JPH0441164Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention is a continuous heat treatment furnace for heat-treating a strip-shaped material to be treated. , relates to an atmosphere sealing device that prevents outside air from entering from outside the furnace.

[Conventional technology]

A gas sealing device in a continuous heat treatment furnace for metal strips is disclosed in Japanese Patent Application Laid-Open No. 1983-1989, characterized in that a gas curtain is formed at the inlet or outlet of the strip by circulating the furnace atmosphere.
This is known from Publication No. 150610, etc. moreover,
A throat is provided outside the opening of the furnace body at the inlet and outlet of the material to be treated, a jet nozzle is provided within the throat so as to face the material to be heated, and inlets are provided at both sides of the jet nozzle in the furnace length direction. A gas seal device is disclosed in Japanese Patent Application Laid-Open No. 1983-1991, which has a damper that can be opened and closed at the intake port near the heated material inlet/outlet of the throat, and circulates the gas sucked from the intake port to the jet nozzle by a circulation fan. According to Japanese Patent No. 238425, two rows of jet nozzles are formed at regular intervals,
A gas seal device in which an intake port is provided between the jet nozzles is known from Japanese Patent Laid-Open No. 60-238426.

In the conventional gas seal device described above, a gas sealing effect can be expected if the strip threading level is stable, but if the strip threading level fluctuates due to fluctuations in strip tension, etc. If there is a bend in the width direction called C warp, the gas curtain effect from the jet nozzles installed on both sides of the strip becomes unbalanced, resulting in a problem in that the sealing performance deteriorates.

For example, Fig. 4 shows an example of a conventional sealing device, in which the threading level of strip 2 changes and
Since the distance between the jet nozzle 10a and the position 20 of the strip 2 when the strip is in the position is larger than that of the strip 2 during stable sheet passing, the flow velocity of the sealing gas jetted from the jet nozzle 10a is is greatly attenuated by the time it hits the strip 2 at position 20, and the gas curtain effect is significantly reduced. In the worst case, the stop 2 will come into contact with the jet nozzle 10b, causing a scratch on the strip 2.

Even if such fluctuations in the threading level of the strip or C warping are temporary, the sealing performance deteriorates and, for example, H ₂ gas is added to the furnace atmosphere, such as in a bright annealing furnace. This is a very important safety issue when using

In order to solve this problem, in conventional gas sealing devices, it is possible to increase the pressure inside the furnace or to provide support rolls or sealing rolls before and after the sealing device in order to stably pass the strip. However, increasing the furnace pressure has the problem of increasing the consumption of the furnace atmosphere, and providing support rolls or seal rolls not only increases equipment costs, but also increases the equipment cost.
There is a problem in that it disturbs the tension control of the strip.

[The problem that the idea aims to solve]

The object of the present invention is to provide an atmosphere sealing device for a heat treatment furnace that can completely solve such problems.

[Means to solve the problem]

The gist of the present invention is that, in a device that seals the atmospheric gas in the heat treatment furnace at the inlet and outlet of the heat treatment furnace, inert gas is sprayed at a predetermined interval on both sides of the strip 2. , pressure pads 5a, 5b are arranged to stabilize the passing position of the strip 2, and a predetermined position of the pressure pads 5a, 5b is arranged between the pressure pads 5a, 5b and the strip 2. The present invention provides an atmospheric gas sealing device for a heat treatment furnace, characterized in that seal skirts 6a, 6b, 6c, and 6d are provided at positions.

[Effect]

The strip 2 passes through pressure pads 5a and 5b provided at the inlet seal of the heat treatment furnace.
At this time, the threading level of the strip 2 is stabilized by the static pressure generated by the pressure pads 5a and 5b, and C warping of the strip 2 is prevented. Further, a seal skirt attached to the pressure pad between the pressure pads 5a, 5b and the strip 2 allows the pressure pad 5 to be
The static pressure generated at a and 5b can be maintained,
The strip 2 can be transported more stably. In addition to forming a strong gas curtain by themselves, the pressure pads 5a, 5b enhance the gas curtain effect by the seal skirts 6a, 6b, 6c, 6d.

〔Example〕

An embodiment of the present invention is shown in FIGS. 1 and 2. 1 is a furnace body, 2 is a strip, and 3 is an inlet for in-furnace circulating gas, and the in-furnace circulating gas is injected into the furnace from a seal box 4. 5a and 5b are pressure pads, each having a seal skirt 6.
a, 6b, 6c, and 6d are integrally attached. The atmosphere gas in the furnace is sucked in by the circulation fan 8, is pressurized, and is sent to the pressure pad 5.
a, 5b. pressure pad 5
The seal gas ejected from a, 5b forms a static pressure area, and further seals skirts 6a, 6b, 6
c, 6d.

FIG. 2 shows a case where the strip passing position is shifted toward the pressure pad 5a. The seal skirts 6a, 6b, 6c, and 6d deform and follow the strip while maintaining the static pressure region of the pressure pad, so that the sealing effect does not deteriorate.

FIG. 3 shows a cross section taken along the line XX in FIG. 1. Seal skirt 6 even if strip 2 has C warp.
Since a, 6b, 6c, and 6d deform along the strip shape, a stable sealing effect can be expected.

[Effect of idea]

According to the present invention, it is possible to prevent deterioration in sealing performance due to fluctuations in the level or position of the strip and warping of the strip C, which were problems in conventional gas seal devices.

Furthermore, in the present invention, the seal skirt retains the static pressure generated in the pressure pad.
This helps the static pressure holding force of the pressure pad, making it possible to further stabilize the strip threading level and position, resulting in stable sealing performance due to the strong gas curtain in this static pressure area. It becomes possible to obtain.

In addition, in the present invention, the seal skirt itself can be deformed freely, so it deforms according to the static pressure of the pressure pad and the distance between the pressure pad and the strip, and the seal skirt deforms depending on the static pressure of the pressure pad and the distance between the pressure pad and the strip. The sealing effect can be improved by minimizing the gap between. Further, even if the strip passing position changes, the seal skirt follows the strip due to the static pressure of the pressure pad, and a stable sealing effect can be obtained without deterioration of sealing performance. For example, even if the strip comes into contact with the seal skirt, the seal skirt itself deforms freely, so the strip does not suffer from scratches, providing excellent practical effects.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of one embodiment of the gas seal device of the present invention, FIG. 2 is a detailed explanatory view of the pressure pad and seal skirt, and FIG. 3 is the X--
The X sectional view and FIG. 4 are explanatory diagrams of a conventional gas seal device. 1...Furnace body, 2...Strip, 3...Furnace circulating gas inlet, 4...Seal box, 5a, 5
b...pressure pad, 6a, 6b, 6c,
6d...Seal skirt, 7...Seal hood,
8...Circulation fan, 10a, 10b...Ejection nozzle, 11...Circulation fan.

Claims (1)

[Scope of utility model registration request] In a sealing device that seals the atmospheric gas in the heat treatment furnace at the inlet and outlet of the heat treatment furnace, inert gas is sprayed on both sides of the strip 2 at a predetermined interval to stabilize the passing position of the strip 2. The pressure pads 5a, 5b are arranged, and seal skirts 6a, 6b, 6c, 6d is provided.