Conventional versus specific types of heat exchangers in the case of polluted flue gas as the process fluid – A review

The present contribution shows certain practical aspects of selection and design of heat exchangers for industrial applications where polluted flue gas (off-gas) represents one process fluid. One of the key factors in designing heat exchangers for these applications is the primary selection of a suitable type. The presently available possibilities and methodologies of efficient heat exchanging device selection and supporting software do not allow covering all the needs of related industries. A concrete example of an industrial process furnace is used to demonstrate the issues of “compactness and enhancement vs. reliability” for various temperature levels of high temperature applications. Attention is also given to the specific area of fouling of the heat exchanging surfaces by flue gas. In high temperature applications, it is necessary to pay special attention to all phases of a solution. Heat integration of devices into the plant system and its possibilities are presented. The irreplaceable role of modelling and optimization on the design of heat exchangers and its design details is emphasized which may significantly contribute to final product quality. An important role in high temperature applications is also played by CFD simulations.