JP2011038683A - Horizontal continuous annealing furnace of metal strip - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a horizontal continuous annealing furnace of a metal strip capable of effectively improving the heating capacity. <P>SOLUTION: In the horizontal continuous annealing furnace 10 of the metal strip 20, a support plate 36 made of ceramics is disposed horizontally on the upper part of a heating chamber 12; an electrical heater 44C made of a heating wire is disposed on a top face of the supporting plate 36, in a horizontally-laid state or in a waving state; and radiation heat from the support plate 36 heated by the electric heater 44C is applied to the metal strip 20 which passes through a lower part so as to heat the metal strip. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a horizontal continuous annealing furnace for metal strips, and more particularly to a furnace having characteristics in the structure of a heating chamber.

As shown in FIG. 4, a horizontal continuous annealing furnace in which a metal strip such as stainless steel carried from the furnace inlet is heated by a heater in the heating chamber and then passed through the cooling chamber and carried out from the furnace outlet to continuously anneal the metal strip. Are well known in the art.
In the horizontal continuous annealing furnace shown in FIG. 4, heaters are installed on a side wall surface 200 and a floor surface 202 of a heating chamber formed by lining a heat insulating material composed of a refractory material (refractory brick or ceramic fiber). This heat is directly applied to the metal strip 206 to be processed passing through the furnace to heat it.

Usually, an electric heater 204 made of a heating wire is used as the heater, and a long one is installed in a wavy shape in order to have a required heating capacity.
Specifically, the electric heater 204 on the side wall surface 200 is installed so as to form a wave shape in the vertical direction, that is, the vertical direction along the side wall surface 200 as shown in FIG. 204 is installed so as to form a corrugated shape laterally along the floor surface 202.

In FIG. 4A, reference numeral 210 denotes a hearth roll that supports the metal strip 206.
In FIG. 4B, reference numeral 212 denotes a support pin provided on the side wall surface 200, and the electric heater 204 on the side wall surface 200 is installed in a suspended state and in a vertically corrugated shape by the support pin 212. Is done.

  Since the corrugated surface of the electric heater 204 on the floor 202 is parallel to the metal strip 206, the heat from the electric heater 204 on the floor 202 is perpendicular to the metal strip 206, and the heating efficiency is high.

  On the other hand, since the corrugated surface of the electric heater 204 on the side wall surface 200 is in a direction perpendicular to the metal strip 206, the heat from the electric heater 204 on the side wall surface 200 is a metal as shown in FIG. The contact with the strip 206 does not strike at right angles but obliquely, and the heating efficiency of the metal strip 206 is poor.

  Although the electric heater 204 on the floor surface 202 has a high heating efficiency for the metal strip 206 as described above, when the metal strip 206 breaks in the furnace, the broken metal strip 206 falls on the floor surface 202 and drops to the floor surface. There is a problem of causing an accident that contacts with the electric heater 204 of 202 and is short-circuited to be disconnected.

Therefore, normally, as shown in FIG. 4 (a), even if the guard 214 is partially protruded upward from a plurality of locations on the floor surface 202 and the metal strip 206 is broken, the broken metal strip 206 is not removed from the floor surface. The contact with the electric heater 204 of 202 is prevented.
However, even if it does in this way, it cannot necessarily be said that it is safe against disconnection of the electric heater 204 on the floor 202.

Further, when the guard 214 is partially protruded from a plurality of locations on the floor surface 202 in this way, the installation space of the electric heater 204 on the floor surface 202 is inevitably reduced, and the electric heater 204 on the floor surface 202 is reduced. Heating capacity will be limited.
As a result, in the case of a continuous annealing furnace using this kind of electric heater 204, it is difficult to sufficiently increase the heating capability for the metal strip 206.

  As a means for enhancing the heating capability, a plurality of support pins may be provided on the ceiling surface 208, and the electric heater 204 may be installed on the ceiling surface 208 so as to be suspended by the support pins. In addition, it is difficult to provide the electric heater 204 on the ceiling surface. In addition, the electric heater 204 suspended from the ceiling surface 208 has a corrugated shape in the vertical direction, that is, the vertical direction. There is a problem that the orientation of the metal strip 206 becomes a right angle, and the heating efficiency of the metal strip 206 becomes extremely low, which is not practical.

