Chemistry Reference
In-Depth Information
14
An Investigation on
Drying Process: An
Experimental Approach
A. K. Haghi and G. E. Zaikov
CONTENTS
14.1 Introduction ..................................................................................................... 157
14.2 Background and Basic Concepts ..................................................................... 159
14.3 Experimental.................................................................................................... 166
14.4 Results ............................................................................................................. 166
14.5 Application of Results ..................................................................................... 167
14.6 Conclusion ....................................................................................................... 168
Keywords ................................................................................................................. 171
References ................................................................................................................ 172
14.1 INTRODUCTION
The wood consists not only of water but also of polymers as cellulose, hemicellulose,
and lignin.drying of wood is a complex operation involving transient transfer of heat
and mass along with several rate processes, such as physical or chemical transforma-
tions, which in turn, may cause changes in product quality. The drying of wood is an
important step in the processing of competitive timber. Little detailed information is
available on the alternative of using different heating modes during drying of wood.
This chapter presents experimental works related to the use of electric radiating tech-
nologies in wood drying operation. It includes conventional air-circulation drying, mi-
crowave drying and infrared drying of Guilan spruce woods. The experiments shows
that in microwave heating, the drying time is significantly reduced while the strength
were higher than the strength obtained in conventional and infrared drying.
Drying is the removal of water from wood. The effects of drying methods on me-
chanical properties have been studied for many materials, but wood products have
seldom been the subject. However, unlike many wet materials that must be dried,
wood must be dried at speci¿ ed rates to avoid degrade (value loss). If degrade were
not concern, lumbers could be dried in minutes. As wood dries, then, from the outside
inward, it begins shrinkage.
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