Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/35585
標題: 稻穀乾燥均化時間對乾燥速率與品質之影響
The Effect of tempering period on drying rate and quality of rice
作者: 湯雁翔
Tang, Yen-Teh Sheng
關鍵字: tempering period;均化時間;rice;drying rate;稻榖;乾燥時間
出版社: 農業機械工程學系
摘要: 
The manner of recirculating rice dryers which is extensively
used in Taiwanis intermittent drying. Intermittent drying is
composed of heating and tampering. A drying cycle includes
heating time and tempering time. In a drying cycle, the drying
time is used to be fixed and the tempering time changes and
signifcantly affects the drying rate and milling quality of
rice.this study focus on the effectof tempering time on drying
rate and milling quality of rice for recirculating drying. the
testing items of quality includethe percentage of brown rice,
polished rice, head yield and germination rate. According to
the experimental results, the following conclusions are drawnas
below:<1> If the tempering time is not included, the heating
time is fixed and the tempering time in a cycle increase,
the total heating time become longer. It points out extending
the tempering time for drying cycle can increase the average
drying rate for only the heating period. On the contrary, if
the tempering time is counted, the drying rate will decrease
with the increase of the tempering time.<2> When the drying
air temperature is above 50℃,the percentage of polished rice
for intermittent drying is higher than continuous drying.
Tempering process benefits the production of polish rice.<3>
The drying air temperture influences more on the head yield than
the time ratio of heating and tempering. When the drying air
temperature is over 50℃, head yield drops obviously for both
intermittent drying and continuous drying.<4> The percentage
of head yield of intermittent drying is always higher than
continuous drying. the percentage of head yield decrease with
the decrease of the tempering time. When tempering time is
less then 70 minites, the percentage of head yield declines
significantly. Therefore, in order to prevent the loss of
the percentage of head yield, the tempering time in a drying
cycle should not be less then 1/7.<5> Drying air temperature
influence the percentage of germination more then tempering.
When the drying air temperature is above 60℃, the percentage
of germination drops apparently. The percentage of germination
for intermittent drying is higher than continuous drying.

國內常用之循環式乾燥機,其乾燥方式為間歇乾燥,而間歇乾燥包括乾燥
時間與均化時間,在乾燥時乾燥時間常為固定,均化時間的長短對稻榖乾燥
速率與品質有相當重要的影響。本研究乃針對在間歇乾燥作業,進行均化
時間對稻榖乾燥速率與品質影響之研究。量測品質項目包括糙米率、白米
率、完整米率與發芽率。乾燥試驗結果如下列所示﹕(1) 就不包括均化時
間而言,當固定熱風乾燥時間,增加每循環期之均化時間,則每循環乾
燥時間變長,亦即增加每循環乾燥時間,可以提高實際的乾燥速率;就包含
均化時間而 言,乾燥速率隨著均化時間的增長而降低。(2) 在本試驗
條件範圍內,當乾燥溫度超過50℃時,白米率有明顯隨溫度下降的趨勢,間
歇 式乾燥之白米率大於連續式乾燥,故均化作用有助白米率的提升
。(3) 在本試驗條件範圍內,乾燥溫度對完整米率的影響較乾燥/均化時間
為大;當乾燥溫度 超過50℃以上,無論間歇式乾燥或連續式乾燥,完整
米率皆有明顯的下降。(4) 間歇式乾燥之完整米率大於連續式乾燥,並且
隨著均化時間的減少而降低,當乾燥/均 化時間小於10/70時完整米率
有明顯的下降,每循環乾燥期間乾燥時間與均化時間的比 應大於1:7
。(5)乾燥溫度對發芽率的影響較乾燥/均化時間為大,當乾燥溫度大於60
℃時,發芽率明顯的 下降,間歇式乾燥之發芽率較連續式乾燥為高。
URI: http://hdl.handle.net/11455/35585
Appears in Collections:生物產業機電工程學系

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