feed containers being arranged concentrically with the shaft axis of the respective shaft over which it is installed and constructed to be maintained in rotation during filling thereof of the material to be calcined application_number US 34147682 A description referring now to fig1 there is shown in schematic form a furnace wherein the apparatus of the present invention is utilized in delivering raw material to the shafts of the furnace in fig1 two furnace shafts 1 and 2 are schematically depicted with the upper ends thereof being shown above the shafts 1 and 2 there is provided a support scaffolding 3 which may be composed of braces and girders constituting the basic support structure for the apparatus because of the fact that excess pressure may prevail in the shafts 1 and 2 the shaft throat is adapted to be shut off by means of a shutter or gate valve having a cover 4 adapted to be set upon a gate valve seat 5 the shutter valve is opened by being raised by means of a hoist mechanism 6 which may be comprised of a hydro cylinder and by being rotated away from the gate valve seat 5 by means of a turning device 7 when the throat is shut the shutter valve is swung by means.