JP2572729B2 - Heat treatment equipment for powder - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a powder heat treatment apparatus. Manufacture of various powders such as silica, tungsten, rare metals, etc. in a high temperature atmosphere by reaction and firing to produce new materials and catalysts of high purity represented by fine ceramics such as silicon nitride and silicon carbide. doing. The present invention provides a powder as described above,
In particular, the present invention relates to a powder heat treatment apparatus capable of economically and efficiently performing a reaction, calcination, and the like, even if it is an ultrafine powder having a particle size of 30 μm or less.

<Prior art and its problems> Conventionally, as a heat treatment apparatus for producing silicon nitride, silicon carbide, or the like, a raw material powder is allowed to stand in a vessel using a heater as a heating source, and a high temperature of nitrogen gas or carbon dioxide gas is used. A material which is subjected to a heat treatment in an atmosphere is used. However, in such a conventional apparatus, since the nitriding reaction and the carbonization reaction of the raw material powder occur due to the contact between the raw material powder and the reaction gas, when the raw material powder layer is thickened, unreacted substances increase, and such unreacted substances increase. To avoid an increase in the number of reactants, there is a problem that a remarkably long reaction time is required. Conversely, if the raw material powder layer is made thin, there is a problem that the whole work such as taking in and out of the raw material powder and products becomes too complicated.
A heat treatment apparatus using a laser as a heating source is also used, but in this case, there is a problem that it is difficult to control the temperature.

<Problems to be Solved by the Invention, Means for Solving the Problems> The present invention provides a powder heat treatment apparatus that solves the above-described problems of the conventional apparatus.

That is, the present invention is provided in a heating chamber surrounded by a heat-insulating furnace body having a bottom opened, a heat-insulating pedestal provided near the bottom of the furnace main body, and the furnace body and the pedestal. With a heater and a heat-resistant container, the furnace body is supported on a base,
The pedestal is supported by a base via a spring, a vibration motor is mounted on the pedestal, and the heat-resistant container is supported by the pedestal. The powder heat treatment apparatus is characterized in that a certain free movement is given to the powder in the heat-resistant container by operating the motor and sending gas into the heat-resistant container through the perforated plate. Related.

The heat treatment apparatus for powder according to the present invention is an apparatus for performing heat treatment such as reaction and baking on the powder under a high temperature atmosphere, a heat insulating furnace body having a bottom opened, and a furnace close to the bottom of the furnace body. And a heat-insulating pedestal provided in the heating chamber surrounded by the furnace body and the pedestal. The furnace body is divided into a furnace body and a pedestal, a heating chamber is formed by being surrounded by the furnace body and the pedestal, and a heater and a heat-resistant container are provided in the heating chamber.

The furnace body is supported by the base, the pedestal is supported by the base via a spring, a vibration motor is mounted on the pedestal, and the heat-resistant container is supported by the pedestal. Is provided with a perforated plate. When the vibration motor is operated, the furnace body does not vibrate, but only the pedestal supported by the spring vibrates.Therefore, the heat-resistant container supported by the pedestal vibrates, and the powder inside the heat-resistant container vibrates. Added. When gas is fed into the heat-resistant container through the perforated plate, a dispersing action is added to the powder in the heat-resistant container. When a mechanical vibration action and a dispersing action by gas introduction are applied to the powder in the heat-resistant container, the powder forms a fluidized bed given a certain free motion.

<Operation> Since vibration is applied only to the pedestal instead of applying vibration to the entire furnace body, a mechanical vibration system can be reduced in size and energy required for vibration can be reduced. Further, a fluidized bed given a certain kind of free motion is formed on the powder, and in this state, the surface is brought into contact with, for example, nitrogen gas or carbon dioxide gas to cause a reaction. According to the present invention, the reaction and firing of the powder can be performed economically and efficiently.

Hereinafter, the configuration of the present invention will be described in more detail with reference to the drawings.

<Embodiment> FIG. 1 is a longitudinal sectional view schematically showing an embodiment of the present invention. The furnace body 20 is constructed of a furnace shell 21 having a substantially inverted U-shaped vertical section and a heat insulating material 31 attached to the inner peripheral surface of the furnace shell 21.
Reference numeral 21 extends downward and is supported by the base 11.
A pedestal 51 is provided near the opened bottom of the furnace body 20, and the pedestal 51 is a furnace shell 22 having a substantially U-shaped vertical section and a cylindrical shape attached to the inner peripheral surface of the furnace shell 22. The heat insulating material 32 and the refractory material 34 embedded in the cylindrical space of the heat insulating material 32 are constructed. The furnace shell 22 is supported on the base 11 via springs 61 and 62, and a mounting frame 23 extends downward from the furnace shell 22,
The vibration motor 71 is mounted on the mounting frame 23.

