Fluidised bed heat treatment furnace for metal objects - with separate combustion and treatment zones

摘要

A furnace has a bed of heat resistant particles, inlets for feeding gases into the bed to fluidize it, feeding apparatus for fuel and air leading to a combustion zone of the bed and for provision of a treatment gas to a treatment zone of the bed. It is used for carburuzing metal parts and heat treatment of metal parts in a neutral atmosphere, and avoids the use of elementary carbon and cyanide cpds and increases the speed of gas carburizing e.g. using a hydrocarbon.