JPH0684866B2 - Continuous heat treatment furnace - Google Patents

Description

TECHNICAL FIELD The present invention relates to a heat treatment furnace capable of continuously treating various powders and granules up to a high temperature range of more than 2000 ° C.

[Conventional technology]

In general, there are two types of heat treatment furnaces: one that heats by combustion and one that generates heat by electric resistance. In addition to the batch type, a continuous type structure using various tunnel furnaces is known as the structural type of the furnace.

[Problems to be Solved by the Invention]

Among these conventional heat treatment furnaces, the combustion furnace has the advantages of low heat source cost and no need for large-scale power receiving equipment, but it causes noise, vibration, rise in ambient temperature due to exhaust gas, etc. and environmental pollution compared to the electric resistance furnace. In addition, there are some inconvenient factors such as expansion of equipment space and difficulty of automatic start. On the other hand, the electric resistance furnace can maintain a clean furnace environment in which high temperatures can be obtained relatively easily, noise, vibration, exhaust gas, etc. are minimal, temperature control is easy and good temperature distribution can be obtained. Although it has many advantages, it is inferior to the combustion furnace in terms of heat cost.

For continuous tunnel furnaces, truck furnaces, pusher furnaces,
There is a method such as the Belcon furnace, but when using a dolly, the heat loss brought out by the dolly is large, complicated equipment such as a feeder and a return device is required in the pusher furnace, and the ceramic material used for the chain in the Belcon furnace There is a problem that the operating temperature of the furnace is determined by the above. Moreover, since a normal tunnel furnace is not of a completely closed type, when a gas atmosphere other than the atmosphere is required, a large amount of atmosphere gas must be fed in, and heat loss due to exhaust gas cannot be ignored.

The present invention solves the problems of the heat treatment furnace having the conventional structure, and provides a hermetically sealed type heat treatment furnace capable of continuously processing various powders by the electric resistance method to a high temperature range exceeding 2000 ° C. It is a thing.

[Means for Solving the Problems]

That is, the continuous heat treatment furnace according to the present invention is equipped with a rotary disk that is horizontally rotated by a driving means inside a closed inner box that is covered with a heat insulating material, and supplies the object to be processed to the upper surface of the rotary disk. Feeder, a rod-shaped or plate-shaped heater for heating the rotating disk installed on the upper and / or lower part of the rotating disk corresponding to the diagonal position of the feeder and the collector, and the inflow port on the outer edge of the rotating disk surface. In such a state, it is installed in a position adjacent to the feeder, each collector is provided for collecting the heat-treated object through the scraper, and the disk area up to the feeder and the heater on the rotating disk surface is preheated and heated. The disk area corresponding to the heat generating part is classified as the heating area, and the disk area from the heater to the collector is classified as the cooling area. It characterized in construction to forming.

The closed inner box is formed of a high temperature heat resistant material such as a carbon material, and the periphery thereof is covered with a heat insulating layer such as carbonaceous granular material and carbon fiber and an inorganic heat insulating board. In addition, it is desirable that members such as a rotary disk, a feeder, a scraper, and a collector installed inside the closed inner box are also made of a carbon material. As the heater, for example, a rod-shaped or plate-shaped carbonaceous resistance heating element is preferably used, and the upper portion of the rotary disk corresponding to the diagonal position of the feeder and the collector,
Set at the bottom or top and bottom.

The preheating zone, heating zone, and cooling zone are designed so that the positional distance between the feeder and the heater and the heater and the collector are approximately equal on the rotating disk surface, and the disk between the feeder and the heater is arranged in the rotating direction of the rotating disk. An area is divided into a preheating area, a disk area corresponding to a heater heating portion is a heating area, and a disk area from the heater to the collector is a cooling area. It is not necessary to install compulsory preheating means or cooling means in the preheating zone and the cooling zone.

[Work]

In the continuous heat treatment furnace having the above structure, the object to be processed dropped from the feeder continuously passes through the preheating zone, the heating zone and the cooling zone together with the rotating disc horizontally rotating in the closed inner box,
Finally, it is collected by the scraper in the collector.
Through this furnace operation, the outflow of heat to the outside of the system is effectively controlled, and it is possible to easily secure a temperature in the high temperature furnace of over 2000 ° C. Further, since it is a hermetically sealed type, it is not necessary to send in a large amount of atmospheric gas, and it is possible to reduce heat loss accompanying exhaust gas, save space in the furnace body, and simplify equipment.

〔Example〕

 Embodiments of the present invention will be described below with reference to the drawings.

1 is a longitudinal sectional view showing an embodiment of the present invention, FIG. 2 is a plan sectional view taken along the line AA 'in FIG. 1, and a perspective explanatory view showing the main part of the furnace in FIG. Is.

