Leading Particulars; General Description; Markings; Control Panel And Gauges - Atlas Copco CD7 Bedienungsanleitung

CD7 – CD12 – CD17 – CD24 – CD32 – CD44 – CD60
Safety during use and operation
1 To lift an air dryer, all loose or pivoting parts shall first be securely fastened.
2 Lifting acceleration and retardation shall be kept within safe limits.
3 No external force may be exerted on the air valves, e.g. by pulling on hoses or by
installing auxiliary equipment directly to a valve.
4 Close the compressor air outlet valve before connecting or disconnecting a hose.
Ascertain that a hose is fully depressurized before disconnecting it.
When blowing through a hose or air line, ensure that the open end is held securely. A
free end will whip and may cause injury.
Never play with compressed air. Never apply it to your skin or direct an air stream at
people. Never use it to clean dirt from your clothes. When using it to clean down
equipment, do so with extreme caution and use eye protection.
5 Wear ear protectors when environmental noise can reach or exceed 90 dB(A). Beware
of long-time exposure to noise.
6 Periodically check that:
– all safety equipment is in good working order,
– all hoses, cables, wiring and/or pipes are in good condition, secure and not rubbing,
– there are no leaks,
– all fasteners are tight,
– all electrical leads are secure and in good order,
– air outlet valves and manifold, hoses, couplings, etc. are in good repair, free of wear
or abuse.
Safety during maintenance and repair
Maintenance and repair work shall only be carried out by adequately trained personnel; if
required, under supervision of someone qualified for the job.
1 Use only the correct tools for maintenance and repair work.
2 Before removing any pressurized component, effectively isolate the compressor from
all sources of pressure and relieve the entire system of pressure. Do not rely on non-
return valves (check valves) to isolate pressure systems.
3 Never weld on, or in any way modify, pressure vessels.
4 Special service tools are available for specific jobs and should be used when
recommended. The use of these tools will save time and prevent damage to parts.

LEADING PARTICULARS

General description

The CD air dryers are built to remove moisture from compressed air
for industrial purposes. All units are designed for indoor use.
An overview of the main parts of the dryer units is given in figure 1:
1 .....Tower A
2 .....Tower B
3 .....Inlet valve
4 .....Outlet valve
5 .....Solenoid valves

Markings

A brief description of the markings provided on the unit is given
hereafter. Refer to figure 2:
1..... A high voltage is present.
2..... The unit is switched off.
3..... The unit is switched on.
4..... Air outlet.
5..... Air inlet.
6..... When the indicator shows blue, the dryer is ready for operation.
When pink, the desiccant needs to be reactivated.
4
6 .... Timer
7 .... Silencer
8 .... Canopy
9 .... Control panel
10 .. Moisture indicator

Control panel and gauges

The CD dryer is equipped with a number of control elements and
indicators. Refer to figure 3:
H1........Power on control lamp (yellow)
Indicates that the power supply has been switched on.
H2........Operation control lamp (green)
Indicates that the unit is working.
S1........On/off switch
Used to switch the unit on (position I) or off (position O).

OPERATION

Description

The construction of the air dryer is simple, reliable and easy to
service. The dryer has two towers containing the adsorbing material
or desiccant. This desiccant is a very porous grain material which can
adsorb large amounts of water vapour.
The operation cycle of the dryers is repetitive and is controlled by a
factory-setted timer. While the desiccant in the first tower dries the
compressed air, the desiccant in the second tower is being
regenerated and vice versa. Regeneration of the desiccant is
achieved by means of purge air from the drying tower.
The compressed air entering the dryer is led to one of the towers by
means of the inlet valve. The position of the inlet valve depends on the
condition (activated or not) of the solenoid valves. As the air flows
upwards through the tower, the desiccant adsorbs the water vapours
and the compressed air is dried. Once the top of the tower is reached,
the air leaves the dryer via the outlet valve (= nozzle).
A small portion of the dried air does not leave the dryer immediately
via the nozzle valve but is expanded to atmospheric pressure and
flows downwards through the other tower, regenerating the desiccant.
This regenerating air is finally released via the solenoid valve and the
silencer. These solenoid valves are controlled by the timer.
After a certain period, the cycle will restart. The fully regenerated
tower will now dry the air whereas the other tower will be regenerated.
The condition of the desiccant can be checked by means of the
moisture indicator. If the indicator shows blue, the desiccant will
guarantee a proper operation. If it shows pink, the desiccant needs to
be regenerated.
In case a power failure should occur during operation or in case the
on/off switch was put in position O, the timer module will restart from
zero. In case the remote control connector P4 was short-circuited, the
dryer will remember the remaining drying time of the unit, continuing
the drying cycle after connector P4 is opened again.
P4 is connected to a NC voltage free contact of the compressor line
contactor. If no free contact is available, an additional voltage free
contact should be installed on the line contactor of the compressor.
During unload, the outlet valve of the regenerating tower is closed.
That way, the pressure in this tower will increase up to net pressure.
From that moment on, purge air is no longer consumed. During load,
the outlet valve is opened and both towers continue their cycle.
It is forbidden to connect the P4 when an air receiver is installed
before the CD dryer (refer to figure 4).
P4 can only be connected when the air receiver is installed after the
CD dryer.
2904 0105 04