| 摘要 |
1,218,530. Axial-flow fans. NORDISK VENTILATOR CO. A/S. Jan. 26, 1968 [May 24, 1967], No. 35861/70. Divided out of 1, 216, 703. Heading F1C. [Also in Division F4] A fan for ventilating buildings comprises a cylindrical intake duct 45 fitted coaxially around a cylindrical exhaust duct 44, air being impelled in opposite directions through the two ducts by respective impeller vanes 39, 38 driven by a common motor 37. A common damper for the two ducts 44, 45 comprises a pair of pivoted semi-cylindrical members 51 of the same diameter as the portions 49 of a cylindrical wall separating the two ducts. When the damper members 51 are pivoted into the fully open position in which they form a continuation of the wall portions 49, air is drawn from above the roof into the top of the intake duct 45 and discharged below the ceiling through twelve nozles 46, while air is withdrawn from the building through the exhaust duct 44. Guide vanes 68 allow independent control of the flow through the individual nozzles 46. The air is heated or cooled by passing warm or cold water through heat exchangers 47. When the damper members 51 are pivoted into the position in which their ends 52 abut, shaped edges 53 (56) abut the outer cylindrical wall 48. The ducts 44, 45 are then completely blocked in an upward direction, while an aperture 50 is then open to permit the air within the building to be recirculated. In the intermediate position shown, the damper members 51 permit both recirculation of air within the building and supply of fresh air from outside. Adjustment of the damper members 51 may be done manually or automatically in dependence on temperature or humidity. |
