Shell-and-tube apparatus for heat recovery from a hot process stream

Abstract

A shell-and-tube apparatus (), suitable for use as a waste heat boiler, comprising a vessel with an exchanging section () and a separating section (), wherein: said exchanging section () contains a bundle of U-tubes () fed with an evaporable liquid medium such as water (W) and exposed to a hot gas (G) flowing in a hot chamber around said tubes, so that said medium is partially evaporated in the tubes while recovering heat from hot gas flowing in the hot chamber (); said separating section () comprises a collection chamber () in communication with outlet of the tubes () to receive the partially evaporated medium leaving the tubes; said separating section () is arranged to provide separation of vapour fraction and liquid fraction from the partially evaporated medium at least partially by gravity; the apparatus also comprises means for controlling the liquid level in the collection chamber and for a partial recycle of the non-evaporated liquid.