JPH07252539A - Induction heating device of metal strip - Google Patents

Abstract

PURPOSE:To enable the rapid heating of a metal strip without causing damage to the metal strip by arranging induction heating devices and float-up nozzles along a carrying path of the metal strip formed in the horizontal direction. CONSTITUTION:Plural induction heating devices 4 (4a, 4b, 4c) and plural pieces of float-up nozzles 5 (5a, 5b, 5c) are arranged along the carrying path 1 of a metal strip 3 formed in the horizontal direction. The coated metal strip 3 is carried along the carrying path 1 toward the arrow mark 2 direction and heated by supplying the electric power to the induction heating devices 4 and floated up by blowing the suitable temp. of gas from the float-up nozzles 5. By this method, the metal strip 3 is carried in the extremely light condition having no flaw and little tension and can efficiently be heated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal strip which is designed to be heated rapidly during the process of transporting the metal strip along the transport path of the metal strip formed in the lateral direction. The present invention relates to an induction heating device.

[0002]

2. Description of the Related Art An induction heating device for heating a metal strip is disposed along a metal strip transport path formed in a lateral direction, and the metal strip is removed during the process of transporting the metal strip. Induction heating devices for metal strips that are adapted to heat rapidly are known.

[0003]

In this conventional horizontal type metal strip induction heating device, the metal strip is slightly loosened during the process of transporting the metal strip in the lateral direction, so that the induction heating device during transport is not affected. It may come into contact and scratch the metal strip. In order to prevent this, it is possible to arrange rollers for supporting the metal strips at various places, but if the metal strips are heated to a high temperature for annealing or coated on the surface, the metal strip surface There is a problem that a contact flaw with a fine supporting roller is attached. In addition, the metal strip comes into contact with the support roller, and thus unnecessary tension is applied to the metal strip,
There was also a problem of quality deterioration.

The metal strip induction heating apparatus of the present invention is provided to solve the above-mentioned problems (technical problems) of the prior art.

A first object is to convey a metal strip by arranging an induction heating device for heating the metal strip along a conveyance path of the metal strip formed in the lateral direction. The object of the present invention is to provide an induction heating device for a metal strip, which is adapted to rapidly heat the metal strip to improve its quality. A second object is that the metal strip being transported for heating is always in a floating state. The third purpose is to prevent the flaws from coming into contact with other objects such as the induction heating device, and the third purpose is the contactless levitating state of the metal strip during the transportation process for heating. Is to prevent unnecessary tension from being applied to this.

Other objects and advantages will be readily apparent from the drawings and the following description in connection therewith.

[0007]

In order to achieve the above object, the induction heating device for a metal strip according to the present invention heats the metal strip along a transportation path of the metal strip formed in the lateral direction. And an levitation nozzle for levitation of the metal strip by the jet fluid.

[0008]

An induction heating device for heating the metal strip is arranged along the transportation path of the metal strip formed in the lateral direction, and a levitation nozzle for levitation of the metal strip by the jet fluid is arranged. When the metal strip is levitated by the jet fluid, the metal strip is flawless, has less tension, and is transported very easily.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1 and FIG. 2, reference numeral 1 denotes a transport path of the metal strip formed in the lateral direction, along which the metal strip 3 is moved in the direction of the arrow 2. Generally, the metal strip 3 has a thickness of 0.1 to 4.0 mm and a thickness of 250 to 200.
0 mm width, various materials such as iron, aluminum, stainless steel are targeted.

Reference numeral 4 is a well-known induction heating device, which is composed of two or more well-known induction heating devices. Also, as shown, 4a-4c
The induction heating device may be composed of three or any number (for example, 2 to 8) of induction heaters. The length in the direction of each of these arrows 2 is about 0.5 to 3.0 m, and the width is determined corresponding to the width of the metal strip 3 as is well known. The heating capacity and the number of these are determined by the furnace length and the planned temperature rise temperature of the metal strip.

