Apparatus for heat treatment of particulate materials

• US 8,523,963 B2
• Filed: 08/08/2005
• Issued: 09/03/2013
• Est. Priority Date: 10/12/2004
• Status: Expired due to Fees

• Current Assignee: Rainbow Energy Center LLC
• Original Assignee: Great River Energy
• Inventors: Bullinger, Charles W., Ness, Mark A., Sarunac, Nenad, Levy, Edward K., Armor, Anthony F., Wheeldon, John M., Coughlin, Matthew P.
• Primary Examiner(s): Goloboy, James
• Assistant Examiner(s): HINES, LATOSHA D
• Application Number:
  US11/199,838
• Publication Number:
  US 20060107587A1
• Time in Patent Office: 2,948 Days
• Field of Search: 422/198, 422/204, 446/26, 446/29
• US Class Current: 44/629
• CPC Class Codes: C10L 9/08 by heat treatments, e.g. calcining
• CPC Class Codes: F23K 1/04 Heating fuel prior to delivery to combustion apparatus
• CPC Class Codes: F26B 3/08 so as to loosen them, e.g. to form a fluidised bed "fluidised-bed" technique in general B01J8/24; centrifugal fluidised beds F26B7/007
• CPC Class Codes: F26B 3/082 arrangements of devices for distributing fluidising gas, e.g. grids, nozzles F26B3/0926 takes precedence; such devices per se B01J8/44

Abstract

The present invention constitutes a heat treatment apparatus like a fluidized-bed dryer for heat treating a particulate material in a low temperature, open-air process. Preferably, available waste heat sources within the surrounding industrial plan operation are used to provide heat to the dryer. Moreover, conveyor means contained within the dryer can remove larger, denser particles that could otherwise impede the continuous flow of the particulate material through the dryer or plug the fluidizing dryer. This invention is especially useful for drying coal for an electricity generation plant.

Claims

1. An apparatus for heat treating a product within a manufacturing operation to which at least two different types of waste heat are accessible, comprising:

(a) a vessel for receiving the product;

(b) a first waste heat source of heat;

(c) a first heat exchanger operatively connected to the vessel with the such first waste heat source provided to such first heat exchanger;

(d) a second waste heat source of heat different in type from the first waste heat source;

(e) a second heat exchanger operatively connect to the vessel with such second waste heat source provided to such second heat exchanger;

(f) whereby predetermined amounts of heat content contained within the first waste heat source and second waste heat source are delivered to the vessel;

(g) wherein the product is maintained within the vessel exposed to the combined first waste heat source and second waste heat source for a sufficient temperature and time duration to achieve the desired degree of heat treatment;

(h) a sparging pipe operatively connected to the vessel for delivering a gaseous stream to the vessel during the heat treatment process to reduce the incidence of condensation within the vessel; and

(i) wherein “

waste heat source”

means a gaseous or liquid stream having an elevated heat content resulting from an operation of a process or piece of equipment separate from the heat treatment apparatus, such gaseous or liquid stream being used for the secondary purpose of providing heat content to the heat exchanger instead of being discarded.

2. The heat treatment apparatus of claim 1, wherein the waste heat source is selected from the group consisting of cooling water streams, hot condenser cooling water, hot stack gas, hot flue gas, spent process steam, and discarded heat from operating equipment.

3. The heat treatment apparatus of claim 1, wherein the vessel is a fluidized-bed dryer.

4. The heat treatment apparatus of claim 1, wherein the vessel is a fixed-bed dryer.

5. The heat treatment apparatus of claim 1, wherein the product is particulate material.

6. The heat treatment apparatus of claim 1, wherein the equipment is used within an electricity power plant.

7. The heat treatment apparatus of claim 1, wherein the temperature delivered to the vessel by the heat source is about 300°

F. or less.

8. The heat treatment apparatus of claim 1 further comprising at least one additional heat source in the form of a waste heat source or a principal heat source delivered to the vessel by means of an associated heat exchanger, wherein “

principal heat source”

means a quantity of heat produced for the principal purpose of providing heat content to the associated heat exchanger.

9. The heat treatment apparatus of claim 1 further comprising a conveyor means contained within the vessel for transporting a portion of the product having a higher specific gravity than the specific gravity of other product contained within the vessel during the heat treatment process to a remote region of the vessel to enhance heat treatment of the remaining, lower-specific gravity product within the vessel.

10. The heat treatment apparatus of claim 9, wherein the conveyor means is a screw auger.

11. The heat treatment apparatus of claim 9 further comprising a scrubber assembly operatively associated with the vessel whereby the conveyor means transports the higher specific gravity portion of the product during the heat treatment process completely outside of the vessel into the scrubber assembly for further processing, use, or disposal of the product.

12. The heat treatment apparatus of claim 11, wherein the further processing of the higher specific gravity portion of the product comprises removal of residual lower specific gravity product that is entrapped within the higher specific gravity product.

13. The heat treatment apparatus of claim 11, wherein the further processing of the higher specific gravity portion of the product comprises treatment of at least one undesirable constituent contained within the product.

14. The heat treatment apparatus of claim 13, wherein the undesirable constituents is selected from the group consisting of sulfur, ash, and mercury.

15. The heat content apparatus of claim 1, wherein the heat treatment of the product comprises a reduction in moisture content of the product.

16. The heat treatment apparatus of claim 5, wherein the particulate material comprises coal.

17. An apparatus for drying product, for use in an industrial plant having a waste heat source, comprising:

(a) a fluidized-bed dryer unit having an interior for receiving the product, wherein product disposed in the dryer unit travels from one end of the dryer to the other end while being dried;

(b) an air or inert gas fluidizing stream for fluidizing the product particles contained within the dryer unit;

(c) a first heat exchanger for transferring heat from the waste heat source to the fluidizing stream to increase its temperature before it flows to and through the dryer unit;

(d) a second heat exchanger for transferring heat from the waste heat source to a third heat exchanger embedded within the dryer unit;

(e) wherein the interior of the vessel is heated to about 300°

F. or less; and

(f) wherein “

waste heat source”

means a gaseous or liquid stream having an elevated heat content resulting from an operation of a process or piece of equipment separate from the heat treatment apparatus, such gaseous or liquid stream being used for the secondary purpose of providing heat content to the heat exchanger instead of being discarded.

18. The coal drying apparatus of claim 17 further comprising a second waste heat source different in type from the first waste heat source, wherein a combination of the heat contained within the two waste heat sources is delivered via associated heat exchangers to the first heat exchanger operatively associated with the fluidizing stream, or the second heat exchanger operatively associated with the third heat exchanger embedded within the dryer unit.

19. A particulate material drying apparatus incorporated into an industrial plant operation having at least two different types of waste heat, such apparatus comprising:

(a) a fluidized-bed dryer unit having an interior for receiving the particulate material, wherein particulate material disposed in the dryer unit travels from one end of the dryer to the other end while being dried;

(b) an air pre-heater operatively disposed between the dryer unit and the two different waste heat sources to transfer heat from each of the waste heat sources to an air stream passing through the air pre-heater before it flows to and through the dryer unit, wherein the air stream fluidizes the particulate material particles contained within dryer unit;

(c) a heat exchanger operatively connected to the dryer unit for transferring heat from at least one of the waste heat sources to the dryer unit for increasing the interior temperature of the dryer unit; and

(d) wherein “

waste heat source”

means a gaseous or liquid stream having an elevated heat content resulting from an operation of a process or piece of equipment separate from the heat treatment apparatus, such gaseous or liquid stream being used for the secondary purpose of providing heat content to the heat exchanger instead of being discarded.