JP2003221618A - Method and apparatus for heating metal strip with belt- shaped flame burner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent unnecessary consumption of fuel, and to uniformly heat a metal strip. <P>SOLUTION: In the method for heating the metal strip (10) with the belt- shaped flame burner, which heats the metal strip with several burners 22 arranged in a width direction of the metal strip, this heating method is characterized by moving the burners 22 along the width direction of the metal strip, according to the width of the metal strip, and extinguishing the fire of the burners in the region of no metal strip thereunder. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for heating a metal strip by a strip flame burner for heating the metal strip by a plurality of burners arranged side by side in the width direction of the metal strip, and more particularly to a stainless steel strip. It is suitable for heating before hot tandem rolling, etc., or for continuous annealing, and it is possible to uniformly heat a metal band without wasting fuel, and a belt-shaped flame The present invention relates to a method and an apparatus for heating a metal strip with a burner.

[0002]

2. Description of the Related Art SUS30 is used by a tandem rolling mill.
4. When cold-rolling metastable austenitic stainless steel such as SUS301, a heating device was provided on the inlet side of the tandem rolling mill to heat the stainless steel strip for the purpose of avoiding an increase in load due to work hardening. Japanese Patent Application Laid-Open No. 63-10009 proposed by the applicant to carry out warm tandem rolling later.
It is described in.

In a heating device for heating such a metal strip, generally, as proposed by the applicant in Japanese Patent Application Laid-Open No. 2-112818, as shown in FIG. 1, as a heating device 20, a stainless steel strip (hereinafter simply referred to as steel) is used. For the sake of convenience, metal strips other than stainless steel are also referred to as steel strips.) 1
As shown in FIG. 2, an object having a large number of rows of burners 22 (upper and lower six in the example of FIG. 1) is used in the longitudinal direction of 0 (conveyance direction), according to the conveyance speed of the steel strip 10. The heating control is performed to change the number of ignition rows of the burner 22 in the longitudinal direction of the steel strip.

In FIG. 1, 12 is a support roll and 2 is a support roll.
4 is a flame formed by the burner 22, 26 is an inner wall of the heating device, 28 is an outer wall, 30 is a fuel gas supply pipe,
Reference numeral 32 is a combustion air supply pipe.

[0005]

However, in the above heating device for heating steel strips of various widths, as shown in FIG. 3, the width of the steel strip 10 is smaller than that of the burner 22. If it is narrow and narrow, the flame that does not hit the steel strip is
There is a problem that wasteful fuel is consumed as a result without contributing to heating. Further, at that time, there is a problem that the exhaust gas temperature rises, the load of the heat exchanger and the exhaust device for cooling the exhaust gas increases, and the capacity thereof increases at the time of design.

The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to uniformly heat the metal strip without wasting fuel.

[0007]

DISCLOSURE OF THE INVENTION The present invention is a method for heating a metal strip by a strip flame burner for heating the metal strip by a plurality of burners arranged in the width direction of the metal strip. The burner is moved in the width direction of the metal strip and the burner in the region where the metal strip is not present is extinguished, thereby solving the above-mentioned problems.

Further, a pilot burner for ignition is arranged at one end side in the width direction of the metal strip so as to extinguish the burner in a region opposite to the pilot burner.

The present invention is also a heating device for a metal band using a belt-shaped flame burner that heats the metal band by means of a plurality of burners arranged in the width direction of the metal band. The above problem is solved by providing

Further, a pilot burner for ignition disposed on one end side in the width direction of the metal strip is further provided, and the burner in the region opposite to the pilot burner is extinguished.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION An example of an embodiment of the present invention will be described in detail below with reference to the drawings.

