Continuous production closed retort charcoal reactor

Abstract

A method and apparatus for continuously producing charcoal and graphite of selectable varying degrees of volatile content from all types of waste wood, bark and vegetable matter are disclosed. The method uses horizontal force fed retorts arranged in tiers of rows across the width of a refractory oven. Because it can use various organic material, including wood waste, mixed up with bark in any ratio, the invention provides a solution to the forest industry waste proliferation problem. Organic material is carried through the retort by a screw which has its flights interrupted in gas collection areas. Loose plugs of organic material form in the gas collection areas and prevent the escape of gases by way of the ends of the retort. Gases are collected by gas vents which connect to the retort in the gas collection areas.

I claim:  
     
         1 . An apparatus for producing charcoal, the apparatus comprising: 
 (a) a furnace;    (b) a retort tube extending substantially horizontally through the furnace;    (c) a screw element extending through the retort tube, the screw element comprising a generally helical flight; and,    (d) one or more gas vents penetrating the retort tube;    wherein the flight comprises two or more sections separated by one or more longitudinally extending gaps wherein the flights of the screw element are substantially removed, the gaps being coincident with the one or more vents.    
     
     
         2 . The apparatus of    claim 1    wherein the retort tube extends through a furnace capable of heating the retort tube to a temperature of at least 600° C.  
     
     
         3 . The apparatus of    claim 1    comprising an exhaust gas collection system, the exhaust gas collecting system comprising a system of pipes connected to the retort at positions coincident with the gas vents which collect and draw gases away from the retort.  
     
     
         4 . The apparatus of    claim 1    wherein an internal diameter of the retort tube is about 12 inches and a diameter of the flights is about 11½ inches.  
     
     
         5 . The apparatus of    claim 1    wherein the screw element has a pitch in the range of 6 inches to 8 inches.  
     
     
         6 . The apparatus of claims  1  wherein the gaps extend longitudinally along the retort tube for distances in the range of 8 inches to 24 inches.  
     
     
         7 . The apparatus of    claim 1    comprising a sawdust feed system, the sawdust feed system comprising an air blower connected to direct a stream of air into a an inverted conical drying chamber; a sawdust feeder connected to deliver sawdust into the stream of air; and a second conduit connected to deliver sawdust from an outlet of the drying chamber and the inlet end of the retort tube.  
     
     
         8 . The apparatus of    claim 1    wherein the retort tube is cylindrical and has a substantially constant diameter.  
     
     
         9 . An apparatus for producing charcoal, the apparatus comprising: 
 (a) a furnace;    (b) a retort tube extending substantially horizontally through the furnace;    (c) a screw element extending through the retort tube, the screw element comprising a generally helical flight;    (d) one or more gas vents penetrating the retort tube; and,    (e) a sawdust feed system connected to deliver sawdust to an inlet end of the retort tube;    wherein the flight comprises two or more sections separated by one or more longitudinally extending gaps wherein the flights of the screw element are removed; the gaps are coincident with one or more vents; an exhaust gas collection system comprises a system of pipes is connected to the retort at positions coincident with the vents; and wherein a first longitudinally extending gap adjacent an inlet end of the retort tube has a length of about 8 inches to 24 inches beginning at about 20 inches to 48 inches from the inlet end of the retort tube and a second longitudinally extending gap adjacent the outlet end of the retort tube has a length of about 8 inches to 24 inches beginning at about 136 inches from the inlet end of the retort tube.    
     
     
         10 . A method for producing charcoal, the method comprising: 
 (a) introducing organic material into an inlet end of a generally horizontal heated tubular retort, the retort having at least one gas vent at a position spaced longitudinally from the inlet end;    (b) carrying the material to a volume in the retort adjacent the vent;    (c) advancing the organic material through the volume by introducing more of the organic material into the volume; and,    (d) after advancing the organic material through the volume, delivering the organic material through the retort to an outlet end of the retort wherein the organic material is substantially converted to charcoal before it is delivered to the outlet end of the retort,    maintaining the retort at a substantially constant temperature and controlling the quality of charcoal delivered at the output end of the retort by varying the rate of feed of the organic material through the retort by controlling the rate of rotation of a screw having flights extending to an upstream side of the volume.    
     
     
         11 . The method of    claim 10    comprising collecting gases at the vent and burning the collected gases.