JPS5892786A - Rotary type reaction furnace - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] This invention is based on silicon nitride powder *! This article concerns an improved rotary one-type reactor that enables α-type silicon nitride powder to be obtained efficiently and in high yield.

Silicon nitride, especially alpha silicon nitride (α type 81, N4)
The sintered body has high mechanical strength and spall resistance, and is currently attracting attention from various quarters as a electrified silicon structure.Therefore, various studies are being conducted on the production of electrified silicon powder, which is the raw material for electrified silicon. , proposals have been made. Patent application 1977-113
762, patent application 1851-7694, patent application 1972-150
802, patent application i852-16037, patent application 1972-48
373 is an example. However, all of these proposals relate only to methods for producing silicon nitride powder.

By the way, the problem in the production of silicon nitride powder is 1. In addition to the koji process itself, various problems have been pointed out in the structure of the reactor used during production.
As a result of our efforts to develop an optimal reactor for efficient production, we have completed the following three inventions.

In other words, the invention of @l has a raw material powder inlet at one end and a reaction product outlet at the other end, tilts a rotary leech tube with an atmosphere of N or gas inside, and rotates the rotary leach tube. At the same time, the reactor for producing silicon nitride powder is designed to heat and react the raw materials transferred from the input port to the output port using a heating device. Rotary reach five-! It is a one-type reactor that is characterized by being installed inside the... ! The invention g2 is characterized in that instead of providing a scraping device in the reactor according to the first invention, the heating device attached to the reactor can be moved to the outer periphery of the reactor wall where reaction by-products adhere,
The invention of @3 is also characterized in that, instead of providing a scraping device, the furnace wall in the local area where reaction by-products adhere is made porous, and nitrogen gas blowing holes are provided here. These inventions will be described below based on the illustrated embodiments.

FIG. 1 shows an embodiment of the first invention of the present application.

In the figure, L denotes a furnace body, and this furnace is entirely made of a rotary reach.

A furnace body 2 composed of a cylindrical graphite container is arranged so as to be inclined as a whole, and the outside thereof is covered with a heat insulating material 3. A raw material inlet 5 and a reaction product outlet 6 are provided on both side lids 41e41 of the furnace body. In order to maintain the inside of the furnace in a nitrogen atmosphere, a nitrogen gas inlet 1 is provided on the side where the reaction product is deposited, and nitrogen gas is introduced through this port. 8 is a high frequency induction filter, and 0g fixed to the outer periphery of the reaction zone of the furnace body 2 is an exhaust gas outlet.

10. Scraping of reaction by-products provided in % in the invention -
It is a place. The furnace body in this invention is rotatable about a central axis in the longitudinal direction or can be rotated within 36 degrees, and is conveniently connected to a device (not shown) that applies appropriate vibrations. The reactor according to the present invention is as described above, and its operation is as follows.

**After the coil 1 is energized to heat the inside of the furnace, N heavy gas is introduced into the furnace through the gas inlet r, and raw materials are introduced through the raw material input port 5. At the same time, the furnace body is rotated or rotated so that the input raw material is rolled in the furnace.

The raw material used in the present invention is, for example, silica powder or 5i
- Add at least 11111 of silicon nitride powder, silicon carbide powder, and silicon oxynitride powder to compound powder and cargane powder containing the o component to prepare a mixed raw material powder,
This is used by granulating it so that the minor axis is 30 mm or less. The heating temperature is usually 1,300 to 1,550°C so that the reduction and nitriding reactions of silica can be carried out satisfactorily. Furnace rotation/
The transfer rate varies depending on the temperature inside the furnace, the amount of raw material supplied, etc., but if it is too slow, a good transfer state of the raw material cannot be obtained, and if it is too fast, the granulated particles will break, so it is determined at a degree that satisfies both of these conditions. . When raw materials are continuously supplied under such conditions, the input raw materials react while forming a fluidized bed in the inclined furnace body while passing from the inlet to the outlet, and are sequentially transferred to the outlet. Silicon nitride powder is continuously obtained through the outlet 6. The rolling of the furnace body can be done by rotating the outer furnace body not only by 360° or more, but also by applying appropriate vibrations to the outer furnace body by rotating by less than 360". As described above, the reduction and nitriding reaction of silica is carried out over a long period of time. 81 on the inner wall of the furnace
Reaction by-products containing C as a main component solidify. This reaction by-product is vaporized in the reaction zone where the heating device is installed, but just before it is discharged into the atmosphere from the exhaust gas exhaust hole, it is cooled, solidified, and deposited on the upper part of the furnace inner wall. .

According to the results of experiments, the inner diameter of the furnace reaches Vl 0, which significantly impedes the smooth flow of raw materials and the N3 bus, and as a result has an adverse effect on the reaction.

