DE102007021924A1 - Coal dust combination burner - Google Patents

Abstract

In the inventive burner for the oxidizing gasification of dust-like fuels under high pressures of, for example, 80 bar (8 MPa) and temperatures of, for example, 1200 to 1900 ° C in reactors with liquid slag for the oxygen gasification, the individual dust supply pipes (4) in Burner designed so that while maintaining the input pipe cross-sectional area of the cross-section systematically merges into an annular space adapted, curved, surface-parallel rectangular channel (6). In this case, it is achieved that the fuel feed ends immediately adjacent to the oxidant channel and the delivery speed provided in the feed element is maintained until it exits. This measure ensures a trouble-free promotion of dust-like fuel and reduced when not in operation necessary for flushing the feed element inert gas.

Description

The This invention relates to a combination pulverized coal burner, the one for the oxygen gasification of dusty Fuels (lignite and / or hard coal or similar dust-like Fuels) under high pressures and temperatures in reactors is used with liquid slag prints.

Of the The subject of the application relates to a burner for oxidizing gasification of dusty fuels.

Known are coal dust combination burners for the partial oxidation dust-like fuels with a cylindrical water-cooled Housing and inner coaxially arranged annular spaces for the supply of dusty fuel and the oxidizing agent.

In the center of this burner is another small gas / oxygen burner, which serves as an ignition or pilot burner and is equipped with an optical flame monitoring and high-voltage ignition device. It serves to start up the o. G coal dust burner, as in the documents DE 271038 A3 and DE 4306980 C2 disclosed.

The Feeding the dusty fuel takes place outside and inside the burner by one or more Tube. Inside the burner is / are the feed tube (s) led to the burner exit so that they at least one make a full turn around the axle and then close the torch outlet tangent hired end. At the end of the Dust pipes (s), the dust enters tangentially into a cylindrical Annular space.

at the transition from the pipe surface into the annulus comes abruptly to an area enlargement and thus the fall in the dust velocity. By increase Although the number of dust tubes within the annulus of the Area jump reduced, but not canceled. As a result of this fact, there is an uneven Distribution of the dust flow within the annulus. hereby it can lead to an asymmetrical flame formation with one-sided reaction space load come.

• 1. komplizierte Ausführung der Rohre innerhalb des zylindrischen Ringraumes im Brenner
• 2. nach dem Austritt des Kohlenstaubes erfolgt ein unvermeidbarer Flächensprung der zum Absinken der Staubgeschwindigkeit führt.
• 3. durch diesen Flächensprung wird der nachfolgende Ringraum ungleichmäßig mit Kohlenstaub gefüllt, sodass die Mischung mit dem Oxydationsmittel unterschiedlich ist.

The known burner has the following disadvantages:

• 1. complicated design of the tubes within the cylindrical annulus in the burner
• 2. after the exit of the coal dust an unavoidable skip occurs which leads to a decrease of the dust velocity.
• 3. by this surface jump, the subsequent annulus is unevenly filled with coal dust, so that the mixture with the oxidant is different.

task The invention is the creation of a pulverized coal burner under the conditions of coal dust gasification under pressure reliably is working. The coal dust combination burner is designed by constructive Measures should be designed so that even at the pressure gasification of dusty products safe operation with uniform Flame formation is guaranteed.

The object is achieved in an outlined by the features of the preamble article in that in the burner, the individual dust supply elements are designed so that while maintaining the substantially circular input pipe cross-sectional area, the cross section systematically (continuously in the conveying direction) in an annular space adapted curved, surface-parallel rectangular channel ( 6 ) passes over.

By this inventive design of the feed elements for the dust-like fuels is achieved that the fuel supply ends immediately adjacent to the Oxydationsmit telkanal and the conveying speed provided in the feeding element is maintained until exit. This measure secures a trouble-free promotion of the dust-like Fuel and reduced during non-operation, the flushing the feed element, necessary inert gas.

advantageous Further developments of the subject of the application are specified in the subclaims.

Of the Subject of the application is hereinafter as an exemplary embodiment to an extent necessary for the understanding of Figures explained in more detail. Showing:

1 a schematic cross-sectional view of the compact burner according to the invention and

2 a schematic longitudinal sectional view of the compact burner according to the invention.

In the same designations denote the same elements.

The coal dust combination burner according to the invention has a centrally arranged pilot burner part 1 with fuel gas and Oxydationsmittelzuführung, a flame monitor and a high-voltage electrical ignition on. Around this assembly is an annulus 2 for supplying the oxidizing agent for the coal dust combination burner. At the annular Outlet openings are swirl vanes 3 arranged to swirl the oxygen flow.