  The following Patent Document 1 discloses that a dustproof plate is provided in the upper part of the heating chamber and is partitioned into a ceiling space and a heating space. This plate is for dustproofing. Thus, the present invention is different.

Japanese Patent No. 4268281

The present invention has been made for the purpose of providing a horizontal continuous annealing furnace for a metal strip capable of effectively enhancing the heating capability of the metal strip in the heating chamber against the background described above.
Another object of the present invention is to provide a horizontal metal strip that can effectively prevent disconnection of an electric heater installed on the floor even if the metal strip breaks, and can further enhance safety. An object is to provide a continuous annealing furnace.

  Thus, according to the first aspect of the present invention, there is provided a heating chamber formed by lining a heat insulating material composed of a refractory material, and the metal strip carried from the furnace inlet is heated by the heater in the heating chamber and then passed through the cooling chamber. In a horizontal continuous annealing furnace of a metal strip that is continuously annealed by being carried out from the furnace outlet, a support plate made of ceramics is provided in the upper part of the heating chamber, and the ceiling space above and lower side of the support plate are placed. The support plate is divided into heating spaces, and an electric heater composed of a heating wire is installed on the upper surface of the support plate as a heater in a state of undulating in the horizontal direction along the upper surface, and the support plate heated by the electric heater The radiant heat from is applied to a metal strip passing underneath and heated.

  According to a second aspect of the present invention, in the first aspect, an electric heater made of a heating wire is installed on the floor surface of the heating chamber as the heater in a state where the electric heater is formed in a wavy shape laterally along the floor surface. A cover plate made of a ceramic plate is placed on the floor so as to cover the heater from above, and the radiant heat from the cover plate heated by the electric heater is applied to the metal strip passing above to heat the cover. It is characterized by being.

Effects and effects of the invention

  As described above, according to the present invention, in a horizontal continuous annealing furnace, a support plate made of ceramics is installed horizontally on the upper portion of a heating chamber, and an electric heater made of heating wire is placed on the upper surface of the support plate in a lateral direction along the upper surface. It is installed in a wavy shape, that is, in a state lying on its side, and radiant heat from a support plate heated by an electric heater is applied to a metal strip passing below and heated.

If it does in this way, the heat from the electric heater installed in the upper surface of a support plate can be applied to a lower metal strip via the support plate which consists of ceramic plates, and this can be heated.
In addition, since the corrugated surface of the electric heater on the upper surface of the support plate is parallel to the metal strip, heat from the electric heater can be efficiently applied to the metal strip through the support plate.
Then, by installing the electric heater on the upper surface of the support plate together with the electric heater on the side wall surface of the furnace and the electric heater on the floor surface, it is possible to effectively enhance the ability to heat the metal strip.

  Next, according to the second aspect of the present invention, the electric heater is installed on the floor surface of the heating chamber in a state where the electric heater is horizontally waved along the floor surface, and a cover plate made of a ceramic plate is placed on the floor so as to cover the electric heater from above. The radiant heat from the cover plate that is installed horizontally and heated by the electric heater is applied to the metal strip that passes above and heated.

In this way, even if the metal strip breaks in the furnace and hangs down, it is possible to reliably prevent the broken metal strip from coming into direct contact with the electric heater on the floor surface. In addition, it is possible to reliably prevent problems such as disconnection of the electric heater installed on the floor surface due to breakage of the metal strip.
In addition, if it does in this way, it will become possible to ensure the installation space of the electric heater to a floor surface sufficiently widely, and it will become possible to raise the capability of the heating by the electric heater of a floor surface more than before.

It is the figure which showed the horizontal type | mold continuous annealing furnace of one Embodiment of this invention. It is the figure which showed the cross section of the heating chamber in the same embodiment, and the arrangement pattern of an electric heater. It is the perspective view which notched and showed the heating chamber in the same embodiment partially. It is the figure which showed the prior art example of the horizontal type | mold continuous annealing furnace.

