Gas Turbine Handbook : Principles and Practices

118 Gas Turbine Handbook: Principles and Practices
Figure 8-1. Courtesy of American Air Filter International. A schematic
view of an inertial separator showing the paths taken by the
clean air flow through the separator and the dirty air out of the
separator.
Another type of filter is the cannister filter (Figure 8-3). This
filter is provided with and without a self-clean feature, and with and
without prefilters. Unlike barrier type filters, the cannister filters do
not include an intermediate filter stage (although it has been proposed
to install the cannister filter as the intermediate filter stage immediately
upstream of a high efficiency barrier filter). The “ self-clean”
cannister filter design uses high pressure compressor air to backflow
or reverse flow each filter cartridge. The reverse flow is designed to
blow excess dust from the element. In principle these filters would accumulate
a dust load to increase efficiency up to a target level. At the
target differential pressure the reverse flow, self-clean, feature would