Comparative Evaluation of Hot-Air and Superheated-Steam Impinging Stream Drying as Novel Alternatives for Paddy Drying
Journal article
Authors/Editors
Strategic Research Themes
No matching items found.
Publication Details
Author list: Swasdisevi T., Devahastin S., Thanasookprasert S., Soponronnarit S.
Publisher: Taylor and Francis Group
Publication year: 2013
Journal: Drying Technology (0737-3937)
Volume number: 31
Issue number: 6
Start page: 717
End page: 725
Number of pages: 9
ISSN: 0737-3937
eISSN: 1532-2300
Languages: English-Great Britain (EN-GB)
View in Web of Science | View on publisher site | View citing articles in Web of Science
Abstract
An investigation was conducted on impinging stream drying of moist paddy using hot air and superheated steam as the drying media. Drying experiments were divided into two parts: namely, one-pass and two-pass drying. The volumetric water evaporation rate, volumetric heat transfer coefficient, and specific energy consumption of the drying system at various conditions were assessed; in the case of superheated-steam drying, the effect of steam recycle was also assessed. The quality of dried paddy was evaluated in terms of color, head rice yield, and degree of starch gelatinization. In the case of one-pass drying, an increase in the drying temperature led to a significant increase in the volumetric water evaporation rate and volumetric heat transfer coefficient. On the other hand, in the case of two-pass drying, an increase in the drying temperature led to a significant decrease in the volumetric heat transfer coefficient; the volumetric water evaporation rate was not significantly affected, however. The specific energy consumption decreased with an increase in the drying temperature. At the same temperature, using superheated steam as the drying medium led to lower specific energy consumption; higher level of steam recycle also led to more energy conservation. The color of the dried paddy was not affected by the change in the drying temperature; superheated-steam-dried paddy was redder and more yellow than the hot-air-dried paddy. An increase in the drying temperature led to decreased percentage of head rice yield. Superheated-steam drying helped enhance the level of starch gelatinization in comparison with hot-air drying at the same temperature. Nevertheless, drying at the highest tested temperature led to a lower level of starch gelatinization. ฉ 2013 Copyright Taylor and Francis Group, LLC.
Keywords
Multi-pass drying, Process intensification, Starch gelatinization
Contact Information