JPS6321561Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] Gas seal to prevent leakage and movement of gas in the furnace, or intrusion of outside air, etc. in industrial furnaces that continuously heat-treat strip materials such as metal strips. Device.

[Prior Art] Conventionally, a gas sealing device installed at the entrance and exit of a strip in a continuous furnace for heat-treating the strip in an atmospheric gas has been provided with seal rolls at the top and bottom of the strip, and the upper and lower surfaces of the strip are sealed by these rolls. Japanese Patent Publication No. 42-3282 and Japanese Utility Model Publication No. 48/1987 disclose a type in which the belt-shaped material is sandwiched between the two sides, or a gas curtain is formed by placing gas jet nozzles facing each other on both sides of the belt-shaped material.
-Described in Publication No. 100802.

[Problems to be solved by the invention] In the type of sealing rolls that sandwich the strip material,
In addition to the disadvantage of causing contact flaws on both sides of the strip, there is also the disadvantage of poor sealing performance, especially when the width of the strip is narrow, as gaps are created between the seal rolls on both sides of the strip. Further, in the case where the gas ejection nozzles are opposed to each other on both sides of the strip material, there is a problem in that a large amount of expensive inert gas or reducing gas is consumed.

The present invention has been devised to solve these problems and to provide an effective gas seal using as little atmospheric gas as possible.

[Means for Solving the Problems] Rolls are provided that abut and support the belt-like material conveyed substantially horizontally from the lower surface, and rolls facing the upper surface of the belt-like material and extending inwardly toward each other in the width direction of the belt-like material are provided. A pair of slit-shaped gas ejection nozzles are provided at an angle.

[Function] The strip material is stably supported by rolls, and sealing gas is ejected from a pair of slit-shaped gas jet nozzles on the upper surface of the strip material at an angle inward to each other. A static pressure area is formed on the upper surface of the

[Example] In FIGS. 1 and 2, 1 is a furnace body, 2 is a strip-shaped material that is transported horizontally in the furnace, and 3 is a strip-shaped material 2.
4 is a throat formed outside the opening of the furnace body 1 through which the material enters and exits, 5 is the opening of the throat, and within the throat 4 are two rolls that abut and support the strip material 2 from below. 6a and 6b are provided. Reference numeral 7 denotes a roll covering stand which covers the outer circumferences of the rolls 6a and 6b with only a small gap so that there is no ventilation under the rolls 6a and 6b. Reference numeral 8 denotes a chamber provided in the upper part of the inside of the throat 4, and the chamber 8 is provided with a pair of slit-shaped gas ejection nozzles 9a and 9b that are opposed to the upper surface of the strip material 2 and are long in the width direction of the strip material 2. . The gas ejection nozzles 9a, 9b are inclined inwardly from each other as shown in FIG. A sealing atmosphere gas is fed under pressure into the chamber 8 from an air supply source (not shown), and the gas is blown out obliquely toward the upper surface of the strip material 2 from gas jetting nozzles 9a, 9b. Therefore, a region (static pressure region) in which the static pressure of the atmospheric gas is higher than the surrounding area is formed on the upper surface of the strip material 2 between the nozzles 9a and 9b, and therefore exhibits extremely high sealing performance. In that case, the sealing performance can be maintained without being affected by the width of the strip material 2. That is, on both sides of the strip material 2, the atmospheric gas blown from the nozzles 9a and 9b hits the upper surfaces of the rolls 6a and 6b or the roll cover 7, forming a similar static pressure area therebetween, so that the width of the strip material 2 is reduced. Sealing performance is maintained regardless. In addition, as shown in this embodiment, rolls 6a and 6b are placed on the extension line of the gas jet nozzles 9a and 9b.
By arranging the nozzles 9a,
The blowing pressure of gas from 9b is adjusted to the rolls 6a, 6b.
If the load is placed on the gas, it is possible to prevent the strip material 2 from bending due to the gas blowing pressure, so it is desirable to arrange it in this way, especially in the case of a thin strip material.

In this case, the roll 6 is placed on the bottom surface of the strip material 2.
A and 6b cause contact flaws, but the upper surface is not in contact and no flaws occur. For this reason, this device is suitable for strip materials that are painted or plated on only one side, and strip materials that are finished on only one side and do not worry about small scratches on the other side (actually, there are many such materials). Can adapt.

[Effects of the invention] Gas is blown from the nozzle to seal only the top surface of the strip material, so gas consumption is significantly reduced and running costs can be reduced compared to sealing both surfaces using that method. Moreover, it has the advantage of being able to seal reliably regardless of the width of the strip material.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a gas seal device showing an embodiment of the present invention, and FIG. 2 is a sectional view taken along the line X--X in FIG. 1... Furnace body, 2... Strip material, 6a, 6b... Roll, 9a, 9b... Gas ejection nozzle.

Claims (1)

[Scope of utility model registration request] A roll that abuts and supports a strip material conveyed substantially horizontally from the lower surface; a pair of slit-shaped gas ejection nozzles that are opposed to the upper surface of the strip material and are long in the width direction of the strip material and inclined inwardly to each other; A gas sealing device for the furnace body, which is characterized by: