JPH0362619B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a strip flotation device.

The floating system that floats the strip and conveys it horizontally is composed of a floater 02 having a slit nozzle 01, a gas circulation fan 03, and a heat exchanger 04 provided as necessary, as shown in FIG. The strip 06 is floated by generating static pressure in the pressure pad 05 on the floater 02 by the gas blown out from the slit nozzle 01 at high speed.

By the way, since the floater 02 was conventionally composed of a single box, for example, as shown in FIG.
When floating the deformed strip 06' which has a convex shape as shown in b and c, the slit nozzle 06'
1 and strip 06' is large in the center,
Since it is smaller at both ends, the outflow resistance of the gas ejected from the slit nozzle 01 is smaller at the center and larger at both ends, making it difficult for the gas to drift toward the center of the strip 06' and to generate a force pushing up both ends thereof. For this reason, with this single box type floater 02, it is difficult to thread a wide strip with a warp. In addition, FIG. 2a is a front view of the floater during threading, and FIG. 2b is a plan view of the same floater.
c is a side view of the same floater.

Therefore, it has been proposed that the floater 02 is of a multi-box type and a plurality of boxes are arranged in parallel in the width direction of the strip 06' as shown in FIGS. 3a, b, and c. Note that FIGS. 3a, 3b, and 3c are a front view, a top view, and a side view of a multi-box type floater.

Incidentally, in the floater 02, a pressure pad 05 having a rectangular planar shape is provided on the upper surface of each box, and a slit nozzle 01 is provided along the four sides of each pad 05. The pressure inside each box is appropriately controlled, so that the deformed strip 0 convex upwards as shown in the figure.
Even when the strip 6' is passed over the floater 02, the gas does not drift toward the center of the strip 06' as described above, and the required static pressure is generated at both ends. As a result, the strip 06' is smoothly passed through without its both ends coming into contact with the floater 02.

However, in the multi-box type floater 02, as shown in the figure, the slit nozzle 0
1 are arranged parallel to the traveling direction of the strip 06' (the direction of the arrow in Fig. 3b), so when heating or cooling the strip 06' by convection heat transfer, Fig. 5b As shown in the figure, only the portion of the strip 06' facing the slit nozzle 01 is overheated, causing a problem that the temperature in the width direction of the strip 06' becomes non-uniform. Furthermore, the fifth
In the graph shown in the upper part of Figure b, the horizontal axis represents the distance in the strip width direction, and the vertical axis represents the heat flux, and l' in the figure represents the strip passing area.

The present invention has been made to solve the above problems, and its object is to provide a strip flotation device that can equalize the temperature distribution in the width direction of the strip.

In order to achieve the above object, the present invention includes a pressure pad having a planar triangular shape, and a plurality of floater units each having a slit nozzle provided around the pressure pad are arranged in parallel in the width direction of the strip.

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 4b is a plan view of a strip flotation device according to the present invention, FIG. 4a is a sectional view taken along line A-A in FIG. 4b,
FIG. 4c is a diagram showing the static pressure area on the floater unit.

The flotation device 1 according to the present invention is constructed by arranging a plurality of floater units 2 in parallel in the width direction of the strip 6 to be levitated by the flotation device 1. A pressure pad 3 having a planar triangular shape is provided on the upper surface of each floater unit 2, as shown in FIG. 4a, and a slit nozzle 4 is formed around the pressure pad 3. Further, the inside of each floater unit 2 is connected to a separate gas supply system, and the pressure of each floater unit 2 is independently controlled. In the illustrated example, the shape of the pressure pad 3 is an isosceles triangle, but it may have any other triangular shape.

The gas is supplied from each gas supply system into each floater unit 2 through separate piping, and is ejected obliquely toward the pressure pad 3 through the slit nozzle 4, as shown in FIG. 4c. A static pressure area S is formed at the center of the pressure pad 3, which causes the strip 6 to float as shown. Note that the pressure inside each floater unit 2 is controlled independently, so even if the strip is convex upward or downward,
Unbalanced flow of the ejected gas is avoided, and contact of the body or both ends of the strip with the flotation device is prevented.

By the way, since the pressure pad 3 is formed into a planar triangular shape and the slit nozzles 4 are formed around it, when the strip 6 is heated with gas ejected from each slit nozzle 4, for example, the gas hits the strip 6 uniformly in the width direction. As shown in the upper graph of FIG. 5a, the temperature distribution in the width direction of the strip 6 becomes uniform. In the upper graph of FIG. 5A, the horizontal axis represents the distance in the strip width direction, and the vertical axis represents the heat flux, and in the graph, l represents the strip passing area.

As is clear from the above description, according to the present invention, a plurality of float units each including a pressure pad having a planar triangular shape and a slit nozzle provided around the pressure pad are arranged side by side in the width direction of the strip to construct the device of the present invention. Because of that,
The temperature distribution in the width direction of the strip can be made uniform.

[Brief explanation of drawings]

Figure 1 is a perspective view of a conventional floating system; Figures 2a, b, and c are front views, top views, and side views of a single box type floater during sheet threading;
Figures a, b, and c are front views, plan views, and surface views of the multi-box type floater during threading, Figure 4b is a plan view of the strip flotation device according to the present invention, and Figure 4a is the same figure. Fig. 4c is a diagram showing the static pressure area on the floater unit; Fig. 5a is a diagram showing the temperature distribution in the width direction of the strip during threading with the device of the present invention; FIG. 3B is a diagram showing the temperature distribution in the width direction of the strip passed over the multi-box type floater shown in FIG. 3. In the drawings, 1 is a strip flotation device, 2 is a floater unit, 3 is a pressure pad, 4 is a slit nozzle, and 6 is a strip.

Claims (1)

[Claims] 1 A device for floating a strip and conveying it horizontally, which includes a triangular pressure pad facing the strip, and a plurality of floater units arranged in a row in the width direction of the strip, each consisting of a slit nozzle provided around the pressure pad. What is claimed is: 1. A strip flotation device comprising: