JPH10141862A - Rotary heat treatment furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable heat-treatment of a substance for treatment without allowing the substance to stick to or stagnate at the inwall of a furnace core tube, even if the substance is bad in fluidity. SOLUTION: For this furnace, a furnace core tube 10 is inclined and supported horizontally by bearing rollers 20, and the furnace core tube 10 is rotated, and heat treatment is performed while the substance for treatment charged from one end of the furnace core tube 10 is passed to the other end. At least either one of the periphery of the furnace core tube 10 or the periphery of the bearing roller 20 for supporting this periphery rotatably is provided with unevenness 13 and 14 which gives vibration in radial direction to the furnace core tube 10, according to the rotation of the furnace core tube 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary drive type heat treatment furnace suitable for heat treatment of ceramic materials, and more particularly to a heat treatment furnace for performing heat treatment by passing an object to be processed through a hollow core tube to be heated. Things.

[0002]

2. Description of the Related Art Conventionally, when barium titanate is obtained by heat-treating a ceramic material, for example, a mixture of a carbonate and an oxide at a predetermined temperature,
A continuous heat treatment furnace having a structure called a retort type is used (for example, JP-A-5-332680).

As shown in FIG. 1, this heat treatment furnace has a furnace body 1 having both open ends, and a retort penetratingly disposed inside the furnace body 1 in an inclined state, that is, heat-resistant ceramics such as alumina and inconel. A cylindrical furnace core tube 2 made of a heat-resistant metal, a plurality of rollers 3 and 4 for rotatably supporting the furnace core tube 2, a motor 5 for rotating and driving the furnace core tube 2 via the rollers 3, A plurality of heaters 6 and the like are fixed to the furnace body 1 so as to surround the core tube 2. A raw material charging hopper 7 is disposed on the charging port side of the furnace core tube 2.
The raw material S introduced into the furnace core tube 2 from the hopper 7 is continuously conveyed through the furnace core tube 2 to the outlet side by the rotation and inclination of the furnace core tube 2, and is heat-treated during that. The object to be processed after the heat treatment is discharged to the discharge container 8.

[0004]

By the way, in the case of the retort type furnace having the above-described structure, when the material S having poor fluidity such as granules containing fine powder or moisture is to be heat-treated, The workpiece S adheres and stays on the inner wall of the furnace core tube 2,
As a result, as shown in FIG.
Caused an overflow. As the material S having poor fluidity, for example, SS (specific surface area)
= 10-80 m ² / g Ceramic powder, SS <10 m ² / g like Pb-based ceramics, but specific gravity is about 5 like fine powder with poor fluidity due to large specific gravity and fine powder ferrite. Examples include fine powder of SS ≧ 50 m ² / g, or granules having water in a capillary region in a powder-water mixture system.

In order to solve such a problem, a furnace core tube 2 is required.
Although it is possible to make the workpiece flow by increasing the rotation speed of the oil or by increasing the angle of inclination, the heat treatment conditions will change, and the desired powder characteristics will not be obtained. is there.

Accordingly, it is an object of the present invention to provide a rotating machine which can heat-treat an object having poor fluidity without adhering and staying on the inner wall of the furnace core tube and without changing the heat-treating conditions. An object of the present invention is to provide a driving type heat treatment furnace.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a furnace core tube which is tilted and horizontally supported by a bearing roller, the furnace core tube is rotated, and the furnace core tube is inserted from one end of the furnace core tube. In a rotary drive type heat treatment furnace in which heat treatment is performed while passing the processed object to the other end side, an outer peripheral surface of the furnace core tube, and an outer peripheral surface of a bearing roller rotatably supporting the outer peripheral surface At least one of the above is provided with a concave / convex portion for giving a radial vibration to the furnace core tube in accordance with the rotation of the furnace core tube.

When the core tube or the bearing roller is provided with an uneven portion, the distance from the center of the core tube to the bearing roller changes with the rotation of the core tube, and radial vibration occurs in the core tube. Let it. As described above, since factors other than rotation and inclination are added to the flow of the material to be processed in the furnace core tube, the flowability of the material to be processed is improved, and adhesion and stagnation can be prevented, and overflow is also prevented. it can.

