초록 ▼

Gases containing tar and other condensable components are cleaned by cooling them in a circulating fluidized bed reactor (2) provided with cooling surfaces (8). Into the fluidized bed reactor are led solids separated from the cooled gas in a cyclone separator (3) and other solids. Tar and other comp

Gases containing tar and other condensable components are cleaned by cooling them in a circulating fluidized bed reactor (2) provided with cooling surfaces (8). Into the fluidized bed reactor are led solids separated from the cooled gas in a cyclone separator (3) and other solids. Tar and other compounds condense on the solids in a mixing chamber (9) disposed before the cooling surface in the reactor.

대표청구항 ▼

In a circulating fluidized bed reactor having a discrete lower mixing chamber in a lower part of the reactor and a discrete cooling zone, with a smaller cross-sectional area than the mixing chamber, in said reactor spaced above said mixing chamber and the mixing chamber and the cooling zone thus tog

In a circulating fluidized bed reactor having a discrete lower mixing chamber in a lower part of the reactor and a discrete cooling zone, with a smaller cross-sectional area than the mixing chamber, in said reactor spaced above said mixing chamber and the mixing chamber and the cooling zone thus together forming a reactor chamber in the circulating fluidized bed reactor, a method for cleaning hot gases containing substantially predetermined condensable components, comprising the steps of: (a) directing the hot gases containing the predetermined condensable components into the mixing chamber in said lower part of the circulating fluidized bed reactor, so as to fluidize the bed material in the fluidized bed reactor and transport particles through the mixing chamber and the cooling zone spaced above said mixing chamber; (b) reducing the temperature of the hot gases in the mixing chamber, substantially by direct heat transfer, by mixing into the hot gases in the mixing chamber solid particles in an amount having a heat capacity sufficient to cool the gases therein essentially to the condensation temperature of substantially the entirety of the predetermined condensable components of the hot gases in the mixing chamber; (c) directing the mixture of the solid particles and the gases concurrently as a gas-solid suspension having said reduced temperature upwards from the mixing chamber into the cooling zone and with increased velocity through the cooling zone for reducing the temperature of the solid particles and further reducing the temperature of the hot gases; (d) discharging a mixture of cooled solid particles and gases from the cooling zone of the reactor and separating cooled particles from the gases in a particle separator connected to the outlet of the cooling zone; (e) recirculating at least a part of the cooled separated particles into the mixing chamber, for cooling the hot gases therein; (f) feeding additional solid particles into the mixing chamber for increasing the amount of solid particles and thereby the heat capacity flow of the solid particles in the mixing chamber for cooling the hot gases; and (g) controlling the cooling of the hot gases in said mixing chamber by controlling at least the magnitude of one of the flow of the (1) cooled separated particles recirculated and (2) the additional solid particles fed into the mixing chamber thereby to enable the hot gases to be cooled in the mixing chamber to the condensation temperature of substantially the entirety of the predetermined condensable components thereof.