JPH0838923A - Device for heat-treating ceramic material - Google Patents

Abstract

PURPOSE:To provide the heat-treating device with the heat efficiency improved, with the effect of an electrical noise generated by electromagnetic induction on other devices reduced and with the vessel easily exchanged. CONSTITUTION:This device is provided with a horizontally supported columnar cylindrical vessel 1 rotated around the axial center P and many rolling bodies 2 called media (cobbles) contained in the vessel 1. A lid plate 3 is fixed on both ends of the vessel 1, and a hole 4, from which the rolling body 2 is not discharged but the disintegrated ceramic powder S is discharged, is fixed to the lid plate 3. Either the vessel 1 or the rolling body 2 is formed from a conductive material such as a heat-resistant metallic material generating heat by electromagnetic induction. A coil 6 for electromagnetic-induction heating to electromagnetically induce the conductive material is furnished in the vessel 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic raw material heat treatment apparatus used for obtaining a ceramic powder by subjecting a mixture of a ceramic raw material and a solvent (hereinafter referred to as ceramic slurry) to heat treatment such as drying and calcination. .

[0002]

2. Description of the Related Art A ceramic raw material heat treatment apparatus (hereinafter referred to as a heat treatment apparatus) is shown in FIG.
In FIG. 2, a truncated cone-shaped cylindrical container 1 which is supported laterally and is driven to rotate about an axis P, and a large number of rolling elements 2 accommodated in the cylindrical container 1 are provided. And
Cylindrical communication pipes 16 and 17 are connected to the large-diameter side end and the small-diameter side end of the cylindrical container 1, respectively, and the communication pipe 17 of the cylindrical container 1 is lower than the communication pipe 16. It is supported as an inclined state.

Further, the outer periphery of the cylindrical container 1 is surrounded by a housing 5 made of a heat insulating material, and each of the communication pipes 16 and 17 penetrating the housing 5 and protruding to the outside is formed by rollers 8 and 9, respectively. It is supported. And
An electric motor 10 is connected to the roller 8 that supports the communication pipe 16, and the cylindrical container 1 is rotated by the rotational movement of the electric motor 10 being transmitted to the communication pipe 16 via the roller 8. Furthermore, a heating element 18 is provided inside the housing 5 around the outer periphery of the cylindrical container 1, and the cylindrical container 1 is heated by the heating element 18 from the outside.

The heat treatment apparatus is provided with a slurry supply device 11 for supplying the ceramic slurry L into the cylindrical container 1 and a recovery container 15 for recovering the heat-treated ceramic powder S. . The slurry supply device 11 includes a slurry storage tank 12 in which the adjusted ceramic slurry L is stored, a slurry supply pipe 13 and a fixed amount supply pump 14 extending from the slurry storage tank 12, and the slurry supply pipe 13 is drawn into the inside of the cylindrical container 1.

That is, in this heat treatment apparatus, the ceramic slurry L is supplied from the slurry supply pipe 13 into the cylindrical container 1 in small amounts, and the solution in the supplied ceramic slurry L is heated. It is vaporized by coming into contact with the cylindrical container 1 and the rolling element 2 thus formed. On the other hand, the ceramic component in the ceramic slurry L from which the solution component has evaporated is attached to the surface of each rolling element 2.

Since these rolling elements 2 collide with each other as the cylindrical container 1 rotates, the ceramic components on the surface of the rolling element 2 are rubbed together to be finely crushed into ceramic powder S. Communication pipe 1
It is discharged from the outside to the outside and is stored in the recovery container 15.

[0007]

By the way, in the heat treatment apparatus having the above-mentioned conventional structure, the ceramic slurry L is indirectly heated after passing through the cylindrical container 1 and the rolling element 2 heated by the heating element 18. In addition, since the amount of heat that can be supplied to the ceramic slurry L out of the amount of heat consumed by the entire heat treatment apparatus is low, the thermal efficiency is poor, and it is difficult to improve the thermal efficiency due to the structure of the heat treatment apparatus. Further, in order to prevent the heat radiation to the outside of the heat treatment apparatus, the housing 5 becomes thick and the heat treatment apparatus becomes large in size.

Therefore, the applicant of the present application has proposed a heat treatment apparatus which has not been publicly known yet. This heat treatment apparatus has almost the same configuration as that shown in FIG. 2, and increases the amount of heat that can be supplied to the ceramic slurry L to enhance the thermal efficiency and to uniformly heat the heat source 18, so that the heating element 18 is changed to a coil body for electromagnetic induction heating. It is a thing.

Although this heat treatment apparatus has solved the problem in terms of thermal efficiency, it is newly caused by the leakage of magnetic lines of force to the outside of the heat treatment apparatus due to electromagnetic induction and the influence of electromagnetic noise on peripheral instrumentation. There are new problems such as malfunction of the device. In addition, the conventional heat treatment apparatus has a problem that when changing the composition of the ceramic slurry L, the heating element and the roller are obstructive when exchanging the cylindrical container, and the workability of exchanging is poor.