In the present embodiment, as shown in FIG. 1, a burner 22 for heating the steel strip 10 supported by the support rolls 12 from above and below during conveyance is provided with a longitudinal direction (conveyance direction) of the steel strip 10. ) Are arranged in multiple rows (upper and lower six rows in the figure), and the number of ignition rows in the longitudinal direction of the steel strip of the burner 22 is changed according to the transport speed of the steel strip 10, as shown in FIG.
A steel strip heating device that equalizes the amount of temperature rise per unit length in the longitudinal direction of the steel strip is shown in FIG. 4 (transverse sectional view including the piping system diagram) and FIG. 5 (also horizontal sectional view of the upper part). As described above, a large number of upper and lower burners 22 at each position in the longitudinal direction are arranged in the width direction of the steel strip 10 (five in the figure), and below the heating device 20 in which the burners 22 are arranged.
As shown in FIG. 4, a wheel 40 rotatably supported by the frame 38 is provided, and the wheel 40 causes the entire heating device 20 to move laterally on a rail 42 arranged in the width direction of the steel strip 10. I am trying to move.

In the figure, 44 is a fluid pressure (for example, hydraulic, hydraulic or pneumatic) cylinder for moving the heating device 20 in the width direction of the steel strip 10, and 50 (FIG. 5) is a combustion air supply pipe 32. A combustion air supply fan 52 for supplying air is provided with a fuel gas control valve 54 for collectively supplying fuel while controlling the flow rate of fuel at each position (row) in the longitudinal direction.
Is a fuel gas control valve for controlling the fuel flow rate for each burner, and 56 is a pilot burner for ignition, which is arranged in the heating device 20 at one end side (left end in the drawing) of the steel strip 10 in the width direction. Is.

The adjustment of the opening of each control valve 52, 54, the point extinction of each burner 22, the amount of movement of the fluid pressure cylinder 44, etc. are shown in FIG.
Controlled by the control device 60 shown inside, attribute data such as the width of the steel strip 10 is further transmitted to the control device 60 from a computer 62 above it.

As shown in FIG. 4, the lower burner is also provided with the control valves 52 and 54, the pipe 30 and the like, like the upper burner.

In order to heat the steel strip 10 from above and below, for example, the burner 22 has both upper and lower portions of the steel strip 10, for example, 6
The rows are arranged in the longitudinal direction of the steel strip 10 and fixed to the outer wall 28 of the heating device 20 with bolts. Each burner 22
Further, for example, five pipes are also installed in the width direction of the steel strip 10, and the fuel gas supply pipe 30 has control valves 54 and 52 after branching in the width direction of the steel strip 10 and in the collecting pipe portion, respectively. Is provided.

The burners 26 are installed vertically, for example, on the upper and lower surfaces of the steel strip 10, respectively, and eject a fuel gas and combustion air to produce a flame (in the present invention, a strip-shaped flame) across the width direction of the steel strip 10. The steel strip 10 is heated by the belt-shaped flame 24.

In order to keep the temperature of the steel strip 10 on the outlet side of the heating device 20 within a certain range when the transport speed of the steel strip 10 changes, for example, the control valve of the burner 22 is controlled according to the transport speed of the steel strip 10. The opening degree of 52 is adjusted, or the number of ignition rows in the longitudinal direction of the burner 22 is changed. In the latter case, for example, as shown in FIG. 2, the number of ignition rows of the burner 22 is increased when the conveyance speed is high, and the number of ignition rows of the burner 22 is decreased when the conveyance speed is low. However, of course, the present invention is not limited to this, and the opening degree of the control valve 52 may be controlled so as to be continuously adjusted as in the former case. Alternatively, a thermometer may be installed on the outlet side of the heating device 20 and feedback control may be performed to reduce the deviation from the target to zero.

FIG. 3 shows a case where the steel strip 10 having a narrow width with respect to the installation area of the burner 22 is heated. In the comparative example shown in FIG. 3, the flame that does not hit the steel strip 10 does not contribute to heating, resulting in wasted fuel consumption.
Further, in this case, there is a problem that the temperature of the exhaust gas rises and the capacity of the heat exchanger and the exhaust device for cooling the exhaust gas increases, which has been a problem as described above. Therefore, in the present invention, as shown in FIG. 6, in order to cover the region where the steel strip 10 exists in accordance with the width of the steel strip 10, the fluid pressure cylinder 44 is used to cover the entire heating device 20 with the width of the steel strip 10. Direction, and by changing the number of ignitions of the burner 22 according to the width of the steel strip 10, the fuel in the portion where the steel strip 10 does not exist is shut off, and wasteful consumption of fuel is prevented.

