Internal structure of vortex flowmeter

Project Overview

The vortex generator and detection element are important parts of the internal structure of the vortex flowmeter.

1. Vortex generator

The vortex generator is perpendicular to the axis of the measuring pipe. It can be welded into the shell or installed with seals. Its function is to allow the medium to pass through. Finally, regular vortices, namely Karman vortex streets, are generated alternately from both sides of the vortex generator.

The vortex generator is the main component of the vortex flowmeter. It is closely related to the flow characteristics (instrument coefficient, linearity, range, etc.) and resistance characteristics (pressure loss) of the instrument, and has the following characteristics:

1) There should be a non-streamlined and symmetrical cross-section, which can generate uniform vortices when the fluid passes through. The sharp edges of the cross-section can cause the vortices to separate synchronously in the direction of the axis of the generating body.

2) In a wide range of Reynolds number, there is a stable vortex separation point and a constant Strouhal number is maintained.

3) It can generate strong vortex street, and the signal-to-noise ratio of the signal is high, which facilitates signal detection.

4) The shape and structure are simple, easy to process and install and combine various detection components.

5) The material should meet the requirements of fluid properties and be resistant to corrosion, abrasion and temperature changes.

2. Detection element

The detection element is installed on the shell and can be made of thermal, strain, magnetoelectric, capacitor, stress, photoelectric, ultrasonic and other sensitive components. Detect the Karman vortex signal generated by the generator. The detection methods include the following:

1) Use the detection element installed in the vortex generator to directly detect the differential pressure on both sides of the vortex generator;

2) There are openings on the vortex generator Pressure guide hole, install a detection element in the pressure guide hole to detect the differential pressure on both sides of the generator;

3) Detect the alternating circulation around the vortex generator;

4) Detect the occurrence of vortex Alternating differential pressure on the back of the body;

5) Detect the vortex array in the wake.

In addition to the vortex generator and detection components, the internal structure of the vortex flowmeter also includes preamplifier, filter shaping circuit, D/A converter, output interface circuit and other parts. For more technical exchanges, please contact Qingdao Hesheng Measurement and Control, a vortex flowmeter manufacturer!