JPH01266879A - Strip floating and passing device - Google Patents

Abstract

PURPOSE:To prevent the wind ripples formed on a strip surface with a floater which supports the strip with a static pressure without contact by forming the entire part or a part of a pressure bearing surface of a porous material having a large pressure drop. CONSTITUTION:The static pressure is generated between the pressure bearing surface 2 and the strip 5 and the strip can be supported without contact when pressure fluid 4 supplied via a fluid supply pipe 3 is ejected from the many fine pores of said surface at nearly a uniform flow rate. This static pressure has the distribution which is higher in the central part of the pressure bearing surface 2 of the floater 1 and is successively lower nearer the end of the pressure bearing surface 2 and, therefore, the fluid ejected from the surface 2 is different between the central part and the end part. The fluid is ejected uniformly from the entire part of the surface 2 and the fluid ejection rate can be lowered if the surface 2 is formed of the porous material having the large pressure drop in order to uniformize the above-mentioned ejection flow rates. The wind ripples which heretofore generates defect in the painting in an undried state coated on the strip 5 surface are, therefore, prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a non-contact support device for a strip in a drying and baking oven where water adheres to the surface of the strip after passing through a coater.

[Conventional technology]

A contact support device such as a roll cannot be installed inside a drying oven for drying and baking the adhesion of a strip such as a steel plate because it would damage the paint applied to the surface of the strip.

Therefore, the strips were supported only by the rolls installed at the exit of the furnace, and inside the furnace, the strips were continuously threaded while being suspended by catenaries.

[Problem to be solved by the invention]

The conventional adhesion water drying and baking furnace described above had the following problems to be solved. That is, since a strip support device cannot be installed inside the furnace, the catenary of the strip is large, and in order to avoid contact of the strip with the hearth, (1) the furnace height must be increased, which increases construction costs; ) In order to make the catenary smaller, it was necessary to apply more tension than necessary to the strip, which led to problems such as excessive equipment.

Another method is to install conventional Cushion nozzle type floaters as shown in Figure 5 in this furnace at regular intervals in the direction of strip movement to support the strip without contact and reduce the catenary. Conceivable. However, in this Cushion nozzle type floater, the high-speed gas 7a ejected from the slit nozzle 7 collides with the surface of the strip, causing wind ripples on the paint etc. applied to the surface of the strip, thereby reducing the product value. For this reason, the Cushion nozzle type floater could not be used in the attached water drying and baking furnace.

[Means to solve the problem]

As a means for solving the above problems, the present invention is formed by a plenum chamber and a pressure receiving surface, and the fluid sent to the plenum chamber is ejected through the pressure receiving surface, and the strip plate passing on the pressure receiving surface is prevented by static pressure. It is an object of the present invention to provide a strip floating strip passing device in which the entire or part of the pressure receiving surface is formed of a porous material having a large pressure loss in a contact-supporting 70-taper.

[For production]

Since the present invention is configured as described above, it has the following effects. In other words, since the fluid supporting the strip plate etc. is ejected uniformly from the entire porous pressure-receiving surface, the fluid ejection speed from the pressure-receiving surface can be reduced even when ejecting the same amount of flow as a cushion nozzle type floater. . Therefore, the strip can be floated without causing wind ripples on the undried coating applied to the surface of the strip.

〔Example〕

The first embodiment of the strip flotation threading device according to the present invention is described below.
This will be explained based on FIG. FIG. 1 is a perspective view showing a first embodiment of the present invention, and FIG. 2 is a sectional view taken along the line ■-■ in FIG. In both figures, a fluid supply pipe 3 is connected to the floater 1 disposed directly below the strip plate 5, which connects the inside of the chamber 6 to a pressurized fluid supply source (not shown). The pressure receiving surface 2 of the floater 1 facing the strip plate 5 is made of a porous material having a large number of fine pores and having a large pressure loss, such as a bag filter, a ceramic filter, a metal filter, etc. A pressurized fluid 4 such as air, nitrogen, or water supplied through the fluid supply pipe 3 is ejected from the chamber 6 from a large number of fine holes in the pressure receiving surface 2 at a substantially uniform flow rate. This ejected fluid 2a generates static pressure between the strip plate 5 and the pressure receiving surface 2, and this static pressure allows the strip plate 5 to be supported in a non-contact manner.

The static pressure generated between the pressure receiving surface 2 and the strip plate 5 is
The distribution is high at the center of the pressure receiving surface 2 and decreasing as it approaches the end of the pressure receiving surface 2. The fluid ejected from the pressure receiving surface 2 is ejected at a flow rate determined by the pressure difference between the pressure within the chamber 6 and the static pressure between the pressure receiving surface 2 and the strip plate 5. The I]λ output flow rate differs between the parts.

In order to make this jet flow velocity the same, the pressure receiving surface 2
It is desirable to increase the pressure loss in the chamber 6 to increase the pressure inside the chamber 6. For example, 0.3 t, x 80
When a steel plate of 0 W is installed with the floater 1 at a rate of 3 m/min and is supported in a non-contact manner by blowing out room temperature air, a flow rate of about 25 m3/min/m2 is required.

At this time, it is desirable to use a pressure loss of about 200 Aq or more on the pressure receiving surface 2.

Next, as a second embodiment of the present invention, a perspective view in which a part of the pressure receiving surface is formed of a porous material with a large pressure loss is shown in FIG. 3, and a cross section taken along the line IV-IV in FIG. The figures are shown in FIG. 4. In this embodiment, as shown in FIG. 1, when the width of the strip plate 5 becomes narrow, in order to reduce the amount of ineffective ejected gas from the area of the pressure receiving surface 2 where the strip plate 5 is not applied, the left and right sides of the pressure receiving surface 2 are The area near both ends is covered with a sealing material 8 as shown in FIG. 4, and the external appearance is such that a part of the pressure receiving surface 2 is made of a porous material with a large pressure loss. In this embodiment as well, the floating principle, floating performance, etc. of the strip plate 5 are the same as those in the first embodiment described in FIG.

〔Effect of the invention〕

Since the present invention is configured as described above, it has the following effects. In other words, by forming the floater pressure receiving surface with a porous material with a large pressure loss, the fluid is ejected uniformly from the entire pressure receiving surface, so even when ejecting the flow rate of a cushion nozzle type floater and an open chain flow, the fluid is ejected uniformly from the pressure receiving surface. Since the fluid ejection speed can be reduced, it is possible to prevent wind ripples that have caused defects in the wet coating applied to the surface of the strip.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of the first embodiment of the present invention, FIG. 2 is a cross-sectional view taken along the line ■-■ in FIG. 1, FIG. 3 is a perspective view of the second embodiment of the present invention, and FIG. FIG. 3 is a cross-sectional view taken along the line EV-■, and FIG. 5 is a cross-sectional view showing a conventional example corresponding to FIG. C1...Floater 2...Pressure receiving surface 3...
Fluid supply pipe 4... Pressurized fluid 5... Strip plate 6... Chamber chamber (plenum chamber) 8... Seal material. Representatives: Masu-shi, Sakama Akigai, 2 people Figure 1 Figure 2 Figure 5

Claims (1)

[Claims] In a floater formed by a plenum chamber and a pressure receiving surface, fluid sent to the plenum chamber is ejected through the pressure receiving surface, and a strip plate passing through the pressure receiving surface is supported in a non-contact manner by static pressure. 1. A floating strip strip threading device, characterized in that the whole or a part thereof is made of a porous material with a large pressure loss.