Heat transfer analyses using computational fluid dynamics in the air blast freezing of guava pulp in large containers

Abstract

-Heat transfer during the freezing of guava pulp conditioned in large containers such as in stacked boxes (34 L) and buckets (20 L) and unstacked drums (200 L) is discussed. The air velocities across the crosssection of the tunnel were measured, and the values in the outlet of the evaporator were used as the initial conditions in computational fluid dynamics (CFD) simulations. The model tested was turbulent standard k-ε. The CFD-generated convective heat transfer coefficients were mapped on the surfaces for each configuration and used in procedures for the calculation of freezing-time estimates. These estimates were compared with the experimental results for validation. The results showed that CFD determined representative coefficients and produced good correlations between the predicted and experimental values when applied to the freezing-time estimates for the box and drum configurations. The errors depended on the configuration and the adopted mesh (3-D grid) construction.

Computational Applications for the Evaluation and Simulation of the Thermal Treatment of Canned Foods

“…Furthermore, the same authors carried out a similar experiment, but evaluating the effect of intermittent axial agitation (0-146 rpm), and two retort temperatures (111 and 131°C) [139]. In another study, LabVIEW 8.5 was used to compare freezing results of guava pulp packed in stacked boxes, buckets, and unstacked drums, 34, 20, and 200 L, respectively [140].…”

Computational fluid dynamics analysis for improving temperature distribution in a chili dryer

“…Gallegos et al [33] analyzed the effect caused by fitting in the measurements of flow in an air conditioning system. Okita et al [34] investigated the heat transfer process during the freezing of guava pulp contained in a stack of large containers. Recently, several studies have reported the analysis of different kinds of dryers for agricultural products using CFD.…”