Coriolis Mass Flow Meter
Working Principle
The structure of Coriolis Mass Flow Meters was consisted of a pair of bended tubes. The principle is to detect Coriolis force forced a pair of tubes from inner mass flow by fluid.
A new force—Coriolis force would be appear while two conditions met: (1) vibrating with normal frequency in a pair of bended tubes, (2) fluid flowing in tubes. This force was produced upon synthesis from vibrating force and flowing force by fluid in tubes. And tubes would be wresting symmetric the center line because the force forced. Two displacement sensors on sides of tubes detect the force and output electric signals. The signals regulated, mass flow directly produced.
Technical parameters
- Nominal pipe diameter: (unit: mm)DN2, 3, 6, 10, DN15, 25, 32, 40, 50, 65, 80, 100, 150, 200 (customized)
- Medium: liquid, gas, particulates, slurry
- Display: Instantaneous + cumulative + density + temperature (mass flow, density, temperature, volume flow, % concentration)
- Flow range: kg/h, t/h, g/min
- Accuracy: between 0.1% and 0.2%; factory calibration achieves maximum accuracy of 0.1%.
- Medium temperature: -20 to +140°C (-60 to +200°C)
- Power supply: 24VDC (220VAC)
- Output signal: 4-20mA + pulse; HART Modbus
- Material: Measurement tube SS316L, housing SS304;
- Pressure: Maximum pressure up to 42 MPa;
- Connection: Threaded and flanged (clamp) connections;
- Available in integrated and split types, explosion-proof version available;
- Protection rating: IP67
Applications
The mass flow meter can be used in the following fields to meet the requirements of ingredient, mixing processes and commercial measurement.
(1)Chemical:containing chemical reaction system
(2)Petroleum:moisture content analysis
(3)Lipids:including vegetable oils,animal fats and other oils
(4)Pharmaceutical
(5)Painting
(6)Paper making
(7)Textile printing and dyeing
(8)Fuel:crude oil,heavy oil,coal slurry,lubricant and other fuels.
(9)Food:gas dissolving beverage,health drink and other liquid.
(10)Transportation:pipeline liquid measurement.
(11)Low temperature fluid,like liquid oxygen and liquid nitrogen,the low temperature up to -200℃
(12)High temperature fluid,the maximum temperature up to 300℃
(13)High pressure fluid,like slurry flow measurement for oil drilling cementingAdvantages and Limitations
Pros:
1. Directly measures mass flow rate with high accuracy.
2. Measurable fluid range, including various high-viscosity liquids, slurries containing solids,
3. Liquids containing trace amounts of gas, and medium-to-high pressure gases with sufficient density.
4. Insensitive to upstream velocity distribution, therefore no upstream or downstream straight pipe sections are required.
5. Measurement values are insensitive to fluid viscosity; changes in fluid density have minimal impact on the measured value.
6. Very low Coriolis pressure loss.
Cons:
1. Cannot be used to measure low-density media and low-pressure gases; A gas content in the liquid exceeding a certain limit (varies by model) will significantly affect the measured value. (Therefore, the flow meter)
2. Coriolis mass flow meters are relatively sensitive to external vibration interference. To prevent the influence of pipeline vibration, most models of Coriolis mass flow meters have high requirements for the installation and fixation of the flow sensor. They cannot be used in larger pipe diameters, currently limited to below 150 (200) mm.
3. Wear, corrosion, or scale buildup on the inner wall of the measuring tube will affect the measurement accuracy.
4. Most models of Coriolis mass flow meters are large in weight and size. They are expensive.
Selection Criteria
1. Flow range:Maximum flow, rated flow, common flow, minimum flow
2. Pipe dimensions:Inner diameter, outer diameter
3. Media:Density or specific gravity, and viscosity
4. Operating pressure:Operating pressure differs from pipeline design pressure
5. Media temperature:High and low temperatures require additional charges
6. Accuracy requirements:Product precision
7. Power supply: 24V or 220V
8. Process connections: Flanges, threads, clamps, reducers, etc.
Summarize
