Fixed bed double stage coal gasifier description

Double stage coal Gasifier has two gas outlets, can produce different heat value coal gas, the coal after be carbonization fully in the upper part of coal Gasifier, there is almost no tar in the upper coal gas, only a few tar contained in the lower gas.

Fixed bed double stage coal gasifier process

Coal Gasification Equipment

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(1) Process of coal 
The coal is added into the coal Gasifier by lifting system. The first stage is   carbonization layer, coal move down slowly, after dry and carbonization, the moisture of coal is dried out. With the coal moving down, temperature becoming higher, tar and most of sulphide are dried distillation and come out, forming hydrocarbon and light tar, come out with upper coal gas. 
After dried and carbonization, coal become semi-coke and go on moving down. This is the gasify stage, oxidation reduction reaction reacted here, coal gas are produced. Ash and other little coal which haven't be reacted moving down and be get ride of from coal Gasifier by ash scraper.
(2). Process of steam and air
Air and steam used as gasifying agent are blowed into coal Gasifier from bottom. At the temperature of 1100-1200℃, reacted oxidation reduction reaction with coal which have been semi-coke in the gasify stage, producing coal gas. The coal gas are divided into two parts, one part moving up through the down coal gas interlayer, transfer indirectly heat to the coal layer by refractory material, to ensure the coal is fully dry and carbonization during moving down , finally, the coal gas come out from lower coal gas exit, it's called Second coal gas. Another part coal gas go into the carbonization layer, touch directly the coal which moving down slowly for gasify, transfer heat to it for carbonization and dry, at the same time, produce carbonization coal gas, and come out from upper stage coal gas exit, it's called upper coal gas.
(3). Main chemical reaction
2C+O2=2CO  2CO+O2=2CO2  C+O2=CO2  CO2+C=2CO    C+2H2O=CO2 C+H2O=CO+H2  C+CO2=2CO