CompAir 5280D.1.IAC Operator's Handbook Manual page 21

CompAir UK Ltd
5280D Compressor Publication 98407.1440
Page 18
7.3 Cooling Water System
Install a flow indicator and an isolating valve (for maintenance purposes) in the cooling water supply line.
If the quality of cooling water is poor, treat it to prevent corrosion and scale formation. Protect re-
circulating cooling systems against freezing by using proprietary anti-freeze with inhibitors.
The cooling water should be clean and silt free. Arrange the water supply so that there is a minimum
head of 6 m.
It is recommended that a water pump is fitted, in which case it must be inter-locked with the main starter.
If the cooling water is drawn from the site cooling water service, install a solenoid operated stop valve
(again inter-locked with main starter), or pneumatic operated stop valve in the supply line to the
compressor. Never allow cooling water to circulate when the compressor has stopped; this can cause
moisture in the compressed air to condense and seriously affect lubrication.
The quantity of cooling water required depends upon the compressor input power needed. A
temperature rise of approximately 10 ~ 12 °C is suggested for adequate cooling and prevent initial
condensation. To achieve this rise the water flowrate needed is 75 litre/hour per kW input power.
Always check the hardness and quality of the water used.
If a cooling tower is used, seek advice from local specialist organisations for precautions necessary to
prevent a health risk from bacterial growth.
7.4 Vibration
If complete isolation from the building or other equipment is required, mount the compressor and drive
motor, etc. on a common baseframe carried on anti-vibration mounts. Include a pipework vibration
eliminator in the air delivery pipework and a flexible section in the cooling water service piping
immediately before the connection to the compressor.
5.4.1 Vibration eliminators typically consist of a length of flexible thin walled bellows section pipe
carried between two rigid flanged connecting pieces. The flexible section is braided for protection.
Regularly inspect eliminators for damage or abrasion. Provide adequate support immediately
downstream of the vibration eliminator, independent of the compressor unit to isolate it from induced
vibration.
7.5 Air Receiver
It is normal practice to install a receiver of appropriate capacity between this type of compressor and the
user's pipework. As well as providing pulse free pressure for the air system it allows simple collection of
any remaining moisture.
A receiver is essential if air usage is intermittent or fluctuates rapidly such that instantaneous demand
exceeds compressor output.
As a guide select a receiver size sufficient to store air for between one and one and a half minutes
usage. The receiver size can then be calculated from the volume of air delivered by the compressor in
one minute.
For intermittently high air consumption use the same calculation and multiply by a factor of 3.
7.6 Corrosion Protection
Before despatch all compressors are protected against the effects of moisture.
If all blanking covers and protective tapes remain secure and undamaged the effective life of these
processes is 12 months from the despatch date.
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