compartment in the air distribution duct between the
As supply air passes through the coalescer,
AMP and the EDC air ducts. The venturi is sized to
moisture particles are condensed into droplets. After
limit airflow to 67 lb/min from the AMP to the air cycle
the air has passed through the coalescer, hundreds of
cooling system to ensure proper flow division and to
small vanes create a swirling motion of the air and the
prevent excessive flow through the aircraft during the
airborne water droplets. This swirling motion
heating mode. It functions to limit flow through the
centrifuges most of the water droplets from the air into
refrigeration unit in the event the other refrigeration
the coalescer sump, where the water accumulates and
unit is operating at a different bypass setting; that is,
drains overboard. The air, relieved of approximately 70
one refrigeration unit is in maximum cooling while the
percent of its moisture, is then ducted into the aircraft
other is modulated toward heating. A check valve is
and distributed.
located in the outlet of each venturi to prevent reverse
Water Spray System
EDC airflow through the venturi.
The water spray system increases basic cooling
CABIN AND FLIGHT STATION
capacity of the air cycle cooling system by spraying
TEMPERATURE CONTROL SYSTEM
water separator discharge water into the ram air,
cooling it by evaporation before the ram air passes
There are two independent temperature control
through the heat exchanger's secondary section.
systems on the aircraft designed to control the
temperature of the air cycle cooling system output
Flow-Limiting Venturi
air. Each system (fig. 6-6) is composed of a
Each air cycle cooling system has a flow-limiting
selector-indicator, a temperature controller, a master
venturi installed in the left and right sides of the APU
temperature sensor, a duct rate sensor, an ice-limiting
Figure 6-6.--Temperature control system components.
6-7
