JPH066451U - Base plate for batch annealing furnace - Google Patents

Abstract

(57) [Summary] [Purpose] The simple configuration of the base plate does not involve complicated control or large-scale changes to the equipment, and prevents concentrated loads at the outer periphery of the lower end of the coil and also prevents the coil and the lower end face from being concentrated. Uniformize the temperature rise and cooling, and prevent ear distortion quality defects in the outer periphery of the lower end of the coil. [Configuration] In a batch annealing furnace 10, an outer peripheral upper surface portion located outside a coil mounting area of a base plate 14,
An outer peripheral lower surface portion and an outer peripheral side surface portion are covered with a heat insulating material 14B.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a base plate of a batch annealing furnace for batch annealing a thin metal plate coil.

[0002]

[Prior art]

 In the batch type annealing furnace, as shown in FIG. 5, the end face of the coil 4 is mounted on the metal base plate 3 supported by the support base 2 on the hearth 1, and the base plate 3 and the coil 4 are attached to the inner cover 5 by the inner cover 5. The furnace body 7 is covered with a combustion device 6 and is covered with a refractory material. The inner cover 5 is heated from the outside, and the internal coil 4 is indirectly heated. The space between the lower part of the inner cover 5 and the hearth 1 is sealed with sand or ceramic fiber, and the atmospheric gas required for heat treatment is supplied at room temperature from the pipe 8 facing the central hole of the base plate 3.

[0003]

[Problems to be solved by the device]

 However, in the prior art, (a) during the temperature rising process, the base plate is mainly heated from the lower surface and the outer peripheral side surface, and the lower surface becomes higher in temperature than the upper surface on which the coil is placed, causing the base plate to warp (see FIG. )reference). As a result, the coil generates a concentrated load due to uneven support on the outer periphery of the lower end, and the heat input is also uneven because the outer periphery of the coil is large, and uniform heating of the lower end face of the coil cannot be achieved. Further, in the cooling process (b), heat dissipation from the outer peripheral portion of the base plate is promoted, and overcooling of the lower end portion of the coil outer periphery is likely to occur, so that uniform cooling of the lower end surface of the coil is not achieved.

That is, due to the above (a) and (b), a concentrated load is generated on the outer periphery of the lower end of the coil, and the temperature rise and cooling of the lower end surface of the coil become uneven, resulting in ear strain at the lower end of the outer periphery of the coil. So-called quality defects are likely to occur.

The prior art includes the following (1) and (4), but each has the following problems.

(1) Japanese Patent Publication No. 62-16258 discloses heating a coil with a burner provided between a hearth and a base plate in order to heat the coil at a high temperature with a small temperature deviation. However, it is difficult to control the combustion gas so that it does not touch the coil, and the temperature rise and cooling of the lower end surface of the coil cannot be made sufficiently uniform.

(2) Japanese Utility Model Laid-Open No. 61-142853 discloses that a heat insulating material is attached to the upper and lower surfaces of the base plate which are not in contact with the coil. However, the heat input transferred from the outer peripheral surface of the base plate is not transferred to the coil on the upper surface and the temperature does not rise, and the temperature rises on the lower surface. As a result, the above-described warpage of the base plate cannot be prevented.

(3) Japanese Utility Model Publication No. 1-110255 discloses that the base plate is made of ceramics. However, in this case, the material cost of the base plate is high, and the upward warp as described above cannot be completely prevented.

(4) Japanese Patent Laid-Open No. 2-173219 discloses an electric heater installed on the hearth to directly heat the base plate from below. However, in this case, as a result of the temperature of the lower surface of the base plate rising compared to the temperature of the upper surface, it is not possible to prevent upward warping as described above.

The present invention prevents a concentrated load at the outer periphery of the lower end of the coil by a simple structure of the base plate without complicated control and large-scale modification of the equipment, The object is to make the temperature rise and cooling uniform and prevent the quality defect of the ear distortion at the outer peripheral portion of the lower end of the coil.

[0011]

[Means for Solving the Problems]

 In the present invention, the coil end surface is mounted on the upper surface of the base plate, the coils and the base plate are covered with an inner cover, and the inner cover is heated from the outside. In a batch type annealing furnace, the coil is located outside the coil mounting area of the base plate. The outer peripheral upper surface portion, the outer peripheral lower surface portion, and the outer peripheral side surface portion are covered with a heat insulating material.

[0012]

[Action]

 In the temperature rising process, heat input from the outer peripheral parts (outer peripheral upper surface part, outer peripheral lower surface part, and outer peripheral side surface part) of the base plate, which has the largest heat input in the vicinity of the inner cover, is suppressed, resulting in a temperature difference between the upper and lower surfaces. It is hard to occur. Further, the rigidity of the outer peripheral portion of the base plate can be increased by selecting the heat insulating material in the outer peripheral portion. As described above, it is possible to suppress the warp of the base plate, prevent the concentrated load on the outer peripheral portion of the lower end of the coil, and achieve uniform temperature rise of the lower end surface of the coil.

In the cooling process, heat radiation from the outer peripheral portion of the base plate is suppressed, and as a result, supercooling of the lower peripheral portion of the coil can be prevented, and uniform cooling of the lower end surface of the coil can be achieved.

As a result of the above, concentrated load at the outer periphery of the lower end of the coil is prevented, and the temperature rise and cooling of the lower end face of the coil are made uniform. As a result, it is possible to prevent quality defects of ear distortion at the outer periphery of the lower end of the coil.

[0015]

【Example】

 1 is a schematic diagram showing an embodiment of the present invention, FIG. 2 is a schematic diagram showing an example of a heat insulating material coating structure, and FIG. 3 is a diagram showing a temperature difference between a coil outer peripheral mounting portion on the upper surface of a base plate and an outer edge portion of the plate. FIG. 4 is a chart showing distortion of the base plate, and FIG. 5 is a schematic diagram showing a conventional example.

