Oxidant-driven dust recycling process and device for rotary kilns
AssigneesL'Air Liquide, Societe Anonyme pour l'Etude et l'Exploitation des Procedes Georges Claude, American Air Liquide, Inc.
InventorsMahendra L. Joshi, Ovidiu Marin, Olivier Charon, Jacques Dugue
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Abstract
A kiln adapted to recycle kiln dust includes a recycle dust pipe in fluid communication with an oxidant stream to increase the concentration of oxygen in the fluidized recycle dust before the recycle dust stream is directed into the kiln flame. Increasing the oxygen concentration in the recycle dust stream improves the efficiency of the recycling process. A supplemental fuel stream may be introduced into the recycle dust stream to provide an additional flame to preheat the recycle dust stream before the recycle dust stream is directed into the kiln flame.
Claims11
An apparatus for recycling dust in a kiln useful for producing clinkers, comprising:
- a kiln chamber having an inlet and a outlet;
- a first burner positioned so that its flame is directed into said kiln chamber;
- a recycle dust source for providing a fluidized recycled dust stream into said kiln chamber and including a recycle dust feeder pipe having an outlet at a downstream end thereof, said recycle dust feeder pipe adapted to feed recycle dust to the first burner;
- and
- an oxidant source in fluid communication with the recycle dust source for providing a fluidized recycled dust and oxidant stream, wherein the oxidant source comprises an oxidant feeder pipe in fluid communication with the recycle dust feeder pipe at a point upstream of said recycle dust feeder pipe downstream end, and wherein
- the recycle dust feeder pipe has a diameter D, and
- fluid communication between the recycle dust feeder pipe and the oxidant feeder pipe is established at a distance L from an end of said recycle dust feeder pipe, the ratio of L/D being between 0.25 and 4.0.
Dependencies are inferred from the claim text.