Figure 7-19.--Path of contaminated oil through a disc-type purifier bowl (DeLaval).
neck of the top disc. The water forms a seal
Figure 7-17 shows a cutaway view of a disc-
between the top disc and the bowl top. (The
type centrifugal purifier. The bowl is mounted on
top disc is the dividing line between the
the upper end of the vertical bowl spindle, driven
water and the fluid.) The discs divide the
by a worm wheel and friction clutch assembly.
space within the bowl into many separate narrow
A radial thrust bearing at the lower end of the
passages or spaces. The liquid confined within
bowl spindle carries the weight of the bowl spindle
each passage is restricted so it can flow only along
and absorbs any thrust created by the driving
that passage. This arrangement minimizes agita-
action. Figure 7-18 shows the parts of a disc-type
tion of the liquid as it passes through the bowl.
bowl. The flow of fluid through the bowl and
It also forms shallow settling distances between
additional parts are shown in figure 7-19.
Contaminated fluid enters the top of the revolving
bowl through the regulating tube. The fluid then
Any water, along with some dirt and sludge,
passes down the inside of the tubular shaft, out
separated from the fluid, is discharged through
the bottom, and up into the stack of discs. As the
the discharge ring at the top of the bowl.
dirty fluid flows up through the distribution holes
However, most of the dirt and sludge remains in
in the discs, the high centrifugal force exerted by
the bowl and collects in a more or less uniform
the revolving bowl causes the dirt, sludge, and
layer on the inside vertical surface of the bowl
water to move outward. The purified fluid is