原理：当流体流过探头时，在其前部产生一个高压分布区，高压分布区的压力略高于管道的静压。 Principle of Verabar flowmeter : When the fluid flows through the probe, a high-pressure distribution area is generated at the front of the probe. The pressure in the high-pressure distribution area is slightly higher than the static pressure of the pipeline. According to the principle of Bernoulli's equation, when the fluid flows through the probe, the speed increases, and a low-pressure distribution area is generated at the rear of the probe. The pressure in the low-pressure distribution area is slightly lower than the static pressure of the pipeline. After the fluid flows through the probe, a partial vacuum is created at the back of the probe, and vortices appear on both sides of the probe. The cross-sectional shape of the average velocity flow probe, the surface roughness, and the location of the low pressure pressure taking hole are the key factors that determine the performance of the probe. The stability and accuracy of the low-voltage signal play a decisive role in the accuracy and performance of the average speed probe. Verabar's average velocity flow probe can accurately detect the average differential pressure produced by the average velocity of the fluid. The Verabar average velocity flow probe has multiple pairs of pressure taking holes arranged according to certain criteria in the high and low pressure areas, making it possible to accurately measure the average flow velocity.
Verabar flowmeter technical parameters:
Measurement accuracy: ± 1% Repeat accuracy: ± 0.1%
Applicable pressure: 0 ～ 40MPa Applicable temperature: － 180 ℃ ～ ＋ 550 ℃
Upper measurement limit: Depends on the probe strength. Lower measurement limit: Depends on the minimum differential pressure required. Range ratio: greater than 10: 1
Applicable pipe diameter: 38mm ～ 9,000mm round pipe, square pipe Applicable medium: full pipe, one-way flow, one-way gas, steam, and liquid Verabar with a viscosity not greater than 10 centipoise Extensive use for various gases, liquids and steam
Verabar Flowmeter Application:
是通过差压来测量流量的装置，是在皮托管流速测量原理的基础上发展起来的。 Gas / Liquid / Steam Natural Gas / Cooling Water / Saturated Steam Compressed Air / Boiler Water / Superheated Steam Gas / Desalinated Gas Hydrocarbon / Liquid Hydrocarbon Hot Air / Low Temperature Liquid Generator Gas / Heat Conductive Liquid ZP-HLV Verabar Flow Gauge is a device for measuring flow through differential pressure, which was developed based on the principle of pitot tube flow measurement. Measures the flow of fluids such as liquids, gases and steam. Because there are no moving parts, there is almost no pressure loss, convenient installation and maintenance, and extremely low operating costs, which is favored by users. The sensor is composed of a detection rod, a pressure taking port and a guide rod. It crosses the interior of the pipe and is perpendicular to the tube axis. There are multiple pressure measurement holes on the upstream side of the measurement rod to measure the average value of total pressure. The flow surface has static pressure pressure measuring holes, which are led out by the total pressure impulse pipe and the static pressure impulse pipe respectively, and the flow rate through the pipeline is calculated according to the differential pressure value of the total pressure and the static pressure. The static pressure on the backflow surface of the sensor can also be replaced by the static pressure on the wall of the flow tube. The averaging tube flow transmitter is a flowmeter composed of sensors, plenum accessories and differential pressure transmitters, pressure transmitters, flow totalizers and other supporting devices. The averaging tube flow sensor combined with the differential pressure transmitter, pressure transmitter, temperature transmitter and flow totalizer produced by our company can form various types of averaging tube flowmeters. Different types of averaging tube flowmeters can also be made using differential pressure transmitters, pressure transmitters, temperature transmitters and flow totalizers from any manufacturer.
Working principle The average velocity tube flow sensor is developed based on the principle of pitot tube speed measurement. It determines the flow rate by the product of the average velocity of the pipeline and the effective cross-sectional area of the pipeline. Velocity distribution in general pipelines is uneven. If it is a fully developed fluid, its velocity distribution is exponential. 为了准确计量，将整个圆截面分面多个单元面积相等的多个半圆及多个半环。 In order to accurately measure the Verabar flowmeter , multiple semi-circles and multiple semi-rings with the same area of multiple units on the entire circular cross-section are divided. The detection rod of the sensor is composed of a hollow metal tube, and multiple pairs of total pressure holes are drilled on the upstream side. They are respectively located in the center of each unit area and reflect the velocity of the flow in each unit area. Because the total pressure holes are connected, after the total pressure value transmitted to each point in the detection rod is averaged, it is led to the high-pressure joint by the total pressure lead-out pipe and sent to the positive pressure chamber of the sensor. When the sensor is correctly installed on a process pipe with a long enough straight pipe section, there should be no vortex on the flow section. The static pressure of the entire section can be considered constant. There are detection holes on the back or side of the sensor, which represent the entire section. Static pressure. The static pressure outlet pipe is led from the low-pressure joint to the negative pressure chamber of the sensor. The square of the pressure difference between the positive and negative pressure chambers is proportional to the average flow velocity of the flow cross section, and the relationship between the differential pressure and the flow is obtained.