Gasifier ash processing subsystem

• US 20110072722A1
• Filed: 09/29/2009
• Published: 03/31/2011
• Est. Priority Date: 09/29/2009
• Status: Active Grant

• Current Assignee: MSW Power Coporation
• Original Assignee: MSW Power Coporation
• Inventors: Young, Matthew, Anthony, Steven, Chase, Steven, Armstrong, Stephen
• Granted Patent: US 8,591,608 B2
• Time in Patent Office: Days
• US Class Current: 48/87
• CPC Class Codes: C10J 2300/0916 Biomass
• CPC Class Codes: C10J 2300/0956 Air or oxygen enriched air
• CPC Class Codes: C10J 2300/1625 with solids treatment
• CPC Class Codes: C10J 3/34 Grates; Mechanical ash-removing devices
• CPC Class Codes: C10J 3/36 Fixed grates
• CPC Class Codes: F23G 2207/102 for pressure
• CPC Class Codes: F23G 5/002 characterised by their grates F23G5/05 takes precedence
• CPC Class Codes: F23G 5/50 Control or safety arrangements
• CPC Class Codes: F23H 13/08 Grates specially adapted for gas generators and also applicable to furnaces

Abstract

A gasifier includes a combustion zone where a gas is introduced and fuel is combusted and at least one sensor for measuring a predetermined condition in the gasifier. A grate subsystem contains the fuel and includes at least one grinding mechanism. A controller is responsive to the at least one sensor and controls the grinding mechanism by activating the grinding mechanism if the predetermined condition exists to reduce the collection of non-fuel products on the grate subsystem.

Claims

1. A gasifier comprising:

a combustion zone where a gas is introduced and fuel is combusted;

at least one sensor for measuring a predetermined condition in the gasifier;

a grate subsystem for containing the fuel, the grate subsystem including at least one grinding mechanism; and

a controller, responsive to the at least one sensor, for controlling the grinding mechanism, the controller configured to;

activate the grinding mechanism if the predetermined condition exists to reduce the collection of non-fuel products on the grate subsystem.

2. The gasifier of claim 1 in which the sensor is a pressure sensor.

3. The gasifier of claim 2 in which the pressure sensor is responsive to the pressure below the grate subsystem.

4. The gasifier of claim 1 in which the grate subsystem includes at least two downwardly angled fixed grates defining a hopper area between the grates.

5. The gasifier of claim 4 in which the grinding mechanism includes at least two spaced grinding shafts disposed in the hopper area.

6. The gasifier of claim 5 in which each shaft includes a gear meshed with a gear on the other shaft to drive the shafts together.

7. The gasifier of claim 6 in which the grate subsystem further includes a motor for driving a said shaft.

8. The gasifier of claim 7 in which the controller is configured to energize the motor.

9. The gasifier of claim 4 in which the grate subsystem includes two pairs of fixed downwardly angled grates defining two hopper areas.

10. The gasifier of claim 9 in which the grinding mechanism includes two pairs of spaced grinding shafts, one pair disposed in each hopper area.

11. The gasifier of claim 5 in which each grate includes slots between 0.1 and 0.3 inches wide spaced between 0.5 and 0.8 inches apart and there is a gap of between 0.1 and 0.3 inches between the grinding shafts.

12. The gasifier of claim 5 in which the grate subsystem further includes a housing configured as a tray containing the grates and the grinding shafts.

13. The gasifier of claim 12 in which the tray includes spaced side members connected by spaced end members.

14. The gasifier of claim 13 in which the grinding shafts extend between the spaced end members.

15. The gasifier of claim 14 further including bearings on each shaft rotatably coupling the shafts to said end members.

16. The gasifier of claim 2 in which the controller is programmed to:

determine if a pressure output by the pressure sensor meets or exceeds a predetermined pressure,

activate the grinding mechanism if the pressure meets or exceeds the predetermined pressure, and

deactivate the grinding mechanism if the pressure does not meet or exceed the predetermined pressure.

