PROGRESS: Completed Project	PROJECT REF: NA
PROJECT TITLE: Drum Silencer - An effective solution for low frequency noise
PROJECT DESCRIPTION: Introduction: (Maximum 100 words) Low-frequency duct noise is a difficult issue to resolve in commercial reality due to the limited space available and the ineffectiveness of conventional silencer to deal with when the space available to install a silencer is limited. Fibrous absorption material is not effective for frequencies below 200Hz or so, and the technology of active control is not yet reliable and cost effective. The PolyU ahs invented an alternative technology of noise control by using a tensioned membrane to reflect sound. The membrane is installed as part of the duct wall and it presents nil pressure loss to the air flow system. It also prevents contact between the silencer cavity and the air flowing, eliminating dust accumulation and offering a unique environmental advantage. Special Features and Advantages: (Maximum 50 words) 1) No interference change of duct cross section area hence no pressure loss 2) Minimal cavity space occupation for the low-frequency noise being attenuated 3) No fibrous material hence no accumulation of dusts 4) Low cost 5) Can be easily added onto existing installation. Application(s): (Maximum 50 words) 1) HVAC duct noise abatement 2) Industrial piping system, chimneys 3) Engine testing, wind tunnel, or other facilities where flow quality is crucial
FOCUS AREA(S): Environmental technology
KEYWORDS: Low-frequency duct noise silencer
MODE OF COLLABORATION: Consultancy and licensing
STATUS PATENT: Patent_Pending	PATENT NO: NA
ORGANIZATION: The Hong Kong Polytechnic University
CONTACT PERSON: Dr Lixi HUANG	EMAIL: mmlhuang@polyu.edu.hk
TEL: (852)-2766-7818	FAX: (852)-2365 4703
WEBSITE:	DATE: 30/12/2004