Abstract: In a transportation tube for particulate fuel material such as coal to a combustion chamber there is provided an auger mounted in the tube including a shaft and a flight mounted on the shaft. The tube has therein three flat abutment bars fixedly mounted on an inside surface of the tube at the 2-oclock, 5-oclock and 7-oclock positions and extending longitudinally of the tube with an inside surface of the abutment bars located inwardly of the inside surface of the tube and with the flight having an outside edge sitting on the bottom bars and spaced slightly inwardly of the upper bars to help prevent rotation of the material with the flight in the tube to reduce blockages.

Abstract: In a combustion system for particulate fuel including a combustion chamber with an opening at the base of the combustion chamber and a vertical discharge duct pushing the particulate fuel through the opening there is provided a hopper spaced from the combustion chamber and a transportation duct for carrying the particulate fuel from hopper to the discharge duct. In the transportation duct there is provided an auger shaft with a first long auger flight rotated to carry the material from the hopper to the discharge duct. A second shorter flight is arranged on a side of the discharge duct opposite to the hopper in a short tube portion and is rotated in the direction to feed the material back toward the discharge duct. The two flight portions cooperate in pushing the material into the vertical discharge duct as the shaft of the flight is rotated.

Abstract: A furnace heat exchanger tube cleaning apparatus is described. The furnace comprises a combustion chamber for generating heated gases including combustion products, a water jacket containing a liquid to be heated and including heat exchanger tubes passing therethrough and a flue for discharge of the combustion products. In operation, the heated gases including combustion products flow from the combustion chamber along the heat exchanger tubes to the flue. As the heated gases pass along the heat exchanger tubes, heat from the heated gases is transferred to the liquid in the container, thereby heating the liquid. The efficiency of heat transfer is increased by helical flights arranged to depend downward into the respective heat exchanger tubes from a support structure. Specifically, the flights create turbulence in the flow of the heated gases, thereby improving heat transfer.