Vortex flowmeter selection attention?

What are the vortex flowmeter selection precautions? How to determine the installation position of the vortex flowmeter? What are the vortex flowmeter requirements for the field environment? When the vortex flowmeter fluid flows through the column, the vortex crosses and separates in the cylinder. Pressure is generated in the wakes on the sides and behind the cylinder. The detection probe located behind the cylinder is subjected to such a small pulsating pressure, so that the piezoelectric crystal element in the probe is subjected to alternating stress and generates a corresponding alternating charge signal. After the detection amplifier processes the charge signal, the output and flow rate A proportional pulse signal is displayed on the integrator and accumulated.

The vortex flowmeter charge converter converts the alternating charge signal output from the piezoelectric element into a voltage signal proportional to the amount of charge. Amplifier, low-pass filter for signal amplification, noise cancellation. The Schmidt shaper transforms the erbium frequency of the vortex frequency into a pulse signal of a certain amplitude. At the same time, the circuit has a hysteresis on the input and output signals, so that the oscillation caused by the noise can be prevented. The pulse output amplifier amplifies the pulse signal output by the Schmidt shaping circuit.

Vortex flowmeter selection installation notes:

Vortex flowmeter selection and installation one of the matters needing attention: the correct selection: Instrument selection is an important task in the application of the instrument, the instrument in many practical applications with the barrier and the instrument selection and misuse. According to the actual condition of the process, the diameter of the flowmeter should be selected. Under normal circumstances, the diameter of the selected instrument should be such that the minimum flow rate of the gas is not less than 7m/s, and the flow rate of the liquid is not less than 0.7m/s. Try to avoid the frequency of normal flow generated at about 50Hz, because the interference of power frequency interference into the instrument is not easy to be detected, which will cause measurement error. Actual production due to the design of the pipeline is generally large, so the actual fluid flow will be too small, if you select the vortex orifice according to the original pipeline, it will cause inaccurate measurement, or even measurement, so the determination of the lower limit of the vortex flowmeter to Important. Only when the lower limit flow is determined, the most suitable vortex street can be selected.

Vortex flowmeter selection and installation of the second consideration: on-site environment and vibration to take effective measures: vortex flowmeter ambient temperature: -40 °C ≤ T ≤ 55 °C, if you love to heat production equipment, radiation, heat insulation should be taken Ventilation measures. Ambient air: The flowmeter should not be installed in a corrosive atmosphere. If it must be installed, it must be ventilated. Mechanical vibration and impact: Vibration will produce interference signals. If the vibration and impact on the pipeline are strong, and the medium flow rate is both low, it may cause the interference signal to be greater than the flow signal, causing measurement error. Therefore, the flowmeter should be installed in a place with little vibration and impact. The installation position should be at a vibration frequency of 5 to 20Hz. The vibration acceleration should not exceed 1g. Otherwise, vibration reduction measures should be taken.

Vortex flowmeter selection and installation of the installation considerations: Installation point and straight pipe requirements: In the provisions of the length of the straight pipe, pipe inflow and outflow section of the visual inspection should be straight, the sensor should be provided as much as possible to install the control valve, half open valve Downstream, in general, sensors are not installed after the expansion of the pipe. The sensor can be mounted vertically, horizontally or at any other angle, but when tilted vertically, the fluid should flow from bottom to top. Take the setting of the pressure point and measurement point. The pressure point should be outside the sensor 10D. The temperature should be measured outside the 5D.