Refractory armored quench ring

Abstract

An improved quench ring in combination with a reactor vessel having a refractory lined reaction chamber with a bottom outlet and a floor to support the refractory lined reaction chamber, wherein the quench ring is protected by a protective barrier comprising dense refractory brick, dense refractory ramming mix, refractory ceramic fiber, and a metal apron support. The protective barrier is removably attached to a portion of the quench ring hotface and protects the quench ring from the high temperature of the effluent exiting the reaction chamber.

Description

FIELD OF THE INVENTION [0001] The present invention is directed to an improved gasifier within which is a reactor that gasifiers carbonaceous fuel mixtures to produce a hot effluent comprising synthesis gas and residual slag. More specifically, this invention is directed to a support element that is located on the gasifier quench ring within the gasifier and that is used to protect the quench ring from the high temperatures of the hot effluent gas exiting through the reaction chamber floor. The support element protects the quench in such a manner that the quench ring is a refractory armored quench ring. BACKGROUND OF THE INVENTION [0002] In the production of synthesis gas by the partial oxidation of a carbonaceous fuel mixture, the process is conducted most effectively under high temperature and high pressure conditions. For example, for the production of synthesis gas from a carbonaceous fuel such as particulated coal, coke or even oil, a preferred operating temperature range of ab...

AI Technical Summary

Benefits of technology

[0018] Toward overcoming the gasifier operating defects in gasifiers of the type noted, there is presently disclosed a gasifier quench ring which is provided with refractory layers that are located radially inward of the quench ring's normally exposed surfaces. The refractory layers protect the quench ring from exposure to the high temperature synthesis gas and slag exiting the reaction chamber bottom outlet. The quench ring is thereby insulated and physically protected by refractory materials that are supported by a refractory bearing apron. The protective thermal resistant barrier comprises dense refractory materials and insulating refractory ceramic fiber. The quench ring is thereby insulated by the protective thermal resistant barrier which is supported by a refractory bearing apron. The various refractory materials minimize thermal stresses which would normally be encountered by the quench ring during the gasification process.

[0030] Another disadvantage of the prior art that the present invention overcomes is the inability to repair the quench ring while the gasifier is still fairly hot. Because the protective thermal resistant barrier is easily replaceable, it can be done while the gasifier is still moderately hot; and, because the protective thermal resistant barrier prevents damage to the metal surface of the quench ring during gasifier operations, it therefore precludes the need to remove the quench ring from the gasifier.

[0031] Another disadvantage of the prior art that the present invention overcomes is the sharp edges that are on some quench rings. The quench ring in the present invention has a toroidal annular surface. The rounded toroidal shape promotes even cooling of the quench ring and does not increase thermal stresses that are normally found in quench rings having sharp edges / angled surfaces intersections.

Problems solved by technology

The '423 patent, however, fails to protect the quench ring from the harsh thermal elements of the reactor.

Although a portion of the assembly is insulated, it does not provide an effective barrier which would avoid contact between the hot effluent stream and the cold quench ring surface.

There are several problems that are encountered due to the high temperature conditions within the gasifier.

Among those problems are the development of thermal stresses, which often result in damage to the quench ring as a result of the ring's close proximity to the hot effluent stream, and the lack of protection of the metal surfaces of the quench ring.

These problems are often manifested in the form of cracks and fissures which develop in parts of the quench ring.

One problem that may be experienced in gasifiers is the propensity of molten slag to harden and freeze in the gasifier's constricted throat.

This undesirable chilling action can, under particular circumstances, severely block the constricted throat opening, thereby precluding further operations.

Another problem with prior art quench ring and dip tube assembly arrangements includes the inability to repair or partially replace the quench ring while the gasifier is still fairly hot.

Repairing or replacing the quench ring when the entire gasifier has cooled down to approximately less than 100OF significantly delays resumption of the operation of the gasifier.

Yet another problem with the prior art quench ring and dip tube assembly arrangements includes small or ineffectively configured drip edges in the refractory lining above the quench ring.

These drip edges are easily damaged and thus permit the flow of molten slag down along the throat surface and onto the inner diameter surface of the quench ring and even the dip tube instead of inducing the slag to free fall through the dip tube and into the quench bath as intended.

When the flow is misdirected, the molten slag can stick to and freeze on the dip tube inner surface, thereby creating a “shadow” effect wherein the quench water from the quench ring will not adequately coat the inner diameter surface of the dip tube below the frozen slag.

An uncoated, unprotected portion of the dip tube such as this can lead to overheating and burn-through of the dip tube.

Overheating and burn-through are very serious problems for several reasons, not the least of which is that hot, unquenched syngas will subsequently flow into downstream units of the gasification processes that are not equipped for the high temperature unquenched gasses.

Another problem with some prior art is the sharp edges on the quench rings.

These sharp edges are not as effectively cooled by the flowing quench water as are curved or flat surfaces since they result in localized stagnant regions within the flow field.

Accordingly, the sharp edges tend to run hotter, thereby increasing thermal stresses within the quench ring structure.

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