Mechanical problems in the design of a fixed-bed, slagging gasifier
Pressurized, fixed-bed gasification of coal with steam and oxygen is now a well-established commercial technology. It appears commercially feasible to operate a gasifier at three to five times the capacity per vessel cross section that is presently possible with the conventional, dry-ash gasifiers, with a corresponding decrease in steam consumption and wastewater disposal. This requires that partial oxidation and steam-char reactions be carried out at temperatures locally exceeding the melting point of the coal's mineral components, which leave the reaction vessel as a molten slag. The reaction zone must be controlled to avoid excessive thermal, chemical and abrasive destruction of refractory walls, while keeping the slag fluid until it can fall clear of a taphole, heated by external burners, and into a quench bath. Higher in the fuel bed, where drying and devolatilization take place, the coal's settling behavior and tendency to form stable bridges are determined by its chemical and less thorougly studied structural properties. This paper covers operating experiences with such a slagging, fixed-bed pilot gasifier and establishes some design criteria for mechanical components. 27 figures, 5 tables.
- Research Organization:
- North Dakota Univ., Grand Forks (USA). Engineering Experiment Station; USDOE Grand Forks Energy Technology Center, ND
- OSTI ID:
- 6040995
- Report Number(s):
- DOE/FC-1010; CONF-830108-5; ON: DE83012286
- Country of Publication:
- United States
- Language:
- English
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