JPH0777388A - Vertical muffle furnace - Google Patents

Abstract

PURPOSE:To prevent inclining of a sealing unit due to bending of a muffle cause by a thermal expansion, etc., during operating and to always straightly load a metal strip into a vertical muffle furnace without feeding in a zigzag manner in the furnace for continuously heat treating the strip in atmospheric gas. CONSTITUTION:A sealing unit 8 is connected to a lower end of a muffle 3 suspended through a furnace body 1 through a bellowlike stretchable cylinder 7, and suspended via a plurality of regulating shafts suspended from a lower end of the muffle 3 to an outer periphery of the cylinder 7. Thus, the unit 8 is supported adjustably at an inclining angle.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vertical muffle furnace for continuously heat treating a metal strip in an atmosphere gas.

[0002]

2. Description of the Related Art In a vertical muffle furnace, generally, a cylindrical muffle through which an upwardly traveling metal strip penetrates is suspended so as to penetrate through an adiabatic furnace body, and a muffle furnace is provided in a heating chamber between the furnace body and the muffle. Burning by a burner or electric heating is performed, the muffle is filled with a reducing or non-oxidizing atmosphere gas, and the metal strip is subjected to heat treatment such as bright annealing in the atmosphere gas.

A seal device is provided at the strip inlet at the lower end of the muffle to prevent outside air from entering the muffle. As the seal device, the inside of a rectangular tubular seal frame surrounding the strip is provided. In general, a pair of seal rolls, which are pressed against both sides of the strip, are rotatably supported.

[0004]

By the way, since the above-mentioned sealing device is conventionally fixed to the lower end portion of the muffle, the muffle suspended and supported by the upper part is vertically moved by thermal expansion during operation. If the bending occurs due to uneven heating of the muffle when it expands and contracts, the sealing device tilts with the tilting of the lower end of the muffle, and the direction of the strip pinched by the seal rolls deviates from the vertical direction. There was a problem that the strip meandered, contacted the inner surface of the muffle, and caused a plate break accident.

[0005]

The vertical muffle furnace according to the present invention is intended to solve the above-mentioned problems, and the lower end portion of the muffle penetrating the furnace body is hung through a bellows-shaped telescopic tube. A sealing device is connected, and the sealing device is supported by a plurality of adjusting shafts provided downward from the lower end of the muffle to the outer periphery of the telescopic cylinder so that the inclination angle can be adjusted. To do.

[0006]

In this vertical pine-furnace furnace, even if the lower end of the muffle is inclined due to thermal expansion or the like, the sealing device can always be kept horizontal by operating the adjusting shaft.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described with reference to FIGS. In the figure, reference numeral 1 is a vertical cylindrical furnace body constructed on a base 2 by a heat insulating material. Reference numeral 3 is a cylindrical muffle that is suspended by a gantry 40 and penetrates the center of the furnace body 1. A burner (not shown) for heating the muffle 3 is provided on the side wall of the furnace body 1. Further, an atmosphere gas supply source (not shown) is connected to the muffle 3.

Numerals 4 and 5 are an inlet and an outlet formed by providing baffles 6 inside both ends of the muffle 3. A sealing device 8 is connected to the lower end of the muffle 3 via a bellows-shaped telescopic tube 7. Therefore, the strip 9 turns upward through the turning roll 10 on the entry side, passes through the sealing device 8 and is charged into the muffle 3, and is heated to a predetermined temperature in the atmospheric gas, and then moves to the cooling chamber 11. It is cooled and extracted through the turning roll 12 on the delivery side.

As shown in FIG. 2, a sealing material 13 made of ceramic wool is fixed to a lower end opening edge of the furnace main body 1 from which the muffle 3 projects by a snap ring 14 and a set screw 15, and the gap is closed to close the furnace. The outside air is prevented from entering the main body 1. In order to completely prevent the outside air from entering the outside of the sealing material 13, annular fittings 17 and 18 are provided on the outer periphery of the protruding portion of the muffle 3 and the lower end surface of the furnace body 1, respectively. , 18 is a bellows-shaped expandable seal member.