Therefore, in the present invention, in such a case, the operation is stopped, the reaction by-products are scraped off using the scraping device 10, and this is vaporized while being heated, and N and gas are introduced thereto. Discharge outside the furnace. These problems are easily resolved when the vehicle is restarted.

2a illustrates an embodiment of the second invention of the present application. In this invention, unlike the first invention, the movable heating induction coil 11 is gently slid around the outer periphery of the furnace body, and is moved from the reaction zone to the outer periphery of the reaction by-product solidification area. When the reactor is operated, it is cooled, solidified on the inner wall of the furnace, and melted into a 9-reaction hard material.When further heated, it is vaporized and discharged from the furnace through the exhaust port 9. Then, the operation should be restarted again.The second invention has the same structure as the first invention, except that the scraping device is removed in the first invention, and the induction heating device is made movable. , and therefore operate similarly.

FIG. 3 shows an embodiment of the third invention. This invention also has a separate device for removing by-products that adhere to the inner wall of the furnace, and is similar to the inventions No. 1 and IIIE No. 2 except for this point. Removal of reaction by-products in the invention of @3 As shown in Figure 3, a porous lens was fitted in the part of the inner wall of the reactor where the by-products were fixed, and gas was constantly supplied to it for 1 hour.

This is to prevent reaction by-products from sticking to the shell. In this case, a ring-shaped introduction pipe is installed around the outer periphery of the furnace body to enclose the rotating medium KNs gas.
If so, there is no need for a bottle, so the equipment can be used regularly, making it more economical from a physical standpoint.

As described above, the present invention has been widely used in the production of silicon nitride powder using a new method that does not require conventional methods, that is, it is possible to carry out the reduction and nitriding reaction while rolling the raw material powder, and to reduce the amount of reaction by-products produced by the reaction. Since the removal is carried out in a timely manner and the inside of the furnace can always be kept in the hottest condition, the reaction efficiency can be greatly improved.

[Brief explanation of drawings]

Figures 1 to 3 are ζO Yamei's 1 to Il! 9 shows a side cross-sectional view of each of the three embodiments of the four-tary one-type reactor. 1-furnace body, 2-furnace body, 1-insulating material, 41. 4s-plexus, 5-・raw material inlet, C-outlet, r-N, f
1-high frequency induction; il, coolant/exhaust fx @ outlet, 10-scraping device, 11-movable heating induction coil, 1
2- Porous brick. Applicant's agent: Patent Attorney Dosu Hiko Oshiki Procedural Amendment 1. Indication of the case Japanese Patent Application No. 188868/1988 2 Name of the invention Rotary one-way reactor 1 Person making the amendment Relationship to the case Patent applicant Address: 5-26-2 Nishi-Shinjuku, Shinjuku-ku, Tokyo 160 Table Voluntary amendment Amendment Detailed description of the invention column a in the companion specification Subsistence of amendment (1) On page 5 of the specification, lines 14 to 16, it is stated that ``The induction coil 8 was energized to heat the inside of the furnace. After that, Ng gas is introduced into the furnace from the gas introduction lower, and the raw material is introduced from the raw material input port 5.'' The atmosphere is set, the induction coil 8 is energized to heat the inside of the furnace, and raw materials are introduced from the raw material input port 5. ” he corrected. (2) On page 6, line 13 of the specification, the phrase "moving mackerel" is corrected to read "transferred powder bed." (3) On page 6, line 19 of the specification, r SiCJ
Correct the statement to rsiOJ.

Claims (3)

[Claims] (1) A four-tally chain with a raw material powder inlet at one end and a reaction product outlet at the other end with an internal N gas atmosphere is tilted and installed in the reaction zone while rolling. In a reactor for producing silicon nitride powder, which heats and reacts raw materials transferred from an input port to an output port using a heating device, a rotary reach island is used to remove reaction by-products stuck to the furnace wall. A four-tary one-type reactor characterized by being installed inside the reactor. (2) A raw material powder inlet is provided at one end and a reaction product outlet is provided at the other end, the interior is set to a nitrogen or gas atmosphere, and a nine-rotary reach is tilted, and the rotary reach is moved and placed in the reaction zone. In a reactor for producing silicon nitride powder, which is heated and reacted with raw materials transferred from an input port to an output port using a heating device, the heating device can be moved to the outer periphery of the furnace wall where reaction by-products are adhered. A four-tary one-type reactor characterized by the following. (3) A rotary reach is provided with a raw material powder inlet at one end and a reaction product outlet V at the other end, the inside of which is kept in an N3 gas atmosphere at an angle of 1 degree, and the rotary reach is rotated while the reaction takes place. In a reactor for producing silicon nitride powder, the raw materials transferred from the input port to the output port are heated and reacted using a heating device installed in the area. 1. A four-tary one-type reactor, characterized in that the ζ graphene gas is injected into the reactor.