paraffin wax deposition and fouling

U.
The tubes used in the fouling studies had i.d. 13.1 mm.
integration of this equation had to be made numerically and was
Jr
ii(r—y)d(r—y)
Tb = r
. (6.2.2)
(r - y) d (r - y)
— 57 —
The radius of the tubes was therefore 6550 m. In figure 6.2.2.1
an indirect method was used.
I W.
distance of 3000 .tm, almost half the radius. A separate plot extend
plot;ed in figure 6.2.2.2. The velocity at the centre = 1.95 /s
profile does not change much for y > 500 im, which is the approxi
would be obtained. As seen from figure 6.2.2.1 the temperature
where T. is the bulk temperature, T and u the temperature and velocity
at about 3000 m, a fair representation of the true distribution
at distance y from the “wall” and r the radius of the passage. An
the temmerature profiles for run F36 were plotted up to a radial
was obtained at y = 6550 in. The bulk velocity was = 1.60 a/s.
considered too tediQus to be of value in the present xork. Instead,
mate limit of the boundary layer.
ing to the centre of the passage, showed that if the calculated
was selected as 23°C, the calculated temperature profile would
U
S
= 0.82
Tue ratio: -
is only slightly higher than data given by >ucAdams
temperature profile passed or crossed the average bulk temperature
correspond to the average bulk temperature.
The velocity profile for the wall temperature T = 23°C was
Figure 6.2.2.1 showed that if the effective wall temperature
4 for isothermal