Abstract: Method and apparatus for treating waste material in a counterflow furnace wherein the material is introduced at one end thereof and the processed material is discharged from the other end, while air is simultaneously introduced thereto and the gases of combustion are caused to flow in counter-current direction with respect to the material being processed and are exhausted at the first end of the furnace, and wherein the furnace has a natural tendency to form zones of processing including sequentially from the first end of the furnace, a drying zone, a charring and volatile burning zone, a fixed carbon burning zone and an ash cooling zone, the method comprising the steps of bleeding secondary exhaust gases from the middle of the furnace substantially between the fixed carbon burning zone and the charring and volatile burning zone, and adding air to the furnace in the charring and volatile burning zone.

Abstract: Furnace apparatus and method used to heat or incinerate materials which are being stirred or rabbled under atmospheres of corrosive gases, and which employs a new material of construction for fabricating rabble teeth to impart improved resistance to mechanical and thermal shock as well as improved resistance to attack by corrosive gases at elevated temperatures.

Abstract: Method and apparatus for treating waste material in a counter-flow furnace wherein the material is introduced at one end thereof and the processed material is discharged from the other end, while air is simultaneously introduced thereto and the gases of combustion are caused to flow in counter-current direction with respect to the material being processed and are exhausted at the first end of the furnace, and wherein the furnace has a natural tendency to form zones of processing including sequentially from the first end of the furnace, a drying zone, a charring and volatile burning zone, a fixed carbon burning zone and an ash cooling zone, the method comprising the steps of bleeding secondary exhaust gases from the middle of the furnace substantially between the fixed carbon burning zone and the charring and volatile burning zone, and adding air to the furnace in the charring and volatile burning zone.

Abstract: Method and apparatus for treating waste material in a counterflow furnace wherein the material is introduced at one end thereof and the processed material is discharged from the other end, while air is simultaneously introduced thereto and the gases of combustion are caused to flow in counter-current direction with respect to the material being processed and are exhausted at the first end of the furnace, and wherein the furnace has a natural tendency to form zones of processing including sequentially from the first end of the furnace, a drying zone, a charring and volatile burning zone, a fixed carbon burning zone and an ash cooling zone, the method comprising the steps of bleeding secondary exhaust gases from the middle of the furnace substantially between the fixed carbon burning zone and the charring and volatile burning zone, and adding air to the furnace in the charring and volatile burning zone.

Abstract: A method and apparatus for treating off-gas from a furnace for burning organic material in an oxygen deficient atmosphere by passing the hot exhaust gases from the furnace ladened with combustible and noncombustible organic material to a cleaning device, and thence passing the gases to a secondary furnace for combustion therein, and while in the cleaning device removing from the gas therein noncombustible material which would otherwise still be particulate matter in the exhaust from the secondary furnace. In another form of the invention, the exhaust gas from the furnace is passed to a burner and heat exchanger device having an inlet portion for heating the incoming gases, a combustion portion with air inlets for supporting combustion therein, and an outlet portion for cooling the gases, and thereafter the gases are passed to a quenching system.

Abstract: A method and apparatus for incinerating waste material in a multiple hearth furnace having a plurality of vertically spaced hearths wherein waste material is introduced to the furnace at the top thereof and moves downwardly in a generally serpentine fashion moving alternately inwardly and outwardly across the hearths and is discharged at the bottom of the furnace, and including the steps of introducing towards the lowermost hearth thereof air in a quantity less than that theoretically required for complete combustion of the material being processed, thereafter at successively higher hearths ascertaining the temperature at each hearth and adding air thereto in quantities only sufficient to support combustion thereon, and on each hearth in the middle portion of the furnace adding only enough air to each hearth so as to maintain the temperature on that hearth under a maximum predetermined limit, and on the hearths towards the top of the furnace reducing the quantity of air added, and thence discharging the exhau

Abstract: The invention is directed to method and apparatus for treating waste material containing alkali metal in a counter-flow furnace wherein the waste material to be processed is introduced at one end thereof and the processed material is discharged from the other end, while simultaneously air is introduced and the gases of combustion are caused to flow in a counter-current direction with respect to the material being processed and are exhausted at the first end of the furnace, and wherein the furnace has a natural tendency to form zones of processing including sequentially from the first end of the furnace, a drying zone, a charring and volatile burning zone, and a fixed carbon burning zone, and wherein a maximum temperature is maintained in the furnace below about 1400.degree. F. directly adjacent the surface of the bed of material being processed.