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

5..3
T,.J
= Tempera tUre ax thermocouple
.6T o ::: Temperature driving force betHeen batch and heat
transfer mediu:m
hTs-b = Temperature drop be~~een
wall surface and batch
A T w
_ b
::: Temperature drop bet1rJeen measured point in wall
and the batch
l) T\:Ar_s = Temperature drop bet"reen measured point in ",raIl
and wall surface
~Tl_2:::
Change in temperature of batch over time interval
1-2
t
"
t'~
~
U
V
V
Vb
Ve
Vr
Vr *.
·~,~it-
Vr
V z
.. ~~ ..
V z
H
1'1'
'a
T.:Jb
= Time
::: Dliaensionless time defined eq. 3-15
::: Terminal blend time (seconds)
= Overall heat transfer coefficient
= Average velocity in pipe or tube
= Characteristic velocity = 11])&
::: Linear velocity of bob
= Velocity in angular direction
::: Velocity in radial direction
::: Dimensionless Vr defined by eq. 3-39
= DL~ensionless Vr defined by eq. 3-12
::: Velocity in vertical direction
= Dimensionless V z defined by eq. 3-13
= Height of batch
= Width of agitator
= Width of baffles