System and method for gas separation

• US 8,357,232 B1
• Filed: 03/09/2009
• Issued: 01/22/2013
• Est. Priority Date: 03/09/2009
• Status: Active Grant

• Current Assignee: Casella Waste Systems Incorporated
• Original Assignee: Casella Waste Systems Incorporated
• Inventors: Morrison, Garrett L.
• Primary Examiner(s): Greene, Jason M
• Assistant Examiner(s): Bui, Dung H
• Application Number:
  US12/400,628
• Publication Number:
  US 20130025455A1
• Time in Patent Office: 1,415 Days
• Field of Search: 554/47, 554/67, 55469-471, 554/73, 554/60, 554/62, 554/51, 554/56, 554/591, 55404-408, 952/71
• US Class Current: 95/271
• CPC Class Codes: B01D 2256/10 Nitrogen
• CPC Class Codes: B01D 2256/12 Oxygen
• CPC Class Codes: B01D 2256/245 Methane
• CPC Class Codes: B01D 2257/304 Hydrogen sulfide
• CPC Class Codes: B01D 2257/502 Carbon monoxide
• CPC Class Codes: B01D 2257/504 Carbon dioxide
• CPC Class Codes: B01D 2257/55 Compounds of silicon, phosphorus, germanium or arsenic
• CPC Class Codes: B01D 53/24 by centrifugal force centrifuges B04B; cyclones B04C
• CPC Class Codes: Y02E 50/30 Fuel from waste, e.g. synthetic alcohol or diesel

Abstract

The present invention relates to a system and method for the separation of gaseous components from gaseous mixtures in order to control emissions and treatment of the gaseous components. In one embodiment, the system makes use of a fan or gas moving device to first impose centrifugal forces on gas streams as the gas moves from the center of the fan toward the periphery of the fan housing. Heavier gases are forced to the outer regions of the fan housing while lighter gases remain closer to the fan axis. The heavier gases and lighter gases exiting the fan housing flow into a duct at different flow rates, and the heavier gases are diverted from the larger volume gas streams and then processed.

Claims

1. A method of separating a plurality of gas components from a gas mixture by action of centrifugal forces, comprising the steps of:

receiving the gas mixture in one axial direction via an inlet duct;

splitting the gas mixture into a plurality of streams through the inlet duct;

accelerating the plurality of streams in another radial direction by action of the centrifugal

forces;

forcing the plurality of streams through a first gas discharge outlet; and

feeding at least one of the plurality of gas components from the first discharge outlet through a second gas discharge outlet.

2. The method of claim 1, further comprising the step of separating at least one gas

component from the plurality of gas components forced through the first gas discharge outlet.

3. The method of claim 2, wherein the separating step further comprises guiding the at

least one of the plurality of gas components forced through the first gas discharge outlet against a baffle surface.

4. The method of claim 1, wherein the gas mixture is drawn through an

inlet pipe by

induced draft.

5. The method of claim 2, further comprising feeding the plurality of gas components

remaining after separating the at least one gas component to the gas mixture being received.

6. The method of claim 2, wherein the molecular weight of the at least one gas

component of the plurality of gas components is the heaviest in the gas mixture.

7. The method of claim 1, wherein receiving the gas mixture comprises drawing the gas mixture in one axial direction by suction.

8. The method of claim 1, wherein receiving the gas mixture comprises forcing the gas mixture in one axial direction by pressure.

9. The method of claim 8, wherein the pressure may be applied by at least one of fan, pump, and blower.

10. A method of separating a plurality of gas components from a gas mixture by action of centrifugal forces, comprising the steps of:

receiving the gas mixture into a centrifugal fan device in an axial direction through an inlet duct;

accelerating the gas mixture in a radial direction by action of centrifugal forces to form a plurality of gas streams through the inlet duct, wherein each gas stream comprises at least one of the

plurality of gas components;

forcing the plurality of gas streams through a first discharge outlet;

guiding at least one of the plurality of gas streams forced through the first discharge outlet against a baffle surface, wherein contact with the baffle surface forces the at least one gas stream out of the first discharge outlet through a second discharge outlet; and

conducting the remaining of the plurality of gas streams out of the first discharge outlet through a third discharge outlet.

11. The method of claim 10, further comprising feeding at least a first portion of the plurality of gas streams discharged through the third discharge outlet to the gas mixture being received into the centrifugal fan.

12. The method of claim 10, wherein the at least one gas stream discharged through the second discharge outlet comprises the at least one gas component having the highest molecular weight in the gas mixture.

13. The method of claim 10, wherein receiving the gas mixture into the centrifugal fan comprises drawing the gas mixture in the axial direction by suction.

14. The method of claim 10, wherein receiving the gas mixture into the centrifugal fan comprises forcing the gas mixture in the axial direction by pressure.

15. The method of claim 14, wherein the pressure may be applied by at least one of fan, pump, and blower.

16. A system for separating a plurality of gaseous components from a gaseous mixture, comprising:

a centrifugal fan device including a centrifugal fan having an axis and acting as a

rotatably driven pump impeller, said centrifugal fan device having;

a inlet for receiving gas mixture, wherein the inlet separates the gas mixture into a plurality of gaseous components and is located in the vicinity of the axis of the centrifugal fan, and

a gas outlet position tangentially on fan periphery for forcing gas out of the fan

housing at an accelerated velocity;

a discharge outlet in the vicinity of the centrifugal fan periphery for receiving the

forced gas from the centrifugal fan, wherein the discharge outlet is located centrally relative

to the centrifugal fan gas outlet; and

a baffle surface positioned on the periphery of the discharge outlet for guiding at least one gas component of the plurality of gas components through a second discharge outlet.

17. The system of claim 16, wherein the length of the discharge outlet is from about 15 feet to about 25 feet.

18. The system of claim 16, wherein the axis of the discharge outlet form a curvature comprising an interior angle of about 60 degrees.

19. The system of claim 16, wherein the axis of the discharge outlet form a curvature comprising an interior angle of about 90 degrees.

20. The system of claim 16, wherein the centrifugal fan is an induced draft fan.

21. The system of claim 16, further comprising a drive for the centrifugal fan.

22. The system of claim 21, wherein the drive is an electric motor.

23. The system of claim 21, wherein the drive is a belt drive.

24. The system of claim 21, wherein the drive is a variable drive.

25. The system of claim 20, wherein the induced draft fan further comprises:

a hub; and

an impeller comprising a plurality of blades, each of the blades, without directly contacting the hub, spaced about an axis of rotation, wherein air enters axially through an upstream end of the fan and is discharged radially from the fan.