Nitriding sintering furnace

Abstract

The invention belongs to the technical field of industrial kilns, and particularly relates to a nitriding sintering furnace. The nitriding sintering furnace comprises a furnace body provided with a nitriding chamber, a furnace cover, a kiln car capable of entering and exiting the nitriding chamber and a furnace door used for closing the furnace body; a heat insulation layer is arranged in the furnace body; the side wall, for closing the nitriding chamber, of the kiln car is of a composite structure; the composite structure comprises a steel structure layer and a refractory brick layer arrangedon one side, close to the nitriding chamber, of the steel structure layer; a heat insulation channel is formed between the heat insulation layer and the refractory brick layer and comprises a first channel, a second channel and a third channel; the first channel, the second channel and the third channel sequentially communicate from bottom to top; and the second channel is obliquely arranged andis filled with a heat insulation medium. According to the nitriding sintering furnace, tight filling of the heat insulation medium between the kiln car and the furnace body can be ensured during sintering each time, so that the continuous heat insulation effect is ensured, and the furnace door is prevented from overheating.

Description

technical field [0001] The invention belongs to the technical field of industrial furnaces, in particular to a nitriding sintering furnace. Background technique [0002] Nitriding sintering furnace is the core production equipment for producing silicon nitride bonded silicon carbide ceramics, boron nitride, pure silicon nitride, nitride alloy and other products. For example, the mixture of silicon carbide particles and metal silicon powder, after pressing or casting, is placed in a nitriding sintering furnace, and is nitrided and fired in a nitrogen atmosphere at about 1400°C, which can be made into a material with high temperature strength and thermal conductivity. Silicon nitride bonded silicon carbide ceramics with high efficiency, good thermal shock resistance, high load softening point, low thermal expansion coefficient, and high temperature creep resistance. [0003] The furnace door of the existing nitriding sintering furnace is a double-layer steel plate welded stru...

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Problems solved by technology

[0003] The furnace door of the existing nitriding sintering furnace is a double-layer steel plate welded structure, and the temperature in the nitriding sintering furnace is relatively high. When the materials in the kiln car are sintered, due to the heat preservation and sealing between the kiln car and the furnace body The effect is not good, and the temperature of the furnace door is easy to rise. In order to prevent the temperature of the furnace door from being too high, a water-cooling structure is installed between the double-layer steel plates of the furnace door to cool the furnace door through water circulation. However, when the water-cooling structure runs If there is a fault or accidental water stoppage without timely detection, the water located between the double-layer steel plates will be heated and boiled, vaporized, and the volume will expand hundreds of times at the same time, which is less safe, and some water vapor will pass through the partition in the furnace door The hot cotton penetrates into the nitriding sintering furnace and decomposes into H under the high temperature conditions of the nitriding sintering furnace. 2 and O 2 , affecting the purity of the nitrogen atmosphere, resulting in product quality that cannot meet the requirements

[0004] It is also possible to insulate the furnace door from the heat in the nitriding sintering furnace through heat insulating materials, so as to avoid the strength drop caused by the overheating of the furnace door (over 200°C), but the existing heat insulation structure design is unreasonable. The heat insulation material is fully filled into the heat insulation channel, resulting in an unsatisfactory heat insulation effect. On the other hand, the heat insulation material is not filled densely enough, or the volume of the heat insulation material will change after being heated, and the continuous heat insulation of the heat insulation material cannot be guaranteed. effect, resulting in poor practical application effect

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