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EFFECTIVENESS OF PNEUMATIC CONVEYING SYSTEMS FOR COOLING SPRAY‐DRIED FOOD PRODUCTS
Author(s) -
HELDMAN D. R.,
WANG P. Y.,
CHEN A. C.
Publication year - 1971
Publication title -
journal of food science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.772
H-Index - 150
eISSN - 1750-3841
pISSN - 0022-1147
DOI - 10.1111/j.1365-2621.1971.tb04049.x
Subject(s) - forced air , mechanics , thermocouple , tube (container) , thermodynamics , circulation (fluid dynamics) , natural circulation , materials science , mixing (physics) , chemistry , composite material , physics , quantum mechanics
— The cooling effectiveness during pneumatic transport of a spray‐dried food product has been investigated. Differential equations which describe the product and air temperatures as a function of distance from the initial mixing point have been derived and solved. The predicted results have been compared to experimental data obtained in a conveying tube equipped with thermocouples. The results indicated the equilibrium temperature of the air‐product mixture could be predicted and was a function of loading ratio. Increased loading ratio decreased the distance required to reach the equilibrium temperature. The effectiveness of product cooling after reaching the equilibrium temperature was a function of conditions at the conveying tube wall. Results indicated that a water spray over the exterior surface was more effective than forced‐air circulation which, in turn, was more effective than natural air circulation.