Two-Dimensional Heat Flow Analysis Applied to Heat Sterilization of Ponderosa Pine and Douglas-Fir Square Timbers

Authors

  • William T. Simpson

Keywords:

Invasive species, heat sterilization, lumber, timber

Abstract

Equations for a two-dimensional finite difference heat flow analysis were developed and applied to ponderosa pine and Douglas-fir square timbers to calculate the time required to heat the center of the squares to target temperature. The squares were solid piled, which made their surfaces inaccessible to the heating air, and thus surface temperatures failed to attain the temperature of the heating air. The surface temperatures were monitored during heating and related to time by an empirical equation. When this equation was used as the boundary condition in the finite difference solution, calculated time estimates required to heat the center to target temperature agreed favorably with experimentally observed heating times.

References

Kollmann, F. F. P., and W. A. Côté, Jr. 1968. Principles of wood science and technology. Springer-Verlag, New York, NY. 592 pp.nMacLean, J. D. 1932. Studies of heat conduction in wood. Part II. Results of steaming green sawed southern pine timber. In Proc. American Wood Preservers' Association.28:303-329.nMacLean, J. D. 1941. Thermal conductivity of wood. Heating, Piping, and Air Conditioning13:380-391.nSimpson, W. T. 2001. Heating times for round and rectangular cross sections of wood in steam. Gen. Tech. Rep. FPL—GTR—130. USDA, Forest Serv., Forest Prod. Laboratory, Madison, WI.nSimpson, W. T. 2003. Mechanism responsible for the effect of wet bulb depression on heat sterilization of slash pine lumber. Wood Fiber Sci.35(2):175-186.nSimpson, W. T., X. Wang, and S. Verrill. 2003. Heat sterilization time of ponderosa pine and Douglas-fir boards and square timbers. Res. Paper FPL—RP—607. USDA, Forest Serv., Forest Prod. Lab., Madison, WI.n

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Published

2007-06-05

Issue

Number 3 / July 2004

Section

Research Contributions

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