• Magazine of the Korean Society of Agricultural Engineers
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• v.17 no.3
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• pp.3878-3884
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• 1975

This study was carried out to develop the throw-in type thresher with its size as small as possible. Developing the smallest possible size of the throw-in type thresher has been very important to increase mobility and to reduce the machine price. The thresher that developed for this purpose was tested as to threshing and separation performance for the samples collected in eight catch boxes under the concave while threshing. The amount of grain collected in each compartments was measured and the threshing and separating pattern along the total span of the threshing drum was determined. The performance of separating and threshing units of the test thresher and threshing loss was evaluated by use of the developed grain separating apparatus and the method for measuring the grain separating performance of threshers. The results are summarized as follows; 1. The unthreshed grain (drum losses) and semi-threshed grain did not appeared at all throughout the treatments. 2. When threshed by making use of the developed throw-in type thresher, the threshing grain loss at about 25 per cent grain moisture was about one-half when threshed at about 18 per cent grain moisture. 3. And its grain separating loss in higher feed rate was decreased in comparison with that of lower feed rate. These results suggests that the throw-in type thresher may be suitable for wet threshing and for higher feed rate of threshing. 4. Above 60 per cent of total grain passing through concave fell through the screen within a scant 30 cm from the feeding inlet. This threshing pattern may suggest that major threshing action may be finished before about one third of cylinder length. The required separating load extended over the whole drum span is so defferent that separating elements should be redesigned so as to accomodate this variable pattern of separation load. 5. It was apparent from the experiment that the length of the threshing drum of the throw-in type thresher could be reduced from 1285mm to about 1050mm without increasing grain separation loss greatly.

• Journal of Biosystems Engineering
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• v.29 no.5 s.106
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• pp.433-440
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• 2004

Worldwide consumption of vegetable soybean has been increasing recently, but in the process of vegetable soybean production, threshing and separation work accounts fur about $80\%$ of overall labor. Therefore, developing of the vegetable soybean thresher is necessary to reduce the cost of labor. The main objective of this study is to acquire the basic in-formations for design of the vegetable soybean thresher which is suitable for domestic circumstances. We made the experimental system to investigate the threshing and separating performance at the several speeds of threshing cylinder and separating blower according to the kinds of threshing tooth. The result are as follows; Threshing performance of vegetable soybean thresher was shown as the best in case the threshing tooth made of rubber which has the 80 of Shore hardness was used at the circumference speed of cylinder of 5.8$\~$8.1m/s. Also separating cleaning performance of vegetable soybean thresher was shown as the best at more than 1,300 rpm of blower speed and $60\~80\%$ of opening ratio of suction port.

• Journal of Biosystems Engineering
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• v.6 no.2
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• pp.33-47
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• 1982

To modernize the conventional rice post production technology and reduce grain losses, a transition toward the wet-paddy threshing system has been strongly demanded. The head-feeding type thresher with pneumatic separation has been used dominantly for threshing dried-paddy, but some adverse effects in separation performance for threshing wet-paddy is encounterred. In order to solve the problems, the development of thresher with an additional oscillating sieve to the conventional pneumatic separation has been recommanded. This study was intended to evaluate the separating performance of thresher with oscillating sieve which was attached additionally to the conventional auto-thresher equipped with separation system of blower and suction fan. For different feed rates and rice varieties, wet-and dry-material were tested with threshers attached with and without oscillating sieve. Results of the study are summarized as follows: 1. When the feed rates were 480 and 640 kg/hr, there was no statistically significant difference in power reqirements between the threshers with and without an additional sieve device for both dry-and wet-threshing. However, when the feed rate was 960 kg/hr, power requirements of thresher without sieve were greater for wet-paddy threshing than the thresher with the additional sieve separator by about 20% points. 2. With additional oscillating sieve device, the ratios of total weights of whole grains including grains with branch let and damaged grains to the total output did not show statistical difference among the feed rates. However, with pneumatic separation the ratio was decreased as the level of feed rate increased. 3. The total amount of grains with branchlet (including broken panicle) increased with the moisture content. For both the wet-and dry-material threshing with the additional oscillating sieve, the percent of grains with branchlet to the total output decreased greatly as the feed rate increased. 4. The output of the damaged grains increased as moisture content decreased. Especially, for the dry-paddy threshing, the additional sieve separating device produced more damaged grains than the pneumatic separation at all feed rates. 5. Generally, for dry paddy threshing, the separating performance of the thresher with the additional sieve device was better at all feed rates, showing greater difference with increasing feed rates. 6. Separating losses were greater with the pneumatic than sieve separation for both the wet-and dry-threshing. 7. The overall comparison of separating performance of threshers tested with and without an additional sieve device showed that the former was more effective than the latter for the dry-material threshing. However, for the wet-paddy threshing, the separation performance with a sieve device was better than the pneumatic only when the feed rate was high.

