• 제목/요약/키워드: Length grader

검색결과 3건 처리시간 0.019초

벼 품종별 입형분리기 최적 가동조건 (The Optimum Operating Conditions of Indented-Cylinder Length Grader to Remove Broken Rice based on Varietal Characteristics)

  • 이춘기;송진;윤종탁;서종호;이재은;김정태;정건호;김정곤
    • 한국작물학회지
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    • 제54권4호
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    • pp.366-374
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    • 2009
  • 벼 품종특성을 고려한 입형분리 최적조건을 설정하기 위하여 다양한 입형 특성을 갖는 41품종의 쌀을 입형분리의 체눈 직경 3.5, 3.8 및 4.2 mm, 싸라기 수거함의 각도 5, 15, $30^{\circ}$ 조건에서 싸라기 분리능을 비교시험 하였고 다음과 같은 결과를 얻었다. 1. 싸라기 제거율은 기기적 측면에서 체눈의 직경과 깊이 및 싸라기 수거함의 각도, 품종적 측면에서 쌀알의 폭, 길이 및 천립중에 의해 주 영향을 받았다. 2. 싸라기 수거함의 각도는 지면과의 수평한 입형분리체 원통직경을 0도로 할 때 +5도와 +15사이에서 분리능이 좋았으며, +5도 이하에서는 완전미손실율 증가하고 각도가 높아질수록 완전미 손실율은 감소하나 분리된 싸라기 량도 감소되었다. 3. 기존 벼 품종에서 쌀알 기준으로 폭과 길이가 각각 2.9와 5.2 mm이상이고, 천립중이 22g 이상일 경우 4.2 mm이상, 폭이 작고 소립인 경우 3.8 mm, 그 밖의 중소립종은 3.8~4.2 mm의 체눈 직경이 적합할 것으로 판단되었다. 4. 립장이 작고, 립폭은 상대적으로 크면서 두께가 얇은 품종은 그렇지 않은 품종보다 싸라기 분리능이 떨어지는 경향이었으며, 품종에 따라 입형분리기 체눈의 직경은 크고 깊이는 얕은 체 눈 규격이 필요한 것으로 생각되었다. 5. 싸라기 비율이 상대적으로 지나치게 높을 경우에는 다소 완전미율의 소실이 있더라도 권장 체눈 크기보다 큰 쪽을 택하는 것이 싸라기 제거량을 높일 수 있었다.

Analysis of Broken Rice Separation Efficiency of a Laboratory Indented Cylinder Separator

  • Kim, Myoung Ho;Park, Seung Je
    • Journal of Biosystems Engineering
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    • 제38권2호
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    • pp.95-102
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    • 2013
  • Purpose: Using a laboratory indented cylinder separator, broken rice separation experiments were conducted and the characteristics of the separation process were studied to provide information for developing a prototype indented cylinder broken rice separator. Methods: Rice (Ilmi variety) milled in a local RPC was used for the experiment. Rice kernels were classified into four groups according to their length l; whole kernels (I > 3.75 mm), semi-whole kernels (2.5 < I < 3.75 mm), broken kernels (1.75 < I < 2.5 mm), and foreign matters (I < 1.75 mm). A laboratory grain cleaner, Labofix '90 (Schmidt AG, Germany) was used for the experiments. Experiments were designed as a $4{\times}4$ factorial arrangement in randomized blocks with three replications. Cylinder rotational speeds (17, 34, 51, 68 rpm) and trough angles (15, 37.5, 60, $82.5^{\circ}$) were the two factors and feed rates (25, 50 kg/h), indent shapes (Us, $S_1$ type), and indent sizes (2.5, 3.75 mm) were treated as the blocks. Two 125 g samples and one 125 g sample were taken at the cylinder outlet and from the trough, respectively. The whole, semi-whole, and broken kernel weight ratio of the samples and feed was determined by a rice sizing device. From these weight ratios, purities, degrees of extraction and coefficient of separation efficiency were calculated. Results: Trough angle, cylinder speed, and their interaction on the coefficient of separation efficiency were statistically significant. Cylinder speed of 17, 34, and 51 rpm made the most effective separation when the trough angle was $15^{\circ}$ or $37.5^{\circ}$, $60^{\circ}$, and $82.5^{\circ}$, respectively. Maximum values of coefficient of separation efficiency were in the range of 60 to 70% except when the indent size was 2.5 mm and were recorded for the combinations of low cylinder speed (17 rpm) with medium trough angle ($37.5^{\circ}$ or $60^{\circ}$). Indent shape did not appear to make any noticeable difference in separation efficiency. Conclusions: Due to the interaction effect, the trough angle needs to be increased appropriately when an increase in cylinder speed is made if a rapid drop of effectiveness of separation should be avoided. In commercial applications, $S_1$ type indents are preferred because of their better manufacturability and easier maintenance. For successful separation of broken kernels, the indent size should be set slightly bigger than the actual sizes of broken kernels: an indent size of 3.0 mm for separating broken kernels shorter than 2.5 mm.

