Master's Dissertation
DOI
https://doi.org/10.11606/D.3.2013.tde-27122013-113320
Document
Author
Full name
Rafael Viana Benze
E-mail
Institute/School/College
Knowledge Area
Date of Defense
Published
São Paulo, 2013
Supervisor
Committee
Gut, Jorge Andrey Wilhelms (President)
Pessôa Filho, Pedro de Alcântara
Schmidt, Flávio Luís
Title in Portuguese
Modelagem matemática do processo térmico contínuo de alimentos líquidos em trocadores de calor a placas.
Keywords in Portuguese
Modelagem matemática
Pasteurização
Processamento térmico
Simulação
Abstract in Portuguese
Title in English
Mathematical modeling of the continuous thermal processing of liquid foods in plate heat exchangers.
Keywords in English
Mathematical modeling
Pasteurization
Plate heat exchanger
Simulation
Thermal processing
Abstract in English
The main objective of this study was to develop a mathematical model in a plate pasteurizer in order to determine the temperature and lethality distribution along the channels of the heat exchanger in all its sections, in tubular connections and holding tube evaluating the logarithmic decay in concentration of a target microorganism or enzyme activity in a continuous pasteurization process. Mathematical modeling was composed of the differential energy balance and lethality in the channels of the exchanger, the holding tube and its connections, taking into account the heat loss to the environment in the tubes. The constructed model presented a set of ordinary differential equations of first order and its resolution was made by the finite difference method using the gPROMS software. A case study was analyzed and the modeling described the thermal and the lethality process very well and in the future it can be used to optimize the process of pasteurization in plate heat exchangers, aiming the achievement of safe and with high quality products. A verification of the pasteurization process that the model developed contemplates has been performed based on experimental validation using time-temperature integrator and testing with enzymatic indicator (alkaline phosphatase in phosphate buffer), which showed that the model developed satisfactorily approximates the actual results.