摘要 |
<p>A method of preventing corrosion in boiler-plant equipment A method of preventing corrosion in boiler-plant equipment when cooling flue gases originating from a combustion plant, such as flue gases containing sulphur oxide or organic acids, to a temperature beneath the acid dew-point of the gases, in a cooler having heat-exchanging walls. The flue gases are passed to the cooler at a temperature above the acid dew-point. Those surfaces of the heat-exchanging walls, over which the gases flow, are held at a temperature beneath an upper permitted wall-temperature in respect of the material from which the walls are made, and in respect of the prevailing partial pressure of water vapour present in the gases, by means of a coolant, suitably water, located on the other side of the heat-exchanger walls. The partial pressure of the water vapour in the gases can be increased by applying one of the following steps: supplying water or hydrogen-containing compounds to the combustion process, adding water or hydrogencontaining compounds to the gases, or cooling the gases at elevated pressures.</p> |