焦化脱硫废液喷雾干燥提盐洁净技术研究

针对目前焦化脱硫废液制酸和提盐技术造成二次污染和设备腐蚀等问题,提出了焦化脱硫废液喷雾干燥提盐洁净技术,对其工艺进行了研究。以进气温度、进气体积流量、物料进料量、进风压力为影响因素,设计了L9(34)正交试验,对脱硫废液干燥后的粗盐性能(含水率、堆积密度、休止角)及其成分进行了分析,得出焦化脱硫废液喷雾干燥提盐的最佳工艺条件为:进气温度200℃,物料进料量400 m L/h,进气体积流量6 m3/min,进风压力0. 3 MPa;粗盐含水率3. 70%,堆积密度2. 83 g/m L,休止角为27°,粗盐提出率为97. 5%,含水率低而且极易于流动,不粘着,十分有利于焚烧炉焚烧制酸或外销;脱硫废液的COD去除率为97. 37%,冷凝液中固形物的质量分数由原液的31. 5%降至1. 19%,使冷凝液可用于脱硫系统回用;喷雾干燥过程中部分卤素、含氮物质会以气态形式挥发出来,与微量的粗盐颗粒物一同经尾气吸收装置吸收排放。

Study on Clean Technology of Spray-drying Salt Extraction for Coking Desulfurizing Waste Liquid

In order to solve the secondary pollution and equipment corrosion problems of coking desulfurizing waste liquid acid and salt technology,this paper presents a coking desulfurization liquid spray drying salt clean technology,and conducts studies.The orthogonal experiment of L9(3^4)is designed with intake temperature,intake volume flow,material intake quantity and inlet air pressure as the influencing factors,to analyze the crude salt properties(water content,bulk density,rest angle)and composition of desulphurization waste liquid.It is found that the best process conditions for spray drying of coking desulfurizing waste liquid salt is:inlet temperature 200℃,material feed rate of 400 mL/h,volume flow at the inlet 6 m^3/min,into the wind pressure of 0.3 MPa,and powder properties under this condition are:moisture content 3.70%,stacking density 2.83 g/mL and angle of repose 27°,the salt extraction rate is 97.5%,moisture content is low,very easy to flow,non-stick and very good for incineration of acid or export.The COD removal rate of desulphurization waste liquid is 97.37%,and the mass fraction of solid in the condensate has decreased from 31.5%of the original liquid to 1.19%,so that the condensate can be used for desulphurization system reuse.In the spray drying process,some halogens and nitrogenous substances will be volatilized in the form of gaseous gas and they will be absorbed and discharged with the trace amount of crude salt particles through the exhaust absorber.