GB963016A - Improvements in and relating to transverse flow type blowers - Google Patents

Abstract

963,016. Transverse-flow blowers. T. HELMBOLD. Jan. 5, 1961, [April 22, 1960; June 3, 1960; Nov. 19, 1960], No. 475/61. Heading F1C. A transverse-flow blower with a drum-shaped rotor is characterized in that adjacent to the rotor side of a housing part forming a partition between inlet and outlet there is arranged a substantially cylindrical body rotatable in a free or driven manner in the same direction as the rotor and having an axis parallel to the rotor. The substantially cylindrical body may be a solid body or it may be a standing vortex generated by a guiding body outside the rotor. Fig. 7 shows an arrangement of four transverseflow blower impellers 1 discharging to a common diffuser passage 20. The inlet and outlet sides of each blower are separated by a stationary partition 4 and a cylinder 5 located between the impeller 1 and the partition 4. The cylinder 5 is rotated by the fluid or is driven through gearing or the like. This use of a rotary cylinder in place of a stationary wall reduces the formation of boundary layer eddies. In the blower shown in Fig. 5, a pivotable flap 17 is located between the parts 4, 5 to afford an adjustable by-pass from the outlet 3 to the inlet 2, whereby the flow through the impeller can be increased to improve the efficiency at low throughput or during starting. A flow guide member 18 is provided. In another embodiment, the pivotable member 17 is omitted and the adjustable bypass is obtained by displacing the partition 4 relative to the cylinder 5. Fig. 4 shows a blower in which a standing vortex 5a replaces the solid cylinder. The vortex is generated and stabilized by a concave member 8. A pivotable flap similar to the flap 17 shown in Fig. 5 may be provided between the partition 4 and vortex 5a. Adjustment of the flap adapts the size and energy of the vortex 5a to the working conditions of the blower. Concave formations 11, 12, preferably forming part of the blower casing wall as shown, generate further cylindrical standing vortices (not shown), which deflect the air flow towards the casing wall to produce a diffusing effect on the flow. Also, a dragging effect is exerted on any reverse flow which may tend to occur when the blower is heavily throttled. Similar effects are produced by the provision of a cylinder 7 (Fig. 2, not shown), freely rotating or driven in a direction opposite to that of the impeller and disposed in a recess in the wall of the outlet 3.