Experimental Study on Frictional and Sealing Performances of Packing Rings in an Oil-free Gas Compressor

• Published in: Shanghai jiao tong da xue xue bao Vol. 14; no. 6; pp. 725 - 731
• Main Author: 杨学宾 晋欣桥 杜志敏 崔天生 杨绍侃
• Format: Journal Article
• Language: English
• Published: Heidelberg Shanghai Jiaotong University Press 01.12.2009
• Subjects: Architecture; Computer Science; Electrical Engineering; Engineering; Life Sciences; Materials Science; 实验; 密封包装; 性能; 摩擦; 气压缩机; 油环; experimental study; packing rings; frictional performance; sealing; TH 45; oil-free lubrication
• ISSN: 1007-1172; 1995-8188
• DOI: 10.1007/s12204-009-0725-8

To enhance the reliability and to extend service life of packing rings, tribological and sealing perfor- mances are investigated based on the experimental results. Friction force, leakage rate and power consumption of three materials of pressure packing seals are measured in a refitted vertical gas compressor. The rings are made of common filled polytetrafiuroethylene （Filled PTFE）, PTFE reinforced with 30% mass fraction carbon fiber （30%CF~PTFE）, and carbon-carbon composites infiltrated with PTFE （C/C＋PTFE）, respectively. It is found that packing rings will periodically vibrate with the periodic vibration of pressure packing after the travel direction of motion abruptly turns to the reverse direction. Furthermore, the amplitude of vibration slows down with the increasing crank angle. Approximate value of friction force is available by multiple-point fast Fourier transformation （FFT） employed to process the experimental results by reducing the impact of vibration to a great extent. Of three materials of rings employed in experiments, Filled PTFE presents minimal leakage rate accom- panied with maximum power consumption. And 30%CF＋PTFE exhibits minimum friction power and moderate leakage rate. As for C/C＋PTFE, its high mechanical and thermal properties are favorable factors to enhance the ability of operating under high pressure and velocity and to improve the wear resistance. Unfortunately, this also leads to a large leakage rate. Comprehensive consideration should be taken into to evaluate the availability, reliability and service life for a type of packing ring under dry running conditions.