A batch type annealing furnace 10 shown in FIG. 1 is a rotary hearth type continuous annealing furnace, and is supported by a support 13 at four positions on a rotary hearth 12 provided in a fixed furnace body 11. The base plates 14 are provided, the end faces of the coils 15 are mounted on the respective base plates 14, the base plates 14 and the coils 15 are covered by the inner cover 16, and the inner plate is installed by a combustion device (not shown) provided on the furnace body 11 side. The cover 16 is heated from the outside, and the inner coil 15 is indirectly heated. That is, the annealing furnace 10 can simultaneously process four coils 15 in one hearth 12. The space between the lower part of the inner cover 16 and the hearth 12 is sealed with sand or ceramic fiber, and the atmospheric gas required for heat treatment is supplied from the pipe 17 facing the central hole of the base plate 14 at room temperature.

However, the base plate 14 is covered with the heat insulating material 14B on the outer peripheral upper surface portion, the outer peripheral lower surface portion, and the outer peripheral side surface portion, which are located outside the coil mounting area of the stainless alloy main body portion 14A. The heat insulating material 14B is composed of two half ring bodies, each ring body has a U-shaped cross section, and is fitted to the outer edge portion of the main body portion 14A. The thickness of the heat insulating material 14B is, for example, 25% of the thickness of the main body portion 14A. Suitable materials for the heat insulating material 14B include a ceramic fiber felt, a ceramic compression molding plate, and an amorphous fireproof heat insulating material.

In the base plate 14, the shape of the heat insulating material 14B and the attachment structure to the main body portion 14A are as shown in FIGS. 2 (A) to 2 (F), each of which can ensure durability and easy exchange. Aspects can be adopted. The heat insulating material 14B of (A) and (D) can be molded or fitted into the main body 14A. The heat insulating material 14B of (B) and (C) is formed integrally with the main body portion 14A, and has a shape that does not easily come off. The heat insulating material 14B of (E) can be used by cutting a plate-shaped fireproof heat insulating plate. The heat insulating material 14B of (F) is a modification of the heat insulating material 14B of (A) and can be applied without changing the basic shape of the main body 14A.

The operation of this embodiment will be described below. During the temperature rising process, heat input from the outer peripheral portions (outer peripheral upper surface portion, outer peripheral lower surface portion, and outer peripheral side surface portion) of the base plate 14 that has the largest heat input in the vicinity of the inner cover 16 is suppressed. A temperature difference hardly occurs. Moreover, the rigidity of the outer peripheral portion of the base plate 14 can be increased by selecting the heat insulating material 14B in the outer peripheral portion. As described above, the warp of the base plate 14 can be suppressed, the concentrated load at the outer peripheral portion of the lower end of the coil can be prevented, and the uniform temperature rise of the lower end surface of the coil can be achieved.

In the cooling process, heat dissipation from the outer peripheral portion of the base plate 14 is suppressed, and as a result, it is possible to prevent overcooling of the lower outer peripheral portion of the coil and achieve uniform cooling of the lower end surface of the coil.

[0021] As a result of the above, concentrated load at the outer periphery of the lower end of the coil is prevented, and the temperature rise and cooling of the lower end face of the coil are made uniform. As a result, it is possible to prevent quality defects of ear distortion at the outer periphery of the lower end of the coil.

FIG. 3 shows the outer peripheral coil mounting on the upper surface of the base plate in the temperature raising process T near the outer peripheral coil mounting portions (A1, B1) on the upper surface of the base plate for each of the invention sample A and the conventional sample B. FIG. 7 is a diagram showing a temperature difference ΔT (ΔTA = TA2-TA1, ΔTB = TB2-TB1) between the parts (A1, B1) and the plate outer edge parts (A2, B2). According to Inventive Example A, it is recognized that heat input from the outer peripheral portion of the base plate is suppressed.

FIG. 4 is a table showing strain H of the base plate after 53 times of use in the invention sample A and the conventional sample B. According to the invention example A, the strain H can be reduced.

Further, according to the implementation of the present invention, it was also recognized that the standard strain generation rate of the ear strain in the outer peripheral portion of the lower end of the coil can be significantly improved from 32% of the process material average to 5%.

[0025]

[Effect of device]

 As described above, according to the present invention, the simple configuration of the base plate does not involve complicated control or large-scale changes in equipment, so that concentrated load is prevented at the outer periphery of the lower end of the coil and the coil, It is possible to uniformize the temperature rise and cooling of the lower end surface and prevent quality defects such as ear strain in the outer peripheral portion of the lower end of the coil.

[Brief description of drawings]

FIG. 1 is a schematic view showing an embodiment of the present invention.

FIG. 2 is a schematic diagram showing an example of a covering structure of a heat insulating material.

FIG. 3 is a diagram showing a temperature difference between a coil outer peripheral mounting portion on the upper surface of the base plate and an outer edge portion of the plate.

FIG. 4 is a chart showing distortion of a base plate.

FIG. 5 is a schematic view showing a conventional example.

[Explanation of symbols]

 10 Annealing Furnace 14 Base Plate 14B Insulation Material 15 Coil 16 Inner Cover

Claims (1)

[Scope of utility model registration request] 1. A batch type annealing furnace in which an end surface of a coil is mounted on an upper surface of a base plate, the coil and the base plate are covered with an inner cover, and the inner cover is heated from the outside, an outer periphery located outside a coil mounting area of the base plate. A base plate for a batch annealing furnace, characterized in that an upper surface portion, an outer peripheral lower surface portion, and an outer peripheral side surface portion are covered with a heat insulating material.