The Situation: A contractor is looking for a solution to solve a noise problem. His customer has a machine in its production line that uses four small blower fans to create vacuum. The machine uses the negative suction created by these blowers to fold plastic bags on the production line. The machine operators were complaining because of the fan noise and they could not communicate with each other while the blowers were in operation. At its highest level, the customer measured the noise to be 105 dBa.

The blower motor is specifically developed for applications that require high airflow, high motor speed, and medium pressure. The fan and housing are designed and optimized to deliver up to 238 CFM and 70.4 inches of sealed vacuum.

Currently, the blower fans are mounted underneath the production machine which does not provide the easiest access for maintenance. The area under the machine is approximately 5’ wide x 6’ long x 3’ high. The goal is to reduce the decibel reading as much as possible and to improve the maintenance access.

 
The Solution: Our engineer designed a system with 2″ absorption silencers, 4″ thick attenuation flat foam, and a 6’L x 3’W x 3’H base-mounted aluminum sound enclosure with a 350 CFM ventilation fan mounted on the back side of the enclosure.

 
The absorption silencers reduce the high frequency pulsations. The foam attenuates sound waves by absorbing the noise which reduces the amplitude of the waves. The base-mounted sound enclosure allows for easy installation and maintenance. Aluminum construction is lightweight and corrosion resistant. The silencers were installed vertically in order to discharge upward through a drop ceiling and dissipate heat. The final noise level is around 75 dBa.