JPH04314830A - Soaking apparatus for strip - Google Patents

Abstract

PURPOSE:To execute soaking treatment to a steel strip with a simple apparatus in good thermal efficiency by arranging radiant tubes containing electric heater, in parallel crosses so as to surround the steel strip in a soaking chamber in a continuous heat treatment apparatus for steel strip. CONSTITUTION:The steel strip 6 heated at the prescribed temp. in a heating chamber, comes into the soaking chamber 2, and is heated with the electric heaters contained in the radiant tubes 7, 8 arranged in parallel crosses under the prescribed interval in an inner wall part. As only the radiant tubes 7, 8 are penetrated from the outer part toward the inner part in the soaking chamber 2, heat radiation in the soaking chamber 2 is only a little quantity of the radiated heat from these penetrated parts and the soaking chamber itself, and can be restrained to the min. limit. Further, the radiant tubes 7, 8 are arranged in parallel crosses, the radiated heat from surroundings of the soaking chamber can be efficiently compensated with these radiant tubes 7, 8 and needless to say, this apparatus has good soaking effect to both surfaces of the steel strip 6, and further, over-cooling at both edge parts of the steel strip 6 can be prevented and the whole steel strip 6 can uniformly and efficiently be heated.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soaking chamber of a heat treatment furnace for heat treating steel strips.

0002

[Prior Art] Conventionally, in the soaking chamber of a heat treatment furnace, a radiant tube is A heating method is used. This method is
A radiant tube is arranged parallel to the width direction of the steel strip, and a burner is installed at one end of the radiant tube,
The burner is combusted, and the combustion heat of the burner makes the radiant tube red hot, dissipating the heat inside the furnace, supplementing the heat radiating from the furnace wall, maintaining the temperature of the soaking chamber, heating the steel strip, and This is a method of uniform heating.

Furthermore, as shown in Japanese Patent Application Laid-Open No. 60-56025, an electric heater is hung on the wall of a uniformly heated indoor furnace via a refractory hanger, and electricity is applied to the heater to make it red-hot. A method for compensating for more dissipated heat, maintaining the temperature in the soaking chamber, and soaking the steel strip is also disclosed.

0004

[Problems to be solved by the invention] First, in the case of the radiant tube method, the burner is installed on one side of the radiant tube, and an exhaust device is required on the other side to exhaust the combustion exhaust gas generated from the burner. Therefore, it could only be installed horizontally in the width direction. Therefore, only both sides of the strip can be heated. Furthermore, it has been impossible to arrange radiant tubes in a grid pattern surrounding the strip because the exhaust system becomes complicated.

[0005] Furthermore, equipment that uses electric heaters to equalize heat requires a heater hanger to hang the heater.
In addition, this heater hanger requires insulation and strength, so clay bricks are mainly used. This heater hanger has a disadvantage that its thermal conductivity and specific gravity are very high compared to the surrounding fireproof insulation material, resulting in large heat dissipation and a long start-up time at the start of operation.

[0006] In addition, more hardware is required to support the hanger bricks than the number of hanger bricks, and since these hardware are fixed by welding from the furnace shell, heat dissipation from the furnace shell through the hardware is limited. , becomes very large. The heat conduction area of this hardware to the furnace side occupies about 1/3 of the area of the furnace side wall. Therefore, the amount of welding increases, the equipment cost becomes very high, and the required capacity to compensate for the dissipated heat further increases. Also, to prevent the strip from coming into contact with the heater and furnace wall and damaging it due to the meandering of the strip,
A protector is required, and hardware to support the protector must also be installed on the furnace wall, which increases heat dissipation and further increases the required capacity.

[0007]

[Means for solving the problem] Radiant tubes 7 and 8 equipped with electric heaters are arranged in a parallel grid shape in a soaking chamber 2 at predetermined intervals so as to surround the strip. The strip 6 is passed through the soaking chamber 2
Soak to heat.

