Method and apparatus to deliver solid fuel to a combustion zone

Abstract

An apparatus and method for consistently delivering solid fuel to the combustion zone of a furnace is disclosed. The method includes feeding the solid fuel into the material inlet of a rotating rotary air lock valve which may have slanted vanes and moving the fuel from the material inlet of the rotating rotary air lock valve to the material outlet of the rotating rotary air lock valve, and conveying the fuel and gas through a discharge conduit to a fuel feed receiver of a furnace burner having a combustion zone.

1 . Method for delivering solid fuel to a combustion zone wherein the method comprises:
 A selection step which comprises selecting a solid fuel;   An introduction step which comprises introducing the solid fuel into a material inlet of a rotating rotary air lock valve,
 wherein the rotating rotary air lock valve has a central shaft and an axis of rotation of said shaft with multiple vanes defining pockets between said vanes, and a material outlet; 
   A rotating step, wherein the rotating rotary air lock valve moves the solid fuel from the material inlet of the rotating rotary air lock valve to the material outlet of the rotating rotary air lock valve,
 wherein the solid fuel is optionally placed into a receiving chamber; 
   A locomotive step, which comprises contacting the solid fuel with a moving gas, wherein the gas contacts the solid fuel at a location selected from the group consisting of the pocket between the vanes, the material outlet and the receiving chamber to move the solid fuel into a discharge conduit; and   A conveying step, wherein the solid fuel is conveyed by the moving gas through said discharge conduit to a solid fuel feed receiver of a furnace burner having a combustion zone, wherein the solid fuel is transported from the solid fuel feed receiver to the combustion zone.   
   
   
       2 . The method of  claim 1 , wherein the introduction of the solid fuel into the material inlet of the rotating rotary air lock valve is made substantially perpendicular to the axis of rotation of said shaft. 
   
   
       3 . The method of  claim 1 , wherein the introduction of the solid fuel into the material outlet of the rotating rotary air lock valve is kept substantially constant in terms of Btu/hour, by regulating the height of the fuel above the rotary air lock valve. 
   
   
       4 . The method of  claim 1 , wherein the amount of solid fuel occupying a pocket of the rotary air lock valve is known as a dose and wherein the rotary air lock valve receives a plurality of doses over a period of time and at least some of the doses of the plurality are not weighed before entering the pocket. 
   
   
       5 . The method of  claim 1 , wherein the moving gas contains at least one combustion enhancing gas in addition to the oxygen found in atmospheric air. 
   
   
       6 . The method of  claim 1 , wherein the solid fuel has a heat value content greater than 5000 BTU/lb and a moisture content. 
   
   
       7 . The method of  claim 1 , wherein a plurality said vanes are not mounted parallel to the axis of rotation said shaft. 
   
   
       8 . The method of  claim 7 , wherein the amount of solid fuel occupying a pocket of the rotary air lock valve is known as a dose and wherein the rotary air lock valve receives a plurality of doses over a period of time and at least some of the doses of the plurality are not weighed before entering the pocket. 
   
   
       9 . The method of  claim 7 , wherein the introduction of the solid fuel into the material inlet of the rotating rotary air lock valve is made substantially perpendicular to the axis of rotation of said shaft. 
   
   
       10 . An apparatus for delivering solid fuel to a combustion zone, comprising:
 a feed receiver;   a transition area located beneath said feed receiver;   a rotary air lock valve located beneath said transition area and adjacent to the feed receiver;   said rotary air lock valve having a cylindrical housing with a material inlet, a central shaft with multiple vanes defining a pocket between two adjacent vanes;   a moving gas inlet;   a moving gas outlet;   a discharge conduit having a first end and a second end, said first end is attached to said moving gas outlet and said second end is attached to a fuel feed receiver.   
   
   
       11 . The apparatus of  claim 10 , wherein the moving gas inlet and the moving gas outlet are part of the rotary air lock valve, said outlet offset from said inlet by the angle of said vane so that moving gas fed through said inlet is channeled through said pocket to said outlet. 
   
   
       12 . The apparatus of  claim 10 , wherein the apparatus further comprises a receiving chamber located beneath the rotary air lock valve and the moving gas inlet is located on a first end of the receiving chamber and the moving gas outlet is located on a second end of the receiving chamber and the first and second end are opposite of each other. 
   
   
       13 . The apparatus of  claim 10 , wherein the feed receiver does not have a screw conveyer. 
   
   
       14 . The apparatus of  claim 10 , wherein the amount of solid fuel occupying a pocket of the rotary air lock valve is known as a dose and wherein the rotary air lock valve is not connected to a control device which weighs a dose of the solid fuel before entering a pocket. 
   
   
       15 . The apparatus of  claim 10 , wherein the solid fuel enters the material inlet of the rotary air lock valve perpendicular to the axis of rotation of the central shaft. 
   
   
       16 . The apparatus of  claim 10 , wherein a plurality of said vanes are not mounted parallel to the axis of said shaft. 
   
   
       17 . The apparatus of  claim 16 , wherein the amount of solid fuel occupying a pocket of the rotary air lock valve is known as a dose and wherein the rotary air lock valve is not connected to a control device which weighs a dose of the solid fuel before entering a pocket. 
   
   
       18 . The apparatus of  claim 16 , wherein the solid fuel enters the material inlet of the rotary air lock valve perpendicular to the axis of rotation of the central shaft.