paraffin wax deposition and fouling

point temperature interface. Clearly the behaviour of small
It is anticipated therefore that a suspension of wax crystals in
particles depositing came out of solution inside the boundary layer.
solution pour point, it was calculated in section that the wax
where the tube wall temperature was always kept well below the
For the experimental conditions adopted in the fouling studies,
I 0-f —
particles in boundary layers is important in paraffin wax deposition
and fouling.
7.3 Behaviour of ax in Bouncarv Layers
may move due to Brownian motion giving rise to diffusion. During
deposition therefore, both wax particles and molecules probably
deposits. s wax molecules diffuse toward the wall more and more
contribute to the diffusion toward the wall. The diffusional driving
wi devlop ra;idiy. s the wax detosits build up the heat fux
solubility limit. it is therefore likely that wax particles
kerosene existed from the surface of the solid wax to the cloud
probably also influence the moveaent of particles in boundary
of them will come out of solution because of the decreasing
force resulting from the wax depletion at the wail where the wax
If these shearing forces act similarly in boundary layer suspensions
in laminar flow may move small particles away from the tube waZ...
constitute the major proportion of wax deposited.
7.4 3uZ.du of Ds:ts
layers.
they may move particles outside the cloud point ter.perature inter
face, where they will dissolve. Particle interactions will
that is cooled, cepcsition occurs. Velocity and teaterature profiles
As is well known molecules and even small particles in solutions
It was shom in section 2.2.4 that the shear field existing
inen a solution containing a wax foulant enters a clean tue