Lateral Migration: A laminar fluid flow mechanism suited to Biotechnology separations

  • G. J. Purdom
  • C. A. Lambe


This paper describes how a fluid mechanism provides a new method for the separation of drops and particles from the type of dilute suspension common in biochemical processes.

Lateral migration is a low Reynolds number fluid phenomenon observed in laminar duct flow. The mechanism causes the dispersed phase of drops or particles to migrate across flow streamlines to a characteristic equilibrium position. This paper considers only the behaviour of single particles. The equilibrium streamline is dependent on the settling velocity of the dispersed phase, the bulk velocity and the ratio of particle diameter to channel height. Preliminary results, using a scaled-up channel, are presented.

The technique is particularly attractive for the continuous separation of dilute suspensions of droplets and particles ≥50 μm with very low settling terminal velocities and which may be shear sensitive. This type of separation is not effectively fulfilled by continuous centrifuges. The proposed system is both easily and cheaply constructed and since it has no moving mechanical parts is ideally suited to operation behind containment or in aseptic conditions as required by the biotechnology industry.


Buoyancy Force Settling Velocity Poiseuille Flow Channel Height Lateral Migration 
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  1. 1.
    Bretherton, F.P; Slow viscous flow round a cylinder in a simple shear. J. Fluid Mech. 1962, 12, 591–613CrossRefGoogle Scholar
  2. 2.
    .Cox, R.G. and Brenner, H; The lateral migration of solid particles in Poiseuille flow -I. Chem. Eng. Sci. 1968, 23,147–173CrossRefGoogle Scholar
  3. 3.
    .Cox, R.G. and Hsu, S.K; The lateral migration of solid particles in a laminar flow near a plane. Int. J. Multiphase Flow 1977, 3,201–222CrossRefGoogle Scholar
  4. 4.
    Denson, C.D; Particle migration in shear fields. PhD thesis. Univ. Utah, Salt Lake City, Utah, 1965Google Scholar
  5. 5.
    .Goldman, A.J., Cox, R.G. and Brenner, H; Slow viscous motion of a sphere parallel to a plane wall-I Motion through a quiescent fluid. Chem. Eng. Sci. 1967,22,637–651CrossRefGoogle Scholar
  6. 6.
    .Goldsmith, H.L. and Mason, S.G; The flow of suspensions through tubes. J. Colloid Sci. 1962, 17,448–476CrossRefGoogle Scholar
  7. 7.
    .Halow, J.S. Radial migration of solid spheres in Couette systems. PhD. thesis, Virginia Polytechnic Inst, Blacksburg, Va., 1967Google Scholar
  8. 8.
    Happel, J. and Brenner, H; Low Reynolds number hydrodynamics. Noordhoff Pub., 1973.Google Scholar
  9. 9.
    .Hiller, W. and Kowalewski, T.A; An experimental study of the lateral migration of a droplet in a creeping flow. Exp. in Fluids 1987,5,43–48CrossRefGoogle Scholar
  10. 10.
    .Ho, B.P. and Leal, L.G; Inertial migration of rigid spheres in two-dimensional unidirectional flows. J. Fluid Mech. 1974,65, 2,365–400CrossRefGoogle Scholar
  11. 11.
    ssJeffrey, R.C. and Pearson, J.R.A; Particle motion in laminar vertical tube flow. J. Fluid Mech. 1965, 22, 4,721–735CrossRefGoogle Scholar
  12. 12.
    Karnis, A. and Mason, S.G; Particle motions in sheared suspensions. XIII. Wall migration of fluid drops. J. Colloid Interface Sci. 1967, 24, 164–169CrossRefGoogle Scholar
  13. 13.
    Leal, L.G; Particle motions in a viscous fluid. Ann. Rev. Fluid Mech. 1980,12, 435–476CrossRefGoogle Scholar
  14. 14.
    Majumbar, A. and Graham, A.L; Experimental study on the solid particle dynamics in shear flow. Powder Tech. 1987,49,217–226CrossRefGoogle Scholar
  15. 15.
    Mctigue, D.F, Givler, R.C. and Nunziato, J.W; J. Rheology 1986,30,5,1053–1076CrossRefGoogle Scholar
  16. 16.
    .Oliver, D.R; Influence of particle rotation on radial migration in the Poiseuille flow of suspensions. Nature 1962,194,1269–1271,1962CrossRefGoogle Scholar
  17. 17.
    Purdom, G.J.; Lateral migration of single rigid buoyant and neutrally buoyant in two dimension Poiseuille flow. PhD thesis. Imperial College, London, 1990Google Scholar
  18. 18.
    .Rakow, A.L. and Chappell, M.L; Axial migration of spirulina microalgae in laminar tube flow. Biorheology 1987,24,763–768PubMedGoogle Scholar
  19. 19.
    .Repetti, R.V. and Leonard, E.F; Segre-Silberberg annulus formation: a possible explanation. Nature 1964,203,1346–1348CrossRefGoogle Scholar
  20. 20.
    .Segre, G. and Silberberg, A; Behaviour of macroscopic rigid spheres in Poiseuille flow. Part! Experimental results and interpretation. J. Fluid Mech. 1962, 18, 312–317Google Scholar
  21. 21.
    .Small, H; Hydrodynamic chromatography: A technique for size analysis of colloidal particles. J. Colloid Interface Sci. 1974,48, 1,147–161CrossRefGoogle Scholar
  22. 22.
    .Tachibana, M; On the behaviour of a sphere in the laminar tube flows. Rheol. Acta 1973, 12,58–69CrossRefGoogle Scholar
  23. 23.
    .Vasseur, P. and Cox, R.G; The lateral migration of a spherical particle in two-dimensional shear flows. J. Fluid Mech. 1976,78, 2,385–413CrossRefGoogle Scholar
  24. 24.
    Yanizeski, G.M; Phenomenological characteristics of the laminar flow of neutrally buoyant particles in a rectangular of high aspect ratio. PhD thesis. Carnegie-Mellon Univ., Michigan, 1968Google Scholar

Copyright information

© United Kingdom Atomic Energy Authority 1990

Authors and Affiliations

  • G. J. Purdom
    • 1
  • C. A. Lambe
    • 1
  1. 1.Chemical Engineering Division, Harwell LaboratoryAEA TechnologyOxonUK

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