Vortex Flow Meter Introduction

Stress type vortex flowmeter is a type of velocity flowmeter, which is based on the Karman vortex theory and uses piezoelectric crystals to detect the vortex frequency generated when the fluid passes through the triangular column in the pipeline, thereby measuring the flow rate of the fluid. Vortex flowmeters are widely used in industries such as petroleum, chemical, light industry, and power heating. 1、 Introduction: The temperature pressure integrated vortex flowmeter concentrates temperature and pressure compensation in the vortex flowmeter, automatically detects the temperature and pressure of the medium in the pipeline, and automatically participates in the calculation of density, so that the displayed flow rate is accurate. It can display the instantaneous mass flow rate and cumulative mass flow rate of the medium, as well as the temperature and pressure of the medium. It can measure liquids, general gases, saturated steam, superheated steam, etc. 2、 Characteristics: 1. High measurement accuracy and wide range; 2. Wide range of measuring media, capable of measuring liquids, gases, and vapors; 3. The working temperature is high, and the medium temperature can reach 330 ℃; 4. No moving parts, no wear and tear, high reliability; 5. The body is made of stainless steel material, which is corrosion-resistant. 3、 Working principle: When the fluid medium in the pipeline passes through the vortex generator (triangular column), a vortex phenomenon is generated due to local velocity acceleration (as shown in Figure 1). This vortex splits into two alternating columns, which are called Karman vortex streets. The release frequency of Karman vortex street is related to the width size of the triangular column and the flow velocity of the fluid, but not to the characteristic parameters such as temperature and pressure of the medium. It can be expressed as follows: f=StV/d ……………………（1） In the formula, f represents the release frequency of the Karman vortex street St Strouhal number V – Medium flow velocity D – Width of triangular pillar Strouhal number is an important parameter of vortex flowmeter, which is only related to the Reynolds number Re of the medium. As long as the Reynolds number of the medium inside the pipeline remains within the range of 2 × 104 to 7 × 106, the Strouhal number St remains constant. This allows the flow velocity of the fluid medium to be detected by measuring the vortex frequency signal, and then the flow rate of the medium can be calculated based on the flow velocity of the medium. 4、 Installation precautions: 1. In the absence of valves and bends, a straight pipe section of not less than 10D should be left in the front section, and a straight pipe section of not less than 5D should be left in the rear section; if there are valves or bends, the front straight pipe section should not be less than 20D. 2. There should be no leakage between the welding of the two flanges and the pipeline, and the welding slag should be cleaned up after welding. 3. It is not allowed to weld the flange and the body together, as this may damage the probe. 4. The pipeline must not have any vibration to prevent interference signals from being generated.