[0008]

[Operation] The strip heated to a predetermined temperature in the heating chamber is conveyed to the soaking chamber. Inside the soaking chamber, radiant tubes 7 and 8 equipped with electric heaters are arranged in a parallel grid pattern at predetermined intervals so as to surround the strip. The strip 6 is passed through this soaking chamber and heated to a predetermined temperature. At this time, the strip 6 heated to a predetermined temperature is transported while maintaining the heating temperature, with the heat radiated from the furnace body being supplemented by the radiant tubes 7 and 8 arranged in a grid pattern.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a side view of the entire heat treatment furnace showing one embodiment of the present invention, and FIG. 2 is a longitudinal sectional view of the side of a soaking chamber 2. FIG. 3 is a sectional view taken along line AA in FIG. In FIG. 1, a strip 6 heated to a predetermined temperature in a heating chamber 1 is subjected to a predetermined heat treatment while traveling up and down to a soaking chamber 2 and cooling chambers 3 and 4 via rolls.

In FIG. 3, the strip 6 heated to a predetermined temperature in the heating chamber 1 is conveyed to a soaking chamber. In the soaking chamber, radiant tubes 7 and 8 equipped with electric heaters are installed in a grid pattern on the inner wall of the soaking chamber furnace at a predetermined interval. The strip 6 passes through the soaking chamber 2 and is soaked for a predetermined temperature. At this time, in the soaking chamber 2, only the radiant pipes 7 and 8 penetrate from outside the furnace into the furnace, so the soaking chamber 2
The heat dissipated only from this penetration and the furnace body, which can be kept to a minimum. In addition, the radiation tubes 7 and 8
Since the radiant tubes 7 and 8 are arranged in a parallel grid pattern, the heat radiated from around the furnace body can be efficiently supplemented by the radiant tubes 7 and 8, which not only has a uniform heating effect on both sides of the strip 6 but also has a uniform heating effect on both sides of the strip. It also prevents overcooling of the parts.

The radiant tubes 7 and 8 were made by bending a steel plate to a predetermined outer diameter and welding the outer periphery of the same material to the radiant tubes 7 and 8. FIG. 4 shows another embodiment. If the radiant tubes 7 and 8 are inserted into the soaking chamber 2 from the furnace length direction as shown in FIG. 4, the present invention can be effectively applied even if the furnace length becomes long.

FIG. 5 is a detailed view of a radiation tube applied to the present invention, in which a heat transfer heater 10 is installed inside the pipe 9.
It is supported by 12. One end of the pipe 9 is made blind and sealed from the outside air, and the other end is connected to the flange 1.
Install 4 and wrestle with the furnace body. Further, insulation from the heater is achieved by installing an insulating flange 13.

[0013]

[Effects of the invention] By arranging the radiant tubes in a grid pattern in the soaking chamber furnace, the number of hardware attached to the furnace body such as protectors is reduced, and no hanger bricks are used, so heat dissipation is minimized. The thermal efficiency is improved, and the heat capacity during heating is reduced, so the equipment capacity can be greatly reduced, and the equipment effect is very large.

[Brief explanation of drawings]

FIG. 1 is an overall view of a heat treatment furnace, FIG. 2 is a side cross-sectional view of a soaking chamber of the present invention, FIG. 3 is a cross-sectional view taken along line AA in FIG. 2, and FIG. 4 is another embodiment of the present invention. FIG. 5 is a detailed diagram of an example of a radiation tube applied to the present invention.

[Explanation of symbols]

1: heating chamber, 2: soaking chamber, 3, 4: cooling chamber,
5: Roll, 6: Steel strip, 7, 8: Radiant tube,
9: Pipe, 10: Electric heater, 11: Insulator, 12: Insulator, 13: Insulating flange, 14
:Flange.

Claims (1)

[Claims] [Claim 1] A steel plate in which a strip 6 is passed through a heat treatment furnace consisting of a heating chamber, a soaking chamber, and a cooling chamber, and an electric heater is installed in the soaking chamber of the heat treatment furnace in which the strip 6 is heat-treated. A device for soaking a strip, characterized in that radiant tubes 7 and 8 made of aluminum are arranged at a predetermined interval in a parallel grid shape in two soaking chambers and two furnaces so as to surround the strip.