JPS5911648B2 - Flotation device for strip material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device that can stably levitate a moving metal strip material by ejecting gas, and more specifically, it relates to a device that can stably levitate a moving metal strip material by ejecting gas, and more specifically, it is capable of stably levitating even a thick strip material with a large specific gravity in a continuous heat treatment furnace. This is what I did.

As is well known, a floating heat treatment furnace has a plenum chamber facing the upper and lower surfaces of a continuously moving strip material, and uses gas ejected from the plenum chamber to levitate the strip material. Since it has the advantage of no contact and no scratches, it has been widely used in the case of non-ferrous metal strip materials that are soft and easily scratched.

FIG. 1 is a longitudinal cross-sectional view showing an example of a floating heat treatment furnace 15 for continuously annealing strip-shaped materials such as aluminum and copper. In the figure, 1 is the strip-shaped material, 2 is a heating chamber, and 3 is inside the heating chamber. a lower plenum chamber, 4 facing the lower surface of the strip of material 1;
is an upper plenum chamber facing the upper surface; 5 and 6 are heating nozzles that eject hot air; 7 is a cooling chamber; 8 is a lower plenum chamber facing the lower surface of the strip material 1 in the cooling chamber;
9 is the upper plenum chamber which also faces the upper surface;
10 and 11 are cooling nozzles that eject cold air, and 12 and 13 are an inlet conveyance roll and an outlet conveyance roll, respectively. As shown in FIG. 2, which is a cross section of line 25 taken along line A-A in FIG. Valve IT, 18
An appropriate amount of gas is branched and pumped to the lower plenum chamber 3 and the upper plenum chamber 4 via the plenum chamber 30. The lower plenum chamber 8 and upper plenum chamber 9 of the cooling chamber 7 have the same configuration as shown in FIG.
A cooler will be installed in place of 5 and 16. Third
The diagram shows lower plenum chamber 3 and upper plenum chamber 4.
is an enlarged longitudinal cross-sectional view of 35, with distances 31 and 41 from the strip material 1.
Flat plates 32 and 42 are arranged parallel to each other and face each other, and slit nozzles 33 and 43 are formed around the flat plates 32 and 42 so that the gas in the plenum chambers 3 and 4 is inwardly inclined and ejected. There is. A conventional flotation device is generally constructed as described above, and a static pressure of a is generated in the space 31 surrounded by the gas ejected from the slit nozzle 33; A static pressure b is generated in the interval 41, and the difference (a-b) between the two acts as a force to levitate the strip-shaped material 1, as shown in the diagram in the half F of FIG. However, its levitation force was small, and it could be put to practical use in thin light metal strips; however, in the case of copper, for example, under a heat treatment temperature of 800°C, the limit of levitation is a thickness of 1.5 nm or less, and the lower part Even if the speed of gas ejection from the plenum chamber is increased, the fluttering becomes large, and it has been impossible with conventional flotation devices to stably levitate a thicker strip of material.

The present invention aims to solve the above-mentioned drawbacks, and is designed to enable stable floating of even thick strip-shaped materials. Next, referring to FIG. 4, one embodiment of the present invention will be described.
In the lower plenum chamber of No. 0, parallel flat plates 103 are arranged opposite to each other at a constant interval 102 from the lower surface of a strip material 101, and a first stage slit nozzle 104 with an inwardly slanted jet nozzle is provided around the flat plate. Further, a second stage slit nozzle 105 with an inwardly inclined jet nozzle is provided on the outer periphery of the slit nozzle 104, and a third stage slit nozzle 106 with a jet nozzle similarly inclined inwardly is provided on the outer periphery of the slit nozzle 105, The gas pumped into the lower plenum chamber 100 passes through these slit nozzles 1.
04, 105, and 106, all of them are made to eject inwardly.

In this way, a static pressure area is formed in the interval 102 between the strip material 101 and the flat plate 103 surrounded by the three stages of gas curtains ejected from these slit nozzles 104, 105, and 106. 107 is an upper plenum chamber similar to the conventional one, and a slit nozzle 109 is provided around a flat plate 108 to eject gas in an inwardly inclined manner.
A static pressure area is created in the interval 110.

