Diaphragm capsule type double-probe vortex shedding flow meter

Abstract

The invention relates to a diaphragm capsule type double-probe vortex shedding flow meter, which comprises a flow pipe, a generation body, a main probe, a compensation probe and a converter component, wherein a fluid passes through the flow pipe; the generation body is fixed in a cavity of the flow pipe; the main probe is embedded in a pipe body of the flow pipe and positioned above the generation body; the compensation probe is embedded in the pipe body of the flow pipe; the converter component is electrically connected with the main probe and the compensation probe respectively; the main probe is arranged above the generation body and used for detecting a flow signal and a vibration signal of a field pipeline; and the compensation probe is positioned behind the main probe in the flowingdirection of the fluid and used for measuring the vibration signal of the field pipeline. After electrically sent into a converter, signals which are output by the two probes are subjected to spectrum analysis and comparison to obtain a relatively-pure vortex shedding flow signal, so that interference with a measurement result, caused by vibration of the field pipeline, is directly eliminated. Moreover, the main probe and the compensation probe are both diaphragm capsule type vortex shedding flow sensors and embedded inside the pipe body of the flow pipe, so that damage to the probes by cavitation is avoided.

Description

technical field [0001] The invention relates to a vortex flowmeter, in particular to a capsule-type double-probe vortex flowmeter. Background technique [0002] Vortex flowmeter is a flow measuring instrument without moving parts. It has the advantages of wide application range, high measurement accuracy, small wear, linear output signal and long-distance transmission, easy installation and maintenance, etc. Since the late 1960s Since the advent of the vortex flowmeter, after nearly 40 years of development, it has become one of the general flowmeters. The operation mode of the vortex flow sensor is based on the use of the periodic fluctuations in the Karman vortex street. The operation mode of the vortex flow sensor is based on the periodic fluctuations in the Karman vortex street. When After the measured fluid passes through the generator set in the pipeline, this vortex street will be formed, and the detection element (probe) set in the pipeline will feel the frequency si...

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Problems solved by technology

[0003] In the current vortex flowmeter production industry, most of the "cantilever beam" probes installed downstream of the generating body to detect the vortex frequency in the oscillating wake are used. However, due to their structural characteristics, they are resistant to pipeline vibration. The noise capability is very poor; there are also double 'cantilever beam' probe detection structures, and two cantilevers are inserted into the flow field, but the newly added cantilever beam probe makes the noise components in the oscillating wake more complicated, and has produced many influences. The sub-vortex with stable vortex, flow noise, and low-frequency swing interference signal, especially when encountering the impact condition of high-velocity fluid such as "cavitation", the cantilever part is easy to break and the probe fails, and it is difficult to operate under the condition of continuous flow. In order to reduce the impact of the newly added cantilever beam probe on the flow field distribution and the main probe measurement, the distance between the two probes is generally set far enough, which increases the length of the instrument and increases the cost.

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