Development of a Convective Mass Transfer Coefficient Conversion Method

Authors

  • Hwanmyeong Yeo
  • William B. Smith

Keywords:

Mass transfer coefficient, surface emission coefficient, surface moisture content, water vapor pressure, boundary layer theory

Abstract

Because of the difficulty of determining wood surface moisture concentration nondestructively and continuously in unsteady-state drying conditions, theoretically calculated convective mass transfer coefficients have not been well proved by experimental results. The convective mass transfer coefficient conversion method developed using surface moisture data in this study has proven that boundary layer theory is useful for evaluating external resistance during wood drying. Because of this proof, the external resistance for wooden surfaces can be theoretically described in dynamic drying situations.

References

Choong, E. T., and C. Skaar. 1969. Separating internal and external resistance to moisture removal in wood drying. Wood Science 1(4):200-202.nChoong, E. T., and C. Skaar. 1972. Diffusivity and surface emissivity in wood drying. Wood Fiber 4(2):80-86.nGeankoplis, C. J. 1993. Transport Process and Unit Operations. 3rd ed. Prentice Hall Inc., Englewood Cliffs, NJ. 921 pp.nHart, C. A. 1977. Effective surface moisture content of wood during sorption. Wood Science 9(4):194-201.nHolman, J. P. 1989. Heat transfer. McGraw-Hill, Inc., Singapore. 676 pp.nSiau, J. F. 1995. Wood: Influence of moisture on physical properties. Dept. of Wood Sci. and Forest Prod., Virginia Tech, Blacksburg, VA. 227 pp.nYeo, H., W. B. Smith, and R. B. Hanna. 2002a. Determination of surface moisture content of wood utilizing a colorimetric technique. Wood Fiber Sci. 34(3):419-424.nYeo, H., W. B. Smith, and R. B. Hanna. 2002b. Mass transfer in wood evaluated with a colorimetric technique and numerical analysis. Wood Fiber Sci. 34(4):657-665.n

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Published

2007-06-05

Issue

Number 1 / January 2005

Section

Research Contributions

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