Claims
- 1. A system for removal of carbon from fly ash, comprising:
A dilute phase reactor defining a reactor chamber including a particulate bed in which particles of fly ash are received, and having a heating source for heating said reactor chamber; wherein as the particles of fly ash are heated, the carbon therein is heated to a combustion temperature, with the particles of fly ash thereafter conveyed from said particulate bed through said reactor chamber in a dilute phase; an ash capture connected to said reactor chamber for receiving an exhaust air flow containing particles of fly ash in their dilute phase for collecting fly ash particles from the exhaust air flow; and an accumulator that receives and accumulates the collected particles of fly ash from said accumulator and connected to said reactor for supplying a flow of fly ash particles to said particulate bed:
- 2. The system of claim 1 and wherein said particulate bed further comprises a bed of coarse particulate material.
- 3. The system of claim 2 and wherein said coarse particulate material is selected from the group consisting essentially of sand, alumina, silica, and inert oxide materials.
- 4. The system of claim 1 and wherein said reactor comprises an elongated reactor body having a first end at which said particulate bed is positioned, and a second end at which an outlet is formed for the exhaust of combusted particles of fly ash from said reactor chamber in their dilute phase.
- 5. The system of claim 1 and wherein said ash capture comprises a separator having an inlet end at which the exhaust air flow containing particles of fly ash is received from said reactor chamber and an outlet end at which particles of fly ash captured from the exhaust air flow are collected for discharge to said accumulator.
- 6. The system of claim 1 and wherein said ash capture comprises a cyclonic separator dropout chamber or filter chamber.
- 7. The system of claim 1 and wherein said accumulator comprises a stand-pipe defining an internal chamber in which particles of fly ash are accumulated in a bed of a size sufficient to maintain a feed of particles of fly ash from said stand-pipe to said particulate bed of said reactor as the particles of fly ash are conveyed from said particulate bed in their dilute phase.
- 8. The system of claim 1 and further comprising a conduit extending from and connecting said accumulator to said reactor for passage of the flow of particles of fly ash from said accumulator to said particulate bed, and a valve connected to said conduit for regulating the flow of particles of fly ash to said particulate bed.
- 9. The system of claim 1 and wherein said ash capture comprises a primary ash capture and said system further comprises a secondary ash capture connected to said primary ash capture for receiving and separating fly ash particles from an exhaust air flow from said primary ash capture.
- 10. The system of claim 9 and wherein said secondary ash capture comprises a separator having an inlet through which the exhaust air flow from said primary ash capture is received, an ash outlet, and a separator chamber in which ash is collected from the exhaust air flow for return to said accumulator.
- 11. The system of claim 1 and wherein said heating source comprises a gas-fired burner, electric heater, or other fuel burning heater.
- 12. The system of claim 1 and further comprising a motive air source adjacent said particulate bed for directing a flow of air through said particulate bed.
- 13. The system of claim 12 and further comprising a heat exchanger connected to said motive air source for heating the flow of air introduced through said particulate bed.
- 14. A method of removing carbon from fly ash, comprising:
introducing fly ash particles having a residual carbon content into a particulate bed within a reactor chamber; heating the fly ash particles to a temperature sufficient to cause combustion of the residual carbon therein; after the fly ash particles pass through the particulate bed, conveying the fly ash particles through the heated reactor chamber in a dilute phase for continued combustion of the carbon therein; exhausting the fly ash particles in their dilute phase to an ash capture; separating the fly ash particles from air exhausted from the reactor chamber; accumulating the fly ash particles separated from the exhaust air; and discharging the accumulated fly ash particles.
- 15. The method of claim 14 and wherein discharging the accumulated fly ash particles comprises releasing the fly ash particles for cooling and further processing.
- 16. The method of claim 14 and wherein discharging the accumulated fly ash particles comprises returning the fly ash particles to the particulate bed of the reactor chamber for further combustion of carbon therein.
- 17. The method of claim 16 and wherein accumulating the fly ash particles comprises collecting the fly ash particles in a bed and maintaining the collected bed of fly ash particles at a level sufficient to maintain a substantially continuous flow of fly ash particles from the bed of collected fly ash particles to the particulate bed of the reactor chamber as fly ash particles are conveyed from the particulate bed.
- 18. The method of claim 14 and further comprising supplying an air flow to the particulate bed to cause the fly ash particles to move therethrough.
- 19. The method of claim 14 and further comprising exhausting the air separated from fly ash particles to a secondary ash capture and thereafter separating fly ash particles remaining in the exhausted air in the secondary ash capture.
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional Patent Application No. 60/162,938, Filed Nov. 2, 1999.
Provisional Applications (1)
|
Number |
Date |
Country |
|
60162938 |
Nov 1999 |
US |
Continuations (1)
|
Number |
Date |
Country |
Parent |
09705019 |
Nov 2000 |
US |
Child |
10254747 |
Sep 2002 |
US |