Next, embodiments of the present invention will be described in detail with reference to the drawings.
In FIG. 1, reference numeral 10 denotes a horizontal continuous annealing furnace that continuously anneals a metal strip such as stainless steel from the left to the right in the figure, and includes a heating chamber 12, a cooling chamber 14, an inlet seal chamber 16, and an outlet seal chamber 18. ing.
Here, the heating chamber 12 can be provided with a preheating chamber and a soaking chamber.
The cooling chamber 14 can be provided with a slow cooling chamber.

In the figure, 20 is a metal strip and 22 is a hearth roll for supporting it.
A plurality of hearth rolls 22 are arranged along the conveying direction of the metal strip 20.
In this embodiment, the metal strip 20 is carried into the furnace from the furnace inlet 24, transported rightward in the drawing in the heating chamber 12, sent to the cooling chamber 14, and then cooled through the cooling chamber 14. After that, it is carried out of the furnace outlet 26 and subjected to a continuous annealing process.

The structure of the heating chamber 12 is specifically shown in FIGS.
In these figures, reference numeral 28 denotes an iron furnace shell, and a heat insulating material 30 made of a refractory material such as a refractory brick or ceramic fiber is lined over the entire circumference.
The above-described hearth roll 22 is disposed in the upper and lower intermediate portions inside the heating chamber 12, and the metal strip 20 is conveyed in the heating chamber 12 in a direction perpendicular to the paper surface in FIG. 2 while being supported by the hearth roll 22 from below. The
In the figure, 32 indicates a side wall surface, and 34 indicates a floor surface.

In this embodiment, a support plate 36 made of ceramics is provided horizontally in the upper part of the heating chamber 12, and the interior of the heating chamber 12 is covered by the support plate 36 with an upper ceiling space 38 and a lower heating space 40. It is divided into and.
For example, the support plate 36 can be installed such that the receiving portion 42 protrudes from the side wall surface 32 and the end portion in the width direction of the support plate 36 is received from the lower side by the receiving portion 42.
Here, as shown in FIG. 3, the support plate 36 continuously extends in the heating chamber 12 along the longitudinal direction of the furnace (a cover plate 46 described later is omitted in FIG. 3). .

An electric heater 44 </ b> A is installed on the side wall surface 32. The electric heater 44A is composed of a long heating wire, and is installed in a state where the bay is bent in a vertical direction, that is, in a vertical direction as shown in FIG.
As shown in FIG. 3C, the electric heater 44A on the side wall surface 32 is held in a suspended state by a support pin 45 and continuously extends in the longitudinal direction of the furnace.

In this embodiment, the electric heater 44A is composed of a ribbon heater having a strip shape as shown in FIGS. For example, the thickness is about 2 to 3 mm and the width is about 20 to 40 mm.
However, as the electric heater 44A, it is possible to use a round bar having a circular cross section and various other shapes. This also applies to the electric heaters 44B and 44C described later.
The electric heater 44 </ b> A on the side wall surface 32 is provided in the heating space 40 below the support plate 36.

On the other hand, an electric heater (ribbon heater) 44B made of a long heating wire is also installed on the floor surface 34 in a bay bending state so as to form a corrugated shape horizontally with the floor surface 34 as a support surface.
The electric heater 44B on the floor 34 also extends in the longitudinal direction of the furnace.

In this embodiment, an electric heater (ribbon heater) 44C composed of a long heating wire is also formed on the upper surface of the support plate 36 so as to lie sideways with the upper surface of the support plate 36 as a support surface and have a corrugated shape. It is installed with the bay bent.
The electric heater 44C also extends continuously in the longitudinal direction of the furnace as shown in FIG.
In this embodiment, the support plate 36 made of ceramics is heated by an electric heater 44C on the upper surface thereof, and the metal strip 20 therebelow is heated by radiant heat from the support plate 36.

As shown in FIG. 2A, a cover plate 46 made of ceramics is provided on the floor surface 34 to cover and cover the electric heater 44B from above.
The cover plate 46 is provided at a position slightly above the floor surface 34 in a state in which a gap S is formed between the cover plate 34 and the electric heater 44B is positioned in the gap S. .
The cover plate 46 is supported on the floor surface 34 by a support portion 48 at the center in the width direction.

