Figure 10-32.Two-stage flash-type evaporator.
seawater is pumped overboard. Some flash-type
distilling plants have as many as five flash chambers
through which the seawater passes before being pumped
overboard. The vapor is condensed and routed to the
ships freshwater tanks.
Distilling plants range in capacity from 2,000 to
100,000 gpd. The size depends on shipboard needs and
space available. Some ships have only one distilling
unit, while others have two or more.
When you operate and maintain a purifier, you
should refer to the detailed instructions that come with
each purifier. These manufacturers technical manuals
contain information on the construction, operation, and
maintenance of the specific purifier. You need to follow
these instructions carefully. This section of the
TRAMAN contains a discussion and general
information on the methods of purification and the
principles of operation of centrifugal purifiers.
Centrifugal purifiers are used to purify both lube oil and
fuel. However, we will discuss lube oil only since the
principles are the same for both.
A purifier may remove both water and sediment, or
it may remove sediment only. When water is involved
in the purification process, the purifier is usually called
a SEPARATOR. When the principal contaminant is dirt
or sediment, the purifier is used as a CLARIFIER.
Purifiers are generally used as separators for the
purification of fuel. When used for purification of a lube
oil, a purifier may be used as either a separator or a
clarifier. Whether a purifier is used as a separator or a
clarifier depends on the water content of the oil that is
The following general information will help you
understand the purification process, the purposes and
principles of purifier operation, and the basic types of
centrifugal purifiers used by the Navy.