Mass-volume vortex flowmeter
OwnerHyok S. Lewinventor
Life of this patent
Estimating the term…
Abstract
A flowmeter has a vortex generating bluff body (102) disposed across the flow passage (106), a planar member (103) disposed immediate upstream of the bluff body (102) including a plurality of total pressure ports emerging through the leading edge of the planar member (103) and a plurality of static pressure ports emerging through the side faces of the planar member (103), and a vortex sensing device including a planar member (104) and one or two transducers (111 and 112), which flowmeter determines the mass and volume flow rates of the fluid and the density of the fluid from the dynamic pressure determined from the difference between the total and static pressures and the fluid velocity determined from the vortex shedding frequency.
Claims11
An apparatus for measuring flow rate of fluid comprising in combination:
- a) a body including a flow passage;
- b) a vortex generator of an elongated cylindrical shape with a blunt upstream face disposed across the flow passage, said vortex generator including a planar member disposed immediate upstream of the vortex generator on a plane generally parallel to the central axis of the flow passage and to the longitudinal axis of the vortex generator;
- c) at least one stub cylindrical member disposed parallel to the central axis of the flow passage and extending from a portion of leading edge of the planar member in a direction opposite to the direction of fluid flow, said at least one stub cylindrical member including a total pressure port emerging through the tip thereof and connected to a first conduit for tapping the total pressure of the fluid flow and at least one static pressure port emerging through cylindrical surface thereof and connected to a second conduit for tapping the static pressure of the fluid flow;
- d) means for measuring shedding frequency of vortices from the vortex generator;
- and
- e) means for measuring difference between the total and static pressure of the fluid flow.
An apparatus for measuring flow rate of fluid comprising in combination:
- a) a body including a flow passage:
- b) a vortex generator of an elongated cylindrical shape with a blunt upstream face disposed across the flow passage, said vortex generator including a planar member disposed immediately upstream of the vortex generator on a plane generally parallel to the central axis of the flow passage and to the longitudinal axis of the vortex generator;
- c) at least one total pressure port emerging through leading edge of the planar member and connected to a first conduit for taping total pressure of the fluid flow;
- d) at least one static pressure port emerging through at least one of the two side faces of the planar member and connected to a second conduit for tapping static pressure of the fluid flow;
- e) means for measuring shedding frequency of vortices from the vortex generator, said means comprising a vortex sensing planar member disposed downstream of the vortex generator on a plane substantially parallel to the central axis of the flow passage and to the longitudinal axis of the vortex generator in an arrangement allowing at least a minute amount of pivoting movement of the vortex sensing planar member about a pivot axis parallel to the central axis of the flow passage and passing through a midsection of the vortex sensing planar member, and a pair of transducer means respectively connected to two opposite extremities of the vortex sensing planar member, wherein leading edges of two halves of the vortex sensing planar member respectively located on two opposite sides of a plane including the pivot axis are offset from one another by a distance generally equal to a noninteger times the wave length of sinuating streamlines created by the vortices shed from the vortex generator;
- whereby two electrical signals respectively generated by the pair of transducers are combined to cancel noise generated by structural vibrations of the body and obtain a resultant signal representing the vortex shedding from the vortex generator;
- and
- f) means for measuring difference between the total pressure and the static pressure of the fluid flow.
Dependencies are inferred from the claim text.