JPH0633943B2 - Pineapple furnace - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a muffle furnace, and more specifically, to a roll arranged in a muffle furnace when the muffle arranged in the muffle furnace is thermally expanded by heating in the furnace. The sleeve housing the shaft of the body penetrates the furnace body side wall and slides along with the furnace body side wall along with the thermal expansion so as to absorb the difference in thermal expansion.

A conventional muffle furnace has a tubular muffle housed and arranged in a furnace body heated by a gas burner or other electric resistor.
It is configured such that the object to be heated is inserted into the muffle and the content is indirectly heated in a state where the muffle is hermetically sealed and insulated and isolated from the furnace atmosphere. For example, a steel material is reduced or non-oxidized. It is preferably carried out in bright annealing that is annealed in a stream of a characteristic gas.

Problems to be Solved by the Invention Especially, in a roller-hearth-type muffle furnace that continuously performs bright annealing of pipes, drawn materials, etc., rolls are arranged at predetermined intervals along a path line during muffle. Thus, the object to be heated is conveyed while being indirectly heated. The rotation axis of the roll body rotatably arranged in this muffle is
The sleeve is rotatably accommodated in a sleeve extending on both sides in the radial direction of the muffle, and the sleeve projects outward from the side wall of the furnace body. The rotary shaft is configured to be rotationally driven by a drive source arranged outside the furnace body. By the way, in the muffle furnace, the muffle is thermally expanded by the heating of the furnace during its operation, and the muffle expands in the axial direction with time, so that the sleeve and the sleeve penetrating position on the side wall of the furnace are relatively displaced. Therefore, in order to prevent damage to the furnace body due to mechanical stress applied between the sleeve and the furnace side wall during thermal expansion, the sleeve penetration part on the furnace side wall is formed as a long hole along the extension direction of the muffle. Is being attempted. However, in this case, the heat in the furnace body escapes from the gap between the elongated hole and the sleeve, and the thermal efficiency is reduced, which is uneconomical.

For this reason, as another proposal, as shown in FIG. 1, the sleeve is formed by dividing the cylindrical furnace body into each roll body arrangement section and forming an expansion / contraction portion between the divided furnace bodies. The structure is designed to prevent relative deviation between the sleeve side position of the side wall of the furnace body. That is, the furnace body 12 formed of a long cylindrical body in which refractory bricks are stretched on the inner wall of the furnace shell 10 has two furnace bodies 12a and 12b in the illustrated example.
Each furnace body 12 has its center axis aligned in the longitudinal direction, a single muffle 14 is commonly arranged, and a plurality of refractory support members 16 are arranged at predetermined intervals. Supported in.

The muffle 14 is fixed by an anchor frame 18 at the right end of FIG. 1 and is allowed to move only in the left axial direction. Muffle 14
The straight pipes 14a and the corrugated pipes 14b that are expandable and contractible in the axial direction are alternately welded, and the object to be heated is conveyed in the muffle corresponding to the divided sections of the furnace body 12. One roll body 20 is provided for each.
The rotary shaft 22 of the roll body 20 is, as shown in FIG.
The sleeve 24 is connected to the muffle 14 and is axially supported by a sleeve 24 extending in the radial direction. The sleeve 24 penetrates the side wall of the furnace body 12 and protrudes to the outside of the furnace body, and the motor 26 installed outside the furnace drives the rotating shaft 22.

The divided furnace bodies 12 are supported by their respective wheels 28 to support their loads, and are movable in the left direction. Further, each furnace body 12 is always biased to the left in FIG. 1 by the hydraulic cylinder 30 shown when the furnace body is in operation. With such a configuration, even if the muffle furnace is heated by the gas burner 32 and thermal expansion occurs, the furnace body 12 divided into the respective sections has the muffle 1
4 and the sleeve 24 extending from the muffle, so that there is no mechanical strain on the sleeve 24 and the penetrating portion of the furnace side wall.

