Process and equipment for firing pellets
AssigneeVoest-Alpine Aktiengesellschaft
InventorsJohann Haslmayr, Hannes Feichtner
Life of this patent
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Abstract
Pellets to be fired are treated with high-temperature gases which, before being supplied to the pellets, are heated by combustion of fuel in a combustion chamber to a temperature above the temperature at which the pellets are to be treated and high enough to ensure that slag formed during combustion can be tapped in liquid form. Cooler gases are then admixed to the high-temperature gases outside the combustion chamber and before they are supplied to the pellets to cool the gases to the temperature desired for the treatment.
Claims12
In a process of firing pellets in equipment comprising a combustion chamber and a firing zone wherein the pellets are fired with heat-treating gases at a predetermined firing temperature, the steps of
- (a) burning fuel in the combustion chamber to produce high-temperature gases at an elevated temperature exceeding the predetermined firing temperature and sufficient to convert ashes produced during the burning of the fuel into a liquid slag,
- (b) removing the liquid slag from the combustion chamber, and
- (c) admixing cooler gases to the high-temperature gases outside the combustion chamber before the gases are supplied to the pellets to cool the gases to the predetermined firing temperature.
Equipment for firing pellets, comprising
- (a) firing means defining a firing zone and operable to contact pellets with heat-treating gases at a predetermined firing temperature in said firinz zone to produce fired pellets,
- (b) gas-heating means defining a combustion chamber and operable to burn fuel to produce the heat-treating gases at an elevated temperature exceeding the predetermined firing temperature and sufficient to convert ashes produced during burning of the fuel into liquid slag,
- (c) means for removing the liquid slag from the combustion chamber, and
- (d) mixing means arranged between the combustion chamber and the firing means for admixing cooler gases to the heat-treating gases coming from the combustion chamber to cool the heat-treating gases to the predetermined firing temperature before supplying the cooled heat-treating gases to the firing zone.
Dependencies are inferred from the claim text.