Development of a sunflower thresher | |
| Author | Somposh Sudajan |
| Call Number | AIT Diss. no.AE-02-02 |
| Subject(s) | Sunflowers--Harvesting Sunflowers--Seeds Sunflowers--Drying |
| Note | A dissertation submitted in partial fulfillment of the requirements for the degree of Doctoral of Engineering. |
| Publisher | Asian Institute of Technology |
| Series Statement | Dissertation ; no. AE-02-02 |
| Abstract | Threshing of sunflower seeds is a labor-intensive, time and power-consuming operation. Mechanical threshing will minimize the tediousness involved in manual threshing. Thus main objective of this study was to develop a sunflower thresher. The physical properties, size, bulk density, angle of repose, coefficient of friction of seeds and heads were determined at the seed (straw) moisture content in the range of 5.65 to 28.82% (w.b.) {16.89 to 82.62% (w.b.) for the Hysun-33 variety; 6.22 to 16.60% (w.b.) {14.65 to 76.52% (w.b.)} for the Pioneer Jumbo variety, and, 6.56 to 26.07% (w.b.) {15.35 to 85.78% (w.b.) for the Cargill-3322 variety. Hysun-33 is the most popular variety in Thailand. All properties were found to be affected by the moisture content of seed and head. The threshing unit plays and important role in the performance of a thresher. The three types of threshing drums tested were the peg tooth with an open threshing drum, the peg tooth with a closed threshing drum, and the rasp-bar drum. Four threshing drum speeds used were 550, 750, 950 and 1,150 rpm, along with four feed rates of 1,000, 2,000, 3,000 and 4,000 kg (head)/h The output capacity from the rasp-bar drum was higher than that of other types. Threshing efficiency was found higher than 99%. The concave clearances fo 17,23, 29 and 35 mm at four drum speeds of 675, 775, 875 and 975 rpm and three concave hole sized of 7x60 mm, 11x60 mm and 15x62 mm were used for testing. The optimum combination of drum speed, concave clearance and concave hole sizes at 3,000 kg(head)/h was 750 to 850 drum speed (10.99 to 12.46 m/s), 35 mm concave clearance and the concave hole size 11x60 mm. The sunflower threshing unit was set to work with a rasp-bar drum at the above feed ratem concave clearance, drum speed and concave hole sizes. Five blower speeds of 450, 550, 650, 750 and 850 rpm with four level of grain (straw) moisture contents were tested to study the performance of a cleaning unit. The results showed that the moisture contents and blower speed (wind velocity) significantly affected the cleaning efficiency at 1% significance level. The cleaning efficiency varied from 98.13% to 98.93% for a grain moisture content of 6.82 to 12.94% (w.b.) when the blower speed was increased from 650 to 850 rpm. A prototype thresher was designed and fabricated by using the results obtained during above mentioned testes. The thresher consisted of a threshing unit, separating and cleaning unit with shaking sieves and blower, feeding unit and power drive unit. The thresher was driven by a tractor. The results indicated that the operating conditions for optimum performance were 750 rpm (10.99 m/s) drum speed and 2,000 to 3,000 kg (head)/h feed rate. The thresher capacity was 1,081 to 1,098 kg (grain)/h with a threshing efficiency of 99% cleaning efficiency of 99% and specific energy consumption of 3.86 to 4.38 kW-h/ton (grain). The total losses and grain damage were 0.82 to 1.07% and less than 1% respectively. The performance test results at the drum speed of 750 rpm, indicated that the thresher had an average capacity of 1,000 kg (grain)/h, about 0.61% of grain damage, 99.90% of threshing efficiency, 99.25% of cleaning efficiency and 1.71% ot total grain losses. The specific energy consumption of the machine was about 4.15 kW-h/ton. At present wage rate of 5,456 Baht/ton for manual threshing , the sunflower thresher with a rented tractor had a break-even point of 4.9 ton (grain)/year compared to manual threshing. For a one year payback period, the amount of threshed grain is 45 tons at a custom rate of 2,500 Baht/ton or 2.5 Baht/kg, and 82 tons for custom rate of 1,500 Baht/ton. The performance test and cost analysis indicated that the machine can be used economically. |
| Year | 2002 |
| Corresponding Series Added Entry | Asian Institute of Technology. Dissertation ; no. AE-02-02 |
| Type | Dissertation |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Food, Agriculture and Natural Resources (Former title: Department of Food Agriculture, and BioResources (DFAB)) |
| Academic Program/FoS | Agricultural and Food Engineering (AE) |
| Chairperson(s) | Salokhe, Vilas M.; |
| Examination Committee(s) | Singh, Gajendra,Sutat Weesakul;Kittichai Triratanasirichai;Hoki, Makoto,; |
| Scholarship Donor(s) | Faculty of Engineering, Khon Kaen University; |
| Degree | Thesis (Ph.D.) - Asian Institute of Technology, 2002 |