JPH09125162A - Floater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve floatation so that blasting gas is difficult to escape in the width direction of a strip and to stably support the strip, in a floater for carrying the strip for metallic strip tube in afloat during continuous heat treatment furnace. SOLUTION: A horizontal flat plate part 10 faced to the lower surface of the strip 21 is formed on the upper surface of a plenum chamber, and one pair of slitting gas spouting holes 20 opened along the width direction of the strip 21 at the front and the rear ridges of the flat plate part 10 in the travelling direction of the strip, are opened so that the gas blasts to diagonally upper inside toward upper port of the flat plate part 10, respectively. The fixed width buffles 13 risen on the flat plate part 10 are parallel arranged in plural number on the flat plate part 10 in a prescribed interval (g).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a floater for supporting and transporting strips such as metal strips in a continuous heat treatment furnace in a floating state in a non-contact manner.

[0002]

2. Description of the Related Art In order to prevent the occurrence of scratches when a strip such as a metal strip conveyed in a continuous annealing furnace comes into contact with a roll in the furnace, a strip is provided from a plenum chamber provided in the furnace. It has been conventionally known as a method of transporting a strip that the gas is blown toward the lower surface of the strip to float and support the strip by the gas pressure to support the strip in a non-contact manner.

In order to prevent the strip from shifting in the width direction during traveling, for example, the floater disclosed in Japanese Patent Laid-Open No. 61-261440 faces the lower surface of the strip c as shown in FIG. A flat plate portion b is horizontally provided on the upper surface of the plenum chamber a.
And the strip c on the front and rear edges of the flat plate b in the strip running direction.
A pair of slit-shaped fumaroles d that open along the width direction of the
d is opened so that gas is blown obliquely inward from the fumaroles d, d so that a static pressure region is formed between the upper surface of the flat plate portion b and the lower surface of the strip c, and The opening widths of d and d are made wider at both end portions d'compared to the center of the strip c, and a large amount of gas is blown out from the both end portions d ', so that the widthwise displacement of the strip c is automatically corrected. It has a function to perform, that is, a self-centering function.

Further, as shown in FIG. 6, the floater disclosed in Japanese Patent Laid-Open No. 61-201738 has a large number of plenum chambers a provided on the upper and lower sides of the strip c on the surface facing the strip c. Of the nozzles e, e, e ... are tilted toward the center of the running line of the strip c so that the pressure of the blown gas gives the strip c directivity toward the center and has a centering function. It was something that was done.

By the way, in the device having the slit-shaped jet holes d whose opening widths are partially different as described above,
There is a problem in that a sufficient static pressure cannot be obtained because the width of the gas curtain formed by the fumes is not uniform.

Further, since the inclined nozzles e, e, e ... Are inclined uniformly toward the center, the directivity in the central direction is always uniformly exerted on the lower surface of the strip c. However, there is a problem in that the belt c moves on the left and right even if the belt c is on the center line to make the running unstable.

Further, in the conventional floater, it is generally necessary to blow out a large amount of gas from the nozzle in order to levitate the strip plate, so that a large blower must be provided, which causes a problem of high equipment cost. . That is, in the conventional floater, the gas blown toward the lower surface of the strip tends to immediately flow back in the width direction of the strip, so that the required levitation force cannot be obtained unless a large amount of gas is blown out. .

[0008]

Therefore, the present invention improves the buoyant force by making it difficult for the gas blown from the slit-shaped fumes toward the lower surface of the strip to flow in the width direction of the strip, and at the same time, stabilizes the buoyancy. Then, the strip plate can be supported.

[0009]

To this end, the floater of the present invention forms a horizontal flat plate portion on the upper surface of the plenum chamber facing the lower surface of the strip plate, and at the front and rear edges of the flat plate portion in the strip plate traveling direction. A pair of slit-like fumaroles that open along the width direction of the plate were opened so that the gas would blow obliquely upward inward toward the flat plate part, and a constant width that rises above the flat plate part. A plurality of baffles are arranged side by side on the flat plate portion at a predetermined interval. Further, the present invention is characterized in that the floater is aged and a gas outlet for blowing gas upward is opened in a line in the furnace length direction on the upper surface of the baffle. Furthermore, the present invention is characterized in that, in the floater, the line-shaped gas outlets are curved in the width direction of the strip.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an example of an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a longitudinal sectional view showing a continuous heat treatment furnace according to the present invention, FIG. 2 is an enlarged view of the floater, FIG. 3 is a sectional view taken along the line AA, and FIG. 4 is a perspective view of the floater. Show.

In this continuous heat treatment furnace, a pair of upright walls 2 and 2 extending in the width direction of the hearth 1 are integrally raised with the hearth 1 by refractories such as bricks, and the space between the upright walls 2 and 2 is raised. Is provided with a plenum chamber 3, and a floater 4 is supported on the upstanding walls 2 and 2. That is, a flange 6 that is stably placed on the upper end surfaces of the standing walls 2 and 2 is formed at the upper end of the plenum chamber 3 made of a heat-resistant alloy plate such as Inconel 600, and the plenum chamber 2 is placed between the standing walls 2 and 2. 3 is placed in a suspended state, a thin super heat resistant sheet 7 is interposed on the upper surface of the flange 6, and the floater 4 is mounted on the super heat resistant sheet 7. Reference numeral 5 is a fan for sucking hot air provided in the ceiling of the furnace, 9 is an in-furnace duct for feeding the hot air in the furnace sucked by the fan to the plenum chamber 3, and 8 is a radiant for heating provided in the furnace. It is a tube burner.

