Acoustic wind band

A gas exhaust system having an acoustic wind band for exhausting a gas or fluid flowing at a high velocity from a building or room comprising:

• a gas exhausting device for exhausting a gas or fluid from an interior of a building to atmosphere, said gas exhausting device comprising:
• a fan for inducing a flow of said gas from an inlet opening of said gas exhaust device to an outlet open of said gas exhaust device;
• a nozzle positioned above said fan and being in fluid communication with said fan to receive exhaust gas therefrom for expelling said gas to atmosphere;
• wherein one or more primary exhaust flow paths are formed in said gas exhaust device, said one or more primary exhaust flow paths being adapted to receive exhaust gases and guide said exhaust gases to release upwardly though a discharge outlet portion formed proximate said gas outlet opening;
• an acoustic wind band connected to said gas exhausting device, said acoustic wind band comprising:
• a plurality of spaced apart wind band sections, each wind band section having a top end defining a top opening, a bottom end defining a bottom opening, and a side wall disposed between and connecting said top end to said bottom end;
• said plurality of wind band sections being disposed circumferentially around and in vertical spaced relation over said discharge outlet portion of said gas exhaust device and extending generally upward therefrom;
• wherein each wind band section has a height defined by the vertical distance between said bottom end and said top end, and wherein each vertically successive wind band section has a height that is greater than said height of a first lower most wind band section;
• and
• a plurality of passages formed around a peripheral of said acoustic wind band and disposed circumferentially about said discharge outlet portion, wherein each passage draws a secondary flow of gas from environmental atmosphere outside said acoustic wind band to induce said secondary flow of environmental gas from therebelow to mix with and dilute said primary flow of exhaust gas from said discharge outlet portion inside said acoustic wind band;
• an opening formed by said top ends of said wind band sections concentrically with an axis of said discharge outlet portion of said exhaust device through which a high velocity exhaust flume comprising a mixture of said primary flow of exhaust gas from said discharge outlet portion and said secondary flow of environmental gas exits vertically upward.

A method for improving sound attenuation sound in a gas exhaust system using an acoustic wind band, said method comprising.

• providing a gas exhaust device having a gas inlet opening for receiving a gas to be exhausted and a gas outlet opening for discharging said gas to atmosphere;
• disposing an acoustic wind band having a plurality of vertically spaced apart wind band sections over and about said exhaust gas outlet of said exhaust device;
• positioning a first, lower wind band section such that at least a portion of a bottom end of said lower wind band section blocks a direct line of sight from a point outside said exhaust device and said lower wind band section from a point inside said exhaust device and said lower wind band section;
• positioning each vertically successive wind band section having a height that is greater than said first, lower most wind band section such that at least a portion of a bottom end of a vertically successive wind band section blocks a direct line of sight between a point outside a vertically preceding wind band section and said successive wind band section and a point inside said preceding wind band section and said successive wind band section;
• and
• blocking noise generated by said exhaust device and said exhaust gas outlet opening from radiating along a direct line of sight from a point inside said acoustic wind band and said exhaust device to a point outside said acoustic wind band and said exhaust device.

A method for improving the discharge velocity and thereby the effective stack height of a gas exhaust device in a gas exhaust system using an acoustic wind band, said method comprising:

• providing a gas exhaust device having a gas inlet opening for receiving a gas to be exhausted, a high velocity discharge nozzle, and a gas outlet opening for discharging a primary flow of said gas to atmosphere;
• disposing an acoustic wind band having a plurality of vertically spaced apart wind band sections over and about said exhaust gas outlet of said exhaust device;
• forming a plurality of passages for drawing ambient environmental air from a point outside said acoustic wind band to a point inside said acoustic wind band, wherein a number of said plurality of passages corresponds to a number of said plurality of wind band sections, and wherein a first passage is formed between a housing of said gas exhaust device and an inner surface of said lower wind band section and each successive passage is formed between an outer surface of a preceding wind band section and an inner surface of a successive wind band section;
• and
• inducing a plurality of secondary flows of ambient environmental air through said plurality of passages to be mixed with and dilute said primary flow of exhaust gas discharging from said gas outlet opening of said gas exhaust device.