| Author | Direk Chimchana |
| Call Number | AIT Diss. no.AE-09-04 |
| Subject(s) | Rice--Harvesting--Thailand
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| Note | A dissertation submitted in partial fulfillment of the requirements for the degree of Doctoral of Engineering in Agricultural Engineering, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Series Statement | Dissertation ; no. AE-09-04 |
| Abstract | Rice is the major crop of Thailand; covering 50% of total agricultural area. Small land holding of Thai farmers require a different type and level of mechanization. Machines require suitable economy of scale to be financially viable. Harvesting is one of the most labor-intensive operations in rice production. Rice harvesting in Thailand is still facing the problems of labor shortage during peak harvest period. This research was aimed to develop a mini rice combine harvester suitable for small land holding farmers. The developed machine is different from the local design in many aspects such as the under carriage switched from crawler track to rubber tire, and the thresher redesigned from 4 feet local axial flow thresher to the unequal speed co-axial split-rotor thresher. The under carriage with rubber tire reduced the maintenance cost. The redesigned threshers reduced separation loss to lower than 3 percent. The performance evaluation confirmed that total grain losses of the mini combine harvester for rice were lower than 3 percent which within the acceptable limit. The unequal speed co-axial split-rotor thresher for rice prototype was successfully developed and evaluated for its performance. The results revealed that if operated within 655 - 720 rpm separation rotor speed and at 0.6 - 1.8 kg/s material feeding rate, the grain separation losses were 0.7 - 1.3%. Furthermore, this operational range corresponded to lower power consumption. The concept of performing grain separation process at higher rotational speed was verified while keeping threshing process within safe speed limits. The unequal speed co¬axial split- rotor thresher for rice offered fewer grain losses, and it was found suitable for Thai rice having higher moisture content. The field tests of the mini combine harvester for rice were conducted in Ayutthaya province of Thailand. RNAM standard and test codes were followed. Following results were obtained from the evaluation: a)The average forward spec = 3.4 km/hr b)Width of cutting = 1.8 m c)Effective field capacity = 0.391 ha/h = 19.556 rai/day of 8 h work d)Field efficiency = 58% e)Pre-harvest losses = 0.30% t) Header losses or cutter bar losses = 1.2% g)Threshing losses and separating losses at cylinder = 0.96% h)Separation losses at cleaning unit = 0.17% i)Total grain losses of the machine = 2.63%. Economic analysis of the mini combine harvester revealed the payback period of 2-3 years, if the farmer can manage to harvest more than 8.5-11 ha per year |
| Year | 2009 |
| Corresponding Series Added Entry | Asian Institute of Technology. Dissertation ; no. AE-09-04 |
| 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) | Jayasuriya, H. P. W.;Afzulpurkar, Nitin;Soni, Peeyush;Ahmed, Desa; |
| Degree | Thesis (Ph.D.) - Asian Institute of Technology, 2009 |