Investigation of Dynamic Magnetic Fluid Seal Wear Process in Utility Water Environment

Abstract:

Serious problems arise when the magnetic fluid seal technology is needed to use in assemblies working in water or other liquid environment. Some efforts have been up to time made to design hybrid, two stage sealing structures with shields or mechanical seals used as protection measures to the magnetic fluid seal. Anyway, earlier or later there is always problem with direct contact between magnetic fluid and the environmental liquid. In the paper are presented results of experiments carried out with one stage rotating magnetic fluid seal operating in an direct contact with utility water. The special test procedures have been elaborated and practically used, with the aim to define main characteristics of magnetic fluid seals and to simplify experiments. These characteristics were: critical pressure, critical motion velocity and working life of the seal. Four grades of commercial, silicon based magnetic fluids of hydrophobic properties were tested in a single stage sealing system. The results of tests are presented in the form of tables and diagrams. It is concluded that hydrophobic commercial magnetic fluids could be efficiently used in rotating shaft seals however within limited and rather low range of motion velocity.

• Periodical: Key Engineering Materials (Volume 490)
• Pages: 143-155
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.490.143
• Online since: September 2011
• Authors: Zbigniew Szydło, Marcin Szczech
• Keywords: Critical Motion Velocity, Critical Pressure, Magnetic Fluid Seal, Rotating Shaft, Water Environment, Working Life of Seal

References

[1] R.E. Rosensweig, Ferrohydrodynamics, Dover Publications, Inc. Mineola, New York, 1997.

[2] B.M. Berkovsky, V.F. Medvedev, M.S. Krakov , Magnetic fluids engineering applications, Oxford Science Publications, (1993)

[3] E. Blums, A. Cebers, M.M. Maiorov, Magnetic fluids, New York : Walter de Gruyter, 1997.

[4] C. Rinaldi, A. Chaves, S. Elborai, X. He, M. Zahn, Magnetic fluid rheology and flows, Current Opinion in Colloid & Interface Science Vol: 10 Issue: 3-4, October, 2005.

DOI: 10.1016/j.cocis.2005.07.004

[5] D. B. Orlov, at all., Eksperimentalnoe issledovanie resursa magnitozidkostnych uplotnenij pri germetazicii zidkich sred, Magnitnaya Gidrodinamika, No 4, c.127-130, 1989. (in Russian).

[6] J. Kurfess, H.K. Muller, Sealing liquids with magnetic fluids, Journal of Magnetism and Magnetic Materials ,85,(1990)

[7] J. Vihersalo, at all., Sealing of Liquids with Magnetic Fluid Seals, Proc. of 6th Nordic Symposium on Tribology, NORDTRIB'94, Uppsala, Sweden, 12-15 June 1994.

[8] A. F. Chorney, W. Mraz, Hermetic Sealing with Magnetic Fluids, Machine Design; May 7, 1992; 64, 9; ProQuest Science Journals pg. 79.

[9] Y. Mitamura, S. Arioka, K. Sakota, M . Azegami, Application of a magnetic fluid seal to rotary blood pumps, J. Phys.: Condens. Matter 20 (2008) 204145 (5pp).

DOI: 10.1088/0953-8984/20/20/204145

[10] Z. Szydlo, L. Matuszewski, Ring thruster – a preliminary optimisation study of ferrofluid seal and propeller, Polish Maritime Research, 2007 spec. iss. S1 s. 71–74.

[11] Z. Szydlo, L. Matuszewski, The application of magnetic fluids in sealing nodes designed for operation in difficult conditions and in machines used in sea environment, Polish Maritime Research, 2008 vol. 15 no. 3 s. 49–58.

DOI: 10.2478/v10012-007-0083-0

[12] Test Head for Investigation of Magnetic Fluid Seal Parameters. AGH – University of Science and Technology in Krakow; Inventor: SZYDŁO Zbigniew, OCHOŃSKI Włodzimierz, ZACHARA Bolesław. Polish Patent PL 377598 A1. – Appl. 2005-10-12 ; Publ. 2007-04-16., Polish Patent Office Bulletin, 2007 no 8 p.22. (in Polish).

[13] Z. Szydlo, Experiments with magnetic fluid seals (water – air) determination of working life and permissible linear velocity, Research Project No 6.6.130.261, AGH 2008. Not published. (in Polish).

[14] Ferrolabs, Inc. · Sterling, VA United States, http://www.ferrolabs.com/, 2011.

[15] P.P.H.U. "ENES" Pawel Zientek, Warszawa, http://www.magnesy.pl/, 2011.