Atlas Copco GA55 Instruction Book page 19

Instruction book
Ref. Description/recommendation
on
Fig. 2.3
1 Install the compressor on a solid, level floor suitable
for taking the weight.
2 Position of compressed air outlet valve.
3 The maximum total pipe length (including
interconnecting piping between compressor and
receiver) can be calculated as follows:
5
L = (dp x d x p) / (450 x Qc
L = pipe length in m
dp = maximum allowable pressure drop
(recommended 0.1 bar)
d = inner diameter of pipe in mm
p = compressor outlet pressure in bar absolute
Qc = free air delivery of compressor in l/s
4 Ventilation: the inlet grids and ventilation fan should be
installed in such a way that any recirculation of cooling
air to the compressor or dryer is avoided. The air
velocity to the grids must be limited to 5 m/s. The
maximum allowable pressure drop over the cooling air
ducts is 50 Pa.
- For alternatives 1 and 3, the required ventilation
capacity to limit the compressor room temperature
can be calculated as follows:
Qv = 1.06 N / dT for GA Pack air-cooled
compressors
Qv = (1.06 N + 6) / dT for GA Full-feature
air-cooled compressors
Qv = 0.16 N / dT for GA Pack water-cooled
compressors
Qv = (0.16 N + 6) / dT for GA Full-feature
water-cooled compressors
Qv = required ventilation capacity in m³/s
N = nominal motor power in kW
dT = temperature increase in compressor room
- For alternatives 2 and 4: the fan capacity should
match the compressor fan capacity at a pressure
head equal to the pressure drop over the air ducts.
5 The drain pipes to the drain collector must not dip into
the water of the drain collector. Atlas Copco has oil/
water separators (type OSD) to separate the major part
of the oil from the condensate to ensure that the
condensate meets the requirements of the environmental
codes.
2920 1381 02
Ref.
on
Fig. 2.3
6
7
8
9
1.85
)
10
By-pass system for compressors with dryer (optional)
11
12
14
For water-cooled compressors
13
Description/recommendation
Position of control panel.
Position of mains cables.
Provision for inlet and outlet of energy recovery system
(system is optional).
Filter, type DD, for general purpose filtration (optional).
The filter traps solid particles down to 1 micron with
max. oil carry-over of 0.5 mg/m³. A high-efficiency
filter, type PD (optional), may be installed downstream
of a DD filter. This filter traps solid particles down to
0.01 micron with max. oil carry-over of 0.01 mg/m³. If
oil vapour and odours are undesirable, a filter of the
QD type (optional) should be installed downstream of
the PD filter.
The air receiver (optional) should be installed in a frost-
free room on a solid, level floor.
For normal air consumption, the volume of the air net
(receiver and piping) can be calculated as follows:
V = (0.25 x Qc x p1 x To) / f
V = volume of air net in l
Qc = free air delivery of compressor in l/s
p1 = compressor air inlet pressure in bar absolute
f = cycle frequency = 1 cycle/30 s
max
dp = difference between unloading and
loading pressures
T1 = compressor air inlet temperature in K
To = air receiver temperature in K
Dryer by-pass pipe.
Condensate trap.
Dryer by-pass valve (inside the bodywork).
Position of cooling water pipes.
x dp x T1
max
17