The present invention solves these problems and improves the thermal efficiency so that electrical noise generated by electromagnetic induction has little effect on other devices and makes it easy to replace the container. It is intended to be provided.

[0011]

The invention according to claim 1 is
A cylindrical container, which is laterally supported and driven to rotate about its axis, and to which ceramic slurry is supplied, and a large number of rolling elements housed in the cylindrical container are provided. At least one of the moving bodies is made of a conductive material, and is a ceramic raw material heat treatment apparatus in which a coil body for electromagnetic induction heating is arranged in a cylindrical container.

[0012]

This heat treatment apparatus is based on the electromagnetic induction action because either or both of the cylindrical container and the rolling element made of the conductive material are made of the conductive material when the coil body for electromagnetic induction heating is energized. It is heated by self-heating. Since heating due to such self-heating occurs in a uniform state in the entire tubular container, etc., if ceramic slurry is supplied onto the tubular container or rolling element heated by self-heating, the ceramic slurry will be Will be heat-treated under a uniform heating condition.

By arranging the coil body for electromagnetic induction heating in the cylindrical container, the heating element or the coil body for electromagnetic induction heating is arranged outside the cylindrical container as in the conventional example. In comparison, the entire device can be downsized. In particular, compared to a coil container for electromagnetic induction heating arranged outside the cylindrical container, it is possible to reduce the influence of noise on other peripheral devices and eliminate the risk of causing other peripheral devices to generate heat. can do.

Furthermore, since the coil body for electromagnetic induction heating, which is the heating source, is arranged inside the cylindrical container, the heating element and the electromagnetic induction arranged around the cylindrical container as in the conventional case. Since the coil body for heating is not arranged, the tubular container can be easily replaced.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a vertical sectional view showing a schematic structure of a heat treatment apparatus according to this embodiment. In this heat treatment apparatus, the same components as those in the conventional example are designated by the same reference numerals as those in FIG.

As shown in FIG. 1, the heat treatment apparatus according to this embodiment includes a cylindrical container 1 which is laterally supported and is driven to rotate about an axis P, and a large number of cylindrical containers 1 accommodated in the cylindrical container 1. It has a rolling element 2 called media (cobblestone).
As the cylindrical container 1, a cylindrical container having the same diameter is used. Lid plates 3 are attached to both ends of the cylindrical container 1,
The cover plate 3 is provided with holes 4 through which the crushed ceramic powder described later is discharged without discharging the rolling elements 2.

Here, at least one of the cylindrical container 1 and the rolling element 2 is made of a conductive material such as a heat-resistant metal material (for example, stainless steel, titanium, or semi-killed material) that generates heat by a coil body for electromagnetic induction heating described later. Steel). The rolling element 2 may have a spherical shape or a cylindrical shape, and is appropriately selected in consideration of the internal volume of the cylindrical container 1, the average particle diameter of the ceramic powder to be obtained, the maximum particle diameter, and the like. To be done.

Further, the outer periphery of the cylindrical container 1 is surrounded by a housing 5 made of a heat insulating material, and the cylindrical container 1
One end portion on one side projects outward from one end portion of the housing 5 and is supported by the roller 8. The roller 8 is connected to the electric motor 10 and is rotationally driven by the electric motor 10. Further, the other side end of the cylindrical container 1 projects from the other end of the housing 5, and the rotatable roller 9
Supported by. Therefore, this cylindrical container 1
Is driven to rotate at a predetermined rotation speed by the electric motor 10 via the roller 8.

On the other hand, in the cylindrical container 1, a coil body 6 for electromagnetic induction heating is arranged. The coil body 6 for electromagnetic induction heating is connected to an AC power supply 7. Therefore, when the coil body 6 for electromagnetic induction heating is energized, either one or both of the cylindrical container 1 and the rolling element 2 made of a conductive material self-heats based on the electromagnetic induction effect. While being heated.

Furthermore, this heat treatment apparatus comprises a slurry supply device 11 for supplying the ceramic slurry L into the cylindrical container 1, and a recovery container 15 for recovering the heat-treated ceramic powder S. The slurry supply device 11 is installed above one end side of the housing 5 from which the tubular container 1 is projected, while the recovery container 15 having an upward opening surface is the other end of the housing from which the tubular container 1 is projected. It is installed below the department.

The slurry supply device 11 is composed of a slurry storage tank 12 in which the adjusted ceramic slurry L is stored, a slurry supply pipe 13 and a fixed amount supply pump 14 extending from the slurry storage tank 12. The slurry supply pipe 13 is drawn into the inside of the cylindrical container 1. The cylindrical container 1 is installed at a certain angle such that the side on which the slurry supply pipe 13 is drawn is on the upper side and the side on which the ceramic powder S is discharged is on the lower side.