Therefore, if the static pressure applied to the strip material 101 is explained using the diagram shown in the lower half of FIG. A static pressure (c+
d) occurs, and a static pressure (c+d+e) also occurs in the area 1, surrounded by the slit nozzle 106. Furthermore, a static pressure f acts on the upper surface of the strip material 101 at the slit nozzle 109 of the upper plenum chamber 107 . Therefore, in area 1, (e+d+e-f) acts as a force to levitate the strip material 101, in area 12 of its outer periphery, (c+d-f), and further in area 11 of its outer periphery, (c-f ) acts as a buoyant force. In this way, the flotation device of the present invention has a static pressure region surrounded by several stages of ejected gas curtains, so the flotation force can be greatly increased, and as shown in the example, gas is ejected from three stages of slit nozzles. By doing so, it was possible to levitate copper strips up to 2.811 times thicker than conventional materials. Moreover, it has the characteristic of being able to levitate very stably, and this is because, as shown in the diagram in the F half of Figure 4, the static pressure due to the lower plenum chamber 100 is large in the central area 1, and is small in the surrounding area 11. This is thought to be due to the fact that it has a chevron-like shape. FIG. 5 shows the slit nozzles 104, 105 in each stage inside the lower plenum chamber 100.
, 106 into partitioned chambers 111, 112, 113, and gas is force-fed from a circulation fan (not shown) to each partitioned chamber 111, 112, 113 through separate air supply pipes. According to this configuration, the speed of the gas ejected from each slit nozzle 104, 105, 106 can be freely adjusted, and the gas ejection speed of each slit nozzle can be independently adjusted and set so that the strip material 101 is as stable as possible. In addition, even if, for example, the band-shaped material 101 fluctuates and the gas jetting of a part of each slit nozzle deteriorates, stable support of the band-shaped material 101 can be obtained without losing the balance of the overall gas jetting. be. In the above embodiments, several stages of slit nozzles were provided for the lower plenum chamber, but it is easy to provide several stages of slit nozzles for the upper plenum chamber as well as for the lower plenum chamber.Also, in the above embodiments, the strip material is placed in the furnace. Although the description has been made for a horizontal furnace that moves horizontally, the flotation device of the present invention can also be applied to a vertical furnace for stably guiding the strip material.
Furthermore, when the present invention is applied as a sealing device for preventing the outflow of the furnace atmosphere gas at the furnace entrance/exit part, it has the advantage of having a high sealing effect because the static pressure can be high and the sealing effect is high, and the range of applications is extremely wide.

As described above, the flotation device of the present invention can stably levitate even thick strip-shaped materials, so it can greatly contribute to improving the performance of heat treatment furnaces, and is a truly useful invention with a wide range of applications.

[Brief Description of the Drawings] Fig. 1 is a longitudinal sectional view showing an example of a conventional floating heat treatment furnace, Fig. 2 is a sectional view taken along line A-A, and Fig. 3 is a sectional view of the flotation device shown in Fig. 1. It is a diagram showing the static pressure caused by this flotation device in an enlarged longitudinal cross-sectional view. FIG. 4 is an enlarged longitudinal cross-sectional view of an embodiment of a flotation device according to the present invention, and a diagram showing the static pressure caused by this flotation device, and FIG. 5 is a diagram showing an embodiment of the flotation device according to the present invention. It is an enlarged longitudinal cross-sectional view. 100... Lower plenum chamber, 101... Strip material, 102...
・Interval, 103... Flat plate, 104, 105, 1
06...Slit nozzle.

Claims (1)

[Scope of Claims] 1. Flat plates of the plenum chamber are arranged in parallel and facing each other with a distance from the moving band-shaped material, and the first stage is arranged so that the gas in the plenum chamber is ejected inwardly around the flat plates. a second stage slit nozzle is provided on the outer periphery of the slit nozzle, and at least a second stage slit nozzle is provided on the outer periphery of the slit nozzle so that the gas in the plenum chamber is ejected in an inwardly inclined manner;
A flotation device for a band-shaped material, characterized in that a static pressure region surrounded by several stages of ejected gas curtains is formed in the space between the band-shaped material and the flat plate. 2 The flat plates of the plenum chamber are arranged parallel to each other with a distance from the moving band-shaped material, and a first stage slit nozzle is provided around the flat plate so that the gas in the plenum chamber is ejected in an inwardly inclined manner. Further, at least a second stage slit nozzle is provided on the outer periphery of the slit nozzle so that the gas in the plenum chamber is ejected inwardly.
In this way, a static pressure region surrounded by several stages of ejected gas curtains is formed in the space between the strip material and the flat plate, and the inside of the plenum chamber is divided into each stage of slit nozzles, and each partition chamber is divided into two stages. A flotation device for a strip-shaped material, characterized in that gas is separately pumped into the material.