• Journal of Biosystems Engineering
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• v.30 no.3 s.110
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• pp.141-146
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• 2005

Worldwide consumption of vegetable soybean has been increasing recently, but, in the process of vegetable soybean production threshing and seperation work accounts for about $80\%$ of overall labor. Therefore, developing of the vegetable soybean thresher is necessary to reduce the cost of labor. The main objective of this study is to develop the vegetable soybean thresher which is suitable for domestic circumstances. The threshing and separating performance, operating cost, and field capacity of developed vegetable soybean thresher are investigated and analysed. The results are as follows. The effective field capacity of the developed vegetable soybean thresher was shown as 4.8hr/10a, and reduced as much as 11.7 times compared with human labor. The ratio of unthreshed soybean-pod to stem after threshing work was shown as $1.5\%$ and the damaged pod ratio of detached soybean was shown as $1.8\%$. The cost of human labor was shown as 2,560,000 won/ha, but the operating of the developed vegetable soybean thresher was shown as 503,000won/ha. If the vegetable soybean thresher would be used in our farm, the minimum cultivation area appeard to be 22.7a for the cost effective management.

• Journal of Biosystems Engineering
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• v.7 no.1
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• pp.33-41
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• 1982

When wet-paddy is threshed by conventional auto-fed thresher, the threshed material under the concave is difficult to separate with pneumatic separation only. The development of thresher with an oscillating sieve in addition to the conventional pneumatic separation has been recommanded to improve the separation of grains from straw and chaff having high moisture content. This study was intended to evaluate the separating performance of an oscillating sieve and to obtain the effective operation conditions of the sieve separation. The sieve with oscillating in an elliptical motion was developed and installed in the experimental unit which can simulate the separating operation of the conventional auto-fed thresher. Results of the study are summarized as follows: 1. The flowing velocity of grains on oscillating sieve was increased as the sieve frequency increased but the feed rate did not significantly affect the flowing velocity of grains on sieve. 2. The effects of sieve frequency and the direction of sieve rotation on the separating performance by oscillating sieve show that increasing the frequency of sieve driving crank above the 460 rpm in the same direction of material flow (con-flow) improved the separating performance. 3. The height of grain guide plate and air velocity through the sieve to optimize the separating performance of oscillating sieve were experimentally determined to give about 10cm above the sieve and 7 m/s, respectively.

• Journal of Biosystems Engineering
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• v.39 no.4
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• pp.299-303
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• 2014

Purpose: This study set out to develop a machine for separating shatter-resistant sesame after threshing. Methods: Three grades of sieve and different blower speeds were tested for a separation system that had been designed specifically for shatter-resistant sesame. Performance tests were run to evaluate the sieve and blower systems in terms of the sesame separation and loss ratios. Results: Tests of the first separation stage using the sieve system revealed the optimum sieve perforation size to be 5 mm. Tests of the second separation stage using the blower system identified the optimum blower speed as being 220 rpm. The optimum separation and loss ratios, of 96.5% and 3.5%, respectively, were obtained at a blower speed of 220 rpm. Conclusions: These results will be useful for the design, construction, and operation of threshing harvesters. For shatter-resistant sesame, an optimum blower speed of 220 rpm was identified.

