Heat recovery method and installation, particularly for cooling ash

Claim 1

Installation for the recovery of the heat produced in a fluidized-bed combustion furnace, comprising: (a) a combustion furnace comprising a supply inlet for combustible material, means for forming a fluidized bed for combustion producing coarse ash and fine ash, and a purging outlet for the evacuation of the coarsest ash; (b) a separator connected to said combustion furnace by a circuit for evacuating smoke emerging from said furnace and fine ash entrained with said smoke and recovered in said separator; (c) a heat recovery device connected to said separator by a smoke evacuating conduit; (d) a first cooling means supplied with said coarsest ash evacuated from said fluidized bed through said purging outlet, said first cooling means comprising a counter-current cooler traversed by a gas flowing in reverse direction from the coarsest ash and evacuated after heating through a conduit debouching into said conduit for evacuation of the smoke from said separator, upstream of said recovery device; and (e) a second cooling means supplied with the finest ash recovered at an outlet of said separator, said second cooling means comprising a fluidized-bed cooler supplied by a gas in which said finest ash is fluidized, said gas being evacuated through a conduit at the interior of said heat recovery device in a zone where a mixture of smoke coming from said separator and said gas coming from said first cooling means has already been cooled to a temperature of the same order as the temperature of the gases emerging from said second cooling means.