Drying of Rough Rice by Solar Collectors

태양(太陽) 열(熱 )집열기(集熱機)를 이용(利用)한 벼의 건조(乾燥)에 관(關)한 연구(硏究)

  • Chang, Kyu-Seob (College of Agriculture, Chungnam National University) ;
  • Kim, Man-Soo (College of Agriculture, Chungnam National University) ;
  • Kim, Dong-Man (College of Agriculture, Chungnam National University)
  • 장규섭 (충남 대학교, 농과 대학) ;
  • 김만수 (충남 대학교, 농과 대학) ;
  • 김동만 (충남 대학교, 농과 대학)
  • Published : 1979.12.15

Abstract

The flat-plate and tubular soar collectors were designed and constructed for drying the rough rice, and the performance of the collectors and drying effect were investigated when rough rice was packed in grain bin connected to collectors. Average-monthly radiation on a horizontal surface based on bright sunshine in Daejeon area during 1978 was the highest as $16,814\;KJ/m^2{\cdot}day$ in May and the lowest as $4,254\;KJ/m^2{\cdot}day$ in December, and significane was not recognized between the calculated and recorded values. The thermal effciency of collectors were increased as radiation increased during drying period and the average thermal effciency of flat-plate and tubular collectors in 11 to 12 o'clock a.m were 28.12 and 16.75%, respectively. The average inlet temperature of grain bin at 12 o'clock was shown as 20.02 at control 40.5 at grain bin connected to tubular collector and $55.1^{\circ}C$ at grain bin connected to flat-plate collector. In 25 cm rough rice depth in grain bin, tim taken for drying from initial moisture content at 27.4 to decrease upto 17.0% (14.5 % on wet basis) were 32 in control, 18 in grain bin connected to tubular collector and 11 hrs to flat-plate collector, and grain depth influenced drying rate remarkably. In the view point of drying characteristics, drying pattern showed initially falling-rate to constant-rate period finally.

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