BURNING CARBONACEOUS MATERIALS

摘要

1510946 Fluidized-bed combustion METALLGES AG 9 July 1976 [5 Sept 1975] 28750/76 Heading F4B A process for combustion under approximately stoichiometric conditions in which carbonaceous material is fed through a lance 7 to a fluidized-bed reactor 1 which is fluidizedby gas supplied through an inlet 8 and by a secondary gas supplied through an inlet 2 or which can be supplied at a plurality of superimposed levels (2a-2d), Fig. 2 (not shown). At least the secondary gas contains oxygen for the combustion of the carbonaceous material in the fluidized bed. The volume ratio of fluidizing gas supplied at 8 to secondary gas supplied at 2 is in the range from 1 : 20 to 2 : 1 and the two gas supplies are adjusted so that suspension density of the fluidized bed above the inlet 2 level is in the range 15 to 100 Kg/M3. Solids entrained by the exhaust gas from the fluidized-bed are collected in the separator 6 and are recycled through a conduit 9 back into the reactor 1. Surplus solids produced are withdrawn through a conduit 10. Part of the heat of combustion is dissipated through cooling surfaces 3 in the space above the inlet 2 level. Other heat heat exchange surfaces may be located at positions 4 and 5 in the reactor and separator. Solids discharged from the conduit 10 may be fed to a fluidized-bed cooler 14, which is fluidized by oxygen containing gas which is then fed to the inlet 2. The cooler 14 has cooling registers 13 in which solids are cooled indirectly by gas supplied through a conduit 17 and later fed as fluidizing gas to the inlet 8. Part of this gas supply may be used for pneumatically feeding the carbonaceous material through the lance 7. The combustion process may be carried out under superatmospheric pressure.