Compressed air-driven air knives have a low initial purchase price, but a very high operating cost compared to Paxton’s efficient blower-driven air knives. Compressed air knives produce high velocity air for drying and blow off, like blower driven air knives do, but at a much greater operating cost. Common uses for compressed air-driven knives are blowing off, drying or cooling of moving webs, film, sheets, strips, and parts. Compressed air knives operate well in tight spaces. They are also good for intermittent applications; this allows users to turn the air knives on and off as they see fit or for short bursts to conserve energy. Compressed air-driven air knives use about 5 scfm of air per inch when operated at 100 psig, so a 24” air knife will use 120 scfm. If the compressed air knife operates 24 hours a day at a typical electricity cost of $.10/kWhr, being driven by an efficient air compressor, the operating cost is $41.25 per day1. If you need an intermittent drying solution reach out to Vortec today. Vortec is a part of Paxton Products’ business unit, ITW Air Management.
Paxton Air Knives are powered by an electric blower, rather than compressed air. Paxton Air Knives produce high velocity, low pressure air (<3 psi), resulting in high fluid power and high thrust for blow off and drying. The energy required to run an electric blower is about 5 times less than that required for compressed air, as with compressed air, much of the energy is wasted to compress and transport the air. Compressed air systems are 10 – 20% efficient, whereas a Paxton PX-series blower is as much as 80% efficient. And unlike compressed air, the wasted energy of an electric blower is turned into heat, meaning that the outlet air is warmer than ambient, and this has the benefit of facilitating drying. Air from blower-driven air knives are also free from oils, scale and moisture that are present in compressed air. The operating cost of a 24” Paxton air knife under the same conditions as above is only $3.36 per day2. Paxton Air Knives are ideal for continuous drying and blow off operations, particularly in larger applications. Even though the upfront investment is more than compressed air knives, most companies see an (Return on Investment) ROI in a year or less. The blower requires 3-phase, 230- or 460-volt power, and must be correctly sized for the total length and gap of the air knives or number and size of nozzles, to ensure efficient and effective drying and blow off. Depending on the size of the application and the air knives needed, Paxton offers blowers ranging from 3hp to 20hp.
1 .10 cost of kw/h * 17.2 kw/h= $1.72/hr * 8 hr/shift = $13.75/shift * 3 shifts/day * 1 day/week = $41.25/day
2. .10 cost of kw/h * 1.4 kw/h= $.14/hr * 8 hr/shift = $1.12/shift * 3 shifts/day * 1 day/week = $3.36/day
