DIMENSIONLESS CORRELATION FOR ESTIMATING INTERNAL PRESSURE IN THIN-WALLED ALUMINUM CONTAINERS DURING THERMAL PROCESSING

• Published in: Journal of food process engineering Vol. 26; no. 2; pp. 223 - 236
• Main Author: AWUAH, G.B.
• Format: Magazine Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.06.2003; Blackwell
• Subjects: Biological and medical sciences; Food engineering; Food industries; Fundamental and applied biological sciences. Psychology; General aspects; Container; Correlation; Wall; Internal pressure
• ISSN: 0145-8876; 1745-4530
• DOI: 10.1111/j.1745-4530.2003.tb00598.x

ABSTRACT The need for creating container initial pressure, overpressure requirements and maintenance during thermal processing of thin‐walled aluminum containers is briefly discussed. the initial pressure within containers was achieved by injecting liquid nitrogen (LN2) into the container headspace (0.5, 0.75 and 1 in.) prior to seaming. Experiments were conducted using a computer‐controlled retort with water‐immersion as heating medium, and temperatures ranging from 241 to 261F. Product initial temperature varied from approximately 45 to 135F. Container internal time‐pressure history during processing was monitored using a remote pressure sensor mounted within the container. Using water as model food, a dimensionless correlation that related the maximum cortainer pressure to product headspace, initial temperature and pressure was developed. Increasing retort temperature increased the maximum container internal pressure, while increasing product initial temperature decreased the maximum internal pressure developed within the container processing. the effect of product initial temperature on the maximum internal pressure was attributed to the amount/level of entrapped gasses present. Developed correlation using water predicted the internal pressure for 5% bentonite suspension with marginal errors (2 to 7%). However, the model failed to predict the maximum pressure for oil‐filled containers.