Study On Performance Of New Mechanical Seal

Mechanical seal is applied in a variety of mechanical equipment in various industries for its many distinct advantages.The continuous development of industrial technology with the more stringent operating conditions and the new era with environmental and safety guidelines have put forward new and higher requirements for mechanical seal.The research work of mechanical seal is summarized as follows:(a).A new sealing end face groove structure with spiral channel is proposed,in which spiral channel pumps liquid from inside diameter and low pressure side to outside diameter and high pressure side.Part of transported liquid returns to medium cavity through spiral channel,while the other part reaches root of groove on outside diameter side.In this way,low pressure(cavitation)area is formed at root of groove on inside diameter side to draw back fluid to reduce leakage,and high pressure area is formed at root of groove on outside diameter side to improve opening force.Meanwhile,reverse pressure difference formed can block leakage path.(b)To establish corresponding fluid model with groove structure is used to calculate flow field characteristics with Fluent.The results show that pressure difference against leakage direction is formed at leak position between high pressure side and sealing gap and between sealing gap and low pressure side,effectively reducing or even cutting off the leak way in stages.At the same time high pressure benefits to improve opening force.(c)The effects of geometric parameters and operating condition on sealing performance are analyzed.And the effect laws of spiral angle,groove number,groove width,groove depth,dam width,weir width,channel width,channel spacing,end face width on leakage and opening force are obtained.Analysis shows that the effect trends of various parameters on the sealing performance are not consistent,so the design values should be considered synthetically.At the same time,reliability of sealing end face groove structure with high pressure and high speed operating conditions is verified.(d)3d model of moving ring is established and fluid-solid coupling calculation is completed with ANSYS Workbench platform.The effects of deformation and stress distribution of moving ring under all loads including liquid film pressure on sealing performance are analyzed.Two improvement schemes of moving ring structure are put forward from different perspectives.The results show that the best way to improve sealing performance is to choose silicon carbide material together with the first improvement scheme.The research conclusion has much guiding significance for the application of new sealing end face groove structure in practical engineering,and promotes the further development of mechanical sealing technology to the direction of "high operating condition and zero leakage".