With few exceptions, the conventional turbine, paddle, propeller or screw flowmeters employ a magnetic induction or magnetic reluctance transducer in measuring the rotary speed of the rotary members rotated by the fluid dynamic torque exerted thereon by the media flow, which types of transducers are less than desirable because these conventional transducers require a permanent magnet that limits the high temperature applications of the flowmeters beyond the Curie temperature, provide a very weak electrical signal at low velocities of the media, inhibit the start of the rotation of the rotary member under the fluid dynamic torque due to the magnetic force exerted on the rotary member by the permanent magnet included in the transducer, and the transducer cannot be packaged into a thin streamlined structure such as a shroud, tip of blade or hub of the rotary member rotated by the fluid dynamic torque due to the bulk and mass of the permanent magnet or a ferromagnetic element required to construct the transducer. A nonrotating turbine or propeller can be disposed pivotally about an axis of pivot and provided with a bias torque countering the fluid dynamic torque exerted on the nonrotaing turbine or propeller by the media flow, wherein the dynamic pressure of the media flow is determined as a function of the rotary position of the nonrotating turbine or propeller. At the present time, the nonrotating turbine or propeller flowmeter measuring the rotary position of the turbine or propeller and determining the dynamic pressure of the media flow as a function of the rotary position of the turbine or propeller has not been put into the practice.
USPTO Backgrounds
USPTO Backgrounds