Laboratory Scale Test Of The Coke Coal Superheated Steam Gravity Bed Dryer

Coal Moisture Control(CMC)technology is a pretreatment technology for coking coal,that is,the moisture of the coal entering the furnace is accurately controlled from about 12%to about 6.5%before entering the coke oven.The excessive moisture content of coal causes waste of energy in the coking process,reduces the amount of coking water produced,and improves the quality of coke.CMC technology and CDQ technology are also called one of the two key development directions of energy conservation and environmental protection in the coking industry.However,the existing coal moisture control technology and equipment using hot air and superheated flue gas as drying medium have problems such as poor material flowability and easy deflagration.In this paper,a conical porous flap structure is proposed to improve the fluidity of materials during coal conditioning,and the use of superheated steam instead of hot air and superheated flue gas to solve the problem of deflagration in coal conditioning process is designed.The superheated steam is a coking coal gravity bed dryer for drying medium,and a small test bench for coking coal gravity bed dryer is built.The cold and hot test of the coking coal gravity bed dryer is completed,and the coking coal gravity bed is studied.The main research contents and conclusions of the dryer coal conditioning effect are as follows:1)The pressure drop test of the gravity bed drying machine layer was completed,and the variation curve of the total pressure drop AP of the bed with the independent medium flow rate in the bed and the number of conical porous flaps in the bed was obtained.The results show that the total pressure drop ?P of the gravity bed drying machine layer will increase with the increase of the drying medium flow rate in the gravity bed dryer and the number of tapered porous flaps in the bed.Under the test conditions,the initial steam pressure of 2kPa can meet the humidity control demand;2)The humidity control effect of gravity bed dryer was carried out,and the material yield was measured and evaluated.The histogram of coking coal moisture content before and after humidity control was obtained.The results show that the coking coal gravity bed dryer can reduce the moisture content of coking coal from 12%to less than 6.5%,the material yield is over 98%,and the material has good fluidity inside the gravity bed.3)The effect of initial superheated steam temperature on the moisture content of coking coal after humidity control was studied,and the change curve of moisture content of coking coal with initial steam temperature after humidity control was obtained.The results show that the moisture content of the coal material decreases with the increase of the initial temperature of the superheated steam after the humidity adjustment.The initial temperature range of the superheated steam is preferably 230?-240?.4)The effect of superheated steam flow rate on the moisture content of coking coal after humidity control was studied,and the change curve of moisture content of coking coal with superheated steam flow after humidity control was obtained.The results show that the moisture content of coking coal material after humidity control decreases with the increase of the mass flow rate of superheated steam inside the input dryer.Under the test conditions,the mass flow rate of superheated steam is preferably 0.2t/h,corresponding to gravity bed drying.The steam flow rate in the machine tool is 1.4m/s.