JP2002363655A - Continuously annealing furnace of strip - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stabilize annealing quality by preventing tension from being applied to a metal strip as much as possible when the metal strip is heated at a high temperature and preventing the generation of wrinkles, or the like. SOLUTION: A charging port 1 and a discharging port 4 are provided on an upper part of a furnace body, the metal strip 2 charged from the charging port is carried in a furnace in a U-shaped locus, and tapped to the discharging port, a heating zone 6 is provided in a descending area of the metal strip, an intermediate chamber 8 capable of performing soaking or the gradual cooling is formed in a bottom zone of the metal strip, and a cooling zone 11 is provided in an ascending area of the metal strip.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a strip annealing furnace in which a metal strip (a strip-shaped metal material) is continuously conveyed in a furnace and heat-treated.

[0002]

2. Description of the Related Art A floating type continuous annealing furnace for continuously annealing a metal strip in a non-contact state, or a heating zone, a slow cooling zone (or solitary zone), and a cooling zone during a process in which a metal strip is lifted directly above by a tension roller. An up-heat type continuous annealing furnace provided with a band, or a down-heat type continuous annealing furnace provided with a heating zone, a slow cooling zone (or solitary zone), and a cooling zone during the process of lowering the metal strip straight down. Conventionally known.

[0003]

However, these conventional continuous annealing furnaces have a disadvantage that wrinkles are liable to occur because the metal strip at a high temperature after heating is subjected to tension for line drive and tension due to the weight of the metal strip. There is.
In particular, the occurrence of wrinkles is a serious defect in a thin metal strip. In view of the above, the present invention is to prevent the tension from being applied as much as possible when the metal strip is at a high temperature after heating, thereby preventing defects such as wrinkles and stabilizing the quality of annealing.

[0004]

For this purpose, in the continuous strip annealing furnace according to the present invention, a charging port and an extraction port are respectively provided at the upper part of the furnace body, and a metal strip charged from the charging port is U-shaped in the furnace. The metal strip is conveyed and extracted at the extraction port, and a heating zone is provided in a descending area of the metal strip, and an intermediate chamber capable of soaking or gradual cooling is formed in a bottom area of the metal strip. A cooling zone is provided in the rising area of the metal strip. Further, the present invention is characterized in that, in the continuous strip annealing furnace, the length of time the metal strip stays in the intermediate chamber is adjusted by adjusting the turning height of the metal strip in the intermediate chamber. Further, the present invention is characterized in that in the continuous strip annealing furnace, the position of the intermediate chamber can be changed up and down. Further, the present invention provides the strip continuous annealing furnace,
The intermediate chamber is provided with a guide roller abutting on the metal strip.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of a strip annealing furnace according to the present invention will be described. FIG. 1 is a longitudinal sectional view schematically showing the strip annealing furnace. In the figure, reference numeral 1 denotes a charging port formed by providing a pair of seal rollers at the upper part of the furnace body, and 2 denotes a charging roller which is guided by a deflecting roller 3 and is vertically lowered from the charging port into the furnace. It is a metal strip. Reference numeral 4 denotes an extraction port formed by providing a pair of seal rollers at the upper part of the furnace body similarly to the charging port 1, and 5 denotes a turning roller provided at the upper part of the extraction port. The metal strip 2 thus conveyed is drawn in a U-shaped trajectory in the furnace and extracted from the extraction port 4.

Reference numeral 6 denotes a heating zone formed by providing a heat source such as a radiant tube burner 7 on both sides of the descending region of the metal strip 2. Reference numeral 8 denotes an intermediate chamber formed in the bottom area of the metal strip 2, 9 denotes a chamber for soaking or gradual cooling, which is provided in the intermediate chamber so as to face the upper surface of the metal strip 2 and blows out gas. Is a guide roller provided on the surface of the chamber facing the strip. Reference numeral 11 denotes a cooling zone provided with a pair of cooling chambers 12 so that a cooling gas is sprayed on both surfaces of the metal strip 2 in a rising area of the metal strip 2.

For this reason, in the case of low-temperature annealing, the metal strip 2 charged from the charging inlet 1 is heated to 600 to 650 ° C. by passing through the heating zone 6 as shown in FIG. At 8, the metal strip is kept at that temperature for a certain time, and then cooled in the cooling zone 11. Alternatively, in the case of general high-temperature annealing, the intermediate chamber 8 functions as a slow cooling chamber as illustrated in FIG.

Here, the time during which the metal strip 2 stays in the intermediate chamber 8 is determined by sufficiently bending the metal strip 2 in the intermediate chamber 8 as shown by a broken line in FIG. The height can be adjusted by lowering the folding height or increasing the height. Therefore, the setting can be easily changed in accordance with the processing purpose.

Further, the embodiment shown in FIG.
The stretchable bellows-shaped furnace walls 13 and 14 are provided between the intermediate chamber 8 and the heating zones 6 and the cooling zone 11 so that the height of the heating zones 6 and the cooling zone 11 can be adjusted relatively. This is an example of the provision. By allowing the position of the intermediate chamber 8 to be changed up and down in this manner, the soaking or cooling time can be changed over a wider range, and an optimum setting according to the application can be made.

[0010]

As described above, in the strip annealing furnace of the present invention, a charging port and an extraction port are respectively provided on the upper part of the furnace body, and a metal strip charged from the charging port is formed into a U-shaped trajectory in the furnace. While drawing and transporting so as to be extracted at the extraction port, a heating zone is provided in a descending area of the metal strip, and an intermediate chamber capable of soaking or gradual cooling is formed in a bottom area of the metal strip, Since the cooling zone is provided in the ascending region of the metal strip, the tension due to the line drive or its own weight applied to the metal strip can be made extremely small in the zone where the metal strip has the highest temperature, and wrinkles can be formed even with a thin metal strip. It has the beneficial effect of stabilizing the quality of the anneal without causing it to occur.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of a continuous strip annealing furnace according to the present invention.

FIG. 2 is a low-temperature annealing temperature curve of a metal strip.

FIG. 3 is a general high-temperature annealing temperature curve of a metal strip.

FIG. 4 is a longitudinal sectional view showing another embodiment of the continuous strip annealing furnace of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Loading inlet 2 Metal strip 4 Extraction port 6 Heating zone 8 Intermediate chamber 9 Chamber 10 Guide roller 11 Cooling zone

Claims (4)

[Claims] Claims: 1. A charging inlet and an extracting port are provided at the upper part of a furnace body, respectively.
The metal strip loaded from the loading port is conveyed in a furnace in a U-shaped trajectory to be extracted at the extraction port, and a heating zone is provided in a descending region of the metal strip,
A continuous strip annealing furnace characterized in that an intermediate chamber capable of soaking or gradual cooling is formed in a bottom region of the metal strip, and a cooling zone is provided in a rising region of the metal strip. 2. The continuous strip annealing furnace according to claim 1, wherein the stay time of the metal strip in the intermediate chamber is adjusted by adjusting the turning height of the metal strip in the intermediate chamber. 3. The continuous strip annealing furnace according to claim 1, wherein the position of the intermediate chamber can be changed up and down. 4. The continuous strip annealing furnace according to claim 1, wherein a guide roller abutting on the metal strip is provided in the intermediate chamber.