17. The gasifier of claim 16 in which the controller is further programmed to activate the grinding mechanism for increasing time intervals until the pressure does not meet or exceed the predetermined pressure.

18. A gasifier grate subsystem comprising:

at least two downwardly angled fixed grates defining a hopper area between the grates;

at least two spaced grinding shafts disposed in the hopper area; and

a controller, responsive to a sensor, configured to actuate the grinding shafts if a predetermined condition exists to reduce the collection of non-fuel products on the fixed grates.

19. The gasifier grate subsystem of claim 18 in which each shaft includes a gear meshed with a gear on the other shaft to drive the shafts together.

20. The gasifier grate subsystem of claim 19 in which the grate subsystem further includes a motor for driving a said shaft.

21. The gasifier grate subsystem of claim 19 in which the controller is configured to energize the motor.

22. The gasifier grate subsystem of claim 18 in which the grate subsystem includes two pairs of fixed downwardly angled grates defining two hopper areas.

23. The gasifier grate subsystem of claim 22 in which there are two pairs of spaced grinding shafts, one pair disclosed in each hopper area.

24. The gasifier grate subsystem of claim 18 in which each grate includes slots between 0.1 and 0.3 inches wide spaced between 0.5 and 0.8 inches apart and there is a gap of between 0.1 and 0.3 inches between the grinding shafts.

25. The gasifier grate subsystem of claim 18 further including a housing configured as a tray containing the grates and the grinding shafts.

26. The gasifier grate subsystem of claim 25 in which the tray includes spaced side members connected by spaced end members.

27. The gasifier grate subsystem of claim 26 in which the grinding shafts extend between the spaced end members.

28. The gasifier grate subsystem of claim 27 further including bearings on each shaft rotatably coupling the shafts to said end members.

29. A gasifier grate control system comprising:

a grate subsystem for containing fuel in a gasifier, the grate subsystem including at least one grinding mechanism; and

a controller, responsive to at least one sensor, for controlling the grinding mechanism, the controller configured to actuate the grinding mechanism if a predetermined condition exists to reduce the collection of non-fuel products on the grate subsystem.

30. The gasifier grate control system of claim 29 in which the sensor is a pressure sensor.

31. The gasifier grate control system of claim 30 in which the pressure sensor is responsive to the pressure below the grate subsystem.

32. The gasifier grate control system of claim 29 in which the grate subsystem includes at least two downwardly angled fixed grates defining a hopper area between the grates.

33. The gasifier grate control system of claim 32 in which the grinding mechanism includes at least two spaced grinding shafts disposed in the hopper area.

34. The gasifier grate control system of claim 33 in which the grate subsystem further includes a housing configured as a tray containing the grates and the grinding shafts.

35. The gasifier grate control system of claim 34 in which the tray includes spaced side members connected by spaced end members.

36. The gasifier grate control system of claim 35 in which the grinding shafts extend between the spaced end members.

37. The gasifier grate control system of claim 29 in which the controller is programmed to:

determine if the sensor output meets or exceeds the predetermined condition,

activate the grinding mechanism if the sensor output meets or exceeds the predetermined condition, and

deactivate the grinding mechanism if the sensor output does not meet or exceed the predetermined condition.

38. The gasifier grate control system of claim 37 in which the controller is further programmed to activate the grinding mechanism for increasing time intervals until the sensor output does not meet or exceed the predetermined condition.

39. A gasifier comprising:

means for combusting fuel;

sensor means for measuring a predetermined condition in the gasifier;

a grate containing the fuel; and

means for automatically removing clinkers on the grate in response to the sensed predetermined condition.

40. The gasifier of claim 39 in which the means for automatically removing the clinkers includes at least one grinding mechanism activated by a controller responsive to the sensor means.

41. A method of controlling a gasifier including a grate, the method comprising:

detecting at least one gasifier condition indicative of clinkers on the grate;

in response, automatically activating a grinding mechanism to remove the clinkers; and

deactivating the grinding mechanism when the gasifier condition no longer exists.