Problem Solving - Quincy QHD750 Instruction Book

8

Problem solving

8.1 Problem solving
Symptom
Poor dewpoint
Too high purge
consumption
The dryer produces
a lot of noise
90
Possible cause
Free water in compressed air inlet
Temperature of compressed air is
too high
Working pressure is too low
Poor regeneration
Poor desiccant
Damaged desiccant
Oil vapors adsorbed by desiccant
Dryer is stopped
Desiccant has become
oversaturated for a longer period
Incorrect purge nozzle installed.
Incorrect purge nozzle installed.
Safety valve of silencer is opened
Check the silencers and their
fixation
Incorrect adjustment of
regeneration valve
Corrective action
Check the condensate separators and
drains upstream of the dryer if they are
operating correctly
Clean compressor after-cooler
Check outlet pressure of compressor and
check pressure drop over dryer, filters
Too small purge nozzle for higher working
pressure installed.
Regeneration silencers clogged. Check
the service indicator. The regeneration
pressure should be less than 300 mBar
Check if all other described symptoms are
applicable. Solve them
Replace desiccant. Check the
maintenance schedule for normal
replacement periods
Air flow too high during start-up. Replace
desiccant. Install sonic nozzle to avoid
problems in the future High pressure
difference between vessels when
switching. This indicates that a too small
purge nozzle is installed
Remove some desiccant from the bottom
part of the vessel. Yellow colored
desiccant indicates oil vapor adsorption
Check that the dryer is turned on.
Replace desiccant
Compare the actual working pressure with
the ordered optimized purge nozzle.
Higher working pressures result in higher
purge consumption that creates more
noise.
See symptom Too high purge
consumption
See symptom Too high purge
consumption
Replace the silencer if necessary
Adjust the opening time of the
regeneration valves with the needle valve
on the actuator
Instruction book
9829 2151 14