GB1318986A - Cross flow blower - Google Patents

Abstract

1318986 Transverse-flow blowers K ZENKNER 9 Oct 1970 [10 Oct 1969] 48109/70 Heading F1C [Also in Division F2] A wedge-shaped vortex-forming tongue 2', Fig.2, with its two sides 6', 7' subtending an angle of about 10 degrees to about 60 degrees is spaced from the rotor periphery by approximately 5% to approximately 15% of the rotor diameter, the angle subtended at the rotor axis betweenthe tongue and the beginning 9 of a spinal guide wall 3 being approximately 130 degrees to approximately 180 degrees. The spacing a between the beginning 9 of the wall 3 and the rotor periphery is approximately 10% to approximately 30% of the rotor radius, successive spacings a 2 , a 3 and a 4 at respective intervals of 60 degrees, 30 degrees and 30 degrees increasing by respective amounts in the region of 5%-30%, 10%-30% and 20%-35%, a final increase in the region of 20%-50% occurring to provide a spacing a 5 at the end of the spiral. The remainder 11 of the wall 3 is either straight on, as shown, of reversed curvature. The spiral subtends an angle of 140 degrees - 190 degrees . at the rotor axis; it may be made up of circular arcs of differing radii, the radii reaching a maximum and then decreasing towards the end of the spiral. The side 6' of the tongue 2' has a length at least equal to 15% of the rotor radius and is at an angle of about 15 degrees to about 45 degrees to the tangent at the nearest point on the rotor periphery. The rounded tip 14 of the tongue has a radius which is 5%-25% of the rotor radius. A convergent portion of the outlet 19 which increases the outflow velocity by at least about 20% has a length l equal approximately to 0À75- 1À25 of the rotor radius. The distance between the side 7' of the tongue 2' and the wall 3, expressed as a fraction of the rotor radius, is approximately 0À75 to approximately 1À50 at the narrowest part of the outlet and 1-2 at the widest part. Formation of a boundary layer in the inflow to the blower may be prevented by a tongue 30, Fig. 4, having permeable sides 30a, 30b through which air can flow from the outlet to the suction side of the blower, this flow being controlled by a filling 31 of glass wool, stone wool, foamed artificial material or filtering material impregnated with synthetic resins which also has a silencing effect.