| 摘要 |
A shaft furnace for reacting two gases, e.g. metal halides and oxygen, in a fluidized bed of inert solid particles, is provided at its base with separate sets of passageways for the individual reactant gases which fluidize the bed, each passageway containing a constriction such that the pressure drop thereacross is equal to at least half that from bottom to top of the bed when fluidized. The constrictions are preferably in the form of removable discs having a central orifice. The passageways are so arranged in the base that the separate gases intermingle in the bed. The inert solid has a particle size of 40-1000m and the furnace has a diameter of at least 15 inches. Specific reference is made to the production of titanium dioxide from titanium tetrachloride and oxygen and aluminium trioxide from aluminium trichloride and oxygen according to the process described and claimed in Specification 919,019, Fig. 1 shows furnace 1 having a heat insulating base through which the fluidizing reactant gases pass via manifolds 25 and 26 to two sets of passageways 312, 212 and 112, each containing constriction plates 43. The bulk of the product formed is entrained in the effluent gases which pass out through <PICT:0919020/III/1> port 126. Further bed material is supplied from solids feed device 71 through flanged pipe 70 and surplus is removed through conduit 170 into vessel 81. Fig. 5 shows refractory tubes 400 having downwardly sloping outlets 410 fitted into the passageways of base 11. The gases are supplied through inlets 406,407 into windboxes 404,405 and thence through screw plugs 402 which contain orifice constrictions 403. Specifications 724,193, 761,770, 794,666 and 813,489 also are referred to. |
