| Author | Predicala, Bernardo Z. |
| Call Number | AIT Thesis no. AE-95-17 |
| Subject(s) | Grain--Drying
|
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of
Engineering |
| Publisher | Asian Institute of Technology |
| Abstract | Thin-layer drying and rewetting equations for paddy were developed from a series of
tests with fixed inlet air conditions ranging from 30° to 50°C and 30% to 90% relative
humidity (RH) for drying and 30° to 40°C and 70% to 90% RH for rewetting experiments.
The developed thin-layer models were of the modified exponential form. Both drying and
rewetting models estimated experimental data with relatively high accuracy when compared
with the predictions made by several published thin-layer drying and rewetting equations. The
accuracy of estimating the rewetting test data was improved when a correction was applied to
adjust equilibrium moisture content (EMC) values predicted by known EMC isotherm model
in the light of experimental EMC data. The experimental rewetting test data was also predicted
with acceptable accuracy by selected thin-layer drying models.
The results of eight multi-layer drying tests conducted using two levels of airflow, inlet
air temperature and initial grain moisture content were simulated using different approaches
available in the AIT Drying Simulation package. The simulation results indicated that the
selection of both thin-layer drying and rewetting equations used in Thompson (1968) model
directly affected the accuracy of the resulting predictions of moisture content in grain bed. The
suitability of grain-to-air (G/ A) ratio as a criterion for determining the range of applicability
of different simulation approaches was evaluated by considering different layer depths in
simulation runs for the same set of data. It was established that simulation approaches based
on equilibrium models [Thompson (1972) and Mixed model] performed better at high (G/A)
ratios whereas the Thompson (1968) model predicted moisture contents in grain-bed with
acceptable accuracy even at low (G/A) ratios. |
| Year | 1995 |
| 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) | Canadian International Development Agency; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1995 |