Apparatus for the preparation of a compound or an alloy

Claim 1

In apparatus for the preparation of a compound or alloy which includes one compound having considerably higher vapor pressure than the other, the apparatus including a closed horizontal reaction tube whose ends are surrounded by closely spaced hollow, cylindrical heating ovens, the tube and ovens being arranged in a closed pressurized vessel with the ovens one behind the other in the axial direction of the tube, with additional heating means surrounding a narrow portion of the reaction tube situated between the heating ovens, and means to move at least a portion of the closed horizontal reaction tube through the narrow zone between said heating ovens, an arrangement which permits improved cooling of the narrow zone between the heating ovens comprising: (a) the heating ovens spaced from the inside of the pressurized vessel so that a free space remains between said ovens and said vessel at all points, said space being in communication with the narrow zone between the heating ovens; (b) means closing off the ends of the heating ovens facing away from the tube; (c) a cooling gas of high thermal conductivity filling said free space and contacting the inside of said pressurized vessel; and (d) means for cooling said pressurized vessel, whereby said pressurized vessel will cool said cooling gas causing convection currents to be set up which, because of said ovens being closed off will be concentrated in the narrow portion of said tube between said ovens to thereby carry out improved cooling of the tube at said narrow portion.