Abstract: An apparatus for distributing pneumatically conveyed solid pulverulent material over an annular area of large diameter comprises an enclosure defining an annular chamber having a substantially vertical axis, a closed upper end and a lower end, an upper portion adjacent the closed upper end and a lower portion adjacent the lower end. A section defined by a plane extending perpendicularly to the axis has a constant area in the upper portion and an area decreasing progressively towards the lower end in the lower portion. An annular outlet opening or a series of annularly arranged outlet openings is defined by the lower end, and an inlet conduit for a flow of gaseous fluid for pneumatically conveying the solid pulverulent material into the chamber is connected to the upper chamber portion so that the gaseous fluid flow penetrates the chamber in an approximately radial direction.

Abstract: Pulverized mineral material is calcined by suspending it in a current of gas constituted by a combustive gas and a fuel whose combustion furnishes the necessary calories for the calcination. To enable solid fuels rich in ash, substantially inert and difficult to condition to be used, the fuel is gasified in a fluidized bed hearth by blowing air from below through the bed whereby a gaseous fuel is disengaged from the bed and flows upwardly with the very finest particles of the solid fuel suspended therein. This is mixed with air and the mineral material to calcine the same.

Abstract: Pulverized mineral material is calcined by suspending it in a current of gas constituted by a combustive gas and a fuel whose combustion furnishes the necessary calories for the calcination. To enable solid fuels rich in ash, substantially inert and difficult to condition to be used, the fuel is gasified in a fluidized bed hearth by blowing air from below through the bed whereby a gaseous fuel is disengaged from the bed and flows upwardly with the very finest particles of the solid fuel suspended therein. This is mixed with air and the mineral material to calcine the same.