Our coal gasifier is characterized by high capacity, complete gasification and better coal adaptability, high gas calorific value, easy operation and strong safety performance. It is widely used in many industries. Wholly water-jacketed structure, self-produced steam with a pressure of 49 kpa which can be used as gasifying agent. Automatic coal feeding device of multi-type structures such as double bell jar, upper flashboard and lower bell jar, upper roller, middle flashboard and lower bell jar and upper roller with double bell jar are optional, but double bell jar type can only be chosen if manual coal feeding device is used. Such structures are characterized by easy operation, convenient maintenance and good gas tightness.