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Analysis of Sealing Effectiveness Based on Spring Stiffness of a Spring-Energized Static Seal

스프링 보강 정적 실의 스프링 강성에 따른 기밀 성능 해석

  • Jang, Soo Yeon (Dept. of Mechanical Engineering, Hannam University) ;
  • Sung, In-Ha (Dept. of Mechanical Engineering, Hannam University)
  • 장수연 (한남대학교 기계공학과) ;
  • 성인하 (한남대학교 기계공학과)
  • Received : 2018.09.28
  • Accepted : 2018.11.25
  • Published : 2018.12.31

Abstract

Unlike a typical static seals, spring-energized static seals exhibit improvement in leak-tightness by reinforcing the spring inside the aluminum lining. Thus, spring-energized static seals are widely used in various industrial fields, such as aerospace, semiconductors, and petrochemical industries. The primary objective of this study is to develop design guidelines for spring-energized static seals in a wide range of temperatures, including that of cryogenic environments, by analyzing the required performance and influence of design variables through simulations. There are various parameters that can be controlled to design a leak-tight seal. In this study, the finite element analysis (FEA) is performed by controlling the parameters related to the spring and the thickness of the aluminum lining, and the result of the leakage between the seal and the casing is confirmed. Considering the influence of each parameters, all of them are found to be important. However, it is observed that the spring-related variables are more important than the aluminum lining or other variables when complexity is considered. We can identify the threshold value of spring stiffness that changes leak-tight performance of the seal by performing FEA. Simulation results, under the conditions that are considered in this study, show that spring stiffness should be at least 3.6 N/m to maintain leak-tightness caused by the sufficient contact force between the aluminum lining and the upper and lower casings.

Keywords

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Fig. 1. Characteristic curve of a spring-energized static seal.

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Fig. 1. Characteristic curve of a spring-energized static seal.

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Fig. 2. A 3D model of spring-energized seal for finite element analysis.

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Fig. 2. A 3D model of spring-energized seal for finite element analysis.

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Fig. 3. Inner pressure applied to outer lining and casings.

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Fig. 3. Inner pressure applied to outer lining and casings.

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Fig. 4. Contact forces between the outer lining and upper/lower casings shown in the FE analysis results with respect to coil thickness.

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Fig. 4. Contact forces between the outer lining and upper/lower casings shown in the FE analysis results with respect to coil thickness.

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Fig. 5. Contact forces between outer lining and casings obtained from the case of 0.4 mm coil thickness.

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Fig. 5. Contact forces between outer lining and casings obtained from the case of 0.4 mm coil thickness.

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Fig. 6. Spring stiffness and related parameters.

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Fig. 6. Spring stiffness and related parameters.

Table 1. Material properties used in FE analysis

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Table 1. Material properties used in FE analysis

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Table 2. Effect of coil thickness and number of coils

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Table 2. Effect of coil thickness and number of coils

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Table 3. Effect of the elastic modulus of spring

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Table 3. Effect of the elastic modulus of spring

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References

  1. Park, S. H., Shin, D. P., Bae, J. S., Rhee, H. J., Jung, H. G., Park, T. J., "Failure of mechanical seals in pumps for commercial ships", Proc. of KSTLE Autumn Conference, pp. 139-144, 2005.
  2. Jo, J. H., Rhim, Y. C., Lee, S. C., Kim, C. H., "Development of cryogenic test rig for ball-bearing and evaluation of the performance of the prototype ball-bearing of turbo pump", J. Korean Tribol. Lubr. Eng., Vol. 28, No. 4, pp. 167-172, 2012.
  3. Park, M. J., Jeon, S. M., Yoon, S. H., Kim, J. H., "Cryogenic leak test of LOX pump static seal", Aerospace Eng. Technol., Vol. 8, No. 1, pp. 73-81, 2009.
  4. Seok, H. S., Ha, T. W., "Prediction of annular type seal leakage using 3D CFD", J. Korean Tribol. Lubr. Eng, Vol. 25, No. 3, pp. 150-156, 2009.
  5. Kwak, H. D., Jeon, S. M., Kim, J. H., "Development of inter-propellant seal for high thrust turbo pump," J. Korean Tribol. Lubr. Eng., Vol. 24, No. 6, pp. 349-354, 2008.
  6. Gillen, P., "Verification of back-plate sealing performance against Li-infiltration and corrosion-induced damage based on the bayonet back-plate concept", Fusion Eng. Design, Vol. 82, No. 15, pp. 2601-2607, 2007. https://doi.org/10.1016/j.fusengdes.2007.06.041
  7. Matweb, http://www.matweb.com