GASIFYING BURNER WITH INERT GAS CURTAIN BETWEEN PILOT BURNER AND POWDER BURNER
A burner is provided for gasifying powdered fuel with a free oxygen-containing oxidant at temperatures up to 1900° C. and pressures up to 10 MPa. The burner includes a powder burner part having an oxidant channel and a powdered fuel channel, and a central pilot burner part. An annular channel for the outflow of an inert medium is arranged at the burner mouth between the pilot burner part and the powder burner part.
This application claims priority of German Patent Office application No. 102012216505.3 DE filed Sep. 17, 2012. All of the applications are incorporated by reference herein in their entirety.
FIELD OF INVENTIONThe invention relates to a burner for gasifying powdered fuel with a free oxygen-containing oxidant at temperatures up to 1900° C. and pressures up to 10 MPa comprising a powder burner part having an oxidant channel and a powdered fuel channel and also a central pilot burner part.
The invention further relates to a gasifying burner having an integrated pilot burner and ignition appliance for gasifying powdered fuels with a free oxygen-containing oxidant at pressures up to 10 MPa and temperatures above the melting point of the inorganic components of the powdered fuels.
BACKGROUND OF INVENTIONPulverized coal combination burners are known for the partial oxidation of pulverized fuels having a cylindrical water-cooled housing and internal annular spaces for feeding the pulverized fuel and the oxidant. The gasifying burner forms, together with the reaction space delimitation of the gasifier, the inner contour of the gasification space. There is a high thermal stress of the components in contact with the reaction space interior. The technology is extensively described in “Die Veredelung und Umwandlung von Kohle” [Refining and conversion of coal], published by the Deutschen Wissenschaftlichen Gesellschaft für Erdöl, Erdgas und Kohle e.V., [German Scientific Society for Petroleum, Natural Gas and Coal e.V.], December 2008, chapter “GSP-Vergasung” [GSP gasification]. The gasifying burner contains, in the center, a gas-oxygen burner which acts as ignition and pilot burner and is equipped with an optical flame monitoring and a high-voltage emission appliance. It serves for starting up the gasifying burner.
There are also gasifying burners in which the burner end surfaces facing the hot gasification space are water cooled. The supply of the powdered fuel and the gasifying agent are organized in such a manner that intense mixing and reaction occurs directly at the burner mouth, wherein temperatures far above 2000° C. occur in the flame root. The gasification pressure can be up to 10 MPa. In spite of the indirect cooling with water, the burner end surfaces are subject to an extreme thermal stress which leads to increased wear by corrosion and erosion, and greatly limits the availability of the gasifying burners. The problem is additionally intensified in that the pilot burner in the center of the combination burner is operated at an oxygen index of 0.3 to 0.5 and the gas generated in this process is burnt unhindered with the free oxygen-containing gasifying agent and in the process very high temperatures are generated.
SUMMARY OF INVENTIONThe problem of the invention is to develop a burner for gasifying powdered fuel in such a manner that the wear on the burner mouth due to the thermal stress is reduced.
The problem is solved by the features of the independent claim(s).
According to the invention, an inert gas curtain is used in order to delay the mixing of the reaction partners and thus keep the flame remote from the burner mouth.
The position and shape of the gasifying and pilot burner flame is modified in such a manner that the heat input into the burner end surfaces facing the hot gasification space is decreased. This is achieved in that the reaction partners oxidant and fuel are separated by one or more inert gas curtains. As a result, the reaction velocity is reduced, the flame is extended, the flame temperature is decreased and the gasification flame is moved away from the burner end surfaces.
Advantageous developments of the invention are specified in the subclaims.
The invention will be explained in more detail hereinafter as an exemplary embodiment in a scope necessary for understanding, with reference to figures. In the drawings:
In the figures, the same references denote the same elements.
In a gasifying reactor having a gross output of 500 MW, a combination burner according to
In a gasifying reactor, under the same conditions as in the present example, a combination burner according to
The invention is also provided by a burner for gasifying powdered fuel with a free oxygen-containing oxidant at temperatures up to 1900° C. and pressures up to 10 MPa, in which, between the annular channel for the oxidant (4) and the outflow for the powdered fuel (3), an annular channel for the outflow of an inert medium (12) is arranged. In a particular development, this burner can be designed by a centrally arranged pilot burner (2) to form a combination burner.
LIST OF REFERENCE SIGNS
- 1 Powder burner part
- 2 Pilot burner part
- 3 Powdered fuel channel
- 4 Oxidant channel
- 5 Gasification space
- 6 Fuel gas channel
- 7 Oxygen channel
- 8 Cooling channels
- 9 Cooling channels
- 10 Cooling channels
- 11 Inert gas curtain between the pilot burner part 2 and the oxidant channel 4
- 12 Inert gas curtain between the oxidant channel 4 and the powdered fuel channel 3
Claims
1. A burner for gasifying powdered fuel with a free oxygen-containing oxidant at temperatures up to 1900° C. and pressures up to 10 MPa, the burner comprising:
- a powder burner part having an oxidant channel and a powdered fuel channel, and
- a central pilot burner part,
- wherein an annular channel for the outflow of an inert medium is arranged at the burner mouth between the pilot burner part and the powder burner part.
2. The burner as claimed in claim 1,
- wherein the oxidant channel of the powder burner part is arranged immediately adjacent to the annular channel for the outflow of the inert medium.
3. The burner as claimed in claim 1,
- wherein an annular channel for the outflow of an inert medium is arranged between the oxidant channel and the powdered fuel channel.
4. The burner as claimed in claim 1,
- wherein the inert medium is provided by nitrogen.
5. The burner as claimed in claim 1,
- wherein the inert medium is provided by carbon dioxide.
6. The burner as claimed in claim 1,
- wherein the inert medium is provided by steam.
7. The burner as claimed in claim 1,
- wherein the inert medium is provided by water.
8. The burner as claimed in claim 1,
- wherein the inert medium is provided by any desired mixture of the group nitrogen, carbon dioxide, steam and water.
9. The burner as claimed in claim 3,
- wherein various inert media are provided from the group consisting of nitrogen, carbon dioxide, steam and water for the annular channel for the outflow of an inert medium between pilot burner and powder burner part and also the annular channel for the outflow of an inert medium between the oxidant channel and the powdered fuel channel of the powder burner part.
Type: Application
Filed: Sep 17, 2013
Publication Date: Mar 20, 2014
Inventors: Dietmar Adler (Grossschirma), Norbert Fischer (Lichtenberg), Manfred Jänig (Grunewald), Jürgen Noack (Dresden), Manfred Schingnitz (Freiberg)
Application Number: 14/028,632
International Classification: F23D 1/00 (20060101); F23D 14/78 (20060101);