Thermal treatment of granular or lumpy material, particularly firing lime, dolomite, magnesite or the like and furnace therefor
AssigneeKlockner-Humboldt-Deutz Aktiengesellschaft
InventorHeinrich Buchner
Life of this patent
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Abstract
A calcining method and apparatus are provided wherein material to be treated is fed into the top of the furnace and the finished material discharges from the bottom of the furnace and cooling and combustion air enters under forced draft through the bottom of the furnace and flows upwardly through the column of material. A part of the fuel supply is delivered to the region between an upper preheating zone in the furnace and a subjacent combustion or firing zone and the balance of fuel required for firing is introduced into the combustion zone about its periphery. Provision is also made for bypassing part of the cooling air from a lower cooling zone to the combustion zone, with intermediate cleaning of the bypassed air.
Claims19
A method of thermal treatment of granular and/or lump material, and in particular for calcining of limestone, dolomite, and magnesite, or the like, in a vertical furnace provided with fuel supply means connected to burner means, and which in respect to a vertical furnace chamber passage provides a preheating zone in the upper portion of said passage, a combustion zone below the preheating zone and a cooling zone below the combustion zone and a column of material to be treated travels in a downward direction through the passage and air moves in an upward direction through the passage, comprising:
- introducing material to be calcined into the top of the furnace chamber passage to descend as a column substantially filling the preheating, combustion and cooling zones;
- introducing a part of the required fuel for promoting calcining combustion into the upper portion of the furnace chamber passage and at substantially the core area of the material column under the preheating zone;
- and
- directing the remaining fuel requirements into the combustion zone area of the furnace chamber passage toward the periphery of the column of material.
A shaft furnace for the thermal treatment of granular and/or lumpy material and in particular for calcining of limestone, dolomite, magnesite, or the like, including a material treating passage chamber having therein an upper preheating zone, a combustion zone therebelow and a cooling zone below the combustion zone, and wherein the material to be treated travels as a substantially chamber-filling column downwardly and air and combustion gas move in upward direction through the material column, comprising:
- means for introducing material to be calcined into the top of the furnace chamber;
- means in the upper portion of the chamber under the preheating zone for introducing part of required calcining fuel into substantially the core area of the material column;
- and
- means for introducing the balance of the fuel requirement into the combustion zone of the chamber and toward the periphery of the material column in the combustion zone.
Dependencies are inferred from the claim text.