Although the uneven portion may be provided at any part of the furnace core tube, it is desirable to provide the uneven portion on the inlet side of the furnace core tube.
In other words, if uneven portions are provided on both the inlet side and the outlet side of the furnace core tube, the entire furnace core tube vibrates, and the conveyance speed of the workpiece flowing in the furnace core tube changes with respect to the target speed. , Heat treatment conditions may change. On the other hand, when the uneven portion is provided on the input port side of the furnace core tube, while improving the fluidity of the inlet portion having the lowest fluidity, the overall transport speed of the workpiece is hardly changed, This is because the heat treatment conditions are stabilized.

In the case where the above-mentioned uneven portion is provided, it is preferable to provide a ring-shaped portion around the furnace core tube and provide the uneven portion on at least one of the ring-shaped portion and a bearing roller supporting the ring-shaped portion. In this case, an arbitrary vibration characteristic can be set according to the outer shape of the ring-shaped portion or the bearing roller.

The uneven portion in the present invention includes not only a simple uneven portion but also a case where a projection, a groove, a knurl, or an outer shape is polygonal, and generates vibration in a radial direction with the rotation of the furnace core tube. Any shape may be used as long as the shape is to be made.

[0012]

FIG. 3 shows an example of a rotary drive type heat treatment furnace according to the present invention. In the figure, the structure other than the furnace core tube 10 and the bearing rollers 20 and 21 is the same as that of the heat treatment furnace shown in FIG.

The furnace core tube 10 is a cylindrical tube made of a heat-resistant ceramic or a heat-resistant metal, and has ring-shaped portions 11 and 12 fixed to the outer periphery of the inlet and outlet ends. The ring-shaped portion 11 on the inlet side has a polygonal surface (for example, regular octagon) 13 on the outer periphery as shown in FIG. 4, and a groove 14 is formed on the top to form an uneven portion. I have. On the other hand, the outlet-side ring-shaped portion 12 has a cylindrical shape.
The furnace core tube 10 includes bearing rollers 20 and 2 provided at front and rear portions.
The support 1 supports the input port 10a in a state where the input port side 10a is slightly inclined (for example, the inclination angle is 5 °). The bearing rollers 20, 21 are also cylindrical as in the prior art. In this embodiment, the bearing roller 20 on the inlet side is driven by the motor 5, but the bearing roller 21 on the outlet side may be driven.

In the heat treatment furnace having the above-described structure, when the bearing roller 20 is driven, the furnace core tube 10 is rotated following the drive. At this time, since the concave and convex portions 13 and 14 are formed in the ring-shaped portion 11 on the input port side supported by the bearing roller 20, the furnace core tube 10 vibrates in the radial direction when passing over the concave and convex portion. Therefore, even if the material to be processed S introduced from the inlet side 10a of the furnace core tube 10 is a substance having poor fluidity,
The core tube 10 is smoothly conveyed to the outlet side 10b by the three elements of rotation, inclination, and vibration. As a result, it is possible to prevent the workpiece S from adhering or staying on the inlet side 10a of the furnace core tube 10, and to prevent the workpiece S from overflowing.

FIG. 5 shows a second embodiment of the present invention. In the first embodiment, the uneven portion is provided on the inlet-side ring-shaped portion 11 of the furnace core tube 10. In this embodiment, however, as shown in FIG. Is provided. Therefore, a small amplitude vibration can be given to the furnace core tube 10 by the uneven portion (vertical groove) 22 of the bearing roller 20, and a large amplitude vibration can be given to the uneven portion 13, 14 of the ring-shaped portion 11.

FIG. 6 shows a third embodiment of the present invention, in which small projections 15 are randomly formed on the cylindrical outer peripheral surface of the inlet-side ring-shaped portion 11 of the furnace core tube 10. In this case,
As the bearing roller, a cylindrical roller may be used.
A roller having an uneven portion as described above may be used.

The present invention is not limited to the first to third embodiments. In the above embodiment, the concavo-convex portion is provided on the ring-shaped portion 11 of the furnace core tube 10.
1 may be formed in a cylindrical shape, and an uneven portion may be provided only on the bearing roller 20.

