Fluid sprinkling – spraying – and diffusing – Rigid fluid confining distributor
Reexamination Certificate
1999-06-15
2001-02-27
Kashnikow, Andres (Department: 3752)
Fluid sprinkling, spraying, and diffusing
Rigid fluid confining distributor
C239SDIG001, C239S424000, C148S325000, C148S639000, C420S062000, C029S890020
Reexamination Certificate
active
06193173
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a burner, for example for a furnace in the glassmaking industry, comprising an injector one end zone of which is intended to be exposed, during operation of the burner, to high temperatures.
2. Description of the Related Art
Burners generally comprise an injector fitted into one wall of a combustion chamber and intended to inject an oxidizer and/or a fuel into the latter in order to initiate or maintain a combustion process. Consequently, during operation of the burner, the injector is exposed to high temperature gradients, given that the end of the injector emerging in the combustion chamber is subjected to the temperature prevailing in the combustion chamber, i.e. greater than 1000° C., while its other end, on the feed side, is at a temperature close to ambient temperature.
In order to ensure proper operation of the burner and thus that of the combustion chamber, such an injector must be regularly inspected, and possibly cleaned or replaced.
It will therefore be understood that these injectors are periodically subjected to large heat shocks, and occasionally to mechanical shocks during handling.
Injectors are known which are made of so-called “refractory” stainless steels having a limiting service temperature of 1200° C. and containing a high percentage of nickel.
Although these injectors suitably withstand both the heat shocks and the mechanical shocks, they are often chemically attacked, which impairs their mechanical properties and requires them to be replaced.
In addition, it has proved the case that the nickel present in this steel is a catalyst for the carbonization reaction on the injector, i.e. the growth of solid structures composed of graphitic carbon and starting at the end of the injector. The formation of these graphitized protuberances frequently leads to deflections of the jets of fuel or of the oxidizer and, consequently, to deflections of the flame which, eventually, may strike the quarl and melt it.
The object of the invention is to alleviate these various drawbacks by providing a burner comprising an injector which has good thermal resistance and good mechanical strength, while preventing any risk of the end of the injector being carbonized.
SUMMARY OF THE INVENTION
For this reason, the subject of the invention is a burner comprising an injector one end zone of which can be taken to high temperatures during operation of the burner, characterized in that the said end zone is made of an alloy comprising between approximately 16 and 22% by weight of Cr, between approximately 3 and 6% by weight of Al, between approximately 0.1 and 1.0% of Ti, between approximately 0.1 and 1.0% by weight of Y
2
O
3
and between approximately 70 and 80% by weight of Fe.
The burner according to the invention may in addition include one or more of the following characteristics:
the said alloy comprises approximately 19% by weight of Cr, 5.5% by weight of Al, 0.5% by weight of Ti, 0.5% by weight of Y
2
O
3
and 74.5% by weight of Fe;
the length of the said end zone, in the injection direction of the injector, corresponds to that part of the injector which can be taken to a temperature of greater than 700° C. during operation of the burner;
the said length of the said end zone is between approximately 30 and 200 mm;
the said end zone is formed by a piece joined to the injector by screwing;
the said end zone has undergone a heat treatment at a temperature of greater than 800° C. in an oxygen-rich atmosphere;
the heat treatment is carried out a temperature of around 1000° C. and the atmosphere contains at least 21 mol % of oxygen.
The subject of the invention is furthermore a process for manufacturing an injector for a burner, characterized in that it comprises the following steps:
at least one end zone of the injector, which can be taken to high temperatures during operation of the burner, is made of an alloy comprising between approximately 16 and 22% by weight of Cr, between approximately 3 and 6% by weight of Al, between approximately 0.1 and 1.0% by weight of Ti, between approximately 0.1 and 1.0% by weight of Y
2
O
3
and between approximately 70 and 80% by weight of Fe; and
the said end zone is subjected to a heat treatment at a temperature of greater than 800° C. in an oxygen-rich atmosphere.
The process according to the invention may, in addition, include the following characteristic, in which the said heat treatment is carried out at a temperature of around 1000° C. and in that the atmosphere contains at least 21 mol % of oxygen.
Other features and advantages of the invention will emerge from the following description, given by way of example and without any limiting character, together with the appended drawing which shows, diagrammatically, in partial cross section, a burner according to the invention.
REFERENCES:
patent: 4402746 (1983-09-01), Ramanarayanan et al.
patent: 5209772 (1993-05-01), Benn et al.
patent: 5490775 (1996-02-01), Joshi et al.
patent: 5770547 (1998-06-01), Phong
patent: 5772427 (1998-06-01), Laurenceau et al.
patent: 5839980 (1998-11-01), Snyder
patent: 5931654 (1999-08-01), Chamberland
patent: 2035634 (1991-08-01), None
patent: 0 571 984 A1 (1993-12-01), None
patent: 0 646 751 A1 (1995-04-01), None
patent: 04083820 (1992-03-01), None
patent: 05098397 (1993-04-01), None
patent: WO 97/22547 (1997-06-01), None
Patent Abstracts of Japan, vol. 098, No. 001, Jan. 30, 1998.
Bodelin Pierre
Guedra Jean-Paul
Meyer Annie
Recourt Patrick
Burns Doane , Swecker, Mathis LLP
Kashnikow Andres
Kim Christopher S.
L'Air Liquide Societe Anonyme pour l'Etude et l'E
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