Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 11
    Electronic Resource
    Electronic Resource
    Oxford, UK and Malden, USA : Blackwell Science Inc
    Journal of food process engineering 28 (2005), S. 0 
    ISSN: 1745-4530
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: This article presents a mathematical model describing the unsteady heat and mass transfer during the freeze drying of biological materials. The model was built from the mass and energy balances in the dried and frozen regions of the material undergoing freeze drying. A set of coupled nonlinear partial differential equations permitted the description of the temperature and pressure profiles, together with the position of the sublimation interface. These equations were transformed to a finite element scheme and numerically solved using the Newton-Raphson approach to represent the nonlinear problem and the interface position. Most parameters involved in the model (i.e., thermal conductivity, specific heat, density, heat and mass transfer coefficients etc.) were obtained from experimental data cited in the literature. The dehydration kinetics and the temperature profiles of potato and apple slabs were experimentally determined during freeze drying. The simulation results agreed closely with the water content experimental data. The prediction of temperature profiles within the solid was, however, less accurate.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 12
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Journal of food process engineering 22 (1999), S. 0 
    ISSN: 1745-4530
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Process Engineering, Biotechnology, Nutrition Technology
    Notes: Drying kinetics of the product are the most important data required for the design and simulation of air dryers. This essential information can be obtained through simple lab-scale experiments. Nevertheless, due to the uncertainty of the process, specially when dealing with biological materials, all the necessary data at different operating conditions are not usually available. On the other hand, drying kinetic models are either too simple to expect reasonably good predictions, or too complicated to be applied easily.The key assumptions of a previously developed lumped-parameter model for air drying kinetics were revised to examine their application to biological materials. A short cut method has been developed to simulate kinetic curves from a minimum number of experimental data. A simple parameter study was carried out to detect the most important variables that affect the mass transfer Biot number in order to predict kinetics data safely. Experimental (hot air) drying curves for bananas, grapes and mushrooms were obtained in a lab scale dryer, at different air temperatures (50 to 70C) and air velocities (1 to 3 m/s). A comparison between experimental and predicted data was done for different operating conditions.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...