Most high-temperature rotary joints utilize rubber O-rings as sealing structures, which are not only wear-resistant but also exhibit a high friction torque. During the shrinkage processing of the rotary joint, the glass lining tube is supported between the rotary joints at the inlet and outlet ends. It is necessary to ensure that the glass lining tube rotates at a constant speed while maintaining the sealing between the two ends of the glass lining tube and the rotary joint device, to prevent gas leakage inside the tube and prevent external air from entering the joint tube.
High-temperature rotary joints must first cope with high-temperature environments and media, so the seals are required to have high temperature and corrosion resistance. Springs cannot be ignored either. According to the load conditions, they are divided into three categories: one is the spring with a service life of more than 106 cycles, another is the spring with a service life of 103 to 105 cycles and subjected to impact loads, and the third is the spring with a service life of less than 103 cycles under variable loads. The allowable stress of the rotary joint spring subjected to strong pressure treatment can be increased by 25%, and the allowable stress of the spring subjected to vanadium spray treatment can be increased by 20%.
The specific pressure of the spring load on the normal direction of the end face and spherical surface is called spring specific pressure, which has a significant impact on the sealing performance of high-temperature rotary joints. The higher the specific pressure, the better the sealing performance, but the increased frictional heat generation on the end face often reduces the sealing reliability and causes abnormal wear. When high-temperature rotary joints transmit fluid media, the pressure of the fluid has a great influence on the specific pressure on the end face. In the joint structure, the specific pressure caused by the fluid medium on the normal direction of the end face and spherical surface is sometimes several times or even tens of times greater than that generated by the spring, which cannot be ignored.
The glass lining tube is fused at high temperatures, and the exhaust gas discharged from the lining tube is at a very high temperature, which requires the high-temperature rotary joint to operate under high pressure at 200°C. The sealing performance of the rotary joint is directly related to the processing quality of the product; poor sealing leads to poor reliability, resulting in frequent repair and maintenance, which greatly affects equipment operation.
