HIGH-TEMPERATURE BENDING MOMENT SENSOR FOR VORTEX FLOWMETERS Russian patent published in 2020 - IPC G01F1/32 

FIELD: chemistry; physics.

SUBSTANCE: invention relates to fluid, gas or steam vortex flowmeters, in particular, to bending moment sensors used and intended for recording frequency of vortices formed in flow of liquid, gas or vapour behind streaming body. In a bending moment sensor for fluid or gas vortex flowmeters, having a hollow cylindrical metal body, ending on one side with a bottom connected to a wedge-like wing, and on the other side with a pressure-tight input with two or more coaxial cables having screen and central conductors connected to the piezoelectric unit located inside the housing and representing at least one pair of piezoelectric plates with parallel planes polarized in thickness and having metallized surfaces, according to the solution, each of the piezoelectric plates has the shape of a hexagon formed by a rectangle and a square, one of the sides of which is aligned with the short side of the rectangle, and the other is an extension of the long side of the rectangle, so that the square forms a projection, which is a continuation of the metallized plane of the piezoelectric plate on the side of the sealed input, width of the projections is half the width of the short side of the piezoelectric plate, the conductors of the coaxial cable are connected to the projections of each of the plates, plates are turned one relative to each other by 180 degrees relative to the long side and are oriented to each other so that ledges with conductors are located on the side of the sealed input, wherein the projection of one plate is shifted along the width of the plate relative to the projection of the other one by half of the width of the plate, wherein plates are fixed in housing by means of layer of high-temperature adhesive substance so that ends of plates, free from protrusions, are fixed in centre of bottom of housing near wedge-like wing, and ends of plates with projections and conductors are fixed to housing on the side of sealed input, wherein height of layer of adhesive from each of ends is not more than 1/5 of length of plate, and in parallel to long side of plate on side of sealed input microcavity is installed, penetrating layer of adhesive substance.

EFFECT: technical result is increased level of channel balancing by changing design of piezoelectric assembly and its fixation in sensor housing by means of high-temperature adhesive substance; as well as broader functional capabilities of sensor (increasing number of signal channels); this will allow simplifying the design of the flow meter by installing, for example, one four-channel sensor instead of two two-channel sensors.

4 cl, 6 dwg, 1 tbl