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

摘要

A shell-and-tube apparatus (1), suitable for use as a waste heat boiler, comprising a vessel with an exchanging section (2) and a separating section (3), wherein: said exchanging section (2) contains a bundle of U-tubes (4) 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 (7); said separating section (3) comprises a collection chamber (16) in communication with outlet of the tubes (4) to receive the partially evaporated medium leaving the tubes; said separating section (3) 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.