Method and apparatus for charging a bulk material supplemental fuel into a long cement kiln

An apparatus for improved manufacture of cement clinker in a wet or dry process long rotary kiln for processing a mineral material therein to produce cement clinker, said kiln comprising a rotary vessel having a fired lower end and an adjacent clinkering zone, an upper kiln gas exit end and an adjacent mineral drying zone, an intermediate calcining zone along its length, and a kiln gas stream flowing from the fired lower end to the upper gas exit end, the kiln being modified to burn a bulk material supplemental fuel in a secondary burning zone of the kiln, said apparatus comprising:

• a port formed in the rotary vessel upstream relative to kiln gas flow of the drying zone;
• a tube extending into the rotary vessel in communication with the port to prevent an in-process mineral material in the rotary vessel from escaping through the port;
• and
• a bulk material fuel charging apparatus including a hopper for receiving the bulk material, a barrel in communication with the hopper, a cylinder having a piston for moving a ram located within the hopper from a retracted position to an extended position to load a portion of the bulk material into the barrel and form a fuel charge, and an air cannon in air flow communication with the barrel for injecting air into the barrel to force the fuel charge out of the barrel, through the tube, and into an interior region of the rotary vessel.