GB973475A - Improvements in or relating to cross-flow blowers - Google Patents

Abstract

973,475. Transverse-flow blowers. APSLEY METAL PRODUCTS Ltd. Jan. 11, 1962 [March 8, 1961], No. 8415/61. Heading F1C. In a transverse-flow blower, the wall of the casing between the inlet and outlet openings is so shaped in a plane transverse to the rotor axis as to provide an intake part connected by a step part to a throat part of smaller crosssection the wall having a continuous smooth surface, the intake part leading into the step part and the latter leading to a part of the throat directed substantially parallel to an envelope surface of the rotor blade tips, so that, when the rotor rotates in a direction in which the tips of the blades lead in the direction of rotation, then the tip of any one blade sweeps first past the throat part, then past the step part and finally past the intake part. In the transverse-flow blower shown, a wall 6 extending between the inlet 4 and outlet 5 comprises a throat part 11 concentric with the rotor 1, followed (in the direction of rotation of the rotor) by an intake part 7 receding from the rotor, the two parts being joined by a step part 8 substantially perpendicular to the rotor periphery. This construction reduces noise. The lengths of the parts 7, 8 and 11 are substantially in the ratio 4 to 1 to 2, the corners between the parts being rounded off. An arcuate wall 14 receding from the rotor in the direction of rotation has an extension 13 which, together with an extension 12 of the wall 6, forms an exit passage leading to the outlet 5. Instead of being parallel as shown, the extensions 12, 13 may be divergent or convergent. A normal to the cross-section of the exit passage is inclined at 140 degrees to a normal to the plane of the inlet 4. Electric or other heating elements may be provided in the exit passage.