Wastewater flow meterIt is a key equipment used to measure wastewater flow rate, based on different physical principles to achieve flow measurement. Common principles include:
Principle of Electromagnetic Induction
The electromagnetic flowmeter generates induced electromotive force by cutting the magnetic field of conductive wastewater, which is proportional to the flow rate, and then calculates the flow rate.
Advantages: unobstructed flow components, low pressure loss; High measurement accuracy (± 0.5%~± 1%); Strong corrosion resistance, suitable for conductive liquids such as acid-base salt solutions and wastewater.
Limitations: Unable to measure non-conductive liquids (such as oils and gases); There is a requirement for conductivity (≥ 5 μ S/cm).
Principle of Time Difference in Ultrasonic Propagation
The ultrasonic flowmeter calculates the flow velocity by measuring the time difference between the propagation of ultrasonic waves in the fluid, and combines it with the cross-sectional area of the pipeline to obtain the flow rate.
Advantages: Non contact measurement, no pressure loss; Suitable for large-diameter pipelines (DN300 and above); Can measure fluids containing solid particles or bubbles.
Limitations: Sensitivity to pipeline material and roughness; Accuracy decreases at low flow rates.
Principle of Doppler Effect
Doppler flowmeter calculates flow velocity by detecting the frequency changes of ultrasonic waves reflected by suspended particles or bubbles in the fluid.
Advantages: Suitable for fluids with non full pipes or high levels of impurities (such as sewage outlets); Easy installation and low cost.
Limitations: There are requirements for the concentration of scatterers in the fluid; The straight pipe section requires a length of ≥ 20D.
Vortex principle
The vortex flowmeter calculates the flow velocity based on the vortex frequency generated when the fluid flows through the blocking fluid.
Advantages: Simple structure, no movable parts; Range width ratio (10:1-100:1).
Limitations: Sensitivity to vibration; Not suitable for fluids containing long fibers or easily tangled materials.