The Feeding the dusty fuel takes place outside and inside the burner by one or more Tubes, in the embodiment three. In the burner are the individual pipes designed so that while retaining the substantially circular inlet tube cross-sectional area, the cross-section systematically (continuously in conveying direction) in a ring channel adapted, curved, surface-identical Rectangular channel passes. The rectangular channel at the burner mouth So is by two spaced, z. B. 25 mm arc sections with the same angle α (alpha), z. B. 80 degrees around the central axis given.

in this connection it is advantageous if the ratio rectangle width to rectangular or circular arc section length in proportion of about 1: 5,3 is executed. To avoid stagnation in the dust flow promotion, the rectangle width should not be dimensioned smaller than 25 mm. The transition of the pipe cross-sectional area to the final rectangular area is within the Ring channel (inside the burner towards the burner mouth) so shape the final rectangular area reached at the burner outlet.

In a further embodiment of the invention, the extension beams cut the walls of the annular space ( 4 ) in the direction of the burner mouth, the central axis. By this measure, an advantageous flame geometry is achieved.

The depending on the number of provided feed elements between the rectangle exits remaining unneeded spaces can be closed immediately at the exit and in the Cooling circuit to be included.

By the execution of the oxidant supply with swirl vanes 3 the escaping oxygen flow is strongly rotated, in which the dust jets emerging through the specially designed feed elements are sucked.

Due to the shape of the dust feed elements up to the burner mouth and the immediate entry into the rotating oxygen flow, there is no more surface gap with different dust velocities at the dust outlet. This achieves uniform flame formation and stabilization. At the same time can by a different employment of the swirl blades 3 the flame formation can be influenced in their width and length.

The invention comprises a pulverized coal burner for the pulverization of dust-like fuels under high pressures of, for example, 80 bar (8 MPa) and temperatures of, for example, 1200 to 1900 ° C in reactors with liquid slag discharges for oxygen gasification, consisting of a cooled housing ( 7 ) for receiving a centrally located pilot burner ( 1 ) for the commissioning of the pulverized coal combined burner unit with a gas and oxidant supply as well as an integrated flame monitoring and high-voltage ignition, one around this pilot burner ( 1 ) arranged annular channel ( 2 ) for the supply of the oxidizing agent and a further ring channel arranged around the oxidizing agent ring channel with integrated feed elements ( 4 ) for the supply of pulverulent fuels, characterized in that a plurality of feed elements ( 4 ) and these feed elements ( 4 ) inside the burner of a circular cross-section ( 5 ) under surface equality systematically up to the burner outlet in a the annular channel radius adapted curved rectangular cross-section ( 6 ) in the width / length ratio of about 1: 5.3, wherein the width of the Recheckquerschnitts should not be less than 25 mm, and at the outlet end immediately adjacent to the annular channel for Oxidantsmittelzuführung, at its exit swirling devices ( 3 ) are present, which put the Oxydationsmittelstrom in strong rotational movement and thus allow the design of influencing the flame geometry.

1

pilot burner with gas and oxygen supply and integrated flame monitoring and high voltage ignition device

2

Oxydationsmittelzuführung for dusty fuel

3

swirl blades for turbulence of the oxidizing agent

4

feed pipe for dusty fuel

5

cross-section the feed tube for the dusty Fuel (round)

6

cross-section the feed tube for the dusty Fuel (rectangular)

7

appearance Water cooling part

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 271038 A3 [0004]
• - DE 4306980 C2 [0004]

Claims (5)

Burner for the oxidizing gasification of dust-like fuels, comprising a centrally arranged pilot burner part ( 1 ), a concentric annular channel ( 2 ) for supplying the oxidizing agent, concentrically around the annular channel ( 2 ) arranged annular space in which a plurality of dust supply elements ( 4 ) Are disposed characterized in that each dust supply elements are implemented in the burner so that (while maintaining the input pipe cross-sectional area, the cross-section in a systematically the annular space adapted, curved, square channel coextensive 6 ) passes over. Burner according to claim 1, characterized in that The rectangular width of the rectangular channel should not be smaller than 25 mm is. Burner according to one of the preceding claims characterized in that the rectangle width to rectangle length in the ratio of about 1: 5.3 are executed. Burner according to one of the preceding claims characterized in that depending on the number of provided Dust feed elements between the rectangular outlets remaining unneeded rooms immediately closed at the outlet and included in the cooling circuit are. Burner according to one of the preceding claims, characterized in that the extension jets of the walls of the annular space ( 4 ) cut the central axis in the direction of the burner mouth.