The fluidized bed drying of paddy in two stages | |
| Author | Somnuek Supawaropas |
| Call Number | AIT Thesis no.AE-96-35 |
| Subject(s) | Rice--Drying Fluidization |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering |
| Publisher | Asian Institute of Technology |
| Abstract | A model of fluidized-bed type dryer was constructed and tested for its performance characteristics. Tests were carried out to study fluidized-bed drying of paddy in two stages and associated changes in its quality in terms of head rice yield and whiteness of milled rice. Drying air temperatures ranged from 55 to 150 °C in first-stage drying and from 60 to 80 °C in the second stage drying tests. The moisture removal during both first and second stage drying of paddy was best represented by the modified logarithmic model. It was found that air temperature in the range of 105 to 135 °C can be used in first stage drying of paddy with initial moisture content of 26% wb for exposure time less than three minute without causing appreciable change in head rice yield or whiteness ratio. However, the most suitable drying air temperature was determined to be 95 °C in first stage drying to reduce the initial moisture content of paddy from 26% wb to about 18% wb in 2.5 minutes. Air temperatures of 60 to 70 °C could be used in second stage to further reduce the moisture to 14.5% wb in about 4 to 6 minutes. Tempering of grain for four hours was allowed in between the two stages of drying. The fluidized-bed drying of paddy using high air temperatures results in an probably due to the partial gelatinization of starch in rice kernels. However, the head rice yield decreased with exposure time both in first and second stage drying tests. It was found that the paddy drying process in a fluidized-bed required careful monitoring to prevent the deterioration of grain quality parameters such as head rice yield and whiteness of the milled rice. |
| Year | 1996 |
| 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) | Jindal, Vinod Kumar; |
| Examination Committee(s) | Athapol Noomhorm;Vincent, Jean-Claude; |
| Scholarship Donor(s) | Queen Sirikit Scholarship; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1996 |