It’s possible to use compressed air storage like a bank account to ride out deficits in compressed air capacity that might ordinarily cause the plant pressure to fall to unacceptable levels.
Consider the pressure/amp profile shown at the right. The compressed air demand exceeds the capacity of the compressor on two occasions causing the compressor discharge pressure to fall, but the plant pressure is held steady because air stored in a receiver tank was sent to make up the difference. No extra compressor needed run, no additional peak demand charges were incurred.
The system in question has a 1,000-gal storage receiver installed that contains stored air because it is held at 108 psi during normal conditions. The plant pressure runs at about 93 psi and is regulated with a pressure/flow controller. This 15-psi differential between the pressures makes about 140 cubic feet of stored compressed air available to transient demands before another compressor would need to be started to recover the pressure.
But in this case, no additional compressor was required. After the high peak demand ended, the available capacity of the compressor was used to fill the tank back up again, ready for another peak.
All the while, the plant pressure remained regulated at around 93 psi — low enough to adequately feed all the plant demands; the lower constant pressure acting to reduce artificial demand that might cause more compressed air to flow at higher pressure.
Just like money in the bank, this storage reserve helps address a short term supply deficit!
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