​Keeping quiet with ATCO’s In-Duct Acoustic Test Rig 

ATCO Emissions Management (ATCO) is always researching and improving its technologies, introducing eight products to ATCO’s industry-leading product line in the last four years alone. ATCO’s product development program is a combination of engineering theory, computer simulation analysis, and physical models. Its latest tool: the In-Duct Acoustic Test Rig.

There is no one-size-fits-all solution when it comes to a work site. Every location has its own unique challenges. The same industrial building might require different acoustic treatments to address noise emission in every direction, keeping neighbours in mind. Acoustic designs are frequently tailored to site requirements because standardized products would not be economically feasible for the scale and range of performance needed. Developing design tools to achieve guaranteed performance on customized products means testing prototypes under actual flow conditions.

ATCO uses proprietary software, NoiseCalc, to calculate the performance of baffles used in gas turbine exhausts, HVAC systems, filter houses and other in-duct applications. The test rig will help expand the capabilities of NoiseCalc and also allow ATCO to test the acoustic and aerodynamic properties of other in-duct elements found in heat exchangers and emission control systems. Previously, much of ATCO’s R&D testing was conducted by collecting data in the field and by using external labs, but with ATCO’s new In-Duct Acoustic Test Rig, ATCO collects data and tests designs much more rapidly. Using the existing expertise of four on-site ATCO engineers, the test rig is a controlled environment that uses standardized measurement procedures.

The test rig is made up of two modules built from re-purposed shipping containers, a gantry system for installing specimens, and a control room.

A high-power low-noise fan provides airflow conditions up to those seen in turbine exhaust applications. Fan noise is then silenced by a large silencer as air flows into the acoustic test sections.

The first section, the source module, contains a loudspeaker system and a duct that transmits the test signal into the test specimen. Downstream of the test specimen, another module contains acoustic and airflow measurement instrumentation. At the end of the second module, there is an anechoic termination, which prevents sound from reflecting back into the duct. The rig is operated from an adjacent control room.

“It’s basically a quiet wind tunnel with big speakers inside”, explains Chris Giesbrecht, Manager Acoustical Engineering.

Together, these sections represent ATCO’s newest development tool for acoustical products which reduce the cost and uncertainty of noise control for its customers. Field conditions may be as varied as ATCO’s clients, but with the In-Duct Acoustic Test Rig, ATCO has a tool that facilitates testing to develop consistently high quality products.