Operation; Description; Pneumatic Diagram - Atlas Copco CD65 Bedienungsanleitung

CD65 – CD80 – CD100 – CD140 – CD170 – CD230 – CD280 – CD390 – CD520

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-set timer and a PDP-sensor. 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 which is controlled by the pneumatic actuator.
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 non-return valve
A small portion of the dried air does not leave the dryer immediately
via the non-return 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 exhaust valve and the
silencer.
A second small portion of the dried air flows via the control air valve,
an air filter and the pressure regulator (only for the 16 bar units) to the
solenoid valves which are controlled by the Elektronikon® and to the
PDP-sensor The air leaving the solenoid valves (when energized) is
used to control the pneumatic actuator and the pneumatic valves.
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 PDP-sensor measures the pressure dewpoint of the air wich is
leaving the drying tower. When the PDP temperature is below the set
point then the drying tower will keep on drying until the PDP
temperature exceeds the set point. Then the regenerated tower will
start drying the compressed air and the other tower will be
regenerated.
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Pneumatic diagram

Figure 3A shows the pneumatic diagram of the dryers CD65 up to
CD280:
A .... Tower A
AF.. Air filter
B .... Tower B
CA . Control air valve
IV ... 3-way valve
N.... Nozzle
NV . Non-return valve
P1 .. Pressure transmitter 1
P2 .. Pressure transmitter 2
Figure 3B shows the pneumatic diagram of the dryers CD390 and
CD520:
1 .... Butterfly valve
2 .... Adsorption tower A
3 .... Adsorption tower B
4 .... Outlet check valve tower A
5 .... Outlet check valve tower B
6 .... Purge nozzle
7 .... Pilot air valve
8 .... Pilot air filter
9 .... Exhaust valve tower A
10 .. Exhaust valve tower B
11... Exhaust silencer tower A
12 .. Exhaust silencer tower B
13 .. Inlet filter (optional)
14 .. Outlet filter (optional
15 .. Needle valve PDP sensor
PA .. Pneumatic actuator
PR.. Pressure regulator
....... (only for 16 bar units)
PV .. Pneumatic valve
S .... Silencer
SV .. Solenoid valve
TV .. Pneumatic valve
Y1 ....... Solenoid valve tower A
Y2 ....... Solenoid valve tower B
PT01 ... Pressure transmitter
tower A
PT02 ... Pressure transmitter
tower B
TT01 ... Inlet temperature
transmitter
PDP01 Outlet dewpoint sensor
DP02... Delta P switch inlet filter
(optional)
DP03... Delta P switch outlet filter
(optional)
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