ISSN:
1750-3841
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
: Convective heat transfer coefficient (hp) between fluid and particle in continuous tube flow were compared for 2 configurations of holding tubes: one conventional having a circular cross section (CHT) and the other having noncircular cross section (NCHT). A stream of plastic spheres was fed into the holding tube to simulate a food system with particulates. Live vegetative cells of Bacillus stearothermophilus were immobilized in aqueous gellan cubes and injected into the holding tubes with water as a carrier medium. The observed inactivation levels were compared with predicted values calculated from transient heat transfer equations solved by an explicit finite difference technique. Mean effective hp values ranged from 400 to 2500 W/m2.K for the NCHT and 350 to 1700 W/m2.K for the CHT at a Reynolds numberrpanging from 6000 to 13000. The difference in hp levels between the 2 configurations increased with the flow rate and temperature. Although no relation was observed between hp values and liquid to particle relative velocity, a trend between pipe Reynolds number and hp values was observed. The presence of a large number of particles in the holding tube significantly influenced hp values. Keywords: heat transfer coefficients, holding tube, Reynolds number, particle
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1365-2621.2005.tb09974.x
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