Page 20 - Reciprocating Compressors Operation Maintenance
P. 20
Reciprocating Compressors and Their Applications 7
2, By dynamic action imparting velocity to the gas. This velocity is
then converted into pressure. Flow rate and pressure ratio both vary
as a function of speed, but only within a very limited range and then
only with properly designed control systems. Figure 1-4 shows the
basic idea.
High Velocity
Low Static Pressure
Low Velocity
High Static Pressure
FIGURE 1 -4. Velocity energy being converted to pressure energy.
Total energy in a flowing air stream is constant. Entering an enlarged
section, flow speed is reduced and some of the velocity energy turns into
pressure energy. Thus static pressure is higher in the enlarged section.
The principal types of compressors are shown in Figure 1-5 and are
defined below. Cam, diaphragm, and diffusion compressors are not
shown because of their specialized applications and relatively small size.
