Feeding powdered coal to high pressure reactor - by extruding moist coal into high pressure gas stream, drying and sepg. dry extrudate

摘要

Drycoal is fed to a high pressure gasifier vessel by feeding powdered coal having a predetermined percentage of water to an extruder. The mixt. is continuously extruded into a high pressure stream of gas so that it is dispersed into powdered coal mixed with the gas stream. The stream is then dried and the dry dispersed extrudate separated from the gas and fed into the gasifier vessel. Pref. the drying is by upward flow in a high pressure fluidised dryer using superheated steam as the heat source sepn. occurs in a high pressure cyclone separator. The sepd. gas is cooled, has water in it removed and is recirculated after being compressed. The feed arrangement enables the feeding of a high concn. of coal/water mixt. into the high pressure system so that in many cases the natural coal and water content is close to the concn, required for extrusion. Thus, little if any, additional water is necessary. The energy required to dry the coal under pressure is about the same as that required if the coal were dried and then injected.