Journal of Zhejiang University SCIENCE A
ISSN 1673-565X(Print), 1862-1775(Online), Monthly

2007   Vol. 8   No. 11   p. 1762~1774

On-line Access Date:   Oct. 31, 2007
[ Home Page ]   |   [ Full Text ]

Resuspension of wall deposits in spray dryers

HANUS M.J., LANGRISH T.A.G.†‡

(School of Chemical and Biomolecular Engineering, University of Sydney, Sydney, NSW 2006, Australia)
Corresponding Author
E-mail: tim.langrish@usyd.edu.au
Received Apr. 4, 2007 revision accepted July 16, 2007

Abstract: Wall deposition occurs in spray dryers when dried or partially dried particles contact and adhere to the walls during operation, thus reducing the yield of product collected. Wall deposits also present a product contamination risk and a fire or explosion risk when spray drying products that oxidize exothermically, such as milk powder. Re-entrainment is the resuspension of spray dryer wall deposits into the main gas stream for collection as product. Literature suggests that the process for re-entrainment of particles from spray dryer wall deposits is strongly dependent on particle size and gas velocity.

Key words: Wall deposition, Spray dryers, Dried particles, Re-entrainment, Adhesive forces
doi:10.1631/jzus.2007.A1762             CLC number: TQ018; TE624.41

References:

[1] Akiyama, T., Tanijiri, Y., 1989. Criterion for re-entrainment of particles. Powder Technology, 57(1):21-26.

[2] Bagnold, R.A., 1941. The Physics of Blown Sand and Desert Dunes. Methuen and Co. Ltd., London, p.57-76.

[3] Bika, D., Tardos, G.I., Panmai, S., Farber, L., Michaels, J., 2005. Strength and morphology of solid bridges in dry granules of pharmaceutical powders. Powder Technology, 150(2):104-116.

[4] Boonyai, P., Bhandari, B., Howes, T., 2004. Stickiness measurement techniques for food powders: A review. Powder Technology, 145(1):34-46.

[5] Braaten, D.A., 1994. Wind tunnel experiments of large particle reentrainment-deposition and development of large particle scaling parameters. Aerosol Science and Technology, 21(2):157-169.

[6] Cerbelli, S., Giusti, A., Solidati, A., 2001. ADE approach to predicting dispersion of heavy particles in wall bounded turbulence. International Journal of Multiphase Flow, 27(11):1861-1879.

[7] Chen, X.D., Rutherford, L., Lloyd, R.J., 1994. Preliminary results of milk powder deposition at room temperature on a stainless steel surface mimicking the ceiling of a spray dryer. Transactions of the Institute of Chemical Engineers, 72(C):170-175.

[8] Cleaver, J.W., Yates, B., 1973. Mechanism of detachment of colloidal particles from a flat substrate in a turbulent flow. Journal of Colloid and Interface Science, 44(3):464-474.

[9] Cleaver, J.W., Yates, B., 1976. The effect of re-entrainment on particle deposition. Chemical Engineering Science, 31(2):147-151.

[10] Corn, M., Stein, F., 1965. Re-entrainment of particles from a plane surface. American Industrial Hygiene Association Journal, 26(4):325-336.

[11] Farber, L., Tardos, G.I., Michaels, J.N., 2003. Evolution and structure of drying material bridges of pharmaceutical excipients: studies on a microscopic slide. Chemical Engineering Science, 58(19):4515-4525.

[12] Gotoh, K., Masuda, H., Higashitani, K. (Eds.), 1997. Powder Technology Handbook (2nd Ed.). Marcel Dekker, New York, p.133-154.

[13] Goula, A.M., Adamopoulos, K.G., 2005. Spray drying of tomato pulp in dehumidified air: I. The effect on product recovery. Journal of Food Engineering, 66(1):25-34.

[14] Hamill, L., 1995. Understanding Hydraulics. Macmillan Press, London, p.106.

[15] Hays, D.A., 1991. Role of Electrostatics in Adhesion. In: Lee, L.H. (Ed.), Fundamentals of Adhesion. Plenum Publishing Corporation, New York, p.249-278.

[16] Hein, K., Hucke, T., Stintz, M., Ripperger, S., 2002. Analysis of adhesion forces between particles and wall based on the vibration method. Particle and Particle Systems Characterization, 19(4):269-276.

[17] Hogg, T.W., Healy, T.W., Fuerstenau, D.W., 1965. Mutual coagulation of colloidal dispersions. Transactions of the Faraday Society, 62(1):1638-1651.

