| 摘要 |
<p>The invention relates to a centrifugal fan of a drum shape in a spiral housing, designed specially as an integral part of other devices such as burners, air conditioning units, etc. for relatively high flow rates and relatively low static pressures preferentially. It has metal-strip blades of a bow-shape cross-section clamped in on both ends and turned with their concave side in direction of rotation. The essence of the invention is, that the fan's exterior systemic rotor diameter can be - by an appropriate choice of blades and dimensioning of blade crown - reduced in comparison with already known fans of this kind for such an amount, that one or several further fan stages can be introduced within the extent of the available space of the device for which a respective fan has been planned. The concept of these stages is based essentially upon the structure of the radial steam turbine according to Ljungstroum.</p> |
