Sound Attenuating Baffle Including a Non-Eroding Liner Sheet

Abstract

A sound attenuating baffle device used in a duct receiving a gaseous flow in a flow direction therethrough, includes a baffle casing supported within the duct and a fibrous sound absorbing material occupying the hollow interior of the baffle casing. One or more perforated sheet members at least partially defines the exterior of the baffle casing across which the gaseous flow of the duct is arranged to be directed. A liner sheet of a non-eroding, sound absorbing foam material is supported within the hollow interior of the baffle casing against an interior surface of the perforated sheet member(s) so as to span across each of the perforations and prevent direct communication of the fibrous sound absorbing material with the perforations to prevent erosion of the fibrous sound absorbing material into the gaseous flow through the duct.

Description

[0001]This application claims the benefit under 35 U.S.C. 119(e) of U.S. provisional application Ser. No. 62 / 312,661, filed Mar. 24, 2016.FIELD OF THE INVENTION[0002]The present invention relates to a sound attenuating baffle intended to be mounted within the duct of an air distribution HVAC system, a ventilation system, mounted directly to a fan or other air movement system for either air or gas streams in which the baffle is typically oriented in the flow direction through the duct. More particularly the present invention relates to a sound attenuating baffle the type including an outer baffle casing which is at least partially perforated and which contains fibrous sound absorbing material therein, and which is further provided with a liner sheet against an interior surface of the perforations in the outer baffle casing to prevent direct communication between the fibrous sound absorbing material and the perforations so as to prevent eroded fibrous sound absorbing material from bei...

AI Technical Summary

Benefits of technology

The patent describes a design for a silencer that prevents fibrous material from erosing or breaking down. The design includes a liner sheet that is supported within the hollow interior of the baffle casing against an interior surface of a perforated sheet member. This liner sheet spans each perforation and prevents direct communication between the fibrous material and the perforations, thus improving the acoustic performance and protecting the silencer's absorptive media from erosion. The design also utilizes foam material that has self-supporting properties and higher noise reduction coefficients compared to film liners, making it easier to install and repeatable. Overall, the design provides better protection against fibrous material erosion and improves the overall performance of the silencer.

Problems solved by technology

Silencers with rectangular shaped baffle devices or circular centerbody baffle devices introduce aerodynamic losses due to the nature of the silencer orientation and installation conditions, resulting in blockage of the cross-sectional area, and aerodynamic friction and dump losses.

Thin film liners are not acoustically porous and generally do not provide any desirable absorptive properties.

In order to achieve higher levels of sound attenuation, baffle device lengths and the quantity tend to increase significantly, due to this degradation in performance related to traditional film liners.

Images