FLUE GAS COOLING AND CLEANING SYSTEM

摘要

An improved flue gas cooler (10), or bank of coolers (10), handles flue gas G from aluminium reduction cells in an aluminium smelter plant. The or each flue gas cooler (10) has a gas inlet chamber (14), a gas outlet chamber (16), and a matrix of gas cooling tubes (18) extending between the inlet chamber and the outlet chamber. Each cooling tube (18) has a bell-shaped inlet end (19) comprising an aerodynamically curved gas-accelerating profile effective to facilitate streamlined flow of flue gas G into the tube. The improved flue gas cooler makes it possible to connect the flue gas cooler to receive hot raw flue gas G direct from the aluminium reduction cells without getting clogged by dust and sublimates present in the flue gas. Once cooled, the flue gas can be safely passed on to a flue gas cleaning plant of the dry scrubbing type. The improved flue gas coolers are advantageously part of a system for using heat energy from the flue gas, in which a closed circuit coolant circulation system circulates coolant through the flue gas cooler and a heat exchange arrangement (24). Heat energy extracted from the coolant by the heat exchange arrangement (24) may be used to increase the efficiency of further plant coupled to the heat exchange arrangement.