The floater 4 includes a horizontal flat plate portion 10 facing the lower surface of the strip plate 21, a pair of inclined side plates 11 provided at front and rear edges of the flat plate portion 10 in the strip plate traveling direction, the flat plate portion 10 and the slanted plate. A pair of slit-like fumaroles 20 that are formed of a pair of upright plates 12 for supporting the side plates 11 and open along the width direction of the strip 21 are formed at the front and rear edges of the flat plate portion 10 in the strip traveling direction. The gas in the chamber 3 is supplied to the flat plate portion 10 respectively.
It is opened so that it blows up diagonally upward. In addition,
The flat plate portion 10, the inclined side plate 11, and the upright plate 12 are based on nickel (Ni), and chromium (Cr), iron (F)
e), aluminum (Al) and titanium (Ti) are contained in a predetermined amount, and fine particles of refractory metal oxide are dispersed in the material. That is, Y ₂ O ₃ , C
_{e2 O 3, Z r O 2} , Al 2 O 3, G d2 O 3, selected from 1
Alternatively, it is composed of an oxide dispersion strengthened alloy containing 0.1 to 2% by weight of fine particles or fine powders of two or more kinds of refractory metal oxides in a dispersed state. This oxide dispersion strengthened alloy is, for example, 18 to 40 wt% chromium, 5 wt% or less iron, 5 wt% or less aluminum, 5 wt% or less titanium,
The balance is nickel, and the austenite matrix is a metal material containing 0.1 to 2% by weight of fine particles of a refractory metal oxide in a dispersed state. The oxide dispersion-strengthened alloy contains 5% by weight or less of cobalt (C
_o ) may be included.

Since the flat plate portion 10, the inclined side plate 11 and the upright plate 12 thus formed contain fine particles of a refractory metal oxide dispersed in a nickel-based alloy matrix, that is, an austenite matrix, they have a high melting point stable at high temperatures. Fine particles of metal oxides can generate Y ₂ O ₃ even in a high temperature environment.
Decomposes into 2Y and 3O, and the 3O does not react with the matrix to form TiO ₂ or Al ₂ O ₃ and maintains mechanical strength from room temperature to high temperature, for example, even at a high temperature of 1200 ° C. or higher. Can maintain strength.

On the flat plate portion 10, a plurality of baffles 13 each having a constant width and protruding in a semi-cylindrical shape are arranged side by side at a predetermined interval g. Reference numeral 14 is a stop pin for fixing the baffle 13 to the flat plate portion 10. A line-shaped gas outlet 15 curved in the furnace width direction is provided on the upper surface of each baffle 13 so that the gas in the plenum chamber 3 is also blown toward the lower surface of the strip 21 from the gas outlet 15. Is configured. Each of the baffles 13 is formed of a heat resistant alloy such as Inconel 600. Reference numeral 16 is an inclined plate-shaped guard plate provided on both side edges of the flat plate portion 10.

For this reason, the gas blown out from the slit-shaped fumarole 20 becomes difficult to move in the width direction of the strip due to the baffle 13 obstructing the gas, and the staying time of the gas at the interval g between the baffles 13 is long. Therefore, the static pressure of the gap g can be increased and the levitation force is increased.

Further, the gas blown out from the gas outlet 15 directly acts to levitate the strip 21 and also acts as a gas curtain, making it more difficult to move the gas at the interval g in the width direction. It is more effective to increase. As shown in FIG. 4, the gas outlet 15 is formed in a shape curved in the width direction of the strip plate 21.
When the strips 21 having different widths are conveyed, the gas blown out from the gas outlets 15 can be evenly applied to both side edges of the strip 21 to stabilize the traveling. Further, the shape of the gas outlet 15 is not limited to that shown in FIG. 4, and may be, for example, a V-shaped (V-shaped) curved shape, and the curved direction is curved outward as shown in FIG. It may be curved or curved inward.

[0017]

As described above, in the floater of the present invention, the plurality of baffles are arranged side by side on the flat plate portion at a predetermined interval, so that the gas blown out from the slit-shaped fumes can be moved in the width direction of the strip plate. Since the gas retention time is limited and the gas retention time on the flat plate portion can be lengthened, the static pressure is increased, the floating force of the strip plate is increased, and the traveling is stabilized.

[Brief description of the drawings]

FIG. 1 is a vertical cross-sectional view of a continuous heat treatment furnace showing an embodiment of a floater according to the present invention.

FIG. 2 is an enlarged view of a main part of FIG.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is a perspective view of a floater according to the present invention.

FIG. 5 is a perspective view of a conventional floater.

FIG. 6 is a vertical sectional view of a conventional floater.

[Explanation of symbols]

 3 Plenum chamber 4 Floater 10 Flat plate part 11 Inclined side plate 12 Standing plate 13 Baffle 15 Gas blowout port 20 Fume nozzle 21 Strip plate g Interval

Claims (3)

[Claims] 1. A pair of slits formed on the upper surface of the plenum chamber so as to face the lower surface of the strip plate, and at the front and rear edges of the flat plate portion in the traveling direction of the strip plate along the width direction of the strip plate. -Like fumaroles were opened so that the gas was blown obliquely upward and inward toward the flat plate portion, and baffles of constant width that bulge on the flat plate portion are arranged at a predetermined interval on the flat plate portion. A floater characterized by being arranged in parallel. 2. The floater according to claim 1, wherein a gas outlet for blowing gas upward is provided on the upper surface of the baffle in a line in the furnace length direction. 3. The floater according to claim 2, wherein the line-shaped gas outlet is curved in the width direction of the strip plate.