Rotary Flow-Meters

1,153,423. Rotary fluid-flow meters. BRITISH OXYGEN CO. Ltd. July 11, 1966 [April 9, 1965], No.15251/65. Heading F1F. A rotary meter for measuring the aggregate volume, or volume per unit time, of a gas flowing therethrough, includes a cylindrical stator 7 containing a rotor 1 fixed to a rotatable shaft 3, which is carried by struts 6 and connected to a pointer 9 by a gear-train 8, the rotor being made of corrugated sheet-metal, the corrugations being radially orientated to obviate flexing of the rotor during operation thereof. The gas enters a casing surrounding the stator through an inlet 10 and flows towards the rotor through a plurality of tangentially-orientated slots 11, which render the gaps within the stator turbulent so as to effect rotation of the rotor, the gas being ejected axially through a passage 12. An axially-movable tube 13 can be used to reduce the effective size of the slots 11 when the rate of flow of the gas is substantially less than normal, reduction in said size being effective to increase the angular velocity of the gas within the stator. Alternatively, the tube is rotatable relative to the stator and furnished with slots such that it can be used to partially obturate the slots 11. A dial associated with the pointer 9 has two scales corresponding to the positions of the said tube when it is fully retracted and when it is partially obturating the slots 11, respectively. The rotor may be furnished with ribs, to effect stiffening thereof, instead of the corrugations; and the tube 13 may be both axially movable and rotatable.