Optimization of the temperature, humidity and air velocity distribution in the steam dry kiln, 5: Test for practical application of flat squares with pith
2006
Ito, Y.(Hokkaido. Forest Products Research Inst., Asahikawa (Japan)) | Nakajima, A. | Ohsaki, H. | Ueno, E. | Nagasawa, T.
Flat squares with pith, 114 (T) x 255 (W) x 3,650 (L)mm, of Todomatsu (Abies sachalinensis Masters) wood were dried in a kiln using high temperature drying schedules. The air velocity in the dry kiln, temperature and humidity of the kiln were measured. Uneven drying was evaluated and the effects of uneven drying and wetwood on characteristics of the flat squares were investigated. The following results were obtained: l) By carrying out proper package piling of specimens, there was near uniformity of the air velocity and temperature distribution inside the dry kiln, because the difference in air velocity of the upper course, the middle course and the lower course was small. 2) Surface check area: When the extent of wetwood was middle or less, the surface check area per specimen was 22.0 cm(2) or less; therefore it was small without hindrance to the practical use. 3) Honeycomb area: The honeycomb area per specimen was 0.1 cm(2) or less; therefore, it was small without hindrance to use. 4) Moisture content (MC) after kiln-drying: When the extent of wetwood was middle or less, the MC standard as the structural lumber for architecture could be met.
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