| Author | Prayoon Lasutta |
| Call Number | AIT Thesis no.AE-06-10 |
| Subject(s) | Tea--Drying
|
| Note | A thesis submitted in partial fulfillment of the requirements for the
degree of Master of Engineering, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. AE-06-10 |
| Abstract | A rotary tea dryer prototype was developed eliminating the identified problems of the existing design. A new design concept of spiral material conveying system and modified parameters on power transmission. heat sources, drying capacity, insulation, air circulation system, controls and instrument arrangement were considered in the new prototype. The maximum temperature of this rotary tea dryer was 150 °C and the operating temperature "as 120 °C (80 % of maximum temperature). Futhermore, the range of rotor speed was 0.25 - 0.55 rpm with corresponding retention times of 30 - 66 min. The range of drying tempet-ature of panned tea in the rotary dryer was 80 to 110 °C. The time requirement to dry the panned tea from initial moisture content in the range 30 - 40 % wb to final moisture content of 4 - 8 % wb was 40, 50 and 60 min at 100, 90, and 80 °C of drying temperature respectively. The moisture ratio decreased exponentially as the drying time increased, and the drying rate increased with the increase of temperature. The overall performance of the rotary tea dryer was evaluated based on retention time, final moisture content, power consumption, color, aroma and taste of tea-water. Optimum operating condition was at 100 °C for 40 min of retention time with thermal efficiency around 92.26 %. The maximum drying capacity was 120 kg/day of dried tea (8 hour of working day) with optimum power consumption of 3.47 kW for combined heat sources fin-coil and infrared heaters. The nominal power consumption of infrared, fin-coil and combined heaters were 1.03, 3.69 and 4.66 kW respectively with corresponding retention times SO, 60 and 40 min. A simulation model was developed using least square method to predict the drying characteristics; moisture ratio of the dried tea at different drying temperatures |
| Year | 2006 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. AE-06-10 |
| Type | Thesis |
| 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) | Jayasuriya, H. P.W.; |
| Examination Committee(s) | Salokhe, Vilas M. ;Athapol Noomhorm ; |
| Scholarship Donor(s) | Royal Thai Government Fellowship |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 2006 |