• Title/Summary/Keyword: Angle Milling Head

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Study on the Improvement of Milling Recovery and Performance (IV) -Rice Whitening Performance of the Combined Abrasive- and Friction-type Whiteners- (도정수율(搗精收率)과 성능향상(性能向上)을 위(爲)한 연구(硏究)(IV) -연삭(硏削)·마찰(磨擦)의 조합식(組合式) 정백작용(精白作用)이 정백성능(精白性能)에 미치는 영향(影響)-)

  • Kim, Sam Do;Chung, Chang Joo;Noh, Sang Ha
    • Journal of Biosystems Engineering
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    • v.7 no.2
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    • pp.72-85
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    • 1983
  • Rice whitening is performed by basically two different whitening actions known as abrasive and frictional. The former adopted in the emery stone abrasive type whiteners and the latter in the jet-air friction type. Comparative milling yields and whitening efficiencies between the whitening system consisting of jet-air friction type whiteners only and the system consisting of both abrasive- and jet-air friction-types have not yet been rigorously defined. This study was to examine the effect of combined operations of abrasive- and jet-air friction-type rice whiteners on milling yields and whitening efficiencies. The small capacity commercial units of the abrasive- and friction-type whiteners were used for the experiments. The combinations of whitening treatments were: 1) Once in the abrasive type and then two to three times in the friction type, 2) twice in the abrasive and then two to three times in the friction type and 3) three to five times in friction type. In these tests, counter pressures for the friction type whiteners were established differently as required to get about the same degree of whitening at the end of predetermined numbers of the repeated operations. The speed of emery stone and the slot angle of the screen were also the factors varied in the abrasive type whitener. Sheukwang rice variety having 13.05% M.C. was used in the tests. The dependent variables were the milled- and head-rice recoveries and electricity consumption. The results of the study are summarized as follows: 1. It was found that in the whitening systems consisting of abrasive- and friction-type whiteners slot angle of the screen, the rotational speed of emery stone roller had significant effect on the milling yields and whitening efficiency. In general, the increase of the emery stone roller speed from 690 to 950 rpm presented a positive effect on milling yield, and one-pass abrasive milling combinations had higher milling yields than two-pass abrasive milling combinations. 2. It was apparent that if the slot angle of the screen and the speed of emery stone roller are modified and set at an optimum level, the combination whitening system consisting of abrasive- and friction-type whiteners is better than the pure frictional whitening system consisting of jet-air friction type in terms of milling yields and efficiencies. 3. In the rice whitening system consisting of abrasive- and jet-air friction-type whiteners, the best whitening performance was obtained when the slot angle of the screen and the rotational speed of emery stone roller were $45^{\circ}$ and 950rpm, respectively, for the one-pass abrasive milling combinations. However, for the two-pass abrasive mi11ing combinations, the best performance was obtained with $75^{\circ}$ of slot angle and 950 rpm of the emery stone roller speed. 4. As compared with pure frictional whitening systems, the combination systems produced more milled rice by 0.8-1.0% point and more head rice by 0.5-1.5% point, and consumed less electricity by 0.15-0.20 KwH per 100kg of milled rice when the abrasive whiteners were operated in the modified conditions as described in item 3 above. Further study is recommended to find out optimum operational and design conditions of abrasive type whiterners.

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A Study on the Application of Machine Simulation and Angle Milling Head of a 6-Axis Parallel Kinematic Machine (6축 병렬기구 공작기계의 머신 시뮬레이션과 앵글밀링헤드 적용에 관한 연구)

  • Lee, In-Su;Kim, Hae-Ji;Kim, Nam-Kyung
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.16 no.5
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    • pp.47-54
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    • 2017
  • This study examines the implementation of a kinematic machining tool to evaluate the interference and collision phenomenon of 5-axis machining of wing ribs from airplanes, particularly for a large-size model airplane. We develop a machine simulation model of a parallel kinematic machining tool that can operate in a virtual space, which is equivalent to the authentic conditions in the field. The investigation of the simulation function elements indicates the necessity to generate the 6-axis machining, which attaches an angle head to the main axis of the machine. Using an NC program for the wing ribs, we attempt to verify the correspondence and conformity between the machine simulation model and the actual equipment.

Characterization of Grain Quality under Lodging Time and Grade at Ripening (등숙기 도복 시기 및 정도에 따른 쌀 품질 특성)

  • Jeong Eung-Gi;Kim Kee-Jong;Cheon A-Reum;Lee Choon-Ki;Kim Sun-Lim;Brar Darshan-S.;Son Jong-Rok
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.51 no.5
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    • pp.440-444
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    • 2006
  • This study was carried out to compare the grain quality under lodging time and grade at ripening. Ripened grain ratio and 1000-grain weight were higher with lodging of plants at $45^{\circ}$ angle from the ground and increased with crop development. The number of spikelets, as well as the protein and amylose content of the grains, were higher in plants under severe or complete lodging than those under lodging at $45^{\circ}$ angle from the ground. Palatability and sensory evaluation values were higher in plants under lodging at $45^{\circ}C$ angle from the ground than those under complete lodging. Brown rice: rough rice ratio was higher with lodging of plants at $45^{\circ}C$ angle from the ground and increased with crop growth. Milling recovery and milled rice recovery were higher with lodging of plants at $45^{\circ}C$ angle from the ground, whereas chalky grain, cracked grain and damage grains were higher at complete lodging.