A recent Plant Services blog post taught people by video how to construct and use a compressed-air-powered broom out of PVC piping. While the item was very entertaining to most, those in the compressed air efficiency business were horrified by the publicity which runs opposite to the advice that we have been working to send. The well-meaning technician sought to save plant personnel the work of pushing a broom, why strain your back when you can push the dust with compressed air? He likely thinks compressed air is free.
But if we've all been paying attention over the years, we have learned that compressed air is not free. It is one of the most inefficient ways to power anything. In a perfect, leak-free system, only about 12% of the energy you put in an air compressor comes out as mechanical energy. In a real-world system with pressure differentials, leaks, and compressor inefficiencies, sometimes less than 5% of the energy gets to the end user. The air pressure that comes out of the end of a 1/4-inch blowing device at 100 psi consumes 25 hp worth of compressed air power, costing $18,600 if in continuous use.
Innovative people often come up with exciting and unique ways to do some important tasks with readily available compressed air. But the energy cost of the air must be factored into the equation. If the operation can be better done using some energy source that is less energy-intensive, then the compressed air use might be deemed inappropriate.
It is not only energy that can be affected; a fleet of air-powered brooms at cleanup time could use all of the capacity of the plant compressor, causing low pressure. This low pressure can affect production, perhaps causing product quality issues. The long-term use might cause thousands of dollars to be spent on new air compressors and other equipment to solve the pressure problem.
Problematic, too, are the safety and environmental issues caused by high-velocity particles driven by compressed air into the faces of workers or the sound pollution caused by the release of the air through orifices.
The construction and use of compressed-air brooms is a bad idea for so many reasons. Please forget the idea and move on.
Learn more about inappropriate uses at Compressed Air Challenge's next Fundamentals of Compressed Air Systems seminar. Check out the calendar at www.compressedairchallenge.org.