Patent ID: 6463810
Filing Date: 2002-10-15
Classification: G01F

Abstract:
A precision flowmeter adapted to measure at least one of mass flow rate and flow velocity of a fluid, at steady or transient state, in a bi-directional low-velocity flow system, the flowmeter comprising:a tubular main body adapted to be connected with a pipeline of the flow system, an interior of the tubular main body including, in order from an upstream end to a downstream end, an upstream tubular channel section, a throat channel section, and a downstream tubular channel section, the throat channel section including an upstream conical channel section having an end adjoining the upstream tubular channel section, a cylindrical throat portion formed at a middle of the throat channel section and having an end adjoining the upstream conical channel section, and a downstream conical channel section having an end adjoining the throat portion and another end adjoining the downstream tubular channel section; a plurality of pressure taps, the plurality of pressure taps including dynamic pressure taps and static pressure taps, passing from the interior of the tubular main body and through a wall of the tubular main body; and a plurality of impact tubes located circumferentially spaced-apart on the upstream conical channel section and extending axially parallel through a conical wall of the tubular main body toward a center of the cylindrical throat portion, wherein dynamic pressure taps correspond in number to the plurality of impact tubes and communicate with inner ends of the corresponding plurality of impact tubes, and static pressure taps pass through walls of the upstream and downstream tubular channel sections and through the tubular throat portion.