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

and if' lO"V'l$'
a sm.all amount of' wate~ was added -Go make up
fol' I!,..,.apora tiol"i los ses (0 A series of Fower m~!HilSU3Jl'(!I)ments were
then made. At each speed the dymrunometer s~aleg the rotational
speed, and the flm.id height we:pe noted.
There vIas not mueh
variati1!lB. in ~ight because the baffles elimina:ced vOJ?tex
f'ormatiol'l..
However, there were slight increases and these
't-lere taken int ten di.f'f'erm t speeds were investigated
~nd
f'our were selected f'or heat transfer runs.
The heat transfer run was started by tu:Mll.il1lg en the
recorder and steam (low pressure, 8-12 paig.). The water
drain valve was closed when steaM started to bellow out of
it. The rotational speed was measured with a Smiths Haad
Tachometer (11[04el ATH7,,:f: 0.5% aecW?acy).. Between :minute
:
number four and six the condensate was colleeted ~d weighted.
The 8te~ and eondensate temperatures were eaehread ~ee
different times. When the batch temperature reached 80-90 0 C
the s team was shut off and the Hater drain opeBed.
CGolfmg water was then turned OB and set at about 95 ~epeent
The
of' the rotometer flow rate. Tke speed 1-J'as also mea..::rured
twiee more aRd water floH rate H'as checked periodically ..
When the batch temperature was e@oled to 25-30 0 C the cooling
91
water was turned o~~
and the jaeket drained.
The s trip chart f'rom. a typical run is shovm il'!!. Figu.:ve
4-5.. During hl~ heating cycle the wall temperature is higher