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A computational model for temperature and sterility distributions in a pilot‐scale high‐pressure high‐temperature process
Author(s) -
Knoerzer Kai,
Juliano Pablo,
Gladman Simon,
Versteeg Cornelis,
Fryer Peter J.
Publication year - 2007
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.11301
Subject(s) - thermocouple , materials science , volume (thermodynamics) , cabin pressurization , sterilization (economics) , thermal conduction , thermal , composite material , mechanics , thermodynamics , physics , monetary economics , economics , foreign exchange market , foreign exchange
High pressure high temperature processing is a candidate food sterilization process in which heat is generated volumetrically within the food as a result of rapid pressurization to 600 MPa or higher. For commercial viability the temperature profile in the process should be as uniform as possible. A model has been developed to predict the flow and temperature fields inside a pilot scale (35 L) vessel during the pressure heating, holding and cooling stages of the process. Simulations on the empty vessel show that thermal conduction causes excessive cooling. The model agrees well with experimental results in which thermocouples are used to measure temperature throughout a metallic composite carrier inserted into the vessel. The model is used to design a Polytetrafluoroethylene (PTFE) carrier which produces thermal uniformity within the carrier. Predicted variations of sterility resulting from a process are produced using the F 0 ‐value distribution. No significant reduction of spores was seen in the empty vessel, while more than 94.6% of the PTFE carrier volume achieved a reduction greater than 10 12 . © 2007 American Institute of Chemical Engineers AIChE J, 2007