DEVELOPING AN EFFECTIVE METHOD TO DETERMINE THE DEVIATION OF F VALUE UPON THE LOCATION OF A STILL CAN DURING CONVECTION HEATING USING CFD AND SUBZONES

摘要

A numerical simulation was applied to determine the temperature profiles ofrnwater in a can with a diameter of 52.3 mm and a height of 124.0 mm. Cold pointsrnat different heating times were determined, and the degree of pasteurization (Frnvalue) of each cold point was calculated. Subzones in both vertical and horizontalrndirections were introduced to determine the deviation of F value upon the locationrnin the can during a convective heating, and the average F value of eachrnsubzone was estimated. The slow heating zone (SHZ) was determined byrnoverwrapping the subzones with the lowest average F values in the vertical andrnhorizontal direction. The cold point was continuously moved during the thermalrntreatment and even at 600 s, the SHZ determined by this subzone method maintainedrna single zone, unlike the cold points. The relative difference of F valuernbetween the SHZ and the cold point was approximately 0.575%. The subzonernmethod is thus an effective way to determine the SHZ and F value, which is anrnindicator of the sterilization.