Page 58 - Shaping A Sustainable Future

The air compressor is turned on continuously and shared 1. Move the unit next to the coolant tank, lock the
between 35 CNC machines. The power consumption of rear casters and place the coolant outlet hose
the air compressor is 3,300 W. Operating the compressor assembly into the coolant tank.
for 24 hours a day will take up 3.3 kW x 24 hrs = 79.2
kWh per day. This equates to 79.2 kWh x 365 days = 2. Turn the air pressure switch on.
28,908 kWh annually.
3. Place the aluminium chip vacuum tube into the
coolant tank and sweep the tank thoroughly.
An annual carbon emission was calculated as 28,908
kWh x 0.4188 kg CO = 12,107 kg CO . This conversion 4. When cleaning the tank, remove the aluminium
2
2
factor of 1 kWh is equivalent to 0.4188 kg of carbon chip vacuum tube and allow the residual coolant
emission, was obtained from www.ema.gov.sg. to clear from the vacuum tube and hose.
In our environmental review process, the supervisor 5. Allow coolant return hose to drain back into the
explained the impacts of the chip not being removed tank completely.
from the coolant. We understand that it is an essential
process for the company. The chip conveyor will take 6. Change to a different style of fitting intake tube for
away the chips when the cutting fluid is processed if fine chips if desired.
the metal chips are not cleaned out in time. However,
some of the waste debris left at the bottom of the water 7. Open the pressure relief valve, and then open the
top cover.
tank will then support the growth of anaerobic bacteria,
causing the release of odour and acidification of the 8. Remove the filter basket and empty the chips.
cutting fluid. This causes the quality of the cutting fluid
to deteriorate, which reduces the effectiveness of the 9. Clean the filter basket with a high-pressure coolant,
coolant. wash down gun or air and replace the filter into
the unit.
The air compressor that supports the chip vacuum
machine uses the principle of a negative pressure 10. Clean and reinstall the O-Ring, as shown in Figure
vacuum in exchange for a large suction volume for 11. Be sure the surfaces are clean. Then replace
continuous filtration to intercept impurities and the Clear Cover Window.
suspended particles. This saves time and labour costs to
clean the water tank.

During the company visit on 12 March 2020, the
supervisor took time to show us how this chip cleaning O-Ring
system works. Here are the steps we managed to note
down for the process:

Figure 11: O-Ring of the compressor

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