Coriolis Mass Flow Meter

The Coriolis mass flowmeter is a high-precision instrument that directly measures the mass flow of fluids. It works based on the Coriolis effect (Coriolis force) generated by the fluid in the vibrating pipe. Its core principle is that when the fluid flows through the vibrating measuring tube, a Coriolis acceleration proportional to the mass flow rate is generated, causing a phase difference or distortion in the measuring tube. The mass flow rate can be calculated by detecting the phase difference.

Core characteristics and technical points

1. Measurement principle

- The measuring tube generates periodic vibrations under the action of the driving component. When the fluid flows, a Coriolis force perpendicular to the flow direction is generated, causing the inlet section and the outlet section to vibrate and produce a phase time difference (Delta-T). This phase difference is strictly proportional to the mass flow rate of the fluid.

- The formula is: ΔFc = 2ω·qm·Δx (ΔFc is the Coriolis force, ω is the angular velocity, and qm is the mass flow rate).

2. Typical structure

- Sensor: including a vibrating tube (single tube/dual tube), a driving coil, and an electromagnetic signal detector. Vibrating tubes can be divided into straight tubes, U-tubes, Q-tubes, etc. Straight tubes have less pressure loss and are easy to clean.

- Transmitter: Processes phase difference signals, outputs mass flow and density data, and has temperature/pressure compensation function.

3. Core advantages

- High precision: The measurement accuracy is 0.1-0.2%, with good repeatability, and can directly output mass flow (kg/h) without conversion.

- Multi-parameter measurement: Synchronously measure fluid density and temperature, and some models support concentration analysis.

- Strong adaptability: Suitable for high-viscosity liquids, non-Newtonian fluids, slurries and high-pressure gases (such as LNG, CNG), and is insensitive to changes in fluid properties (temperature, pressure, viscosity).

- High reliability: No moving parts and flow-blocking elements, long life and low maintenance requirements.

4. Application areas

- Key industries: petrochemicals (raw material ratio, trade settlement), pharmaceuticals (high-purity media), food (viscous liquids), energy (natural gas metering), new energy, etc.

- Limitations: Not suitable for gas-liquid two-phase flow with gas content exceeding the threshold, and large pipe diameter has high cost.

5. Technical innovation: The Coriolis flowmeter realizes direct measurement of mass flow, breaking through the limitations of traditional volumetric flowmeters, and is recognized as one of the mainstream flow meters in the 21st century.