Notes for interrupted mains voltage
38
HDK-CNG_EN_03_2016
Shutting down and restarting the dryer
In the following cases, the dryer must be fully shut down and depressurised:
In the event of an emergency or malfunction
For maintenance
For disassembly
Formation of an explosive gas mixture!
An explosive mixture of gases can form if gas escapes while oxygen
enters the dryer.
Risk of injury from escaping compressed air!
Never remove any parts of the dryer, or manipulate the same in any way,
for as long as the plant is still pressurised! Suddenly escaping
compressed air might cause serious injuries.
Before carrying out any work on the dryer, first depressurise the plant.
On no account place the dryer into service or take the dryer out of service
without inerting it beforehand!
Together with air, natural gas can form an explosive gas mixture and
therefore poses a considerable danger. An explosive atmosphere can
build up especially during commissioning and when replacing the drying
agent. To avoid this, the dryer must be purged with inert gas both before
placing into service well as before taking out of service (e.g. before
maintenance). You will find information on inerting on Page 15.
Notes for interrupted mains voltage
Note the following instructions in the event of the power supply to the dryer being
cut unexpectedly.
In the event of a power failure or of the dryer being switched off using the On/Off
switch, any main valve open then closes, resulting in
pressure at the delivery side of the dryer rising while the compressor is running
(up to the controlled shutdown point of the compressor),
vessel pressure (without startup fixture) dropping when natural gas outlet valve
is opened, if natural gas is being sourced from the grid,
no further natural gas enters the downstream natural gas system.
Note:
As soon as the dryer is switched on again, the programme continues
the cycle from the point at which it has been stopped.
