Auger for transporting particulate material with a reduced tendency to block

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.

1 . A combustion apparatus comprising:
 a combustion chamber;   a transportation duct for transporting a particulate fuel material to the combustion chamber including a substantially horizontal transportation tube having a first feed end and a second end;   a hopper for discharging into the transportation tube at said first feed end for transportation therealong;   an auger mounted in the transportation tube for transporting the particulate material therealong including a shaft extending along the transportation tube and a flight mounted on the shaft for rotation therewith arranged such that rotation of the shaft tends to move the particulate material toward the combustion chamber;   the tube having therein at least one abutment member fixedly mounted on an inside surface of the tube and extending longitudinally of the tube with an inside surface of the abutment member located inwardly of the inside surface of the tube and with the flight having an outside edge at or inwardly of the inside surface of the abutment member.   
     
     
         2 . The combustion apparatus according to  claim 1  wherein said at least one abutment member extends axially of the tube. 
     
     
         3 . The combustion apparatus according to  claim 1  wherein there is provided a plurality of abutment members at angularly spaced positions around the tube. 
     
     
         4 . The combustion apparatus according to  claim 1  wherein there are two bottom abutment members adjacent a bottom of the tube with each located on a respective side of a bottom center line of the tube. 
     
     
         5 . The combustion apparatus according to  claim 4  wherein the outer edge of the flight rests on the inside surface of the two abutment members so as to be supported spaced from the inside surface of the tube. 
     
     
         6 . The combustion apparatus according to  claim 4  wherein there is at least one additional abutment member at a position spaced angularly from the two bottom abutment members. 
     
     
         7 . The combustion apparatus according to  claim 4  wherein there is at least one additional abutment member at a position spaced angularly from the two bottom abutment members and located at a position spaced angularly from the top center line of the tube. 
     
     
         8 . The combustion apparatus according to  claim 7  wherein said at least one additional abutment member is located at a position spaced angularly from the top center line of the tube toward the side of the top center line which side is angularly advanced relative to the direction of rotation of the flight in the tube. 
     
     
         9 . The combustion apparatus according to  claim 4  wherein there is a single additional abutment member at a position spaced angularly from the two bottom abutment members and located at a position spaced angularly from the top center line of the tube toward the side of the top center line which side is angularly advanced relative to the direction of rotation of the flight in the tube. 
     
     
         10 . The combustion apparatus according to  claim 1  wherein said at least one abutment member comprises an elongate bar having a width in the angular direction of the tube which is greater than a height in a radial direction of the tube. 
     
     
         11 . The combustion apparatus according to  claim 1  wherein the at least one abutment member extends substantially along the full length of the tube from the hopper to the combustion chamber. 
     
     
         12 . The combustion apparatus according to  claim 1  wherein the radius of the outside edge of the flight is smaller than the distance of the inside surface of the abutment member from the axis of the tube. 
     
     
         13 . The combustion apparatus according to  claim 1  wherein there is provided a substantially vertical discharge tube having a bottom end attached to the transportation tube and a top end communicating with the combustion chamber for feeding the particulate fuel material from the transportation tube upwardly into the combustion chamber.