However, in the above-mentioned furnace body structure, since the furnace body is divided and supported so as to be movable, the structure must be complicated, and the expandable seal portion formed in the divided region of each furnace body is It is pointed out that metal fatigue easily breaks and the life is short. Further, it is difficult to reduce the mutual distance between the roll bodies 20 arranged in the muffle 14, and during the operation of the muffle furnace, the furnace bodies 12 are constantly urged in the thermal expansion direction by the hydraulic cylinders 30 as described above. Therefore, there is a problem that the installation cost and running cost of the device increase.

Object of the invention In view of the problems inherent in the roller-hearth type muffle furnace described above, the present invention has been proposed to preferably solve this problem, and when the muffle furnace thermally expands, It is an object of the present invention to provide a simple furnace body structure that appropriately absorbs the difference in thermal expansion, thereby achieving reduction in manufacturing cost and running cost.

Means for Solving the Problems In order to achieve the above-mentioned object, the present invention stores a muffle in a furnace body heated by a required heating body, and indirectly conveys a heated object in the muffle by a roll body. In a muffle furnace driven by a driving source disposed outside the furnace body, the sleeve that extends in the radial direction from the muffle and accommodates the rotating shaft of the roll body inside is heated. A refractory block slidably inserted in a longitudinal gap formed on both side walls of the furnace body.

Examples Next, a muffle furnace according to the present invention will be described below with reference to the accompanying drawings with reference to preferred examples. 3 is a partially cutaway side view of a muffle furnace according to the present invention, FIG. 4 is a transverse sectional view taken along the line AA of FIG. 3, and FIG. 5 is a partially cutaway perspective view of a main part related to the present invention. , FIG. 6 is an enlarged view of the main part shown in FIG. It should be noted that members that are substantially the same as the members described in connection with FIG.

The furnace body 12 of the muffle furnace according to the illustrated example is constructed by lining a refractory brick structural material 34 on a furnace shell 10 formed by combining steel columns and beam members into a required shape. That is, as shown in FIG. 4, the furnace body 12 comprises the arch-shaped ceiling portion 12a and the vertical side wall portions 12 on both sides by the structural member 34.
b, 12b and a hearth 12c, the muffle 14 is horizontally inserted into the furnace, and is supported by a support member 16 provided on the hearth at appropriate intervals.

In the muffle 14, rolls 20 for conveying the object 36 to be heated are arranged at appropriate intervals, and the rotary shaft 2 thereof is provided.
2 is inserted and axially supported in a sleeve 24 connected to the muffle. The sleeve 24 horizontally extends from the muffle 14 to both sides in the radial direction, penetrates the vertical side walls 12b of the furnace body 12 and protrudes to the outside of the furnace body, and drives the rotary shaft 22 by a motor 26 installed outside the furnace. Is configured.

Then, in the present invention, as a structure in which the above-mentioned sleeve 24 penetrates the side wall of the furnace body and projects outward, a refractory block is slidably inserted in the longitudinal gap formed on both side walls of the furnace body, The sleeve is inserted through the refractory block. In particular, as shown in FIGS. 5 and 6, the vertical side walls 12b of the furnace body 12 are preliminarily formed with parallel gaps spaced at predetermined intervals at corresponding positions along the muffle 14 extending in the longitudinal direction. A predetermined number of refractory blocks 38 are arranged in this parallel gap. For example, the vertical side wall forming portion of the furnace shell 10 is provided with a support beam 40 that horizontally projects toward the inside of the furnace, and is reinforced by vertical ribs 42 at key portions in the longitudinal direction thereof. The loads on the arch-shaped ceiling portion 12a and the upper portions of both side wall portions 12b of the furnace body 12 are supported by the support beams 40. On both sides of the hearth 12c, the structural material 3 has the required height.
4 to build up the lower part of the side wall 12b,
As a result, a parallel gap extending in the longitudinal direction is formed between the support beam 40 and the lower side wall 12b.

