The heat transfer study on heating and cooling performed
in a closed cardboard carton container commercially
used in table grape transportation, showed that the
simple correlation [Nu = 1.5(GrPr)1/4], gives a good estimate
(p < 0.05) of the heat transfer coefficient regardless
if the container is empty or loaded with grapes, under heating
or cooling. For the container, the Grashof number: Grz,
was defined in terms of the height of the carton, and validated
in the range of: 12–16 cm.
This correlation, when extended to mass transfer:
[Sh = 1.5(GrmSc)1/4], making use of the Chilton–Colburn
analogy, give a good estimate of mass lost when applied
to methyl jasmonate vapor generators to be used in grape
packages in the range of 0–25 C.
The proposed correlation gives a better estimate of the
heat and mass transfer coefficient, than those found in
the literature, when evaluated for cardboard carton containers
of the kind used in international commercial cold
transport of table grapes. A more accurate estimate of
the heat transfer coefficient, will make possible a better prediction
of thermal behavior inside the carton container,
due to thermal rise in the storage, therefore it will make
possible more reliable predictions of potential damage
due to mold growth.
In situations that gas generator are used to control mold
growth, this correlation, expressed in terms of the Sherwood
number, can be used for the proper design of the generators
with a better estimated of operating life span, due
to mass loss.