1.63C,which can predict the wind temperature very well.?3?The kinetic model of spray drying process:The kinetic model of spray drying process was established through the study of the spray drying process of the desulphurized waste liquid in Wuhan Iron and steel group.According to the test results,the inlet temperature,outlet air temperature as the research object,the linear regression of the salt water content data obtained for water content of=1E+10?T_m^-4.3814.381 and its function model.In the range of temperature,the water obtained by test that FGD spray dried salt rate consistent with model.At first,with the increase of temperature,the moisture content showed a fast decreasing trend.When the?T_m increased to 151,the inlet air temperature was 215 degrees,and the outlet temperature increased to 102 degrees.?4?Desulphurization waste liquid with sodium carbonate as the base source:The best condition for decolorizing pretreatment was 2 hours decolorizing time,and12g activated carbon was added to the activated carbon for every 300ml desulphurization waste.The optimum process conditions for spray drying process are:intake temperature 200?,material feed volume 400m L/h,intake volume flow rate6m3/min,inlet pressure 0.3MPa.Salt water content is 3.70%,the bulk density is2.83g/mL and the angle of repose is 27 degrees.Salt water content is low and extremely easy to flow,no adhesion,is conducive to the incinerator burning acid or export.Salt complex has very strong water absorption,easy bibulous agglomerate,and has strong corrosive.Coking desulfurization wastewater COD removal rate was97.37%,the mass fraction of solids in the liquid condensate from 31.5%to 1.19%,the salt rate reached 96.5%,the condensate can be used in desulfurization system.Some halogen material coking desulfurization waste liquor spray drying process and nitrogen substances in gaseous form and volatilized and trace salt particles with exhaust gas suction device to absorb,volatilization of HCl,up to 87.7mg/L.?5?Desulphurization waste liquid with ammonia as the base source:The optimum conditions are as follows:the intake temperature is 180 C,the material feed volume is 400mL/h,the volume flow rate is 5m3/min,and the inlet pressure is0.3MPa.The air temperature is within the range of 80-85.Salt complex has strong absorbent,rehydration rate is slightly lower than the coarse salt salt Yegang wuhan.Coking desulfurization wastewater COD removal rate was 95.44%,the mass fraction of solids in the liquid condensate from 36.3%to 0.97%,the salt rate reached 97.3%,the condensate can be used in desulfurization system.Some halogen material coking desulfurization waste liquor spray drying process and nitrogen substances in gaseous form and volatilized and trace salt particles with exhaust gas suction device to absorb,volatilization of HBr,up to 126.3mg/L,followed by HCl.The above research results show that the waste water from coking desulfurization wastewater can be recovered and utilized by spray drying process,no exhaust gas emission and no two pollution.It is an efficient,green and harmless way to treat coking desulfurization waste liquid.