Considerations in Designing a Recovery Steam Generator for Incineration Plants

The design of recovery steam generators for incineration plants encounters certain specific problems, related to the nature of the exhausted gases, which, if not properly faced, can strongly condition the conduction of the whole system. Two problems, namely, demand for particular attention: the corrosion at high temperature and the formation of organochlorine compounds, in presence of ashes and/or deposits for definite temperature intervals. These phenomena can be controlled and minimized, whenever possible, by limiting to the greatest extent the regions where the temperatures of the metallic walls and of the ashes and/or deposits are within the critical interval. The paper analyzes, as a function of operative conditions, these temperature profiles, in order to individuate those situations which may reveal dangerous and to define some criteria to achieve a final configuration for the generator to minimize, as far as possible, the above mentioned problems, increasing as well the reliability of the system.