The telescopic tube 7 is formed of a thin stainless plate in a bellows shape, and an annular mounting member 20 fixed to the outer periphery of the lower end portion of the muffle 3 is attached to the flange 2 at the upper end of the telescopic tube 7.
1 is airtightly fixed by a large number of bolts 23, and the flange 22 at the lower end of the telescopic cylinder 7 is airtightly fixed by a large number of bolts 24 to the outer peripheral edge of the top plate 26 of the seal frame 25 of the sealing device 8. ing. Further, the adjusting shafts 27 are provided downwardly around the outside of the telescopic cylinder 7 from four places around the mounting bracket 20, and the lower ends of the adjusting shafts 27 are provided with nuts 28, 28.
Are connected to the flange 22 and the top plate 26 by means of the four adjusting shafts 27 to support the sealing device 8. 36 is the top plate 2
6 and a water cooling jacket formed on the outer surface of the seal frame 25.

The sealing device 8 is a rectangular tubular seal frame 2.
5, a pair of air cylinders 30, 30 are provided on the bottom plate 29 of 5,
Rubber seal rolls 31, 31 are rotatably supported at the tip ends of the operating shafts of the air cylinders 30, 30 via bearings 34, and the seal rolls 31, 31 are supported by the air cylinders 30, 3.
With the elasticity of 0, the strip 9 is pressed against both sides.
Further, 32 is both end faces of the seal rolls 31, 31 and the bottom plate 2.
9 is a resin seal ring that is interposed between the side plate 33 and the side plate 33 that is provided on the lower surface of 9. Reference numeral 35 denotes a spirit level provided on the outer surface of the seal frame 25.

In the vertical muffle furnace configured as described above,
When the muffle 3 is bent and the sealing device 8 is tilted due to the expansion and contraction of the muffle 3 during operation, by adjusting the screwing amount of the nuts 28 on the four adjusting shafts 27 supporting the sealing device 8. Adjust the sealing device 8 so that it is horizontal. At that time, the level can be surely detected by performing the operation while looking at the level 35. The bellows-shaped expandable cylinder 7 absorbs the inclination of the sealing device 8 and constantly gas-tightly seals the space between the expandable cylinder 7 and the muffle 3. By keeping the sealing device 8 horizontal in this manner, the strip 9 sandwiched between the sealing rolls 31 and 31 and traveling upward and inserted into the muffle 3 is always guided straight and does not cause meandering.

By supporting the sealing device 8 on the lower end of the muffle 3 in such a manner that the tilt angle can be adjusted,
Even for a strip having a thickness deviation in the strip width direction in the press process, it is possible to guide the strip straight into the furnace by appropriately inclining the sealing device 8. Further, although this embodiment has been described with respect to the inlet of the strip, it can be similarly applied to the sealing device of the outlet.

[0014]

As described above, the vertical muffle furnace of the present invention is
Even if the muffle bends, the inclination of the sealing device can be appropriately corrected, so that the strip can always be inserted straight into the muffle, and a trouble due to meandering can be prevented.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a vertical muffle furnace showing an embodiment of the present invention.

FIG. 2 is an enlarged vertical cross-sectional view of a main part of the vertical muffle furnace shown in FIG.

3 is a sectional view taken along the line AA of FIG.

FIG. 4 is a sectional view taken along line BB of FIG.

[Explanation of symbols]

 1 Furnace Main Body 7 Bellows-shaped Telescopic Cylinder 8 Sealing Device 9 Strip 25 Seal Frame 27 Adjusting Shaft 28 Nut 31 Seal Roll

Claims (1)

[Claims] 1. A sealing device is connected to the lower end of a muffle suspended through the furnace body via a bellows-shaped telescopic tube, and is directed downward from the lower end of the muffle to the outside periphery of the telescopic tube. A vertical muffle furnace in which the sealing device is supported by a plurality of adjusting shafts provided so as to be adjustable in inclination angle.