쌀의 품질평가 현황과 금후 연구방향 (Trend and Further Research of Rice Quality Evaluation)

  • 손종록;김재현;이정일;윤영환;김제규;황흥구;문헌팔
    • 한국작물학회지
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    • 제47권
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    • pp.33-54
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    • 2002
  • Rice quality is much dependent on the pre-and post harvest management. There are many parameters which influence rice or cooked rice qualitys such as cultivars, climate, soil, harvest time, drying, milling, storage, safety, nutritive value, taste, marketing, eating, cooking conditions, and each nations' food culture. Thus, vice evaluation might not be carried out by only some parameters. Physicochemical evaluation of rice deals with amy-lose content, gelatinizing property, and its relation with taste. The amylose content of good vice in Korea is defined at 17 to 20%. Other parameters considered are as follows; ratio of protein body-1 per total protein amount in relation to taste, and oleic/linoleic acid ratio in relation to storage safety. The rice higher Mg/K ratio is considered as high quality. The optimum value is over 1.5 to 1.6. It was reported that the contents of oligosaccharide, glutamic acid or its derivatives and its proportionalities have high corelation with the taste of rice. Major aromatic compounds in rice have been known as hexanal, acetone, pentanal, butanal, octanal, and heptanal. Recently, it was found that muco-polysaccharides are solubilized during cooking. Cooked rice surface is coated by the muco-polysaccharide. The muco-polysaccharide aye contributing to the consistency and collecting free amino acids and vitamins. Thus, these parameters might be regarded as important items for quality and taste evaluation of rice. Ingredients of rice related with the taste are not confined to the total rice grain. In the internal kernel, starch is main component but nitrogen and mineral compounds are localized at the external kernel. The ingredients related with taste are contained in 91 to 86% part of the outside kernel. For safety that is considered an important evaluation item of rice quality, each residual tolerance limit for agricultural chemicals must be adopted in our country. During drying, rice quality can decline by the reasons of high drying temperature, overdrying, and rapid drying. These result in cracked grain or decolored kernel. Intrinsic enzymes react partially during the rice storage. Because of these enzymes, starch, lipid, or protein can be slowly degraded, resulting in the decline of appearance quality, occurrence of aging aroma, and increased hardness of cooked rice. Milling conditions concerned with quality are paddy quality, milling method, and milling machines. To produce high quality rice, head rice must contain over three fourths of the normal rice kernels, and broken, damaged, colored, and immature kernels must be eliminated. In addition to milling equipment, color sorter and length grader must be installed for the production of such rice. Head rice was examined using the 45 brand rices circulating in Korea, Japan, America, Australia, and China. It was found that the head rice rate of brand rice in our country was approximately 57.4% and 80-86% in foreign countries. In order to develop a rice quality evaluation system, evaluation of technics must be further developed : more detailed measure of qualities, search for taste-related components, creation and grade classification of quality evaluation factors at each management stage of treatment after harvest, evaluation of rice as food material as well as for rice cooking, and method development for simple evaluation and establishment of equation for palatability. On policy concerns, the following must be conducted : development of price discrimination in conformity to rice cultivar and grade under the basis of quality evaluation method, fixation of head rice branding, and introduction of low temperature circulation.