Apparatus for injecting fluidization gas

Claim 1

Apparatus for injecting starting-up fluidization gas between a lower level and an upper level of a bed of material held in an enclosure having a bottom, which apparatus comprises at least one conduit which can be connected at one end thereof to a fluidization gas delivery means and can extend in the enclosure between the bottom of the enclosure and an upper fluidization level, a plurality of nozzles which are provided on the at least one conduit such that the or each conduit has at least one nozzle for blowing fluidization gas into the enclosure from the respective conduit the nozzles being disposed in several planes which are spaced in a direction along the length of the at least one conduit so that the nozzles can be spaced between the upper fluidization level and the bottom of the enclosure, and means for selectively communicating in succession the nozzles which are in the successive spaced planes with the fluidization gas delivery means, such that the highest nozzle or nozzles can be communicated with the fluidization gas delivery means and then the lower nozzles successively, said at least one conduit consisting of a first outer conduit which is closed at one end thereof and a second conduit which is mounted inside the first conduit and spaced from the said closed end, one of the first and second conduits being provided with the said nozzles on a side wall thereof, the nozzles being spaced circumferentially and the said one conduit being closed at that end which is remote from the closed end of the first conduit, and said means for selectively communicating comprising a movable transverse shutter which is connected to an operating member and is mounted in the said conduit which has the nozzles, the conduit not having the nozzles being connected to the fluidization gas delivery means via that end thereof which is remote from the said closed end of the first conduit.