Abstract:

The mechanical seal device of the reaction vessel operates under dry friction conditions without liquid lubrication and cooling, which poses a challenge to the wear resistance of the materials. The temperature rise and deformation of the end face significantly affect the sealing performance. A well-performing end face pair can effectively reduce the friction coefficient and extend the service life. Based on the mechanical seal structure and sealing ring materials of the reaction vessel, the tribological properties of six types of graphite, namely, antimony-impregnated graphite M106D, resin-impregnated graphite M106K, EK60, EK2200, MAT4000, and MoS₂-modified graphite MAT240, when paired with silicon carbide were evaluated using a friction and wear testing machine system. Based on the average friction coefficients obtained from the tests, a thermal-mechanical coupling simulation model was constructed using simulation analysis software to explore the temperature variation and deformation patterns of the end faces of different graphite materials. Combining the test and simulation results, EK2200 graphite was selected as the optimal soft ring material for dry friction conditions. The temperature rise process of the EK2200 graphite-SiC friction pair was tested on a self-designed test bench and compared with the simulation results. The research results showed that EK2200 graphite had the lowest average friction coefficient, the lowest wear rate, and the best surface morphology, making it the most suitable for dry friction. Compared with other graphite materials, the maximum temperature and deformation of the end face of EK2200 graphite decreased by 39.81% and 56.42%, respectively. The maximum deviation between the highest temperature values obtained from experiments and simulations was only 6.37%, which strongly validated the rationality and accuracy of the finite element model. Graphite EK2200 material had the best dry friction adaptability and effectively reduced the temperature rise and thermal deformation of the end face, thereby improving the sealing performance and extending the service life. This provided an important reference for the design and application of mechanical seals for vessels under dry friction conditions.

Key words: mechanical seal for kettle, graphite, attrition, end face deformation, numerical simulation, heat transfer

摘要：

反应釜的机械密封装置在无液体润滑和冷却的干摩擦工况下运行，使材料的耐磨性能面临考验，且端面温升形变严重影响密封性能，而性能优良的端面配副可有效降低摩擦系数并延长使用寿命。本文基于反应釜机械密封结构及密封环材料，使用摩擦磨损试验机系统评估了浸锑石墨M106D，浸渍树脂石墨M106K、EK60、EK2200、MAT4000以及MoS₂改性石墨MAT240六种牌号石墨与碳化硅配对时的摩擦学特性；基于试验所得平均摩擦系数，利用仿真分析软件构建了热-固耦合仿真模型，探究了不同石墨材料的端面温变与形变规律；结合试验和仿真结果筛选出表现最优的EK2200石墨作为干摩擦工况下密封软环材料，通过自主设计试验台对EK2200石墨-碳化硅摩擦副的温升过程进行测试，并与仿真结果进行比对。结果显示，EK2200石墨具有最低平均摩擦系数、最低磨损率以及最佳表面形貌，在干摩擦下适应性最佳；相较于其他石墨材料，EK2200石墨端面最高温度与形变量分别显著下降了39.81%和56.42%；试验与仿真所得最高温度值最大偏差仅6.37%，有力证明了有限元模型的合理性和精确性。石墨EK2200材料具有最佳干摩擦适应性能，且有效降低了端面温升与热力形变，从而提升了密封性能并延长了使用寿命，可为干摩擦工况下釜用机械密封装置的设计与应用提供重要参考。

关键词: 釜用机械密封, 石墨, 磨损, 端面形变, 数值模拟, 传热