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TEMPERATURE VARIATIONS IN the OUTLET FROM SCRAPED SURFACE HEAT EXCHANGERS
Author(s) -
HÄRRÖD MAGNUS
Publication year - 1990
Publication title -
journal of food process engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.507
H-Index - 45
eISSN - 1745-4530
pISSN - 0145-8876
DOI - 10.1111/j.1745-4530.1990.tb00058.x
Subject(s) - dynamic scraped surface heat exchanger , laminar flow , heat exchanger , viscosity , mechanics , chemistry , heat transfer , thermodynamics , materials science , heat flux , composite material , physics , critical heat flux
The radial temperature differences and the stability of the temperatures in the product outlet from scraped surface heat exchangers (SSHE) have been investigated over wide ranges of operating conditions. When the flow was vortical, the temperature were stable and no radial differences occurred. When the flow was laminar, channelling effects occurred. the radial temperature differences of the outlet from SSHEs were sometimes very large. the flow was unstable; this was most obvious from the temperature variations close to the blades. In some cases the central parts of the product passed straight through the SSHE without being heated or cooled. Thus, efficient mixing of the product after the SSHE is of primary importance in many applications with high‐viscosity products, e.g., aseptic processing, or the modelling of the performance of SSHEs. A static mixer after the SSHE eliminated the radial temperature differences, but in some cases unstable temperatures remained after the mixer due to unstable flow conditions in the SSHE. the degree of stability was influenced by the design of the SSHE and by the flow rate.