In these figures, 1 is a closed inner box defined by a carbon material, and the periphery thereof is covered with a carbonaceous granular heat insulating material 2 and a peripheral heat insulating board 3. Inside the closed inner box 1, a rotary disk 4 formed of a carbon material having a gear engraved on its circumferential surface is rotatably mounted by a plurality of bottom surface supporting rollers 5 and side surface supporting rollers 6. 7 is a motor 8
Also, a carbon drive means (pinion) attached to a drive shaft that is connected to the speed reducer 9 and penetrates from the outside of the system is installed so as to mesh with the gear of the rotary disk 4.

10 is a feeder penetratingly installed from the upper part of the sealed inner box 1 in such a form that the supply port 11 is located on the surface of the rotating disk 4, and 12 is a state in which the inlet 13 is on the outer edge of the surface of the rotating disk 4. The collector is a penetrating installation in the lower part of the closed inner box 1, and a scraper 14 is provided on the upper surface of the rotary disk 4 corresponding to the inflow port 13. The object to be processed supplied to the feeder 10 and the collector 12 is the rotating disk 4
They are installed adjacent to each other so that they can be collected by making a full turn around, and appropriate flow rate adjusting devices 15 and 16 such as a balg are attached to each.

Reference numeral 17 is a heater for a rotating disk, which is composed of a rod-shaped carbonaceous resistance heating element, and a plurality of heaters are installed above and / or below the rotating disk 4 in the sealed inner box 1. The heater 17 is installed at a diagonal position with respect to the feeder 10 and the collector 12, and as shown in FIG. 2, a preheating zone, a heating zone and a cooling zone are formed separately on the surface of the rotary disk 4.

During the furnace operation, the heater 17 is energized to raise the temperature of the inside of the closed inner box 1 to a predetermined temperature, and then the driving means 7 is operated to horizontally rotate the rotary disk 4. In this state, when the powdery or granular material 18 is supplied from the feeder 10, the material 18
Moves continuously in the preheating area, the heating area and the cooling area as the rotary disk 4 rotates, and finally falls into the collector 12 by the scraper 14 to complete the heat treatment.

Using the continuous heat treatment furnace of the present invention having the above structure, the temperature was raised from 1000 ° C. to 2000 ° C. at a heating rate of 10 ° C./min, and the temperature was increased to 30 ° C. at 2000 ° C.
After holding for a minute, heat treatment was performed on carbon spheres with an average diameter of 2 mm under the temperature conditions of heating from 2000 ° C to 1000 ° C at a rate of 10 ° C / min.
And, the amount of oxidative consumption of the processed material when the N ₂ gas feed rate is 60 / kg is
It was 0.2%.

For comparison, using a pusher type tunnel furnace with a conventional structure, the temperature was raised from room temperature to 2000 ° C. at a heating rate of 10 ° C./min,
After holding at 2000 ℃ for 30 minutes, from 2000 ℃ to room temperature 10 ℃ /
The same carbon spheres were heat-treated under the temperature condition of lowering the temperature in minutes. The electric power in this case is 60 KW / kg, and the N ₂ gas feed rate is 1
The oxidative consumption at 000 / kg was 1.5%.

〔The invention's effect〕

As described above, according to the present invention, excellent thermal efficiency facilitates
Since a compact and simple structure continuous heat treatment furnace capable of ensuring a high temperature exceeding 2000 ° C. is provided, heat treatment of various powders can be efficiently performed.

[Brief description of drawings]

1 is a vertical sectional view showing an embodiment of the present invention, and FIG. 2 is a plane sectional view taken along the line AA 'in FIG. FIG. 3 is a perspective explanatory view showing a main part of the furnace of the present invention. 1 ... Closed inner box, 2 ... Carbonaceous granular heat insulating material, 3 ... Peripheral heat insulating board, 4 ... Rotating disk, 5 ... Bottom supporting roller, 6 ... Side supporting roller, 7 ... Driving means, 8 ...... Motor, 9 ...... Reduction device, 10 …… Feeder, 11 …… Supply port, 12 …… Collector, 13 …… Inlet port, 14 …… Scraper, 15, 16 …… Flow adjustment device, 17 ・ ・ ・… Heater, 18… Object to be processed.

Claims (1)

[Claims] 1. A closed inner box (1) covered with a heat insulating material (2).
A rotary disk (4) that is horizontally rotated by a driving means (7) is provided inside the feeder, and a feeder (10) for supplying an object to be processed onto the upper surface of the rotary disk, the feeder (1).
0) and the collector (12) diagonally located on the rotary disk, which is installed above and / or below the rotary disk for heating the rotary disk, such as a rod-shaped or plate-shaped heater (17) and the inlet (13) rotate The collector (12) is installed at a position adjacent to the feeder (10) so as to cover the outer edge of the disk surface, and each collector (12) for collecting the heat-treated object through the scraper (14) is arranged and rotated. On the disk surface, the disk area from the feeder (10) and the heater (17) is classified as the preheating area, the disk area corresponding to the heater heat generation area is classified as the heating area, and the disk area from the heater (17) to the collector (12) is classified as the cooling area. A continuous heat treatment furnace characterized by being formed.