The gas/gas heat exchanger allows the transfer of a heat quantity recovered from the raw gas directly to the clean gas side of the flue gas desulfurization unit by a cross- or counter-flow heat exchanger without using a transfer medium. The recovered heat is used to increase the gas temperature downstream of the FGD-process. The higher gas temperature upstream of the stack ensures a regular exhaust of the gas to the atmosphere, and in parallel, the stack is protected against the condensates. Therefore no further corrosion protection for the ducts and the stack is needed, which saves the utility investment. All materials in contact with flue and clean gases are made from fluoropolymer materials. The fundamental design of the system is leakage free. An internal water loop is therefore not needed. The Wallstein-design allows the use of larger tube diameters. This heat exchanger type itself is corrosion resistant on both raw gas and clean gas side. With innovative materials and materials mixtures and also with constructional developments, we permanently optimize our products. Examples are weldable fluoropolymer materials or special tube compensators made of fluoropolymer materials.
