The convective fluid-to-particle heat transfer coefficient (hfp ) is one of the critical factors influencing the process design for multi phase food products, in continuous tubeflow systems. Determination of hfp associated with moving particles poses a unique challenge to investigators because of the difficulty in monitoring the temperature of moving particles without interfering with the particle motion. Two different techniques involving particle motion were developed to evaluate hfp and to study the effects of factors influencing hfp, associated with spherical particles under tube-flow conditions. / Spherical Nylon particles with centrally located fine-wire flexible thermocouples, were suspended from the upper mid-section of a curved glass tube in order to provide lateral movement of the particle as the tube was subjected to oscillatory motion. / A full factorial experimental design was studied involving spherical particles made of Aluminum epoxy and Nylon of different diameters (12.7 to 17.5 mm), particle linear velocities (0.06 to 0.21 m/s), heating medium viscosities (0 to 1% Carboxymethyl cellulose, CMC) and fluid temperatures (60 to 80°C). The above factors had a significant (p < 0.001) effect on hfp. Depending on experimental conditions the values of h fp varied from 350 to 2000 W/m2K. Overall, hfp values associated with the aluminum epoxy particle were about 30% higher than that for the Nylon particle. / A calorimetric method was developed to evaluate hfp associated with a freely moving particle. / The calorimetric method was used to evaluate the effect of fluid flow rate, viscosity and temperature, as well as particle size on the associated hfp under tube-flow conditions. Experiments were carried out using different flow rates (9 to 19 L/min), fluid viscosity (0 to 1% CMC solution) and fluid temperature (50 to 70°C) as well as Aluminum spherical particles of different sizes (19 to 25.4 mm). Values of hfp varied from 650 to 2660 W/m2K, and increased significantly (p < 0.001) with an increase in fluid flow rate and particle size, whereas a decrease was observed with CMC concentration and temperature. / Several correlations were developed in the form of Nusselt number as a function of other influencing dimensionless numbers. Nusselt numbers estimated from the developed equations showed good agreement with the experimental data (0.88 < R2 < 0.99). (Abstract shortened by UMI.)
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.36073 |
| Date | January 1999 |
| Creators | Zareifard, Mohammad Reza. |
| Contributors | Ramaswamy, H. S. (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Doctor of Philosophy (Department of Food Science and Agricultural Chemistry.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001687493, proquestno: NQ55397, Theses scanned by UMI/ProQuest. |
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