This application is a non-provisional patent application of U.S. Ser. No. 61/484,486, filed on May 10, 2011.
Not Applicable.
Not Applicable.
1. Field of the Invention
This invention pertains to gasifiers. More particularly, the present invention pertains to a gasifier equipped with a slag breaker that breaks solidified slag into small chucks of slag that can then easily be discharged from the gasifier. The slag breaker allows slag accumulation within the gasifier to reach an equilibrium and eliminates the need to periodically shutdown the gasifier to remove solidified slag accumulations.
2. General Background
During the gasification process of some fuels, such as wood, grass, and other biofuels, ash is produced as a byproduct. The combustion chamber of some gasifiers operate at temperatures wherein the ash formed during the combustion process liquefies and thereby becomes slag. Such liquified slag often flows down the walls that surround the combustion chamber and either collects at the bottom of the combustion chamber or is discharged from a port at the base of the combustion chamber. After leaving the combustion chamber or after the gasifier has been shutdown, the liquified slag cools and solidifies. The solidified slag is much more difficult than ash to dispose of and manage due to its rigid nature. Moreover, solidified slag can accumulate in undesirable places within a gasifier and can block critical passageways. Thus, dealing with solidified slag can be problematic to the operation of gasifiers.
The present invention provides a solution to the problem of dealing with solidified slag. A gasifier in accordance with invention is configured such that slag is intentionally solidified within the gasifier in form of slag stalactites. A slag breaker periodically breaks the stalactites within the gasifier via impact. The broken slag stalactite chunks then fall into a slag collection region. The broken slag stalactite chunks are small and can be removed from the gasifier much more easily than can a solidified blob of slag or slag that solidified while in contact with a surface of a component of the gasifier.
In one aspect of the invention, a gasifier comprises an internal chamber, a slag collection region, a slag passageway, a slag breaker, and an actuator. The internal chamber comprises a main combustion region that is configured and adapted to gasify fuel. The slag collection region is located beneath the main combustion region. The slag passageway operatively connects the main combustion region to the slag collection region. The slag breaker comprises a face that is movable relative to the internal chamber. The face is configured and adapted to move within the slag passageway in a manner such that the face contacts and mechanically breaks solidified slag into chunks of solidified slag that then fall into the slag collection region. The actuator is connected to the slag breaker and is configured and adapted to move the face of the slag breaker.
In another aspect of the invention, a method comprises gasifying fuel in an internal chamber of a gasifier in a manner creating liquified slag within the internal chamber. The method also comprises solidifying the liquified slag into solidified slag within the gasifier. Furthermore, the method comprises operating an actuator in a manner causing a face of a slag breaker to move into contact with the solidified slag in a manner causing the solidified slag to break into chunks of solidified slag that then fall into a slag collection region of the gasifier. Still further, the method comprises operating a slag removal device in a manner expelling at least some of the chunks of the slag in the slag collection region from the gasifier.
Further features and advantages of the present invention, as well as the operation of the invention, are described in detail below with reference to the accompanying drawings.
Reference numerals in the written specification and in the drawing figures indicate corresponding items.
A gasifier in accordance with the invention is shown in
The components described above form the basic structure of the gasifier 10. However, the gasifier 10 also comprises additional components such as the support legs 42 shown in
The components of the slag handling system include a slag breaker 52 (shown by itself in
In use, fuel is introduced into the main combustion region 14 of the gasifier 10 through the fuel inlet port 24 located on the top cover 22 of the gasifier. Additionally, air is introduced into the tubular air passageway 32 via the air inlet tubes 40. Due to the tangential orientation of the air inlet tubes 40 relative to the tubular air passageway 32, the air spirals downward in the tubular air passageway around the ceramic wall 16 of the gasifier 10. After reaching the bottom of tubular air passageway 32 the air is directed radially inward and is ultimately expelled into the internal chamber 12 through the annular air inlet 36 into the slag passageway 70 that lies beneath the slag outlet 20 of the main combustion region 14 where it then travels upward into the main combustion region through the slag outlet. The guide vanes 38 located in the tubular air passageway 32 near the annular air inlet 36 convert the circumferential motion of the air into radial motion as the air nears the annular air inlet that discharges the air into the internal chamber 12. Water may also be discharge into the air via the water injection system 46 to provide additional hydrogen and oxygen for the gasification process.
