MIL-HDBK-1005/16
h)
The quantity of solids to be removed and handled
i)
The effluent or pretreatment limits to be met
Design criteria should conform to criteria established
by the API, as follows:
a)
Horizontal velocity through the separator should
be less than or equal to 3 feet per minute or equal to 15 times
the rise rate of the oil globules.
b)
Separator water depth should not be less than
3 feet.
c)
The ratio of separator depth to separator width
should typically be in the range of 0.3 to 0.5.
d)
A minimum length-to-width ratio of 5 is
recommended.
e)
Where continuous service is required, a backup
channel or unit should be provided.
For a step-by-step design procedure, refer to API
Publication 421. MIL-HDBK-1005/9 also contains design
information.
5.6.5
Design Criteria for Parallel-Plate Separators.
Parallel-plate OWSs are furnished as pre-engineered, factory-
assembled units. As such, designs vary by manufacturer, and
vendor experience must be used in unit sizing and selection.
In general, however, the parameters and procedures used for the
design of parallel-plate separators are the same as for
conventional separators, except that a smaller design globule
diameter of 60 microns is usually assumed. The perpendicular
distance between plates typically ranges from 0.75 to 1.5 inches
(2 to 4 cm), and the angle of plate inclination from the
horizontal typically ranges between 45 and 60 degrees.
Placement of the OWS to provide accessibility is
particularly important for parallel-plate separators.
Accessibility is essential for maintaining the parallel plates in
the separation chamber, which may require frequent cleaning.
Removal for cleaning with high-pressure cleaning equipment is the
procedure of choice. If cleaning in place is used, a hose
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