The inlet-side ring-shaped portion 1 of the furnace core tube 10
In addition to providing an uneven portion on one or the bearing roller 20 supporting the same, the uneven portion may be provided on the outer periphery of the ring-shaped portion 12 on the outlet side or the bearing roller 21 supporting the same. In this case, the entire furnace core tube 10 can be vibrated.

Further, the bearing roller is not limited to one supporting the inlet and outlet sides of the furnace core tube. In the case of a long furnace core tube, a bearing roller supporting an intermediate portion thereof is arranged. May be. In this case, a ring-shaped portion may be provided in the middle portion of the furnace core tube, and the concavo-convex portion may be provided on the ring-shaped portion or a bearing roller supporting the ring-shaped portion.

The ring-shaped portion of the furnace core tube may be omitted, and an uneven portion may be formed on the furnace core tube itself. However, in this case, the irregularities must be formed directly on the furnace core tube, which makes processing difficult.On the other hand, if a separate ring-shaped portion is attached to the furnace core tube, the processing of the ring-shaped portion is difficult. If the ring-shaped portion is replaced in accordance with the flow characteristics of the object to be processed, one kind of furnace core tube can be applied to heat treatment of various materials. Further, the bearing roller having the uneven portion may be replaced according to the characteristics of the workpiece.

The shape of the concavo-convex portion is not limited to the one having a groove on a polygonal surface as in the embodiment, the one having a protrusion on a cylindrical surface, the vertical groove, etc., and various shapes and combinations can be used. . In any case, the shape and number of the concave and convex portions, the number of revolutions of the furnace core tube 10 and the like are set so as to have a frequency and an amplitude at which the optimum fluidity can be obtained according to the characteristics of the workpiece to be charged. It is desirable.

In the above embodiment, a heater is arranged around the furnace core tube and the furnace core tube is heated by the heater. However, for example, the furnace core tube is formed of a heat-resistant metal, and the furnace core tube is formed on the outer periphery of the furnace core tube. Any other heating method such as a method in which a coil is wound and an AC current is supplied to the coil to inductively heat the furnace core tube may be used.

[0023]

As is apparent from the above description, according to the present invention, at least one of the furnace core tube and the bearing roller for rotatably supporting the furnace core tube is provided with an uneven portion, and Because the radial vibration is given to the furnace core tube according to the rotation, even when heat-treating the workpiece with poor fluidity,
The processing object does not adhere to and stay on the inner wall of the furnace core tube, and it is possible to prevent the processing object from overflowing from the inlet of the furnace core tube.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an example of a conventional rotary drive type heat treatment furnace.

FIG. 2 is a partially enlarged view of the heat treatment furnace of FIG.

FIG. 3 is a cross-sectional view of an example of a rotary drive type heat treatment furnace according to the present invention.

4 is a perspective view of a furnace core tube and bearing rollers of the rotary drive type heat treatment furnace shown in FIG.

FIG. 5 is a second view of the furnace core tube and the bearing roller according to the present invention.
It is a perspective view of an Example.

FIG. 6 is a perspective view of a third embodiment of the furnace core tube according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Furnace tube 11,12 Ring-shaped part 13,14 Uneven part 20,21 Bearing roller 22 Vertical groove (uneven part)

Claims (3)

[Claims] A furnace roller is inclined and supported laterally by a bearing roller, and heat treatment is performed while rotating the furnace core tube and passing an object to be processed introduced from one end of the furnace core tube to the other end side. In the rotary drive type heat treatment furnace, at least one of the outer peripheral surface of the furnace core tube and the outer peripheral surface of a bearing roller rotatably supporting the outer peripheral surface has a radius formed on the furnace core tube according to the rotation of the furnace core tube. A rotary drive type heat treatment furnace comprising an uneven portion for giving a vibration in a direction. 2. The method according to claim 1, wherein the concave and convex portions are provided on at least one of an outer peripheral surface of a furnace core tube on the side of a charging port and an outer peripheral surface of a bearing roller rotatably supporting the outer peripheral surface. Item 4. A rotary drive type heat treatment furnace according to Item 1. 3. A ring-shaped part is provided on the outer periphery of the furnace core tube, and at least one of the ring-shaped part and a bearing roller rotatably supporting the ring-shaped part is provided with a concave-convex part. The rotary drive type heat treatment furnace according to claim 1 or 2, wherein: