1. Closure method.

 

The principle of closure method is to cut off or block the transmission of heat flow generated by fire to components, so that the temperature rise of components with silicon nitride structure does not exceed its critical temperature within the specified time. Because the thermal conductivity of the selected material is small and the heat capacity is large, it can well block the transmission of heat flow to components, so as to play a protective role.

 

2. Spraying method.

 

The spraying method is to spray the fireproof coating directly on the component surface with spraying machines and tools to form a protective layer. Silicon nitride structural fire retardant coatings can be divided into organic fire retardant coatings and inorganic fire retardant coatings according to the different adhesives used. They can be divided into thin coating and thick coating according to the coating thickness. The coating thickness of thin coating silicon nitride structural coatings is generally 2-7mm, which has certain decorative effects. The coating expands and thickens at high temperature, and has the function of fire resistance and heat insulation, The fire resistance limit can reach 0.5 to 1.5 hours. This coating is also known as class structure expansion fire retardant coating. The thickness of thick coating silicon nitride structural fire retardant coating is generally 8 to 20 mm, with small density and low thermal conductivity.

 

To sum up, this is the fire resistance protection method of silicon nitride structure. It can be seen that in order to take protective measures for the structure, it is necessary to do a good job in the protection from the methods of intercepting and spraying, so that it can achieve the original fire resistance of silicon nitride structure.