Removing jet noise

The problem

During its production process, a health care company immersed its pharmaceutical containers in a rinsing bath. Afterwards, to dry off excess moisture, employees placed the containers on a draining bench and blew them dry using a hand-held compressed air hose.

The solution

The plain air hose nozzle was replaced by an induced flow type, the principle being to link a secondary air flow with the primary jet flow and so reduce the strength of the noise-generating turbulence produced in the main jet air flow.

The cost

About £25 per unit. (1995)

The result

A noise reduction of 7 dB during the drying cycle, while still maintaining an effective velocity for moisture removal.

Source

Information supplied by 3M Health Care. Photographs courtesy of Meech Exair. Equipment supplied by Meech Exair.