[18] Hubbe, M.A., 1984. Theory of detachment of colloidal particles from flat surfaces exposed to flow. Colloids and Surfaces, 12(1):151-178.

[19] Kaftori, D., Hetsroni, G., Banerjee, S., 1995a. Particle behaviour in the turbulent boundary layer. I. Motion, deposition, and entrainment. Physics of Fluids, 7(5):1095-1106.

[20] Kaftori, D., Hetsroni, G., Banerjee, S., 1995b. Particle behaviour in the turbulent boundary layer. II. Velocity and distribution profiles. Physics of Fluids, 7(5):1107-1121.

[21] Kousaka, Y., Okuyama, K., Endo, Y., 1980. Re-entrainment of small aggregate particles from a plane surface by air stream. Journal of Chemical Engineering of Japan, 13(2):143-147.

[22] Krupp, H., 1967. Particle adhesion—Theory and experiment. Advances in Colloid and Interface Science, 1(2):111-239.

[23] Marquez, N., 2005. An Investigation and Assessment of Process Design in Spray-Dried Milk Production. Undergraduate Thesis, School of Chemical and Biomolecular Engineering, University of Sydney, Australia.

[24] Masters, K., 1976. Spray Drying: An Introduction to Principles, Operational Practice and Applications (2nd Ed.). George Goodwin Limited, London.

[25] Masters, K., 1996. Deposit-free Spray Drying: Dream or Reality. Proceedings of the 10th International Drying Symposium, IDS’96. Krakow, Poland, A:52-60.

[26] McLaughlin, J.B., 1989. Aerosol particle deposition in numerically simulated channel flow. Physics of Fluids A, 1(7):1211-1224.

[27] O’Neill, M.E., 1968. A sphere in contact with a plane wall in a slow linear shear flow. Chemical Engineering Science, 23(11):1293-1298.

[28] Ounis, H., Ahmadi, G., McLaughlin, J.B., 1993. Brownian particle deposition in a directly simulated turbulent channel flow. Physics of Fluids A, 5(6):1427-1432.

[29] Ozmen, L., Langrish, T.A.G., 2003. An experimental investigation of the wall deposition of milk powder in a pilot-scale spray dryer. Drying Technology, 21(7): 1253-1272.

[30] Ozmen, L., Langrish, T.A.G., 2005. An experimental investigation into wall deposition of milk powder in spray dryers. Developments in Chemical Engineering and Minerals Processing, 13(1-2):91-108.

[31] Reeks, M.W., Reed, J., Hall, D., 1988. On the resuspension of small particles by a turbulent flow. Journal of Physics D: Applied Physics, 21(4):574-589.

[32] Rhodes, M., 1998. Introduction to Particle Technology. John Wiley & Sons, New York, p.2-4.

[33] Seville, J.P.K., Tuzun, U., Clift, R., 1997. Processing of Particulate Solids. Blackie Academic and Professional, London, p.99-125.

[34] Sharma, M.M., Chamoun, H., Sita Rama Sarma, D.S.H., Schechter, R.S., 1992. Factors controlling the hydrodynamic detachment of particles from surfaces. Journal of Colloid and Interface Science, 149(1):121-134.

[35] Tabor, D., 1977. Surface forces and surface interactions. Journal of Colloid and Interface Science, 58(1):2-13.

[36] Tardos, G.I., Farber, L., Michaels, J.N., 2006. The Morphology and Strength of Solidifying Inter-Particle Bridges in a Granule. Retrieved July 31, 2006, from http://aiche.confex.com/aiche/s06/techprogram/p33707.HTM

[37] Verdurmen, R.E.M., Menn, P., Ritzert, J., Blei, S., Nhumaio, G.C.S., Sonne Sorensen, T., Gunsing, M., Straatsma, J., Verschueren, M., Sibeijn, M., et al., 2004. Simulation of agglomeration in spray drying installations: The EDECAD project. Drying Technology, 22(6):1403-1461.

[38] Ye, C., Li, D., 2002. Electrophoretic motion of a sphere in a microchannel under the gravitational field. Journal of Colloid and Interface Science, 251(2):331-338.

[39] Yung, B.P.K., Merry, H., Bott, T.R., 1989. Effects of particle-surface interactions on deposition and re-entrainment of a particulate fouling system. Geothermics, 18(1-2): 327-335.

[40] Zimon, A.D., 1969. Adhesion of Dust and Powder. Plenum Press, New York, p.110.

[41] Ziskind, G., Fichman, M., Gutfinger, C., 1995. Resuspension of particulates from surfaces to turbulent flows—Review and analysis. Journal of Aerosol Science, 26(4):613-644.