Here, the burner 22 has the number of ignition rows adjusted in the longitudinal direction of the steel strip in accordance with the transport speed of the steel strip 10. However, as shown in FIG. 7, the pilot burner 56 for ignition is used.
When the ignition is performed so as to come to the center of the width direction of the steel strip 10, the width center portion of the steel strip 10 is locally heated to a high temperature by the flame 58 from the pilot burner 56 that burns at the time of ignition. In particular, when the conveying speed is slow and the number of ignition rows of the burner 22 in the longitudinal direction of the steel strip is small, there arises a problem that the temperature difference with other portions becomes large. Therefore,
As shown in FIG. 4, the pilot burner 56 for igniting the burner 22 is installed in the heating device 20 at one end side in the width direction of the steel strip 10, and the fluid pressure cylinder 4 for moving the steel strip 10 in the width direction.
4, the heating device 20 is moved according to the width of the steel strip 10 to extinguish the burner on the opposite side in the width direction with respect to the ignition pilot burner 56 with the steel strip 10 interposed therebetween.
Is heated uniformly in the width direction.

The object of application of the present invention is not limited to the above-mentioned embodiment. For example, when the transport speed does not change so much, the control of the number of ignition rows of the burners in the longitudinal direction can be omitted.

Further, in the example described above, the entire heating device 20 is adapted to move in the width direction of the steel strip 10. However, the present invention is not limited to this, and the burner 22 is heated by the heating device 20. Only the group of burners 22 may be moved so as to be movable with respect to each other. Further, the means for moving the heating device 20 or the group of burners 22 in the width direction of the steel strip 10 is not limited to a combination of rails and wheels or a fluid pressure cylinder, and may be appropriately selected such as a rack and a pinion.
Further, the object to be heated is not limited to the steel strip and may be various metal strips.

[0023]

According to the present invention, the metal strip can be heated uniformly in the width direction without wasting fuel.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing the overall configuration of a metal band heating apparatus to which the present invention is applied.

FIG. 2 is a diagram showing an example of a relationship between a metal band transport speed and the number of ignition rows of a metal band longitudinal burner.

FIG. 3 is a transverse cross-sectional view of a heating device for explaining conventional problems.

FIG. 4 is a cross-sectional view including a piping system diagram showing an embodiment of the present invention.

[FIG. 5] Similarly, a horizontal sectional view of the upper portion.

FIG. 6 is a cross-sectional view showing a state where a narrow metal band is being heated in the embodiment of the present invention.

FIG. 7 is a cross-sectional view showing an example of a heating state in a comparative example having an ignition pilot burner in the center.

[Explanation of symbols]

10 ... Steel strip 20 ... Heating device 22 ... Burner 24 ... Flame 40 ... wheels 42 ... Rail 44 ... Fluid pressure cylinder for width direction movement 56 ... Pilot burner 60 ... Control device

Claims (4)

[Claims] 1. A method of heating a metal band by a strip flame burner for heating a metal band by a plurality of burners arranged in the width direction of the metal band, wherein the burner is provided in the width direction of the metal band in accordance with the width of the metal band. A method for heating a metal strip with a strip flame burner, which comprises extinguishing a burner in a region where the metal strip is not present, while moving the metal strip to. 2. The strip according to claim 1, wherein a pilot burner for ignition is arranged at one end side in the width direction of the metal strip to extinguish the burner in a region opposite to the pilot burner. How to heat a metal strip with a flame burner. 3. A heating device for heating a metal strip by means of a belt-shaped flame burner for heating the metal strip by a plurality of burners arranged in the widthwise direction of the metal strip, comprising means for moving the burner in the widthwise direction of the metal strip. A device for heating a metal band by means of a band flame burner. 4. A pilot burner for ignition, which is disposed on one end side in the width direction of the metal strip, for further extinguishing a burner in a region opposite to the pilot burner. A heating device using the band-shaped flame burner according to item 3.