摘要 |
This invention relates to a method of heat treating articles which utilizes a fluidized bed comprising a container containing a mass of refractory particles and having a porous base, a layer of such particles adjacent to the porous base being formed of heavier particles than the remainder of said refractory particles. According to the invention, a non-stoichiometric fluidizing and treatment medium is supplied to the underside of the porous base and flows therethrough into the mass of refractory particles at such a velocity as to leave the heavier particles unfluidized while fluidizing the remainder of the particles. A gaseous medium is also introduced into the container at a position above and spaced from the porous base to together with the non-stoichiometric fluidizing and treatment medium, a combustible mixture which is ignited to heat the mass of refractory particles to a temperature at which the non-stoichiometric fluidizing and treatment medium will carry out the desired heat treatment. |