Therefore, the ceramic slurry L is supplied by dropping from the open end of the slurry supply pipe 13 drawn into the cylindrical container 1 onto the rolling elements 2 in the cylindrical container 1. It will be. The method of supplying the ceramic slurry L is not limited to dropping, and a nozzle (not shown) is attached to the other end of the slurry supply pipe 13 to attach the ceramic slurry L to the upper inner surface of the cylindrical container 1. Needless to say, a supply method such as spraying may be adopted. At this time, the slurry supply pipe 13
It is desirable to provide a valve (not shown) for controlling the supply amount of the ceramic slurry L or the like at an intermediate position or the like.

Next, the process of obtaining the ceramic powder S by performing heat treatment such as drying and calcination on the ceramic slurry L by using the heat treatment apparatus according to this embodiment will be described.

First, while preparing a ceramics slurry L in which components have been prepared by adding and mixing a solution such as water or an organic solvent, a cylindrical container 1 accommodating a large number of rolling elements 2 is driven by an electric motor 10 at 5 to 30 rpm. While rotating at a degree,
By energizing the coil body 6 for electromagnetic induction heating, one of the cylindrical container 1 and the rolling element 2 made of a conductive material is heated to a predetermined temperature while self-heating.

The adjustment of the heating state is performed by controlling the energization of the coil body 6 for electromagnetic induction heating. When only the cylindrical container 1 is made of a conductive material, the rolling element 2 is heated via the self-heated cylindrical container 1, and the rolling element 2 is electrically conductive. When they are made of a material, they are heated by themselves.

Subsequently, the ceramic slurry L stored in the slurry storage tank 12 constituting the slurry supply device 11 is dripped from the open end of the slurry supply pipe 13 to supply the small amount into the cylindrical container 1. Here, the solution component such as water contained in the ceramic slurry L that has been in contact with the rolling element 2 which has been heated in advance is quickly evaporated, and the ceramic component in the ceramic slurry L adheres to the surface of the rolling element 2. And will remain.

At this time, since a large number of rolling elements 2 are mixed with each other as the cylindrical container 1 rotates, the ceramic components remaining on the surfaces of the rolling elements 2 collide with each other. It is crushed by being rubbed against each other.

And finely crushed ceramic powder S
Are discharged through the holes 4 of the lid plate 3 provided in the cylindrical container 1. Then, it will be collected in the recovery container 15 installed on the lower side of the cylindrical container 1. The residence time of the ceramic slurry L in the cylindrical container 1, that is, the time required from the supply of the ceramic slurry L to the discharge of the ceramic powder S is adjusted by adjusting the tilted state and the rotation speed of the cylindrical container 1. Will be controlled by.

The supplied ceramic slurry L
In the case of containing a ceramic component such as iron, the ceramic slurry L is also subjected to the electromagnetic induction action from the coil body 6 for electromagnetic induction heating, and the ceramic slurry L itself generates heat. It will be.

[0030]

As described above, according to the heat treatment apparatus of the present invention, at least one of the cylindrical container and the rolling element is self-heated based on the electromagnetic induction action by energizing the coil body for electromagnetic induction heating. Therefore, the self-heating at this time heats either the cylindrical container or the rolling element in a substantially uniform state over the entire surface.
Therefore, by supplying the ceramic slurry on the rolling elements that are heated by self-heating, the heat treatment is performed on the ceramic slurry under a uniform heating condition. It is possible to suppress the generation of substances, and it is possible to obtain a ceramic powder having uniform and stable characteristics.

Further, unlike the conventional example, the heat insulating material forming the housing is not directly heated by the heating means, and the effect of improving the heating efficiency for the ceramic powder can be obtained.

Furthermore, since the coil body for electromagnetic induction heating is arranged in the cylindrical container, compared to the conventional case where the heating element and the coil body for electromagnetic induction heating are arranged outside the cylindrical container. Thus, the entire device can be downsized. In particular, the influence of electromagnetic noise on other devices in the vicinity can be reduced as compared with the case where the coil body for electromagnetic induction heating is arranged outside the cylindrical container. Compared to the one in which a heating element and a coil for electromagnetic induction heating are arranged around the cylindrical container, the outer circumference of the cylindrical container has a simple structure. The heat treatment equipment can be easily handled by changing raw materials frequently due to small-scale production.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a heat treatment apparatus according to an embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view showing a heat treatment apparatus according to a conventional example.

[Explanation of symbols]

 1 Cylindrical Container 2 Rolling Element 3 Lid Plate 4 Hole 5 Housing 6 Electromagnetic Induction Heating Coil Body 7 AC Power Supply 8, 9 Roller 10 Electric Motor 11 Slurry Supply Device 12 Slurry Reservoir 13 Slurry Supply Pipe 14 Quantitative Supply Pump 15 Recovery Container P axis L L ceramic slurry S ceramic powder

Claims (1)

[Claims] 1. A cylindrical container which is laterally supported and rotationally driven about an axis and to which a ceramic slurry is supplied,
A plurality of rolling elements housed in the tubular container, at least one of the tubular container and the rolling element is made of a conductive material, and electromagnetic induction heating is provided in the tubular container. A ceramic raw material heat treatment apparatus, characterized in that the coil body is provided.