Zeolites as particulate medium for contact heating and drying of corn
General Material Designation
[Thesis]
First Statement of Responsibility
Z. M. Alikhani
.PUBLICATION, DISTRIBUTION, ETC
Name of Publisher, Distributor, etc.
McGill University (Canada)
Date of Publication, Distribution, etc.
1990
PHYSICAL DESCRIPTION
Specific Material Designation and Extent of Item
162
DISSERTATION (THESIS) NOTE
Dissertation or thesis details and type of degree
Ph.D.
Body granting the degree
McGill University (Canada)
Text preceding or following the note
1990
SUMMARY OR ABSTRACT
Text of Note
The potential of granular zeolites as a heating medium for drying corn was evaluated in a batch type experimental dryer. At temperatures from 150-250C and residence times of 3-8 minutes, synthetic zeolites (4A and 13X) removed 9-18 percentage points from the initial moisture of corn. These values were about double those of sand, the most commonly used particulate medium. Using an adiabatic dryer, the kinetics of moisture sorption in corn-zeolite mixtures was investigated. The heating medium in this part of the study was a natural zeolite (chabazite) and the corn was yellow dent type. Diffusivity values for corn were 1.012 usd\timesusd 10 3.127 usd\timesusd 10 cm2/s with zeolite at temperatures of 140-220C. These values are much smaller than those for zeolite. Therefore, it is believed that the diffusion of moisture in corn itself is the main resistance to the transfer of moisture. The heat transfer coefficient between corn and zeolite was found to be in the range of 50-312 W/mK. Luikov's model for simultaneous heat and mass transfer was applied to corn-zeolite mixtures and the equations were solved by the Numerical Method of Lines (NMOL). These numerical solutions agreed closely with the experimental data. The processed corn was subjected to in vivo and chemical analyses. Results of feeding experiments using laboratory rats did not indicate that the nutritive quality of the processed corn was adversely affected. Similarly, the acid detergent fibre analysis did not show a significant reduction in the availability of corn protein.