A cabinet manufacturer was concerned about the efficiency of the many hundreds of compressed air guns used on the production line to clean sawdust and debris from cabinet pieces before they are sent for further processing and assembly. A sales representative had sent him some free samples of some optimized compressed air guns that used specially engineered nozzles designed to draw in ambient air to boost air volumes while the nozzle is blowing. These nozzles also used considerably less air than an equivalent open pipe air nozzle according to the accompanying literature.
The company had been purchasing low-cost safety nozzles that met local safety standards and these had been working well for them, but in the spirit of improvement optimized nozzles were purchased to save energy. After a considerable number of old nozzles had been replaced, the production staff started to notice their air pressure was dropping to lower than desired levels during peak production periods.
An air auditor was called in to take a look—and found, through data logging, that the low pressure was caused by production demand exceeding the supply capacity of the system. He asked if anything had changed recently, which led to the discovery of the new nozzles.
For information purposes, he measured the flow of air consumed by the old nozzles and found that the average consumption was about 4 cfm at 100 psi. A measurement of the new optimized nozzles showed consumption of 25 cfm at the same pressure. The new nozzles were consuming more than 6 times the original volumes which was causing higher than desired peak flows and low plant pressure.
The optimized nozzles were investigated further and it was found that the rated operating pressure was 70 psi, yet the operating pressure used was 100 psi. Further, the nozzles selected were rated for far more blowing force than the production personnel required. This industrial user had “shot himself in the foot” with his selection of his new compressed air guns.
The supplier of the nozzles was able to work with the company to find better nozzles—ones that provided comparable blowing force to the original nozzles, yet operated with lower noise levels and slightly lower air consumption. Once the nozzles were upgraded, the pressure problems went away.
Learn more about appropriate and inappropriate uses of compressed air in our next Compressed Air Challenge seminar in your area. Visit www.compressedairchallenge.org for more information.
By Ron Marshall for the Compressed Air Challenge