SISTEMA E PROCESSO PARA RECUPERACAO DE CONSTITUINTES QUIMICOS OU ENERGIA TERMICA DE UM PROCESSO DE COMBUSTAO EM LEITO FLUIDIZADO

摘要

An apparatus and method for recovering constituents and/or heat energy from a fluidized bed combustion process utilizes a single vessel which combines a combustor for fluidized bed combustion of a chemical mixture fed therein and a heat exchange section. Characteristics of the fluidized bed are controlled by withdrawing an appropriate portion of the larger, unburned constituent particles from the bottom of the combustor, and smaller constituent particles are withdrawn by becoming entrained within the gases of combustion and being transported to the heat exchange section. The smaller particles are separated from the gases without the use of a cyclone separator and accumulate as another fluidized bed in the heat exchange section where heat is adsorbed from the particles for recovery purposes and to cool the particles. A portion of the cooled particles is then recirculated to the combustor by, for example, pneumatic transport methods for controlling the operating temperature of the combustion process. The apparatus is particularly well-suited for recovering process salts and heat energy from the burning of black liquor effluent from a lignocellulosic pulping process.