籾殻・玄米間の水分移動についての考察

During the paddy drying process, the moisture transportation takes place through the husk. Therefore, it is necessary to understand the full mechanism of the paddy drying and to analyse the characteristics of gas transparence in the husk on a micro scale. Furthermore, as the husk and brown rice are composed of different substances, it is important to examine the moisture transportation process such as drying and moisture absolution, and the physical characteristics such as the influences that the substances have. In this study, various drying characteristics were examined by using test equipment. The results of the experiment were obtained as follows: 1.The velocity of moisture transportation from the inner part to the outer part of the husk is higher than the reverse. 2.During the paddy tempering stage of intermittent drying, it increases the velocity of moisture transportation if the initial difference in the moisture content of husk and brown rice and paddy temperature are high. This knowledge can be utilized for the optimum design of paddy dryers.

籾の間欠乾燥において，玄米からの水分の移動は籾殻を通じて行われるので，籾殻と玄米の間の関係を知る必要がある．また，籾殻と玄米は異質な物質で構成されているので，両者間の水分移動は均衡水分，乾物質量比，乾時の形状変化などの物性値に影響される．本報告は籾の間欠乾燥について実験を行い，テンパリング中の籾殻と玄米間の水分移動が籾殻と玄米間の水分差と穀温によってどう影響されるかを調べた．さらに籾殻の通気性を考察するために走査電子顕微鏡を用いて籾殻の断面組織を観察した．