The pressure and temperature within the main combustion region 14 is maintained at levels that are sufficiently high enough to cause the ash generated from the gasification process to liquefy into slag. The gasified fuel exits the gasifier 10 via the gasified-fuel outlet tube 28. In contrast, gravity causes the liquified slag to flow along the inner surfaces of the ceramic wall 16, and to ultimately flow out of the slag outlet 20 at the base of the main combustion region 14. As the liquified slag flows out of the slag outlet 20, the air or air and water mixture chills the slag and solidifies it, thereby forming stalactites of solidified slag that hang from the slag outlet. Such slag stalactites continue to grow downward in the slag passageway 70 until they ultimately extend at least partially through the openings 60 of the breaking members 58 of the slag breaker 52. Periodically, the actuators 66 of the slag breaker 52 are triggered to actuate the breaking members 58. Preferably, the actuators 66 are triggered in an alternating manner rather than simultaneously. More specifically, one of the actuators 66 is preferably triggered in manner causing one of the breaking members 58 to translate horizontally in first direction from a neutral position by approximately two inches, to thereafter return to neutral position, to thereafter translate negative two inches in the first direction, and to thereafter return to the neutral position. After that has occurred, the other of the actuators 66 is preferably triggered in manner causing the other breaking member 58 to translate horizontally in second direction (perpendicular to the first direction) from a neutral position by approximately two inches, to thereafter return to neutral position, to thereafter translate negative two inches in the second direction, and to thereafter return to the neutral position. This movement of the breaking members 58 causes the cylindrical faces 68 of the breaking members to contact and break the solidified slag stalactites in a manner creating chunks of solidified slag that fall through the openings 60 of the breaking members and downward into the slag collection region 72 of the gasifier 10. In the slag collection region 72, the chunks of solidified slag are deflected by the slag chute 54 into the slag discharge auger 56. The size of the chunks of solidified slag allows the slag chunks to be easily discharged from the gasifier 10 via the slag discharge auger 56.
In view of the foregoing, it should be appreciated that the invention achieves the several advantages over prior art gasifiers. For example, it should be appreciated that the present invention provides an efficient way of removing slag from gasifiers in a manner such that the slag build-up reaches an equilibrium and eliminates the need to periodically shutdown the gasifier to remove solidified slag accumulations.
As various modifications could be made in the constructions and methods herein described and illustrated without departing from the scope of the invention, it is intended that all matter contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative rather than limiting. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims appended hereto and their equivalents.
It should also be understood that when introducing elements of the present invention in the claims or in the above description of exemplary embodiments of the invention, the terms “comprising,” “including,” and “having” are intended to be open-ended and mean that there may be additional elements other than the listed elements. Additionally, the term “portion” should be construed as meaning some or all of the item or element that it qualifies. Moreover, use of identifiers such as first, second, and third should not be construed in a manner imposing any relative position or time sequence between limitations. Still further, the order in which the steps of any method claim that follows are presented should not be construed in a manner limiting the order in which such steps must be performed.
Number | Name | Date | Kind |
---|---|---|---|
3276203 | Squires | Oct 1966 | A |
3437561 | Squires | Apr 1969 | A |
4046541 | Anderson | Sep 1977 | A |
5464592 | Brooker et al. | Nov 1995 | A |
7322538 | Gruhlke et al. | Jan 2008 | B1 |
7947216 | Pingel | May 2011 | B2 |
8579212 | Schilder | Nov 2013 | B2 |
20110265696 | Hamasaki et al. | Nov 2011 | A1 |
Number | Date | Country |
---|---|---|
2187122 | May 2010 | EP |
2007811 | May 1979 | GB |
H09095685 | Apr 1997 | JP |
2005078346 | Aug 2005 | WO |
Number | Date | Country | |
---|---|---|---|
20130118389 A1 | May 2013 | US |
Number | Date | Country | |
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61484486 | May 2011 | US |