Typically, the flue gases leaving a modern 3-pass shell boiler are at temperatures of 200 to 300 °C. Thus, there is a potential to recover heat from these gases. The flue gas exit temperature from a boiler is usually maintained at a minimum of 175 °C, so that the sulphur oxidesmore...
A water pre-heater absorbs the flue gas heat into water thus, utilizing the heat from the exhaust gas which would otherwise be wasted. Plant efficiency is therefore further increased when viewed with respect to actual energy content of the fuel. more...