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Intermittent Drying: Energy Expenditure and Product Quality
Author(s) -
Kowalski S. J.,
Pawlowski A.
Publication year - 2011
Publication title -
chemical engineering and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.403
H-Index - 81
eISSN - 1521-4125
pISSN - 0930-7516
DOI - 10.1002/ceat.201100025
Subject(s) - evaporation , humidity , energy consumption , moisture , intensity (physics) , materials science , convection , pulp and paper industry , chemistry , process engineering , thermodynamics , composite material , physics , engineering , quantum mechanics , electrical engineering
Several issues pertinent to intermittent drying of clay‐like materials were analyzed with respect to energy consumption, quality of dried products, and drying time. Experimental tests were performed on the cylindrically‐shaped kaolin samples for batch convective drying realized with both periodically alternated temperature and humidity of the drying air. To assess the benefits from intermittent drying, a series of tests were carried out at both parameters kept constant. The net energy necessary for material heating and moisture evaporation was numerically calculated based on the authors' model of drying kinetics, and related to the experimentally measured total electric energy consumption to evaluate the effectiveness of intermittent drying. The quality of dried samples was quantified in terms of crack intensity and magnitude. It was found that intermittent drying permits much better product quality with comparable drying time and energy consumption when drying occurs under constant conditions.