DUCT FAN Russian patent published in 2017 - IPC F04D17/08 

FIELD: ventilation.

SUBSTANCE: duct fan comprises of a housing 1 with a cylindrical section, a radial impeller 4 formed by a cover 5 and main 6 disk and a backward curved blade 7 between them, the diameter D₂ of which is equal to the diameter of the junction of the blades 7 with the main disk 6, a drive 10 with a fairing 11 including a cylindrical section. The trailing edge 8 of the blades 7 comprises of a section, adjacent to the main disk 6, with a length of 0.32…0.45 of the width b₂ of the blade 7 with a constant distance to the axis of rotation 9 and a section with an increasing distance from the axis of rotation 9 to the trailing edge 8 when approaching the cover disk 5. There are blades of a straightener 3 between the cylindrical sections of the housing 1 and the fairing 11. The diameter of the main disk 6 is (1.01…1.03) D₂, of the cover plate 5 - (1.05…1.15) D₂, the width b₂ of the blade 7 is (0.20…0.48) D₂.

EFFECT: ensuring high values of full efficiency at high values of the capacity factor.

11 cl, 10 dwg