Waste heat recovery is an old technology dating back to the rst open hearths and blast furnace stoves. The drastic escalation of energy prices has made waste heat recovery more attractive over the past two decades. Manufacturing and process industries such as glass, cement, primary and secondary metals, etc., account for a signicant fraction of all energy consumed. Much of this energy is discarded in the form of high-temperature ue gas exhaust streams. Recovery of waste heat from ue gas by means of heat exchangers known as regenerator can improve the overall plant efciency and serves to reduce the national energy needs and conserve fossil fuels. Figure 6.1 shows the cross section of a regenerative furnace . Currently, interest in storage-type regenerators has been renewed due to their applications of heat recovery, heat storage, and general energy-related problems . The objective of this chapter is to acquaint the readers with various types of regenerators, construction details, and thermal and mechanical design. Additionally, some industrial heat recovery devices for waste heat recovery are discussed.