High-purity silicon nitride reacting furnace

Abstract

The invention discloses a high-purity silicon nitride reacting furnace. The high-purity silicon nitride reacting furnace comprises a furnace shell, a furnace chamber and a furnace cover. The two sidesof the furnace chamber are provided with side heating pipes. The side heating pipes are connected with an external power source through electrodes. The lower portion of the furnace chamber is provided with pillars and a supporting plate, and a material box can be put on the supporting plate. The high-purity silicon nitride reacting furnace is characterized in that lower heating pipes are arrangedbetween the supporting plate and the bottom wall of the furnace chamber, and the lower heating pipes are connected with electrodes. The furnace chamber is internally provided with a gas circulating device. The gas circulating device comprises axial fans and a motor. The axial fans are arranged at the lower end of the furnace chamber. The motor is arranged outside the furnace shell. The axial fansare connected with the motor through magnetic coupling. According to the high-purity silicon nitride reacting furnace, moderate heating bodies are added to the bottom of the furnace chamber so that the temperature of the lower portion can be raised to be identical with the temperature of the upper portion, the temperature difference is reduced or even eliminated, by means of the action of the axial fans, the temperature inside the furnace chamber is sufficiently balanced, and the product quality is guaranteed.

Description

Technical field: [0001] The invention relates to a silicon nitride production equipment, in particular to a high-purity silicon nitride reaction furnace. Background technique: [0002] Silicon nitride has a series of excellent thermophysical properties such as good thermal shock resistance, oxidation resistance, high temperature resistance, corrosion resistance, high chemical stability, and high strength, and is an excellent high-temperature structural material. [0003] The silicon nitride reaction furnace burns silica into silicon nitride powder in the state of nitrogen, argon and hydrogen. There are some disadvantages in the traditional silicon nitride reaction furnace: 1. The heating body in the furnace is set on both sides. As a result, the temperature in the furnace is high and low, and the temperature difference is large, which affects the quality of the product. 2. The traditional heat-resistant furnace is generally formed by mullite bricks or corundum bricks. The d...

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Problems solved by technology

[0003] The silicon nitride reaction furnace burns silica into silicon nitride powder in the state of nitrogen, argon and hydrogen. There are some disadvantages in the traditional silicon nitride reaction furnace: 1. The heating body in the furnace is set on both sides. As a result, the temperature in the furnace goes up and down, and the temperature difference is large, which affects the quality of the product.

2. The traditional heat-resistant furnace is generally formed by mullite bricks or corundum bricks. The disadvantage of this kind of masonry is that the brick body will expand locally at high temperature and absorb protective gas, resulting in large gas consumption. In addition, repeated heating During the cooling and cooling process, the gap between the refractory bricks becomes larger, resulting in a large temperature difference and affecting product quality

3. The temperature of the furnace shell is controlled by water cooling. The water cooling mechanism is composed of a water tank and a water pump. The furnace temperature control is entirely regulated by a manual valve. The adjustment of the furnace temperature is realized through the change of the water flow. This method causes a large temperature difference in the furnace shell, which makes the pressure in the furnace fluctuate greatly, which is an unfavorable factor for the reaction.

4. For a long time, in the process of producing silicon nitride raw materials, people have relied on monitoring the temperature of the control instrument of the electric cabinet to control the sintering temperature. However, the temperature in the furnace differs from the temperature of the instrument by tens of degrees, resulting in inaccurate temperature monitoring.

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