JPS6160831A - Operating method of horizontal type continuous heat treating furnace - Google Patents

Abstract

PURPOSE:To save energy to be used, by placing a simplified non-cooling carrying roll between furnace cooling carrying rolls at the time of initial passing of a steel band, removing this roll after the passing and executing an operation. CONSTITUTION:Heat treatment is executed by using a horizontal type heat treating furnace 5 of a continuous molten zinc plating equipment provided continuously and successively with a non-oxidizing furnace 1, a reducing furnace 2, a slow cooling furnace 3, and a rapid cooling furnace 4, and transferring a steel band 7 by a carrying roll 6. In this case, between the cooling carrying rolls 6 in the furnace, a simplified non-cooling carrying roll 9 is placed at the time of passing of the steel band 7, and it is removed after the passing. As for an attaching and detaching mechanism of the simplified non-cooling carrying roll 9, an inserting port 10 is opened in a furnace side wall 8, and the simplified non-cooling carrying roll 9 provided with a roll rotating handle 11 in one end is inserted from the inserting port 10, supported by a roller type bearing 12 and placed in the surface. When a steel band leading bar has passed through, the roll 9 is removed, and the inserting port 10 is closed up with a cover 13.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method of operating a horizontal continuous heat treatment furnace.

(Prior art) As a horizontal continuous heat treatment furnace, for example, a conveyor roll (
The spacing between hearth rolls is 1.5 to 2.5 m),
In addition, in order to prevent plating metal from accumulating on the roll and baking (metal pickup), the surface temperature of the roll is cooled to approximately 300°C or less by internal cooling.
Publication No. 043).

The spacing between these conveyor rolls is important when installing a new furnace, repairing a furnace,
In order to prevent the steel strip from breaking, etc., the copper strip leading pars (needle pars) are arranged at the intervals shown above to prevent them from falling into the roll spacing during the so-called initial threading of the steel strip. After the copper strip has been passed through, it is possible to carry out the heat treatment while transporting the copper strip even if the distance is not as short as this, but at present, the operation is being carried out as is.

However, the number of such conveyor rolls varies depending on the capacity of the furnace, etc., but for example, approximately 50 conveyance rolls are arranged in a heat treatment furnace that has a non-oxidation furnace, a reduction furnace, a slow cooling furnace, and a quenching furnace installed in series. The temperature inside the furnace is about 75℃ at the high temperature section.
At 0°C, at about 500°C in the low-temperature section a), it is not necessary to supply energy that also takes into account the cooling effect of the above-mentioned approximately 50 conveyor rolls below 300°C, which has disadvantages such as large energy loss. It is something.

(Problems to be Solved by the Invention) The present invention advantageously solves these drawbacks and aims to save energy.

(Means for Solving the Problems) The gist of the present invention is to provide a simple non-cooled conveyance between the internal cooling conveyance rolls during the initial passing of the steel strip in the operation of a horizontal heat treatment furnace equipped with cooling conveyance rolls. A method of operating a horizontal continuous heat treatment furnace includes arranging rolls and operating the simple non-cooled conveyor roll after passing through the furnace.

That is, in the present invention, a simple non-cooled roll is arranged between the cooling conveyance rolls, and the interval between the conveyance rolls is shortened to prevent the copper strip leading par from falling into the roll interval part during sheet threading. After that, the operation is carried out with this removed.The interval between the cooling conveyance rolls after removal may be set to a maximum interval of about 10 m as long as it is possible to transfer and hold the copper strip. Can be done.

Next, as the simple non-cooled conveyance roll, it is preferable to have, for example, approximately the same diameter as the above-mentioned cooled conveyance roll, and to be made of stainless steel or the like.

Next, examples of the method of the present invention will be described along with comparative examples, as shown in Fig. 1, which is a horizontal type of continuous hot-layer galvanizing equipment comprising a non-oxidizing furnace 1, a reducing furnace 2, a slow cooling furnace 3, and a rapid cooling furnace 4 successively installed. Using the heat treatment furnace 51c, the steel strip 7 was transferred by the conveyor roll 6 and heat treated as follows.

As shown in FIG. 2, the attachment/detachment mechanism for the simple uncooled conveyance roll is as follows: an insertion opening 10 is opened in the furnace side wall 8, and a simple uncooled conveyance roll 9 with a roll rotation handle 11 attached to one end is inserted into the insertion opening 10. Insert it, hold it with roller bearings 12, and place it in the furnace.

After the copper strip leading par passes through, the roll 9 is removed, the insertion port 10 is closed with a lid 13 as shown in FIG. The heat treatment operation will begin after the removal of the heat treatment is completed.

The present invention will be explained based on the following examples.

After threading, in the present invention, the thermal cooling roll was removed after threading, and heat treatment was performed with cooling rolls spaced at 4 m intervals, and the following results were obtained.

Fuel consumption Heating capacity Invention 22kcat/l 30t/h
r Comparative example 24X10' k at/l
25 t/hr As described above, according to the present invention, extremely significant energy savings have been achieved.

(Effects of the Invention) According to the present invention, a large energy saving effect can be achieved, and the roll unit consumption can be lowered to lower operating costs. Further, effects such as simplifying maintenance and inspection of the heat treatment furnace can be achieved.

[Brief explanation of drawings]

Figure 1 is a schematic explanatory diagram showing an example of horizontal continuous heat treatment, Figure 2
The figure is an explanatory diagram showing a roll attachment/detachment mechanism, and FIG. 3 is an explanatory diagram of a roll insertion opening closing mechanism. 5: Horizontal heat treatment furnace, 6: Hearth roll, 9: i-cooled transport roll.

Claims (1)

[Claims] In the operation of a horizontal continuous heat treatment furnace equipped with cooling conveyance rolls, a simple non-cooling conveyance roll is placed between the internal cooling conveyance rolls during the initial threading of the steel strip, and after passing, the simple non-cooling conveyance roll is removed. 1. A method of operating a horizontal continuous heat treatment furnace, characterized in that the furnace is operated as follows.