Dustolex Centrifugal Fan Blade Options
About Centrifugal Fan Blade Options
Fan in which the air enters the impeller with an essentially axial direction leaves it in a direction perpendicular to the axis.
Negative or reverse blades
(backward curved blades)This is a high efficiency impeller whose rugged structure allows its use not only in air handling systems but also for conveying gas containing a moderate quantity of erosive particulate and in high temperature conditions.
Positive blades
(forward curved blades)The positive blade impeller features lower efficiency compared to its negative bladed counterpart: this type of impeller has the benefit of reducing the facility for the build-up of dust in the lower part of the blades, provided particulate quantities are only moderate. These impellers are also utilised when, for considerations of costs or space, it is not practical to choose a negative blade. A ‘positive bladed’ fan (also sickle shaped blades are considered to be positive), on an equal size basis, develops higher aeraulic performance although it uses percentually more power with respect to the effective increase in performance levels.
Straight blades
(radial)A straight bladed impeller is relatively inefficient and features higher power consumption compared to the far more common backward curved blade type. The rugged mechanical structure and wear resistance are such that these impellers are utilised in the presence of high quantities of erosive particulate or dusty air with suspended material, also containing sawdust, various chips, granular materials and filaments.