초록 ▼

An air duct silencer can be used at the inlet of an air supply fan unit for a building or other large structure. The silencer has an exterior housing with exterior walls forming outer surfaces of the housing and interior walls arranged in the housing, connected to the exterior walls and defining an

An air duct silencer can be used at the inlet of an air supply fan unit for a building or other large structure. The silencer has an exterior housing with exterior walls forming outer surfaces of the housing and interior walls arranged in the housing, connected to the exterior walls and defining an annular airflow passageway extending between an air inlet located at one end and a circular air outlet adapted for connection to the fan unit. The outlet defines a primary central axis extending through the center of the outlet and perpendicular to a plane in which the outlet lies. A central airflow defining member has a second central axis extending from an outer end thereof to an inner end and this axis is substantially coaxial with the primary central axis. This airflow defining member is substantially circular in transverse cross-section along its length and has a relatively wide bulb like end section at its outer end and a narrow end section at the inner end. There is sound absorbing material in the housing which is covered by the interior walls and also in the airflow defining member. The transverse cross-section of the airflow defining member causes the air velocity to be substantially higher at the air outlet than at the inlet.

대표청구항 ▼

1. An air duct silencing apparatus for use as an inlet silencing duct to be connected to an air supply fan unit for a building or other large structure, said apparatus comprising:an exterior housing having exterior walls forming outer surfaces of said housing, an air inlet formed on one end of said

1. An air duct silencing apparatus for use as an inlet silencing duct to be connected to an air supply fan unit for a building or other large structure, said apparatus comprising:an exterior housing having exterior walls forming outer surfaces of said housing, an air inlet formed on one end of said housing, and a circular air outlet formed in an opposite end of said housing and adapted for connection to the fan unit for airflow to the fan unit, said outlet defining a primary central axis extending through the center of said outlet and perpendicular to a plane in which the outlet lies; interior walls arranged in said housing, connected to said exterior walls and defining an annular airflow passageway extending from said air inlet to said air outlet, a substantial portion of said interior walls being made of perforated metal; a central airflow defining member located in and further defining said annular airflow passageway and having a second central axis extending from an outer end thereof to an inner end adjacent said air outlet, said second central axis being substantially coaxial with said primary central axis, said airflow defining member being substantially circular in transverse cross-section along its length and having a relatively wide bulbiform end section at said outer end thereof and a relatively narrow end section at said inner end, and sound absorbing material in said housing and covered by said interior walls and also in said airflow defining member, wherein said airflow passageway tapers inwardly in the direction of said air outlet and the cross-sectional flow area of said annular airflow passageway varies along at least a substantial portion of its length so that airflow speed at said air inlet is low relative to airflow speed at said air outlet when said air duct silencing apparatus is connected to said fan unit and the fan unit is operating.