JPS6214123Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a sealing device for an atmospheric heating furnace.

Heat treatment furnaces for steel strips For example, in continuous annealing furnaces, heat treatment is performed in the furnace to prevent the steel strip from oxidizing.
The furnace is filled with a reducing atmosphere gas such as _H2 - _N2 gas, the inside of the furnace is maintained at positive pressure, and heat treatment is performed in a reducing atmosphere. In this case, as shown in FIG. 1, a sealing device is provided to prevent atmospheric gas from leaking from the inlet/outlet portions 1a, 1b of the steel strip S of the continuous annealing furnace 1. As shown in Fig. 2, the sealing device at the furnace outlet portion 1a has cylinders 2, 2 on both sides sandwiching the steel strip S.
Rotatable seal rolls 3, 3, which are driven back and forth by
3 and are provided with seal members 4, 4 which are in sliding contact with each other. Note that the sealing device of the furnace inlet portion 1b has the same structure as that of the outlet portion 1a. Then, the seal rolls 3, 3 are advanced by the cylinders 2, 2, and the seal rolls 3, 3 are brought into contact with the steel strip 3, thereby preventing leakage of atmospheric gas. In this case, the seal rolls 3, 3 are rotated at the same circumferential speed as the speed of the steel strip S due to friction with the steel strip S, so that surface flaws such as slip marks and scratches are not formed on the surface of the steel strip S. It's summery. However, if the seal rolls 3, 3 do not rotate smoothly due to friction in the bearings, etc., the steel strip S is only in line contact with the seal rolls 3, 3.
Since the force to rotate the seal rolls 3 and 3 is weak,
There was a problem in that the steel strip S remained stopped and surface flaws such as scratches were formed on the surface of the steel strip S. Therefore, in actual operation, a gap of several mm is provided between the steel strip S and the seal rolls 3, 3 to prevent surface flaws from occurring. However, on the other hand, the steel strip S and the seal rolls 3, 3
Since atmospheric gas leaks from the gap between the furnace and the furnace, the amount of atmospheric gas replenishment must be increased to maintain positive pressure inside the furnace, which increases the consumption of atmospheric gas and increases the basic unit of atmospheric gas. It was hot.

This invention was made in view of the above-mentioned circumstances, and its purpose is to provide a sealing device for an atmospheric heating furnace that can improve sealing performance and prevent the occurrence of surface flaws in steel strips. That is.

An embodiment of this invented device will be described below with reference to FIG. Here, the same parts in the drawing are denoted by the same reference numerals as those of the conventional one shown in FIG. 2, and detailed explanation thereof will be omitted. This is a sealing device for the furnace outlet part 1a, and the seal rolls 3, 3 are moved in the direction of movement of the steel strip S so that the seal rolls 3, 3 provided on both sides of the steel strip S are in surface contact with the steel strip S. They are placed a distance d apart from each other. Correspondingly, the mounting portion of the seal member 4 on one side is extended to come into sliding contact with the seal roll 3. Note that the seal rolls 3, 3 at the furnace inlet portion 1b are also arranged in a similar manner.

Then, the seal rolls 3, 3 are pushed out by the cylinders 2, 2, and the seal rolls 3, 3 move to the third position.
Make surface contact with the steel strip S as shown in the figure. As a result, the seal rolls 3, 3 receive a strong rotational force from the steel strip S, so even if there is friction in the bearings,
Since the seal rolls 3, 3 always rotate in synchronization with the steel strip S, it is possible to prevent surface flaws such as scratches from occurring on the surface of the steel strip S. In addition, since the seal rolls 3, 3 are in complete contact with the steel strip S, the leakage of atmospheric gas is extremely reduced.
The basic unit of atmospheric gas can be reduced.

Since the sealing device for the atmospheric heating furnace of this invention is as described above, the sealing roll rotates in surface contact with the steel strip, which improves the sealing performance and prevents the occurrence of surface flaws in the steel strip. can be prevented.

[Brief explanation of the drawing]

Figure 1 is a schematic illustration of an atmospheric heating furnace, Figure 2 is an illustration of a sealing device at the furnace outlet of a conventional atmosphere heating furnace, and Figure 3 is an illustration of a furnace outlet showing an embodiment of this invention. It is an explanatory view of a sealing device. 1... Atmospheric heating furnace, 1a... Furnace outlet section, 1
b...Furnace inlet, 3...Seal roll, S...Steel strip.

Claims (1)

[Scope of utility model registration request] In an atmospheric heating furnace equipped with a rotatable seal roll that is driven back and forth while sandwiching the steel strip at the entrance and exit portion of the steel strip, the seal roll is moved so that the steel strip advances so that the seal roll is in surface contact with the steel strip. A sealing device for an atmospheric heating furnace characterized by being provided spaced apart in the direction.