Improvements in method of introducing fluidising gas into a heated fluidised bed

摘要

A fluidizable bed of granular material is contained in a vessel having a perforated base, which base is separated from the fluidizable bed by a static layer of granular refractory material, the interstices of the static layer being such that the fluidizable bed, though resting on the static layer, shows no tendency to penetrate the static layer appreciably. The static layer may be inhibited from being fluidized either by having a density and a particle size such that an ascending stream of gas is incapable of displacing it or by a mesh covering it. The openings of the mesh permit contact between static layer and fluidizable bed. In the examples (1) fluidizable aluminosilicate particles having a density of 28 lbs./ft3 and a mean diameter of 53 microns are supported on a static layer of silica sand particles having a density of 94,3 lbs./ft.3 and a diameter of 250-350 microns; (2) the silica sand of Example 1 is fluidized on a static layer of bauxite particles having a density of 106 lbs.ft.3 and a mean diameter of 1,000 microns; and (3) Al2O3 particles of density 65,1 lbs./ft.3 and diameter 50-100 microns are supported on a static layer of bauxite as used in Example 2.