Prediction of batch heat transfer coefficients for pseudoplastic fluids ...

6D
and e directions and constant density, the equation becomes
I
A
J(eA i£)_ 0
eJft - (3-7
In the system being considered the mechanical energy input
is negligible compared to the heat transferred through the
1..Jal1s. The energy equation for this case is (21)
d T 0tdT J/p
(-'c;; ( d-c -;- J~ ";-;t
) 7 -f liz dT ) =
J& oiL!
J [;
(3-8
The temperature gradients in the e direction are zero,
and the temperature gradients in the z direction are also
assumed zero..
Therefore equation 3-8 reduces to
Equations 3-5, 3-7 and 3-9 thus describe the model
(3-9
discussed above.
These equations cannot be solved since
the velocity and temperature gradients cannot be expressed
analytically. However, the system can be characterized by
solving the equations dimensionally.
The follo-vring dimensionless variables are defined by
Bird, et al. (21) as
r-lH~ = ( riDs. ) (3-10
Z~:- = z/Ds. 0-11