FILTERS AND STRAINERS
DOE-HDBK-1018/2-93
Miscellaneous Mechanical Components
FILTERS AND STRAINERS
When it is necessary to remove suspended solids from a liquid, the usual method
is to filter or strain the liquid. The two methods differ only in the size of the
mesh being used. Filtering removes the very small solids, and straining removes
the larger solids. Because filtering and straining are for all practical purposes
the same, this chapter will differentiate the two terms on the basis of application
of the filter or strainer.
EO 1.16
DESCRIBE each of the following types of strainers and filters,
including an example of typical use.
a.
Cartridge filters
d.
Bucket strainer
b.
Precoated filters
e.
Duplex strainer
c.
Deep-bed filters
EO 1.17
EXPLAIN the application and operation of a strainer or filter
backwash.
Introduction
Filtration is a process used to remove suspended solids from a solution. Other processes such
as demineralization remove ions or dissolved ions. Different filters and strainers are used for
different applications. In general, the filter passage must be small enough to catch the suspended
solids but large enough that the system can operate at normal system pressures and flows. Filters
and strainers are used throughout most DOE facilities. They are used in hydraulic systems, oil
systems, cooling systems, liquid waste disposal, water purification, and reactor coolant systems.
Cartridge Filters
Figure 20 illustrates a typical multi-cartridge filter. The cartridges are cylinders and usually
consist of a fiber yarn wound around a perforated metal core. The liquid being filtered is forced
through the yarn, which is approximately 1/2 inch thick, and then through the perforations in the
metal core to the filter outlet, which can be at either end. A cartridge filter may include several
cartridges, the exact number depending on the liquid flow rate that must be handled.
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