AirMan PDS185S-6E1, Руководство по обслуживанию

Страница: 15 / 103

1. Specification
1-9
1.6 Capacity Control Device
A131023E
Step Response
Start
Compressed air flows into unloader chamber (A) because solenoid valve for
purge control SV1 is opened at start-up. The pressure in chamber (A) rises
soon to close unloader valve fully and accordingly it can reduce the load at
start-up.
Load operation
After starting, SV1 is closed after automatic unloaded operation, and the air
volume which is sent to chamber (A) increases and decreases according to the
rise and drop of the discharge air pressure and consequently the opening
width of the unloader valve is changed. Further, engine speed (RPM) is
changed by the pressure which PRS1 detects, and it steplessly controls the air
volume in the range from 0 to 100%.
Suction port closing
unload operation
When compressed air pressure exceeds the rated pressure with reduction of
air consumption, PRS1 detects the pressure and it reduces engine speed
(RPM) in proportion to the pressure rise, and it closes unloader valve at the
same time. When compressor air-end becomes vacuum during unload
operation, vacuum noise is caused. To prevent this noise, it opens vacuum
relief valve by detection of secondary pressure of pressure regulator. Thus
high vacuum condition of compressor air-end is prevented.
Purge control unload
operation
When the certain set time (it can be changed.) has passed at lower pressure
than the set negative pressure, detecting the negative pressure inside the
compressor air-end with a pressure sensor PRS2, solenoid valve SV1 opens
and it closes unloader valve. At the same time, it functions to relieve the
compressed air from separator receiver tank to the atmosphere and thus it
lowers the pressure. Thus the compressor power is saved. When air
consumption increases, and the pressure used for load drops below the set
pressure, pressure sensor PRS3 detects it and it disengages the purge control
(SV1 closes) to start full load operation.
Stop
When stopping operation, it opens auto-relief valve to relieve the compressed
air in separator receiver tank to atmosphere, detecting the pressure inside
compressor air-end.
Discount-Equipment.com