In this embodiment, the metal strip 20 is not directly heated by the electric heater 44B on the floor 34, the cover plate 46 is first heated by the electric heater 44B, and the metal strip 20 is heated by the radiant heat from the cover plate 46. .
However, when the atmospheric gas is present in the heating space 40, the metal strip 20 is also heated by the heat transfer effect of the atmospheric gas.
This also applies to heating by the support plate 36.

In the present embodiment, each of the electric heater 44A on the side wall surface 32, the electric heater 44B on the floor surface 34, and the electric heater 44C on the upper surface of the support plate 36 has a corrugated shape.
Of these, the corrugated surface of the electric heater 44A on the side wall surface 32 is perpendicular to the metal strip 20, while the electric heater 44C on the upper surface of the support plate 36 and the electric heater 44B on the floor surface 34 are both metal strips. The corrugated surface is parallel to the surface 20.

Accordingly, the heat from the electric heater 44 </ b> A on the side wall surface 32 strikes the metal strip 20 in an oblique direction.
On the other hand, the heat from the electric heater 44B on the floor surface 34 and the electric heater 44C on the upper surface of the support plate 36 strikes the metal strip 20 through the cover plate 46 and the support plate 36 at a right angle.

As described above, according to the present embodiment, the heat from the electric heater 44C installed on the upper surface of the support plate 36 is applied to the lower metal strip 20 via the support plate 36 made of a ceramic plate and heated. it can.
Moreover, since the wave surface of the electric heater 44C on the upper surface of the support plate 36 is parallel to the metal strip 20, the heat from the electric heater 44C can be efficiently applied to the metal strip 20 via the support plate 36.
Then, by installing the electric heater 44C on the upper surface of the support plate 36 together with the electric heater 44A on the side wall surface 32 of the furnace and the electric heater 44B on the floor surface 34, the ability to heat the metal strip 20 is effectively enhanced. Can do.

Further, according to this embodiment, even when the metal strip 20 is broken in the furnace, it is possible to reliably prevent the broken metal strip 20 from coming into direct contact with the electric heater 44B on the floor surface 34. In addition, it is possible to reliably prevent problems such as disconnection of the electric heater 44B installed on the floor surface 34 due to breakage of the metal strip 20.
In addition, according to the present embodiment, a sufficiently large installation space for the electric heater 44B on the floor surface 34 can be ensured, and the heating capacity of the floor surface 34 by the electric heater 44B can be increased as compared with the conventional case.

Although the embodiment of the present invention has been described in detail above, this is merely an example.
For example, it is possible to install the electric heater 44B on the floor 34 with the conventional structure shown in FIG.
Furthermore, the present invention can be applied to a continuous bright annealing furnace that brightly anneals a metal strip in a reducing atmosphere, and the present invention can be configured in various modifications without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 10 Horizontal type continuous annealing furnace 12 Heating chamber 14 Cooling chamber 20 Metal strip 24 Furnace inlet 26 Furnace outlet 30 Heat insulating material 32 Side wall surface 34 Floor surface 36 Support plate 38 Ceiling space 40 Heating space 44A, 44B, 44C Electric heater 46 Cover plate

Claims (2)

It is equipped with a heating chamber that is lined with a heat insulating material composed of a refractory material. After the metal strip carried from the furnace inlet is heated by the heater in the heating chamber, it is passed through the cooling chamber and carried out from the furnace outlet for continuous annealing. In horizontal continuous annealing furnace for metal strip
A support plate made of ceramics is installed in the upper part of the heating chamber, and is divided into a ceiling space above the support plate and a heating space below the support plate. A heater is installed in a wavy shape along the upper surface, and radiant heat from the support plate heated by the electric heater is applied to a metal strip passing below to heat the heater. A horizontal continuous annealing furnace for metal strips.   In Claim 1, while installing the electric heater which consists of a heating wire as the said heater on the floor surface of the said heating chamber in the state which makes a wavy shape sideways along this floor surface, it is in the state which covers this electric heater from the upper side A cover plate made of a ceramic plate is laid horizontally on the floor, and radiant heat from the cover plate heated by the electric heater is applied to the metal strip passing above and heated. Horizontal continuous annealing furnace for metal strip.

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