Since the heat transfer coefficient is proportional to the temperature
gradient and the surface area of heat transfer, it is possible to
calculate an apparent heat transfer coefficient by dividing the
water evaporation rate by the temperature gradient and the surface
area of heat transfer where we assume that all heat is transferred
to the fries as latent heat. In Fig. 3 the calculated heat
transfer coefficients for three different temperatures and three different
fry dimensions are shown. It is clear from Fig. 3 that the heat
transfer coefficient decreases with increasing fry diameter. This
may be explained by the fact that larger fries require relative more
energy to heat and thus less energy is available to generate vapour,
which results in a lower calculated heat transfer coefficient.