External stress vortex street sensor

Abstract

The invention relates to an external stress vortex street sensor, and belongs to the technical field of fluid measuring equipment. The sensor has a shell, a weight, a piezoelectric crystal and ceramic sheets, wherein the shell has a smooth transition body structure from a cylinder to a cone to a sheet; a cylindrical section of the shell has a hollow structure; the weight is a T-shaped cylinder with a central hole and is inserted into a hollow section of the shell; the upper part of the weight stretches out of the shell and is embedded into a groove of a pressing plate; the pressing plate is provided with a threaded hole connected with a flow meter body; the lower part of the weight is provided with a groove; the piezoelectric crystal is arranged in the groove; the ceramic sheets are arranged on and below the piezoelectric crystal; and the lower ceramic sheet is arranged on the bottom plane of the hollow section of the shell. The sensor has an extremely low requirement on the accuracy of parts, has a structure with low-flow high sensitivity and high-flow high strength, can effectively improve a signal-to-noise ratio under resonant frequency and vibration interference, and can tolerate the impact of a large temperature change, a measuring application range is expanded, the service life of the sensor is prolonged, and the interference resistance of the sensor is improved.

Description

technical field [0001] The invention belongs to the technical field of fluid measuring equipment, in particular to an external stress-type vortex sensor used in a vortex flowmeter which can resist vibration interference and improve service life and stability. Background technique [0002] At present, the traditional vortex street sensor, which uses sheet-like piezoelectric crystals and solidified glue on the front and back of the crystal support frame, cannot simultaneously take into account the high sensitivity of small flow and the high-strength structure of large flow and high frequency, so it cannot be realized for high Flow and low flow detection. Another Chinese invention patent (approval number CN1004834B) involves a wide-temperature piezoelectric vortex flowmeter, which has a tubular surface body. At the center of the end face of the vortex generating body outside the surface tube, there is a vertical axis of the vortex generating body. A hole that is not connected ...

AI Technical Summary

Problems solved by technology

The shell with a smooth and transitional body structure has good rigidity. During use, the stress-bearing parts and stress-transmitting parts are sufficient to withstand the huge vortex lift generated by high-temperature steam up to 280m / s, 300°C and fluid up to 12m / s. At the same time, it can Increase the resonance frequency to 10kH, which is 4 times the frequency of the original vortex street, thus eliminating the occurrence of resonance and solving the problem of sensor fracture in high-speed fluid

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