1、 Overview of Cone Flow Meter:
ARSV cone flowmeter is a new type of high-precision flowmeter that can accurately measure various Reynolds numbers, meeting the application requirements of various media. Its operating principle is the same as other types of differential pressure principles, both based on the principle of energy conservation in sealed pipelines. Due to its unique design structure, the V-cone flowmeter has better performance.
The V-cone flowmeter is a conical throttling device suspended at the center of the pipeline, which obstructs the flow of the medium and reshapes the velocity curve. A low-pressure zone can be immediately formed downstream of the conical shape. There is a differential pressure between the positive pressure upstream of the pipeline and the negative pressure downstream after throttling by the throttling device. The positive and negative pressures are taken out using a pressure tap, with the positive pressure tap located upstream of the pipeline and the negative pressure tap located at the end of the cone. By measuring the differential pressure between the two, the flow rate in the pipeline can be calculated according to the Bernoulli equation. The cone is located at the center of the pipeline, which can optimize the velocity curve of the measured medium. Therefore, the measurement accuracy is high and the requirements for the straight pipe sections upstream and downstream of the instrument are low.
The V-cone flowmeter can measure the flow rate of various media such as gas phase, mixed gas phase, liquid phase, multiphase liquid, gas-liquid two-phase (moisture, liquid phase mass ratio ≤ 5%), powder, high viscosity, high flow rate, dirt, liquid phase containing solid suspended particles, solution vibration, electromagnetic interference, etc. under various working conditions (temperature and pressure). The fluid conditions can range from deep low temperature to supercritical state. The maximum working temperature is 850 ℃ and the maximum pressure is 42.0MPa. If special structural materials are used, the temperature and pressure can be even higher. It can measure a maximum Reynolds number of 5 million and a minimum Reynolds number of 8000 or even lower. Generate full-scale differential pressure signals ranging from a minimum of less than 0.1 kPa to a maximum of several tens kPa.
The flange pressure type cone flowmeter (VF) uses a solid cone to intercept the fluid and measures the pressure on the pipe wall with a flange. Equipped with a remote differential pressure transmitter, it can effectively prevent blockage of the pressure tap and is suitable for media containing solid particles, dust, high viscosity liquids, and dirty media.
2、 Working principle of conical flowmeter
The V-cone flowmeter is a differential pressure type flow meter. The flow meter designed based on the differential pressure principle has a history of more than 100 years of application. The differential pressure flowmeter is based on the energy conversion principle in sealed pipelines, which means that for stable fluids, the pipeline pressure is inversely proportional to the square root of the medium flow velocity in the pipeline: as the velocity increases, the pressure will decrease. When the medium approaches the cone, its pressure will be P1. When the medium passes through the throttling area of the cone, the velocity will increase and the pressure will decrease to P2. As shown in Figure 1, both P1 and P2 are led to the differential pressure transmitter through the pressure tapping port of the cone flowmeter. When the flow velocity changes, the differential pressure value between the two pressure tapping ports of the cone flowmeter will increase or decrease. When the flow rate is the same, if the throttling area is large, the resulting differential pressure value is also large. The β value is equal to the throttling area of the cone divided by the cross-sectional area of the inner diameter of the pipeline (which can be converted into the diameter ratio between the two).
3、 Selection of Cone Flow Meter