Research On Pulverized Coal Preparation Andspray Burning System Based On Rotary Kiln For Magnesium Smelting

In recent years,the coke oven gas of the main fuel of Pidgeon magnesium smelting rotary kiln appear shortage of resources and prices rose,and the technical development of multi-channel pulverized coal burner,the metal magnesium industry pays more attention to the technical way of using the pulverized coal as the fuel to replace the coke oven gas in the rotary kiln for magnesium smelting and the economy brought by the increase production and effect-raising.The research found that the technical attempt of burning pulverized coal is often abandoned because the effect is not good.There are two reasons.One is pulverized coal is not qualified,moisture content and uniformity of pulverized coal exist problems,the other is that the thermotechnical system of rotary kiln and the design of burner is unreasonable.And some of the rotary kiln for magnesium smelting directly use the pulverized coal burner of the rotary kiln for cement lead to parameter mismatch,even appear the accident of the burner is burned.This paper is based on the project " research on the technology and equipment of pulverized coal preparation and spray burning system on magnesium smelting rotary kiln ",which is cooperated by Henan Polytechnic University and Jiaozuo City,Chong Fung Metallurgical Machinery Co.,Ltd.This article aims to develop and research an high efficiency,energy saving,environmental protection,suitable for the magnesium smelting rotary kiln's pulverized coal preparation and spray burning system technology and equipment.The main research contents and results are as follows:(1)The pulverized coal preparation and spray burning system new process is put forward,which is mainly composed of vertical mill roller and five channel pulverized coal burner,especially the hot blast from the end of rotary kiln lead into vertical mill roller,which plays an important role in reducing the moisture content of pulverized coal.Which based on the comparison and analysis of pulverized coal preparation and spray burning system in cement industry and analysis of the requirements for the quality of pulverized coal,the moisture content of pulverized coal and the shape of the flame in the pulverized coal preparation and spray burning system on rotary kiln for magnesium smelting.And the heat balance of vertical mill roller was calculated;(2)On the basis of the research on the structure and theory of the burner.A five channel pulverized coal burner with vortex wind channel and burner position and gesture adjusting device is designed and developed,and energy saving of five channel coal burner was analyzed,at the same time,the calculation and analysis of the air distribution of five channel pulverized coal burner and the advantages of low primary air volume and energy saving of five channel pulverized coal burner are verified;(3)Based on the analysis of the structure and the advantages and disadvantages of the rod valve,flat gate valve and butterfly valve,the development of manual multi blade raw coal regulating valve has been completed,which has the characteristics of flexible adjustment and good sealing from the analysis of structure.And declare national utility model patent;(4)The numerical simulation method is used to study the problem of two-phase flow of pulverized coal conveying,and the conclusion is drawn that when the coal wind velocity is greater than 25m/s,the pulverized coal can be evenly transported in a horizontal pipeline,when less than 25m/s,the pulverized coal will be deposited in the pipeline,which is unfavorable to the transportation of pulverized coal.