recuperators

Recuperators are heat exchangers that recover heat from a hot exhaust or waste gas and transfer it to a cooler incoming stream, such as combustion air or process water. By reclaiming energy that would otherwise be wasted, they improve overall system efficiency in industrial, commercial, and power-generation settings.

In a recuperator, the hot and cold streams pass on opposite sides of a solid heat-transfer surface and exchange thermal energy without mixing. They come in various forms, including plate-fin, tubular, and compact heat exchangers. Some systems use rotating ceramic or metallic media that store heat temporarily; such devices are sometimes described as regenerative heat exchangers rather than recuperators, though the terms are sometimes used interchangeably.

Typical applications include metalworking furnaces, glass and cement production, and other high-temperature processes; gas turbines and reciprocating engines that preheat intake air; district heating and energy recovery ventilation in buildings; and waste heat recovery systems in chemical plants.

Advantages include reduced fuel use, lower operating costs, and lower emissions. Disadvantages include higher initial cost, added pressure drop, potential fouling or corrosion, and limitations related to temperature differences and maintenance requirements.