Disclaimer: This article is not meant to undermine the use of blowers or compressors over the other. Both air sources have its uses based on the applications. This articles must be strictly read for comparison purpose only.
A reciprocating compressor produces pressure through the reciprocating movement of the piston within the cylinder; thus no pressure is produced in the compressor when the Piston moves from TDC (Top Dead Centre) to BDC (Bottom Dead Centre) position.
Blowers operate on rotary principle thus producing pressure all the time.
Waste of Energy:
Air compressors are aimed to deliver a minimum pressure of 70,000 mm wc. Most blow-off applications for Air knife require a pressure of up to 2,000 mm wc. thus, the energy required to produce pressure from 2000 to 70,000 mm wc. is simply wasted (read not utilised). More than 97.15% required to run the compressor is simply wasted.
This is considering a compressor that is aimed to deliver minimum pressure. Most compressors available out in the market are designed to operate at 1,75,000 mm wc.
A standard single stage air compressor powered by 1 HP motor can produce air flow of 6.32 m3/hr.
A single stage regenerative blower (1HP) can produce air flow of up to 200 m3/hr.
A standard regenerative blower can move more than 36 times of air compared to a compressor.
Compressors are huge generally because of the storage tank for compressed air. A single stage 1HP compressor occupies 820mm x 325mm of floor area and takes 765mm vertical space.
Regenerative Blowers are comparatively smaller in size and can be fit within or under an existing machine / system; single stage 1HP regenerative blower can fit within 390mm x 430mm floor space.
As established earlier in this article Compressors waste a lot of energy to deliver pressurised air; thus the running cost of air compressors is higher than Air Blower.
Running cost of Air compressors can be a high as 62% when compared to blower.
Regular maintenance is essential for blower and air compressor to ensure optimum performance. Regenerative blowers are usually directly driven by electric motor hence, lesser parts and less maintenance cost.
Pulleys, belts, bearing, valves, etc. escalate maintenance cost of air compressors.