paraffin wax deposition and fouling

3.5 Conclusions
decreases
At the inceution of an experiment a wax deposit is rapidly laid
Ualker suggested a mechanism to explain the observed ofi’ccts.
extenaive at the colder downstream end of test tubes.
A viuual examination of the paraffin iax clc;pozitn , nhowed them
— cL —
roint the way for farther research.
resultant concentration graaient will cause tne aiffusion o: wax
ness that it becomes mechanically weak an sheds.
to vary from individual earticlos to extended areas, depcndia; on
boundary layer the mixture will become suocrsaturated and the
toe operat:uv; conditions. Toe ucposits were aLso ±ound to oe more
inorta.. mractnon. oker postula;en tnat tots ceposatton toen
gave rise to a secondary layer, that periodically builds up and
sheds. This secondary unstable layer builds un to such a thick
work did show ale fluctuating nature of para::in i’ax cerosats ana
down on the cooled surface from the adjacent mixture. This deronit
and low concentrations the least fouling situation.
onlv nartiallv covers the surface. At some point in the cooled
from the bulk to the waIl. The wax crystals are then transferred
boundary layer, to be most imoortant in reducing deposition,
from the bour.dary layer to the wall, either by diffusion or
sufficient information to study the fundamental mechanism of
si cc cotact ‘
deposition did not occur- over such a time scale as to :3rcv.e
than those formed at higoer concentrations, making high :‘lcwrates
the system studied did not oroduce the exoected resulis
formed at low concentrations appearea to cc mecaaatcay wea.:ar,
foaling which iat be used it. design situations. ::owever, the
!alker considered the residence time of wax artices, in ale
The general conclusion of the fouling work by ‘‘aker is that
w;-i rcrLasra floate. Dc os s
0 he