Oscillatory Flow Mixer for Pulp Bleaching

https://doi.org/10.22146/ajche.50802

Taslim Taslim(1*), Mohd Sabri Takriff(2)

(1) Department of Chemical and Process Engineering, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia
(2) Department of Chemical and Process Engineering, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia
(*) Corresponding Author

Abstract


This paper reports the results of an investigation on the use of oscillatory baffled column as a mixer for pulp bleaching. Unbleached hardwood kraft pulp was bleached using hydrogen peroxide. Variables studied were oscillation frequency, oscillation amplitude, and pulp consistency. The mixing process was achieved by oscillating pulp suspension in a periodically baffled column at a certain frequency and amplitude. The mixing quality of pulp bleaching was quantified using mixing index. The results showed that mixing quality improved with oscillation frequency and amplitude, but decreased with pulp consistency. This typical device is very promising as a mixer for pulp bleaching.

Keywords


baffled column, mixing index, oscillation, peroxide bleaching, kappa number.

Full Text:

PDF


References

  1. Anderson, JR., and Amini, 8., Hydrogen Peroxide Bleaching, In Pulp Bleaching Principles and Practice, Dence, C.W. and Reeve, D.W, Eds., TappiPress, Atlanta, 1996, 411-442.
  2. Bennington,C.P.J.,Kerekes,R.J., and Grace,J.R., Mixing in Pulp Bleaching, J. Pulp Paper Sci., 1989, Vol. 15 No.5, JI86-JI95.
  3. Bennington, e.P.J., Mixing and Mixers, In Pulp BleachingPrinciples and Practice,Dence, e. Wand Reeve, D.W, Eds., TappiPress, Atlanta, 1996, 537-566.
  4. Blacklund, B., and Parming, AM., Effects of Inhomogeneities in Bleaching Studied by Mathematical Simulation, Nordic Pulp Paper Res.J., Vol.2, 1987, 76-82.
  5. Brunold, e.R., J.C.B. Hunn, Mackley, M.R. and Thomson, J. W., Experimental Observationson FlowPatternsand Energy Looses for Oscillatory Flow in Ducts ContainingSharp Edges,Chern.Eng. Sci., Vol.44 No.5, 1989, 1227-1244.
  6. Dickens, A W, Mackley,M.R., and William,H.R., Experimental Residence TimeDistribution Measurements for Unsteady Flow in Baffled Tubes,Chern.Eng. Sci.Vol.44 No. 7,1989,1471-1479.
  7. Gierer, J., Formation and Involvement of Superoxide (02,-/H02-)and Hydroxyl (OH) Radicals in TFC Bleaching Processes, Holzforchung, Vol. 51 No.1, 1997, J34- J46.
  8. Harison, S.T.L., and Mackley, M.R., A Pulsatile Flow Bioreactor, Chem. Eng. Sci., Vol. 47 No.2, 1992, 490-493.
  9. Hewgill, M.R.,. Mackley, MR., Pandit, AB., and Panu, S.S., Enhancement of Gas-Liquid Mass Transfer Using Oscillatory Flow in Baffled Tubes, Chern. Eng. Sci., Vol. 48 No.4, 1993, 799-809.
  10. Howes, T.and Mackley, M.R., Experimental Axial Dispersion for Oscillatory Flow Through a Baffled Tube, Chern. Eng. Sci., Vol. 45 No. 5, 1990, 1349-1358.
  11. Lachenal, D., Hydrogen Peroxide as a Delignifying Agent, In Pulp Bleaching Principles and Practice, Dence, C.W. and Reeve, D.W, Eds., Tappi Press, Atlanta, 1996,347-362.
  12. Mackley, M.R., Using Oscillatory Flow to Improve Performance, The Chemical Engineer, 1987, February, 8-20.
  13. Mackley, M.R., Process Innovation Using Oscillatory Flow Within Baffled Tubes, Trans. 1. ChemE, Vol. 69 Part A, 1991, 197-199.
  14. Ni, x., Zhang, Y and Mustafa,I., An Investigation of Droplet Size and Size Distribution in Methyl-Methacrylate Suspension in a Batch OscillatoryBaffled Reactor,Chern. Eng.Sci~Vol.53 No.16, 1998, 2903-2919.
  15. Ni, x., Brogan, G., Struthers, A, Bennett, D.e. and Wilson, S.F., A Systematic Study of the Effect of Geometrical Parameters on Mixing Time in Oscillatory Baffled Columns, Trans. 1.ChernE., Vol. 76 Part A, 1998, 635-642.
  16. Reeve, D. W, Introduction to Principles and Practice of Pulp Bleaching, In Pulp Bleaching Principles and Practice, Dence, e. Wand Reeve, D.W, Eds., TappiPress, Atlanta, 1996, 1-24.
  17. Tappi, "TappiTestMethods", Vol.1, T236 cm-85, Tappi Press,Atlanta, 1991, p. 1-3.
  18. Taslim and Takriff,M. S., Investigation of Mixing Time in An Oscillatory Baffled Column, Proceedings of the 15thSymposium of Malaysian Chemical Engineers, Johore Bahru, 2001, 4-19.
  19. Torregrossa, L.O., Effect of Mixing on Chlorine Dioxide Bleaching, Tappi Pulping Conference, Houston ,1983, 635-641.



DOI: https://doi.org/10.22146/ajche.50802

Article Metrics

Abstract views : 1743 | views : 972

Refbacks

  • There are currently no refbacks.


ASEAN Journal of Chemical Engineering  (print ISSN 1655-4418; online ISSN 2655-5409) is published by Chemical Engineering Department, Faculty of Engineering, Universitas Gadjah Mada.