• Magazine of the Korean Society of Agricultural Engineers
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• v.17 no.1
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• pp.3655-3665
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• 1975

This study was intended to develop a method for measuring the grain separating performance of threshers. The grain separating apparatus used for the experiment was designed and constructed, the function of which was to separate pneumatically mature and immature grain, chaff, straw, dust, and other impurities from the products of threshing. The apparatus has five material outlets where grains and impurities are fallen down by separation depending upon the specific gravity of the material white it moves above the outlets. The principle of design was to separate the mixture of mature grain, immature grain and chaff as distinct as possible, and to induce the mature grains onto the first outlet, the immature grains onto the second and the third, and the straw wastes onto the forth and the fifth outlets. The developed apparatus was tested to evaluate its separating performance with two rice varieties (Tongil and Mine-hikari) at different moisture levels and air velocities. The optimum conditions for operating the apparatus were found from experiment. The results are summarized as follows; 1. The degrees of separation, especially the amount of immature grain contained in the mature paddy, were dependent upon air speed delivered. The optimum air velocities for this apparatus for each levels of grain moisture contents were found from a series of experiments as follows; 14.7-15.3m/sec. for grain of 16 percent moisture content in wet basis, 15.3-16.0m/sec. for 20 percent, and 16.0-16.4m/sec for 24 percent. 2. Composition ratios determined based on the brine separating method was fairly well acted upon the developed apparatus, indicating its recollecting rate of the mature grains as 97.6 to 99.9 percent. The developed separatus acted similarly upon the two rice varieties which had different composition of immature paddy grain. In other words, the separating performance by the apparatus had a good correlation with the one by the brine separating method. 3. As immature grains were separated out unsatisfactory in these experiments than the brine separating method, further investigation may be needed to improve a separating performance of these materials. But the results obtained suggested a possibility of using the tester to replace the current hand separating method, ther eby enabling more consistent test results and also eliminating nearly all costly hand seperating operations.

• Journal of Biosystems Engineering
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• v.42 no.1
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• pp.12-22
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• 2017

Purpose: This aim of this study was to develop a pick-up type pulse crop harvester for harvesting cut and dried pulse crop. Methods: The pick-up type pulse crop harvester was designed and constructed. Its specifications and operating performance were investigated. Results: Compared with conventional bean harvesters, the pick-up type pulse crop harvester adopted seven rows of chains with tines to pick-up the cut and dried pulse crop on a flat or ridged field, two transverse threshing drums with steel wire teeth to reduce the threshing speed, and a tilt plate and plastic bucket elevator for conveying clean grain to reduce damage. The threshing speed and the oscillating frequency of the separating and cleaning parts according to crop type and condition could be varied easily to efficiently use engine power and to improve harvesting performance. The harvester showed forward speed ranges of 0 ~ 1.5 m/s during harvesting operation, and 0 ~ 2.5 m/s during road travelling. The pick-up width of the harvester was about 1 m. Conclusions: The pick-up type self-propelled 51.5 kW harvester was designed and constructed to harvest cut and dried pulse crop. The effective field capacity of the harvester was predicted as above 40 a/h.

• Journal of Biosystems Engineering
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• v.7 no.2
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• pp.45-56
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• 1983

The purpose of this experiment was to evaluate the effect of the drum structures and crop moisture contents on the performance of newly developed throw-in type axial thersher. Sachun No.2 malting barley with four different crop moisture levels was used as the testing material. Four different types of threshing drum; the cylindrical drum-equipped with teeth or rubber bars and the conical drum-equipped with teeth or rubber bars were tested. The results are summarized as follows; 1. The threshing efficiency of cylindrical drum was higher than that of the conical one, and the drum with teeth was more effective in threshing than the one with bars. However, the higher the threshing efficiency over the whole range of moisture levels and drum speeds given, the more the rapid and unexpectable variations in threshing efficiencies 2. The separation efficiency of the conical drum was decreased as drum speed was increased and was not so much influenced as crop moisture content. But in case of the cylindrical drum, the result was shown in opposite way to that of the conical one. The separation efficiency of the drum with teeth was higher than that of the drum with bars and no significant decrease in separating efficiency was found at wet crop condition. 3. Foreign matters other than grain passing through the concave sieve was decreased as crop moisture content was increased, and the purity was increased at middle range of drum speed regardless of drum types. 4. Minimum grain loss was found at 700 rpm to 800 rpm of drum speed for all types of drums. The effect of crop moisture content on total grain loss was varied with drum types. As far as the grain loss is concerned, the conical drum having teeth was not so greatly influenced by various crop moisture contents and drum speeds as compared with the other types of drum. 5. Generally, the crop moisture content has more relevant effect on the germination than the drum speed regardless of drum types. The germination percentage of grain threshed by the conical drum and the bar attached drum were higher than those of cylindrical one and teeth attached one, respectively.

