BURNER ARRANGEMENT

Abstract

The invention relates to a burner arrangement (1) in particular for heating, drying or keeping warm, in particular a distributor (5) of a continuous casting unit and consisting of a flat arrangement of at least one burner (2). The burner(s) (2) is/are embodied as a porous burner (10).

Description

TECHNICAL FIELD

The invention concerns a burner arrangement, especially for heating, drying and/or keeping hot especially tundishes of a continuous casting installation.

PRIOR ART

In melting operations, for example in steelworks with continuous casting installations, the molten metal is usually brought by a ladle to the casting platform of a continuous casting installation. The hot liquid metal is intermediately buffered by means of a tundish, for example a tundish launder, before it flows into the mold of the continuous casting installation. The tundish also serves the purpose of allowing continuous changing of the casting ladles, thereby making it possible for sequence casting of the metal to be carried out.

The tundishes are usually relined on a cyclical basis and, if necessary, subjected to fresh intermediate repair work and fitted with an immersion tube before each sequence. The tundish is then dried and heated. The heating is carried out by operating a burner with fossil fuels, such as natural gas, and with oxygen carriers, such as air. Commercially available burners, which are built into a heating cover, are usually used for this purpose.

The use of commercially available burners that produce flames results in the generation of fast-moving exhaust gas, which tends to cause striation and as a whole has a low fraction of radiant energy.

The flames produce point-focal heating, which can lead to local overheating, where each flame strikes directly, while other areas tend to be heated too weakly, where the flame is too far away. This causes stresses in the tundish, which can lead to cracking and thus to stoppage of the entire plant. In addition, due to the inhomogeneous heating with the flame, the drying time is prolonged, the service life of the tundish is reduced, and at the same time the energy consumption is very high. CO₂ emissions are also very high. This also increases the consumption of lining material for the tundish, because it must be replaced more often due to increased cracking. This results in higher costs for the energy supply, which makes the plant less economical. Furthermore, the discharge of combustion exhaust gases is very high, which on the whole is not very environmentally friendly and in recent years has come to be seen as especially unfavorable in connection with the discussion of the greenhouse effect.

Burner arrangements of this type are disclosed, for example, by KR 102003005373 A, KR 1020030021728 A, KR 1020040011716 A, KR 1020010091068 A, and KR 09122854 A.

DESCRIPTION OF THE INVENTION, OBJECTIVE, SOLUTION, ADVANTAGES

The objective of the invention is to create a burner arrangement, especially for heating, drying and/or keeping hot especially tundishes of a continuous casting installation, which realizes better utter utilization of the energy that is used, a reduction of CO₂ emissions, a high availability of the installation. A further objective of the invention is to create a method for the advantageous control of a burner arrangement.

The objective of the invention with respect to a burner arrangement is achieved with a burner arrangement, especially for heating, drying and/or keeping hot especially a tundish of a continuous casting installation, with a flat arrangement of at least one burner, where the burner or burners are designed as porous burners.

In this regard, it is especially advantageous if the porous burner has porous burner segments. The porous burner can have one segment or a plurality of segments, which are connected with one another or at least are arranged adjacent to one another except for a slight joint between the segments. In accordance with the invention, the connected segments are connected by connecting means and/or are held, for example, by means of a frame in such a way that a uniform burner is realized by the arrangement of the segments adjacent to one another. In one advantageous embodiment, it is effective if the segments of the porous burner have a flat arrangement in adjacent rows.

To supply fuel and an oxygen carrier, it is effective if the porous burner segments are each supplied with fuel and/or an oxygen carrier by means of supply lines. In this regard, it is advantageous if at least some of the individual supply lines are supplied with fuel and/or with an oxygen carrier by a common supply line. It is also advantageous if, in accordance with another embodiment, a blower is provided to supply the oxygen carrier through the supply lines. In this way, an oxygen carrier, for example, air, is conveyed through the supply lines to the segments by means of the blower.

To manipulate the burner arrangement, it is advantageous if the porous burner arrangement is held by a swivel mount or a swivel arm, which has a joint that allows it to swivel. In this connection, it can be advantageous if, in accordance with another embodiment, the blower is likewise held by the mount or the swivel arm, so that the blower can also be swiveled.

The objective of the invention with respect to a method is achieved by a method for controlling a burner arrangement, in which segments of the porous burner are turned on and/or off as a function of the desired heating intensity or heating power. In this regard, it is advantageous if segments are turned on or off at least in alternating rows or in a checkerboard pattern.

Advantageous refinements of the invention are described in the dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is explained in greater detail below with reference to the embodiment of the invention that is illustrated in the drawings.

FIG. 1 is a view of a burner arrangement of the invention for heating and/or drying a tundish and/or keeping it hot.

FIG. 2 is a top view of a burner arrangement according to FIG. 1.

