Bladeless fan with twin impellers

A bladeless ring fan assembly e.g. a ceiling fan for generating an air flow within a room includes a casing having a plurality of inlet sections 12, 14 and an outlet section 16, 18 for receiving air from the inlet sections. Each inlet section has an air inlet 54, an impeller 56 and a motor 58 for driving the impeller 56 to draw an air flow through the air inlet section 54 and into the air outlet section 16, 18. The outlet section has an interior passage 24 and an air outlet 28 which creates an airflow, and draws secondary air through a bore 20 defined by the casing. The cross sectional area of the internal passage 24 may vary around the bore to maintain a substantially constant flow velocity through the duct. This arrangement allows two smaller impellers to be used, to minimise the size of the duct, and to reduce noise.

Fan nozzle

An annular nozzle 14, for a ceiling fan 10, includes an inner wall 76 defining a bore 78having a bore axis, an outer wall 74 comprising an air inlet, and an annular wall 82 extending between the inner and outer walls. An interior passage 94 extends about the bore axis for conveying air from the inlet to an air outlet 90, wherein the outlet is configured to emit the air flow away from the bore axis. The inner wall may comprise a section adjacent the annular wall which extends towards the annular wall in a direction which tapers away from the bore axis. The air outlet may emit the air flow substantially parallel to said inner wall section.

An Annular Fan Nozzle

An Annular Fan Nozzle

An Annular Fan Nozzle

An Annular Fan Nozzle

Bladeless fan with twin impellers

A bladeless ring fan assembly e.g. a ceiling fan for generating an air flow within a room includes a casing having a plurality of inlet sections 12, 14 and a plurality of outlet sections 16, 18. Each inlet section has an air inlet 54, an impeller 56 and a motor 58 for driving the impeller 56 to draw an air flow through the air inlet section 54 and into the respective air outlet section 16, 18. Each outlet section has an interior passage 24 and an air outlet 28 which creates an airflow, and draws secondary air through a bore 20 defined by the casing. The cross sectional area of the internal passages 24 may vary around the bore to maintain a substantially constant flow velocity through the ducts 24. This arrangement allows two smaller impellers to be used, to minimise the size of the duct, and to reduce noise.

An Annular Fan Nozzle

A fan assembly includes an annular nozzle and means for creating a primary air flow. The nozzle 102 includes an outer wall 106 and an inner wall 108 surrounded by the outer wall, the inner wall defining a bore having a bore axis. The nozzle also includes an interior passage 128 located between the inner and outer walls, and extending about the bore axis for receiving an air flow, and an air outlet 104 located at the front (or trailing edge 118) of the nozzle for emitting the air flow. The nozzle is configured to emit the air flow through the air outlet in a direction extending away from the bore axis, wherein the interior passage comprises a convergent air channel extending towards the air outlet. Variation of the direction of the air flow from the nozzle can be used to vary the degree of entrainment of secondary air flow through the bore.