Performance Analysis Of The Spiral Groove Hydrodynamic Floating Ring Seal

Floating ring seal is a traditional pattern of shaft end seal of turbo-compressor for hazardous process gas. With the rapid development of modern science and technology, in aerospace, petroleum and chemical industry, and metallurgy machinery, the demand of the seal performance of seals has become higher and higher, so people need to continually develop sealing products of superior performance, and it also contribute to the research and development of floating ring structure. In all of floating ring seal, spiral groove floating ring seal not only has pumping effect to reduce leakage, but also produces good hydrodynamic effect to improve the centering adjustment.In this paper, the gas flow field of common floating ring seal and spiral groove floating ring seal were numerically calculated with CFD-FLUENT software, the pressure distribution, the velocity distribution, the particle track and the shear stress distribution were abtained, and the effect of operational and geometrical parameters on the pressure field of spiral groove floating ring seal was analyzed. The result indicates that the spiral groove floating ring seal can produce good hydrodynamic and pumping effect, the parameters, such as speed, pressure difference, viscosity, spiral angle, groove length, groove depth, groove width rate, and floating ring width, have great effect on the pressure field of spiral floating ring seal except groove number. In addition, based on the gas flow field simulation, hydrodynamic force, leakage and frictional torque of floating ring seal were calculated. The influence of speed, pressure difference, eccentricity, radius clearance, and liquid hold-up on the seal performance of the spiral groove floating ring was analyzed and compared with the common floating ring seal. Last, the related regular curves including hydrodynamic force and leakage was abtained with the change of the geometrical parameters of floating ring. The result shows that the geometrical parameters have great effect on the seal performance of spiral groove floating ring, in consideration of lower leakage rate and larger hydrodynamic force, the spiral angle 10～15°, the groove number of 26～30, the groove length between 7～8mm, the groove depth about 25 m, the groove width rate 0.5 and larger floating ring width are appropriate during designing the structure of spiral groove floating ring. The research above provides an important reference example for the design and pattern selection of a floating ring sealing in different working conditions.