Reference numerals 5 (5a, 5b, 5c) denote well-known static pressure type levitation nozzles, which are arranged between the induction heaters and blow out a gas, for example, the atmosphere from the blow-out ports 6. The blowing pressure corresponds to the unit weight of the metal strip 3, and a static pressure is formed on the lower portion 7 of the metal strip 3 so that the lower surface of the metal strip 3 can be supported in a floating state by the static pressure. A levitation nozzle for static pressure is also known in JP-A-55-31178. The blowout temperature is set so as to maintain the temperature of the metal strip heated by the induction heater in the preceding stage. If the temperature of the gas is higher than the temperature of the metal strip and the temperature of the gas has a substantially heating effect, the effect of lowering the growth of the grain size of the metal strip peculiar to the induction heating device is adversely affected, and the coating material is present on the surface. If the temperature of the coating material rises above the temperature of the metal strip material inside and the drying occurs from the surface, causing a bad phenomenon inside, the blowing gas temperature has substantially no heating effect and is the same as the temperature of the metal strip. It is preferable that they are substantially the same or slightly higher. It is to be noted that, as is well known, a pressure gas having an appropriate temperature is sent to each of these floating nozzles 5 through a duct 9. The flowing gas 5d here has a function of carrying out the water that comes out of the coating material. The induction heater 4 and the levitation nozzle 5 are surrounded by an arbitrary case (not shown). The length of the levitation nozzle 5 in the arrow 2 direction is 0.3 to 0.6 m.
Rank. Reference numeral 8 indicates a well-known supporting roller for supporting the metal strip on the inlet side in the cold state.

In the above-described structure, as is well known, the coated metal strip 3 whose surface is coated with an arbitrary coating material in the form of a thin film is directed in the direction of the arrow 2 along the transport path 1. The metal strips are conveyed, and electric power is supplied to the respective induction heaters 4 to blow out gases of appropriate temperatures from the respective levitation nozzles 5, whereby the metal strips are heat-treated (for example, the coating material is dried, baked or annealed). In this case, each induction heater 4 is controlled so that the metal strip 3 that has entered at room temperature has an appropriate temperature at the final stage (for example, 300 ° C., when used for annealing the metal strip, for example, 800 ° C.).
And the blowing temperature of the levitation nozzle 5 are set so as to increase in sequence.

Next, FIG. 3 shows an example of the case where the coating material on the surface of the metal strip 3 is dried, baked or annealed, or in a non-oxidized state. Reference numeral 28 denotes a housing for enclosing the induction heating device 4e and the levitation nozzle 5e in the heating zone 28a, and 29 denotes a duct connected to a supply source 30 for supply of ambient gas (for example, nitrogen gas, mixed gas of nitrogen and hydrogen), 10 is a discharge duct, 11 is a circulation duct with a heater 12 interposed therebetween, 13 is a blower for sending pressurized gas to the levitation nozzle 5e through a distribution duct 14,
Reference numerals 15 and 16 respectively denote heaters for adjusting the gas temperature to the required temperature. Further, 17 is a housing for enclosing the cooling zone 17a, and as is well known, the inside thereof is sequentially cooled by the blown gas 18a, 19a from blowoff ducts 18, 19 in a process in which the metal strip 3e is in a levitation state in the direction of arrow 2e. . Reference numerals 20 and 21 denote a gas cooling cooler and a pressure blower. Reference numerals 22 and 23 respectively denote known metal strip supporting rollers having a gas sealing action. 24 shows the flow direction of gas.

According to the above structure, the same processing as that shown in FIG. 1 can be performed in the atmosphere of non-oxidizing gas. It should be noted that parts having the same or equivalent configurations as those of the previous figure in terms of function and overlapping description will be omitted by adding the letter e to the same reference numerals as in the previous figure and adding the letter e.

[0015]

As described above, the above-mentioned object is achieved by the constitution of the present invention, and there is no fear of scratching the metal strip, no worry of unnecessary tension, and the efficiency of the induction heating device in the state of producing the characteristics. It has the effect of heating well.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a relationship among a metal strip, an induction heating device, and a levitation nozzle.

FIG. 2 is a schematic cross-sectional view showing a floating state of a metal strip.

FIG. 3 is an explanatory diagram showing an example different from FIG.

[Explanation of symbols]

 1 Transport path 3 Metal strip 4 Induction heating device 5 Levitation nozzle

Claims (1)

[Claims] 1. A levitation device for levitation of a metal strip, which is formed in a lateral direction, along with an induction heating device for heating the metal strip, and for levitation the metal strip by a jet fluid. An induction heating device for a metal strip, comprising a nozzle.