Process and apparatus for gasifying solid fuels in gas producers

摘要

462,933. Gas producers. KRUPP AKT.-GES., F. March 17, 1936, No. 7982. Convention date, March 23, 1935. [Class 55 (i)] In a gas producer in which the air supply, with or without steam, and the gas withdrawal are effected in the neighbourhood of the gasefication zone, the former is introduced through a central pipe 12 and the latter removed through outlets 3 in the periphery of the shaft, so as to produce a relatively shallow gasefication zone of truncated conical form with symmetrical flow of the gases therethrough. The direction of gasefication is reversible by interchanging the air supply and gas withdrawal. In a modification of the process, the gas supply and withdrawal are effected at the same level so as to produce a disc-shaped gasefication zone. In the alternative method of working, steam from a heat-exchanger 15, supplied with feedwater from an annular tank 16 in the upper part of the shaft and heated by the evolved gases from the pipe 12, is supplied to an external ring-shaped pipe 6 provided with spaced nozzles 7 terminating in front of nozzle-shaped vertical air inlets 5, the gases thoroughly mixing in an annular channel 4 within the wall of the producer before issuing into the fuel bed through horizontal spaced nozzles 3 arranged below the narrowest section of the shaft. The wall of the producer is thus cooled. If the latter is unnecessary such as with a wall composed of sillimanite, the channel 4 and inlets 5 may be dispensed with. Air may also be mixed with the steam in the heat-exchanger through a valved inlet 19. The single offtake pipe 12 may be replaced by a number of concentrically arranged pipes, these pipes being provided with perforated hoods 13 to prevent removal of fuel particles.. In the reversed method of working, the steam supply pipes 18, 6 are removed and replaced by draw-off pipes for the gaseous products connected to the vertical channels 5. In a modified form of the producer, the cooling channels 4, 5 in the shaft wall are replaced by an air- or water-cooled jacket, and the steam admission nozzles 7 terminate horizontally in front of the horizontal air inlets 3, the latter being also cooled by the jacket through which they pass. The upper part of the jacket is of spiral form to increase the cooling air velocity.