Fissure Occurrence in Vacuum Drying of Raw Rough Rice

生糙米真空干燥中裂纹的发生

• 批准号: 10660238
• 负责人: BEKKI Eiji
• 金额: $ 0.64万
• 依托单位: Hirosaki University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10660238/
• 关键词: vacuum drying; rough rice; brown rice; drying rate; internal fissure; surface crack; moisture extraction; moisture condensation; 真空解除; 減圧度; 乾燥温度; 胴割れ; 真空度; 胴割れ率

To elucidate the relation between drying rate and fissure occurrence in vacuum drying of raw rough rice with high moisture, studies have been done for three years. The experiments were carried out using suitable combinatiouts : three parameters of vacuum pressure, temperature and relative humidity. Also the raw rough rice was partially used to relate the results of brown rice to rough rice. The results were as follows :1. With absolute pressures of 5, 40, 75 and 101 kPa (gauge pressure : -96, -61, -26 and 0 kPa) fixed in a vacuum container, drying rates at 5 kPa were remarkably higher than those at weaker set pressures.2. When the vacuum container was subjected to temperatures of 25, 35 and 45℃ in the air-oven, the effect on drying rate was a notable increase at 45℃ despite lower rates at 25 and 35℃. Thus it is necessary to apply heat together with vacuum pressure.3. Relative humidity inside the vacuum container dropped due to the evacuation of the humid air. Drying rate then increased a little with the lowering of the surrounding humidity and with increasing vacuum pressure.4. Whole fissture occurrence, which included surface cracks typically caused in brown rice, increased with the rise in drying rate. However, only a slight degree of internal fissuring occurred. The use of rough rice resulted in conversely less surface crack but higher internal fissure occurrence.5. Brown rice was easily considered to be injured with air pressure changes because of the rupture of the thin skin film on the grain surface. Nevertheless, the time required for relieving the vacuum was not closely related to surface cracking.6. Varietal differences in drying rate and fissure occurrence were recognized to be of the same degree as that of heated air drying under normal pressure.

为阐明高水分稻谷真空干燥过程中干燥速率与裂纹发生的关系，进行了三年的研究。实验采用真空度、温度和相对湿度三个参数进行。此外，部分使用生糙米将糙米的结果与糙米的结果相关联。结果如下：1.在真空容器中固定5、40、75和101 kPa的绝对压力（表压：-96、-61、-26和0 kPa），5 kPa下的干燥速率显著高于较弱设定压力下的干燥速率.当真空容器在空气烘箱中经受25、35和45 ℃的温度时，尽管在25和35 ℃下干燥速率较低，但在45 ℃下对干燥速率的影响显著增加。因此，有必要施加热量与真空压力一起。3.真空容器内的相对湿度由于湿空气的排出而下降。干燥速率随环境湿度的降低和真空度的增加而略有增加.整个裂纹的发生，其中包括表面裂纹通常引起糙米，增加干燥速率的上升。然而，只有轻微程度的内部裂缝发生。使用糙米则相反，表面裂纹较少，但内部裂纹较多.由于糙米表面的薄皮膜破裂，糙米很容易被认为受到气压变化的伤害。然而，释放真空所需的时间与表面裂纹的关系并不密切。干燥速率和裂缝发生的品种差异被认为是相同的程度，在常压下加热空气干燥。

项目成果

Bekki E.,M.J.C Regalado: "Fissure Occurrence in Vacuum Drying of High Moisture Rice"Proc. of 1999 ASAE/SAE-SCGR Ann. Int. Mtg.. CD-ROM. -996088 (1999)

Bekki E.，M.J.C Regalado：“高水分稻米真空干燥中的裂缝发生”Proc。

Regalado, M.J.C.: "Comparison of Fissure Occurrence in Vacuum Drying of Indica and Japonica Brown Rice Proc.of ASAE Annual International Meeting, 2000"Am.Soc.of Agr.Eng.(ASAE). (CD-ROM) 006017. 10 (2000)

Regalado, M.J.C.：“籼稻和粳稻糙米真空干燥中裂缝发生的比较 ASAE 国际年会，2000 年”Am.Soc.of Agr.Eng.(ASAE)。

Bekki,Eiji: "Fissure Occurrence in Vacuum Drying of High Moisture Rice, Proc. of ASAE Annual International Meeting, 1999 (CD-ROM, Paper NO.996088)"American Society of Agricultural Engineers (ASAE,米国農業工学会). 6 (1999)

Bekki, Eiji：“高水分稻米真空干燥中的裂缝发生，ASAE 年国际会议记录，1999（CD-ROM，论文号 996088）”美国农业工程师学会（ASAE，美国农业工程师学会）。 6 (1999)

Regalado,M.J.C.: "Comparison of Fissure Occurrence in Vacuum Drying of Indica and Japonica Brown Rice, Proc. of ASAE Annual International Meeting, 2000 (CD-ROM, Paper No.006017)"American Society of Agricultural Engineers (ASAE, 米国農業工学会). 10 (2000)

Regalado, M.J.C.：“籼稻和粳米真空干燥中裂缝发生的比较，ASAE 国际年会记录，2000 年（CD-ROM，论文号 006017）” 美国农业工程师学会（ASAE，学术会议） 10 (2000)