The U.S. Centers for Disease Control (CDC) estimates that 1 in 3 adults suffer from hearing loss. The U.S. National Institute for Occupational Safety and Health (NIOSH) further provides that 24% of U.S. workers hearing loss is caused by occupational exposure. To prevent hearing loss, the U.S. Occupational Safety and Health Administration (OSHA) recommends that workers not be exposed to sounds at or greater than 85 decibels (dBA) for 8 hours. Abrasive blast nozzles, however, can produce noise levels upward of 115dBA, for which OSHA sets a max safe exposure time of just 15 minutes per day.
Leveraging cutting edge advancements in jet engine technology, new Blast Ninja abrasive nozzle designs can now reduce noise by up to 17dB, an approximate 50x reduction in sound power, when compared with conventional venturi nozzles of the same bore size. Blast Ninja nozzles accomplish this by reducing the nozzle air exit velocity and sound pressure level, while preserving particle velocity to maintain equal abrasive power. The difference in noise exposure enables operators to be safer and more productive, diminishes operator fatigue, and minimizes employer liability. Furthermore, whereas NIOSH estimates a $100 per dBA of savings when purchasing quieter products, such improvements in acoustical performance can also translate to employer cost savings. The efficacy of Blast Ninja nozzles was evaluated by Oceanit and 3rd party industry partners interested in use or distribution of the nozzles for the industry.
This paper explores the efficacy of such nozzles, and details their performance in different conditions, with different blasting setups, with different abrasives, and on different surfaces.
Abrasive blasting operations used for paint and surface coatings removal are essential for the maintenance of the ships, aircraft, and land vehicles of the United States Armed Forces as well as use industries such as oil & gas, power generation, construction, mining, and infrastructure, among others. Abrasive blasting nozzle design is rudimentary and noise levels produced during abrasive blasting operations in shipyards, maintenance facilities, and factories for removing paint and surface coatings often exceed exposure limits put in place by Occupational Safety and Health Administration (OSHA). Reducing a worker's occupational noise exposure is imperative from a safety and economics perspective.
