GB1350570A - Rotary flowmeters - Google Patents

Abstract

1350570 Rotary fluid-flowmeters B RHODES & SON Ltd 19 April 1971 [23 Oct 1969 28 April 1970] 52025/69 and 20347/70 Heading F1F Fluid-flowing upwardly in a passageway 4 of circular cross-section lifts and revolves a rotor 12 due to the presence of helical vanes 20 and a frusto-conical tail part 100. Fixed axiallystraight guide vanes (not shown) may be lodged in the passageway below the rotor. The angular velocity of the rotor may be detected by e.g. a light source 25 and detector 24. In a second embodiment, Fig. 2, the rotor 6 is ionic and has vanes 32, rotation of the rotor being discerned by a detector 224. Alternatively, the rotor has a cusp-shaped profile, Fig. 3 (not shown). A third embodiment, Fig. 4 (not shown), is generally similar to that according to Fig. 1 saving that the blades of the rotor are axially straight and the guide blades are helical. The rotor may have a tail part with helical grooves formed in its frustoconical surface such that the torque produced by the flow therethrough either assists or opposes that due to the flow between the blades of the rotor, Figs. 5 and 6 (not shown). To permit a larger range of flow-rates (without causing, an excessive rotor speed) the Fig. 1 embodiment may be modified inasmuch as the passageway is given two frusto-conical portions, one being disposed immediately above the other and having a greater apex angle, Fig. 7 (not shown). In a fourth embodiment, Fig.8, compensation for loss of torque due to drag at a conic nose portion 142 is provided by additional torque obtained from drag on a cylindrical part 152 as a result of rotational flow component induced by fixed helical blades 156.