PREFERRED EMBODIMENTS OF THE INVENTION

FIG. 1 shows a view of a burner arrangement 1, especially for heating, drying and/or keeping hot especially tundishes of a continuous casting installation. In this regard, the burner arrangement 1 has a burner 2, which is held on a mount 3 and is designed to swivel by virtue of the fact that the mount 3 has a swivel bearing 4. The mount thus forms a swivel arm. In this regard, the burner can be positioned over the tundish 5, as in heating position 8, in which it heats the tundish, or the burner can be swiveled upward into a parked position 9, so that it is in an essentially vertical position, and the tundish is essentially freely accessible for other work. The swivel arm can be swiveled between these two positions by hydraulic or pneumatic control.

In accordance with the invention, the burner 2 is designed as a porous burner 10. The porous burner 10 has the advantageous property that, as a gas burner, it allows combustion of a gas-air mixture in a porous structure or cell, which gets by to a certain extent or totally without the formation of a flame. As a result, flameless, volumetric combustion of the gas-air mixture is achieved. In this process, combustion in the porous structure is realized, so that after the introduction of the gas-air mixture, a stream of exhaust gas is produced as the reaction product on the discharge side.

The oxygen carrier, for example, air, is blown into the porous burner 10, for example, by means of a blower 6. In this process, the oxygen carrier is drawn in by the blower and supplied to the burner, which is designed as a porous burner 10, by supply channels or supply lines 7.

It is advantageous for the porous burner 10 illustrated in FIG. 2 to be composed of several segments of the porous burner. To this end, the individual segments 11, 12, 13 have an essentially flat arrangement and are connected to at least one supply line 14, 15, by means of which the fuel and/or the oxygen carrier is fed to each segment. In this regard, the air or the oxygen carrier can be introduced into the segments of the porous burner by a blower, as described above. In accordance with another embodiment, it is also possible to provide a supply line for a fuel-air mixture.

The segments, which have a flat arrangement, are advantageously arranged adjacent to one another for this purpose with slight joint spacing, so that a flat arrangement of the porous burner segments in several rows is provided. The segments of the porous burner can be supported by supporting means, for example, in a support frame, which is connected with the swivel arm, so that the flat arrangement of the porous burner segments can be swiveled together with the swivel arm.

The porous burner produces a stream of hot exhaust gases as well as thermal radiation, which are directed at the tundish to heat it, to dry it, to warm it, or to bring it to a desired temperature. The hot exhaust gas reaches the interior of the tundish or the surface of the tundish, which produces a homogeneous temperature distribution and thus counteracts striation. However, due to the fact that a large portion of the energy is converted to radiation, the tundish can also be heated very effectively.

It is especially advantageous that the porous burner is realized as an essentially flat arrangement composed of individual segments of porous burners. This provides the advantageous possibility of controlling the process by turning individual segments or rows of segments on or off independently of one another or turning individual segments on or off independently of one another.

Depending on the heating intensity or heating power to be applied, all of the segments of the porous burner can be turned on, or some individual segments can be turned off. It can be advantageous if segments are turned on or off at least in alternating rows. It can also be advantageous if segments are turned on or off alternatingly in a checkerboard pattern, so that only a fraction of the segments is operated.

LIST OF REFERENCE NUMBERS

1 burner arrangement
2 burner
3 mount, swivel arm
4 swivel bearing
5 tundish
6 blower
7 supply channels or supply line
8 heating position
9 parked position
10 porous burner
11 segment
12 segment
13 segment
14 supply line
15 supply line

Claims

1. A burner arrangement (1), especially for heating, drying or keeping hot especially a tundish (5) of a continuous casting installation, with a flat arrangement of at least one burner (2), wherein the burner or burners (2) are realized as porous burners (10), wherein the porous burner (10) has porous burner segments (11, 12, 13), and the porous burner segments (11, 12, 13) are supplied with fuel and/or an oxygen carrier by supply lines (4), and at least some individual supply lines (4, 14, 15) are supplied with fuel and/or an oxygen carrier by a common supply line, and, in addition, a blower (6) is provided for supplying the oxygen carrier through the supply lines, and wherein the porous burner arrangement (10) is held by a swivel arm (3), which has a joint that allows it to swivel, and the blower (6) is likewise held by the swivel arm (3), so that the blower (6) can also be swiveled.

2. A burner arrangement in accordance with claim 1, wherein the porous burner segments (11, 12, 13) of the porous burner (10) are arranged flat in a row or rows.

3. A method for controlling a burner arrangement in accordance with claim 1, wherein porous burner segments (11, 12, 13) are turned on and/or off as a function of the desired heating intensity or heating power.

4. A method for controlling a burner arrangement in accordance with claim 1, wherein segments (11, 12, 13) are turned on or off at least in alternating rows or in a checkerboard pattern.