Further, each of the plurality of sleeves 24 extending horizontally on both sides of the muffle 14 is in close contact with a through hole formed in a rectangular parallelepiped refractory block 38, as shown in FIGS. 4 and 5. This block is inserted through the support beam 40.
In the parallel gap formed between the lower side wall 12b and
It is slidably movable. That is, the refractory block 38 is assembled in the gap portion, so that the furnace body 1
It constitutes a part of the vertical side wall 2 and is completely sealed in the furnace body. Between the flat upper surface of the lower side wall portion 12b and the refractory block 38, a flexible sheet-like refractory material such as Kao wool (trademark) is provided so that the block can slide more smoothly. It is preferable to lay it.

3 and 4, reference numeral 44 is a ribbon-shaped electric heating element, and 46 is a thermocouple for measuring the temperature in the furnace. Further, the shaft supporting portion between the rotary shaft 22 of the roll pair 20 and the sleeve 24 has a strict shaft sealing structure so that a sealed atmosphere in the muffle 14 is maintained. Further, although not shown in FIG. 3, chambers held in the same manner as the atmosphere inside the muffle 14 are connected to the left-hand upstream side and the right-hand downstream side of the muffle 14, respectively, and the object to be heated 36 is fed from the upstream chamber. The muffle 14 is continuously supplied.

Next, the operation of the muffle furnace according to the present invention will be described.
When the muffle furnace is operated, the temperature inside the furnace rises, and the muffle 14 expands in the longitudinal direction due to thermal expansion. Along with this, the sleeves 24 integrally connected to the muffle and extending in the radial direction also extend in the longitudinal direction. To move in the direction. Therefore, a pressing force is applied to the refractory block 38, into which the sleeve 24 is closely inserted, via this sleeve. However, since the refractory block 38 is slidably inserted in the parallel gap, the block 38 moves along with the sleeve 24 in the extension direction of the muffle 14, and the thermal expansion is suitably absorbed. .

EFFECTS OF THE INVENTION Thus, according to the present invention, even when the muffle furnace is heated to cause thermal expansion, the sleeve extending from the muffle extends and moves with the refractory block forming a part of the side wall of the furnace body, and It is possible to absorb thermal expansion without adding mechanical strain to the sleeve and the penetrating part of the furnace side wall,
There is no heat dissipation from the furnace. Moreover, since the furnace body structure does not need to support the movable body by dividing the furnace body as in the prior art, it is possible to have a simple structure.
It is possible to reduce the installation cost and running cost. Further, since the above-mentioned fireproof block only needs to be provided for each sleeve, there is an advantage that the mutual interval of the roll bodies arranged in the muffle can be easily shortened.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view of a muffle furnace according to the related art, and FIG.
1 is a transverse cross-sectional view taken along the line AA of FIG. 1, FIG. 3 is a side view of the muffle furnace according to the present invention, which is partially cut away, and FIG. 4 is an AA of FIG.
FIG. 5 is a partially cutaway perspective view of a main part relating to the present invention, FIG. 6 is an enlarged view of the main part shown in FIG. 5, and FIG.
FIG. 1 is a schematic plan view showing the arrangement relationship between a sleeve and a refractory block extending from the muffle to both sides in the radial direction.
Shows the state that the roll body is inserted only in the sleeve of the book,
Illustration of the roll body with other sleeves is omitted. 12 ... Furnace body, 14 ... Muffle 20 ... Roll body, 22 ... Rotating shaft 24 ... Sleeve, 38 ... Fireproof block

Claims (1)

[Claims] 1. A muffle is housed in a furnace body heated by a required heating body, and an object to be heated in the muffle is indirectly heated while being conveyed by a roll body, and the roll body is arranged outside the furnace body. In a muffle furnace driven by an installed driving source, a sleeve extending in a radial direction from the muffle and having a rotating shaft of the roll body accommodated therein is formed in a longitudinal gap formed on both side walls of the furnace body. A muffle furnace characterized by being inserted through a refractory block slidably inserted inside.