• Journal of Biosystems Engineering
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• v.5 no.1
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• pp.1-14
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• 1980

Threshing operation may be one of the most important processes in the paddy post-production system as far as the grain loss and labor requirement are concerned . head-feeding type threshers commercially available now in Korea originally were developed for threshing dry paddy in the range of 15 to 17 % in wet basis. However, threshing wet-paddy with the grain moisture content above 20 % has been strongly recommended, especially for new high-yielding Indica -type varieties ; (1) to reduce high grain loss incurred due to the handling operations, and (2) to prevent the quantitative and qualitative loss of milled -rice when unthreshed grains are rewetted due to the rainfall. The objective of this study were to investigate the adaptability of both a head-feeding type thresher and a throw-in type thresher to wet-paddy , and to find out the possiblilities of improving the components of these threshers threshing. Four varieties, Suweon 264 and Milyang 24 as Tongil sister line varieties, minehikari and Jinhueng as Japonica-type varieties, were used at the different levels of the moisture content of grains. Both the feed rate and the cylinder speed were varied for each material and each machine. The thresher output quality , composition of tailing return, and separating loss were analyzed from the sampels taken at each treatment. A separate experiment for measurement opf the power requirement of the head-feeding type thresher was also performed. The results are summarized as follows : 1. There was a difference in the thresher output quality between rice varieties. In case of wet-paddy threshing at 550 rpm , grains with branchlet and torn heads for the Suweon 264 were 12 % and 7 % of the total output in weight, respectively, and for the Minehikari 4.5 % and 2 % respectively. In case of dry paddy threshing , those for the Suweon 264 were 8 % and 5% , and for the Minehikari 4% and 1% respectively. However, those for the Milyang 23 , which is highly susceptable to shattering, were much lower with 1 % and 0.5% respectively, regardless of the moisture content of the paddy. Therefore, it is desirable to breed rice varieties of the same physical properties as well as to improve a thresher adaptable to all the varieties. Torn heads, which increased with the moisture content of rall the varieties except the Milyang 23 , decreased as the cylinder speed increased, but grains with branchlet didnt decrease. The damaged kernels increased with the cylinder speed. 3. The thresher output quality was not affected much by the feed rate. But grains with branchlet and torn heads increased slightly with the feed rate for the head-feeding type thresher since higher resistance lowered at the cylinder speed. 4. In order to reduce grains with branchlet and torn heads in wet-paddy threshing , it is desirable to improve the head-feeding type thresher by developing a new type of cylinder which to not give excess impact on kernels or a concave which has differenct sizes of holes at different locations along the cylinder. 5. For the head-feeding type thresher, there was a difference in separating loss between the varieties. At the cylinder speed of 600 rpm the separating losses for the Minehikari and the Suweon 264 were 1.2% and 0.6% respectively. The separating loss of the head-feeding type thresher was not affected by the moisture content of paddy while that of the Mini-aged thresher increased with the moisture content. 6. From the analysis of the tailings return , to appeared that the tailings return mechanism didn't function properly because lots of single grains and rubbishes were unnecessarily returned. 7. Adding a vibrating sieve to the head-feeding type thresher could increase the efficiency of separation. Consequently , the tailing return mechanism would function properly since unnecessary return could be educed greatly. 8. The power required for the head-feeding type thresher was not affected by the moisture content of paddy, but the average power increased linearly with the feed rate. The power also increased with the cylinder speed.