A heating chamber 41 is formed surrounded by the furnace body 20 and the pedestal 51, and a heater 42 and a heat-resistant container 81 are provided in the heating chamber 41. Supported. A perforated plate 82 is attached to the lower part of the heat-resistant container 81,
A chamber 83 is formed below the perforated plate 82 between the heat-resistant container 81 and the chamber 83, and the chamber 83 is almost covered with the heat insulating material 33. A gas supply pipe 91 is connected to the chamber 83 through the heat insulating material 33, the heat-resistant container 81, and the refractory material.

For example, ceramic fibers can be used as the heat insulating materials 31, 32, and 33, and refractory bricks can be used as the refractory material 34, and further, for example, a carbon container can be used as the heat-resistant container 81. However, the present invention specifically limits such materials. is not. Although not shown, a water-cooling jacket can be attached to the inner peripheral surfaces of the furnace shells 21 and 22, and a supply pipe for raw material powder and a discharge pipe for products can be connected to the heat-resistant container 81 from outside the furnace.

Next, a case where silicon nitride is manufactured using the apparatus of the illustrated embodiment will be described.

The furnace shell 21 is lifted together with the heat insulating material 31 to open the heating chamber 41, and the raw material powder A is put into the heat-resistant container 81. And insulation
The furnace shell 21 is suspended together with the furnace shell 31, and the furnace shell 21 is fixed to the base 11.

Subsequently, nitrogen gas is supplied while the atmosphere in the heating chamber 41 is sucked and exhausted by a vacuum pump (not shown), and the inside of the heating chamber 41 is gas-replaced. Then, while heating the inside of the heating chamber 41 to a predetermined temperature by the heater 42, the vibration motor 71 is operated to vibrate the heat-resistant container 81 together with the receiving table 51, and the piping 91 and the porous plate 82
Through which nitrogen gas is fed from below the raw material powder A. As a result, the raw material powder A forms a fluidized bed given a certain kind of free motion. Even in the case of extremely fine powder which cannot be satisfactorily fluidized by conventional fluidizing means, it is possible to form a fluidized bed as if it were a liquid by synergistic action of vibration and introduction of gas (in this case, nitrogen gas). You can. Thus, the nitriding reaction of the raw material powder A caused by the contact between the surface of the raw material powder A and the nitrogen gas is remarkably promoted.

After the raw material powder A is heat-treated for a predetermined time in the above-described state, the heating by the heater 42, the operation of the vibration motor 71, and the supply of nitrogen gas are stopped, and the mixture is legally cooled. To open the heating chamber 41,
Recover silicon nitride from 81.

<Effect of the Invention> As described above, according to the present invention, even if it is an ultrafine powder having a particle size of 30 μm or less, the reaction and firing of the powder in a high-temperature atmosphere are extremely economical and efficient. There is an effect that it can be performed in an efficient manner.

[Brief description of the drawings]

 FIG. 1 is a longitudinal sectional view schematically showing an embodiment of the present invention. 11 Base, 20 Furnace body, 21, 22 Furnace shell 31, 32, 33 Insulation material, 34 Refractory material 41 Heating chamber, 42 Heater, 51 Cradle 61, 62: Spring, 71: Vibration motor 81: Heat-resistant container, 82: Perforated plate, 83: Chamber 91: Piping, A: Raw material powder

Claims (1)

(57) [Claims] An insulated furnace body having a bottom opened, a heat-insulating pedestal provided near the bottom of the furnace body, and a heating chamber surrounded by the furnace body and the pedestal. It has a heater and a heat-resistant container, the furnace body is supported by the base, the receiving table is supported by the base via a spring, the vibration motor is attached to the receiving table, and the heat-resistant container is supported by the receiving table. The perforated plate is attached to the lower part of the heat-resistant container, and a certain free movement of the powder in the heat-resistant container is caused by the operation of the vibration motor and the introduction of gas into the heat-resistant container through the perforated plate. And a heat treatment apparatus for powder.