Patent EA-003894-B1 (EA)
Title: Method for burning carbonate-containing material
Inventor: PIRIGER HANNES
IPC: F23G5/24
Filed: 2001-04-11
Abstract: 1. A method for burning carbonate-containing material in a shaft kiln, wherein the carbonate containing material is supplied to the shaft kiln with gravity conveying the carbonate-containing material through a preheating zone, at least one burning zone and a cooling zone to a discharge device, wherein a fuel supply in the burning zone or adjacent thereto takes place by means of a plurality of burners and combustion air is supplied under overpressure as cooling air, wherein the fuel supply takes place by means of a plurality of burning lances displaceable into the shaft chamber perpendicular to the shaft wall and positioned with respective orifices of the lances disposed within the chamber and spaced from the shaft wall such that individual flames formed on the burning lances together form a flame area, which at least approximately extends over the entire shaft cross-section wherein using a burning material with a grain size in the range 5 to 70 mm. 2. Method according to claim 1, wherein the fuel supply takes place by means of a plurality of superimposed groups of burning lances with each group arranged at least approximately in the same plane, and as a function of the desired degree of burning in the burning zone a temperature profile passing in the kiln longitudinal direction is regulated by modifying the fuel supply to one or more of the lance groups. 3. Method according to claims 1 or 2, wherein the burning lances are displaced depending on the temperature values determined by temperature probes or on the base of the quality product test. 4. Method according to claims 2 or 3, wherein for a uniform, common coverage of the shaft cross-section by individual, superimposed flame areas, the displacement direction of superimposed burning lances is mutually staggered in the circumferential direction of the shaft. 5. Method according to any one of claims 1 to 4, wherein the burning lances supply in addition to fuel combustion air, whose quantity is adjustable and if necessary can be reduced to zero. 6. Method according to claim 5, wherein the combustion air to be supplied by means of the burning lances is heated within the preheating zone by being passed through heat exchange tubes, which are positioned parallel to the shaft wall, distributed over the kiln cross-section and suspended in the preheating area of the kiln. 7. Method according to any one of claims 1 to 6 in a regenerative method in a multi-shaft kiln wherein a time-alternating supply of combustion air in parallel flow is provided between the respective shafts of the kiln and a continuous counter flow supply of cooling air is provided in a lower area of the shafts, wherein during fuel supply a in a parallel flow to one of shafts, in one or more shafts connected transversely to a previous shaft fuel with combustion air, or without it, is supplied by means of a plurality of burning lances disposed in the burning zone being displaceable transversely relative a shaft kiln wall. 8. Method according to claim 7, wherein fuel is supplied in one of the shafts during an operating period of the regenerative method in parallel flow form by means of a plurality of suspended lances. 9. Method according to any one of claims 1 to 8, wherein the maximum insertion depth of the burning lance extends close to the centre of the shaft cross-section, so that the associated flame reaches the centre and the internal diameter of the shaft chamber is reduced to 3 m. 10. Method according to any one of claims 1 to 9, wherein a cooling medium flows at least through the burning lances projecting furthest into the shaft chamber.