Design and control of energy efficient drying processes with specific reference to foods

Technical Report · Fri Oct 14 04:00:00 EDT 1988

OSTI ID:5864171

Kim, M; Liang, H; Murakami, E; Narsimhan, G; Okos, M; Singh, R; Waananen, K; Xiong, X

This report contains a summary of work performed on tasks 10 to 14. Task 10 involves revision of the drum drying model developed and revised earlier. In its completed form, the model should contain three nonlinear differential equations covering energy, mass transfer and gas phase momentum. The model currently in use now employs the vapor pressure gradient as the driving force. The vapor pressure is obtained from the isotherm of each material of interest. The revision of this model should be complete after an isotherm equation is obtained and tested. Task 11 concerns experimental studies for model verification. Extrusion of pasta at temperatures below 100{degrees}C gave a low porosity product, while higher temperatures caused puffing and increased porosities. Further variations in extrusion temperatures will enable a study of the relationship between food structure and mass transfer rates. Modification of the high pressure drying apparatus is complete; tests with the new dryer should begin next quarter. An additional improvement on the original design was installation of an oil bath, which is shown to provide better temperature control. Task 12 examines the thermal properties of foods. A comprehensive collection of thermal property equations, predictive models and measurement techniques has been compiled. A final report on viscoelasticity and thermal properties is being organized. Task 13 lists recommendations and strategies for dryer design and control. Controller design methods are reviewed, and evaluations are based on accuracy, stability, response time, and robustness of a closed loop system. Task 14 examines moisture mobility and interaction in foods. Methods to measure porosity are reviewed, and a suitable technique will be selected during next quarter. 31 refs., 4 figs. (MHB)

• Research Organization: Purdue Univ., Lafayette, IN (USA)
• Sponsoring Organization: DOE; USDOE, Washington, DC (USA)
• DOE Contract Number: FG07-85ID12608
• OSTI ID: 5864171
• Report Number(s): DOE/ID/12608-T9; ON: DE91010693
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
320300* -- Energy Conservation
Consumption
& Utilization-- Industrial & Agricultural Processes
DESIGN
DOCUMENT TYPES
DRYERS
DRYING
ENERGY CONSERVATION
FOOD
FOOD INDUSTRY
INDUSTRY
ISOTHERMS
MATHEMATICAL MODELS
MEASURING INSTRUMENTS
MOISTURE
PHYSICAL PROPERTIES
POROSIMETERS
POROSITY
PROGRESS REPORT
SHRINKAGE
TEMPERATURE DEPENDENCE
TESTING
THERMODYNAMIC PROPERTIES
VALIDATION
VAPOR PRESSURE