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『Orifice gas flowmeter』Related information(v cone flow meter|rotary gas meter|gallon meter|gear meter|metal tube rotameter|glass tube rotameter|nutating disk meter|transit time ultrasonic flow meter|wedge flow meter|pd meters|hydraulic flow meter|ultrasonic water flow meter|water flow meter|air flow meter|magnetic water flow meter|oxygen flow meter|gas flow meter|argon flow meter|air velocity meter|gasoline flow meter|fuel flow meter|ultrasonic water meter|digital water meter|nitrogen flow meter|solid flow meter|Oxygen tank flow meter|digital water flow meter|diesel fuel flow meter|steam flow meter|02 flow meter|compressed air flow meter|oil flow meter|liquid flow meter)
1. Calculation of Orifice Flow Meter
The core calculation formula of an orifice flow meter is qv=C × ε× A0 × √ (2 Δ p/ρ), and the calculation result directly reflects the flow rate.
1. Basic Parameter Analysis 1 Outflow coefficient C: It is related to the geometry of the orifice plate and the pressure measurement method, and needs to be obtained through experiments or by referring to standard charts. two The coefficient of expansion ε: for liquids, it is set to 1, while for gases, it needs to be corrected through charts based on pressure difference and temperature. three Opening area A0: calculated as A0=π d ²/4, where d is the measured inner diameter of the orifice plate. four Differential pressure Δ p: directly measured by a pressure sensor or U-tube, in Pa. 5. Density ρ: The density of the liquid is less affected by temperature, and the gas needs to be converted according to the working pressure and temperature.
2. Decomposition of Calculation Steps 1 Determine the fluid nature of the Mingshi field: distinguish between liquids or gases, and select the corresponding ε value. two Parameter measurement and acquisition: - Measure the diameter d of the orifice plate opening and calculate A0. - Record the reading Δ p of the pressure differential exciter. -Check the table or conduct experiments to determine C and ε. 3. Substitute into the formula for calculation: evaluate step by step according to qv=C ε A0 √ (2 Δ p/ρ).
III. Example Calculation of Water Flow Measurement in a Pump Pipeline: • Known Conditions: d=0.05m, Δ p=5000Pa, ρ=998kg/m ³ (20 ℃ water), C=0.62，ε=1。 • Calculation process: 1 A0=π× (0.05) ²/4 ≈ 0.00196m ². two Substitute into the formula: qv=0.62 × 1 × 0.00196 × √ (2 × 5000/998
2. The reason for the slow decrease in flow rate of the orifice flowmeter is mainly related to five factors: blockage of the pressure tapping system, wear and deformation of the orifice plate, changes in process parameters, abnormal sales of pipeline working fluid, and improper maintenance of the instrument.
. Specifically, one issue is the blockage of the pressure sensing system. If there are impurities, crystals, or viscous substances in the medium, they will slowly deposit in the pressure sensing tube, causing the transmission of differential pressure signals to be obstructed and the flow display to decrease. For example, in a steam system, if a steam trap fails, condensed water freezes or impurities accumulate, the pressure sensing tube will be blocked; The pressure tapping hole is also easily blocked by particles, oil stains, or scaling in the medium, which makes it difficult to accurately transmit the actual differential pressure value to the transmitter, resulting in low flow display. The second issue is the wear and deformation of the orifice plate itself. Long term exposure to high-speed media can cause the aperture of the