should be used whenever potential noise level dif-
ficulties are anticipated.
Intake resistance to airflow should be no more
than necessary to maintain air quality. The
resistance created by the air intake system will
reduce compressor performance and efficiency. Refer
to the compressor manufacturers manual for
maximum resistance requirements.
Air filters are provided on compressor intakes to
prevent atmospheric dust from entering the
cylinders and causing scoring and excessive wear.
The two most common types of elements in use are
the VISCOUS IMPINGEMENT and the OIL BATH.
Both types are illustrated in figure 11-10.
Figure 11-10.Compressor intake filters.
In the oil bath type, air must pass through an
oil seal that removes dirt particles, and then pass on
through a wire mesh element, which is saturated by
oil carry-over. Any remaining particles of dirt are
removed by the wire mesh element. Captured dust
particles settle to a sump at the bottom of the filter
housing. Oil bath filters are recommended where
dust concentrations are present in the atmosphere.
The viscous impingement filter consists of a
wire mesh filter element, which is coated with oil.
Air passing through the filter element must change
directions many times, causing any dust to adhere to
the oil film.
Silencers are similar to mufflers and function
simply to eliminate objectionable compressor suction
noise. Figure 11-11 illustrates a standard
Figure 11-11.Intake silencer.