A gas generator is a device that uses coal as raw material to produce gas for use in gas equipment. The solid raw coal is added from the top of the furnace and moves downward with the operation of the equipment. While encountering the gasification agent (air, steam) entering from the bottom of the furnace in countercurrent, it is heated by the high-temperature gas of the fuel layer at the bottom of the furnace, causing physical and chemical reactions to produce coal gas.
Principles and classifications of equipment coking properties:
gas generatorThe coking property of coal is the property of whether coal particles can generate coke after being heated by blocking the air. Whether it is a coking process or a gasification process, all or corresponding parts of the coal are always heated in the process of isolating the air. During the heating process, before 200℃, coal releases adsorbed gas, free water and decomposed combined water. Above 250℃, the organic structure of coal begins to decompose, and various gases precipitate. Coal also softens due to heating and forms a viscous colloid.
As the thermal decomposition of the equipment continues, the generated gas causes the colloid to expand. At 550-600°C, the colloid begins to solidify and becomes a porous semi-coke. When the temperature rises to 700°C, the semi-coke further pyrolyzes and releases gas. When the temperature reaches 1000°C, the pyrolysis stops and the volume shrinks, gradually turning into coke with cracks and pores. During the carbonization process, some coal will melt when it reaches a certain temperature (400-450°C). After the volatile matter escapes, it forms a porous hard lump, which is coke. This kind of coal is called caking coal.
1. Because there is coke on the furnace wall, it affects the heating of the water jacket, causing the water jacket to fail to meet the evaporation required in the design.
2. Excessive coking on the furnace top will affect the operation of the stirring rod. Sometimes coking will also cause the coal distribution channel to narrow, and in severe cases, it will affect the coal distribution.
3. There is too much coking at the furnace outlet, which affects the gas flow and causes the furnace outlet pressure to increase.
Coking in a gas generator is related to the type of coal (volatile content), coal particle size, and gasification intensity. If coking forms, deal with it promptly.
