| 摘要 |
PURPOSE:To avoid a large size of the device and increase the air flow capacity with low cost and reduce noises by providing fan main vanes which are equally arranged in a vortex chamber which is outside of the open bore of an air blow ing port and providing auxiliary vanes extended towards the center of the fan with a most balanced arrangement of vanes the number of which is smaller than the number of the main vanes by an odd number of vanes. CONSTITUTION:Small particles ionized among a high tension discharge line 6 and counter electrodes 8 after passing through a front grill 4 and prefilter 5 are arrested by a filter 3 to give clean air. The clean air is sucked in by a fan 21 from a blowing-in port 9a. On the basis of sirocco fan 48 main vanes 21a which are of the same shape and same number are arranged on a circle equally, and 13 auxiliary vanes 21b given by subtracting from the number of the main vanes vanes an odd number 35 are arranged with highest balance and provided by extending from the main vanes 21a. The air flow capacity increases with the increase in the number of the auxiliary vanes 21b, and they are most effective when 13 auxiliary vanes are provided with an increase of about 9 %. Looking at the sound pressure level of noises, it shows that 13 and 15 auxiliary vanes present a lower sound than conventional fans. |
