1、 Product Overview:

The high-temperature Coriolis mass flowmeter has two parallel U-shaped vibrating tubes inside the sensor, with a drive coil in the middle and a pickup coil at both ends. The mass flowmeter directly measures the mass flow rate of the medium passing through the flowmeter, and can also measure the density of the medium and indirectly measure the temperature of the medium. Mass flow meters use thermal sensing measurement. It is an advanced high-precision mass flow measurement instrument. Due to its excellent performance, it has high measurement accuracy, low requirements for fluid state, and small pressure loss. Various specifications of instruments can directly obtain the mass flow rate, volume flow rate, density, and temperature of the measured liquid or slurry, without the need for manual calculation or estimation.

2、 Structural principle:

1. Principle:

The structure of the high-temperature Coriolis mass flowmeter is a double bend tube structure, and its measurement principle is to detect the mass flow rate in the pipeline by measuring the action on the double bend tube. In industrial production processes, it is sometimes necessary to measure the mass flow rate of fluids, such as material balance, heat balance, and batching in chemical reactions. Mass flow rate refers to the mass of fluid flowing through a closed pipeline section per unit time. The instruments used to measure mass flow are collectively referred to as mass flow meters.

2. Structure:

It consists of three parts: sensors, transmitters, and digital indicator accumulators. The sensor consists of three parts: sensing tube, electromagnetic driver, and electromagnetic detector. The electromagnetic driver causes the sensor to vibrate at its natural frequency, while the introduction of flow causes a distortion under the action of the U-shaped sensor, resulting in a phase difference on its left and right sides, which is proportional to the mass flow rate. The electromagnetic monitor converts the phase difference into a corresponding level signal and sends it to the transmitter for electrical processing such as filtering, integration, and amplification. Convert into two forms of output: 4-20mA analog signal proportional to quality and frequency signal within a certain range.

3、 Application scenarios:

The high-temperature Coriolis mass flowmeter is mainly used to measure the mass flow rate, total amount, and density of the medium. At the same time, it can also measure the volume flow rate and total amount, medium temperature, moisture content, alcohol content, concentration of two liquids mixed evenly, and raw material ratio in the process flow. It is mainly applicable to the following industries:

1. The petroleum industry, such as crude oil production measurement, water content measurement, single well production measurement, and crude oil transportation measurement;

2. Chemical industry;

3. Food industry;

4. The paper industry, such as pulp measurement;

5. Textile printing and dyeing industry;

6. Energy transmission metering, such as liquefied gas metering;

7. Environmental protection industry, such as sewage treatment; Measure the density of the slurry during the desulfurization process.

4、 Main features:

1. Directly measure the mass flow rate of fluid inside the pipeline:

High measurement accuracy and good repeatability, capable of directly measuring fluid mass flow rate over a large range; The accuracy of measurement is high, and the mass flow measurement accuracy of this flowmeter is 0.2 level;

2. Stable and reliable work:

There are no obstacles or moving parts inside the fluid measuring tube, so it has high reliability and long service life;

3. Suitable fluid medium surface width:

In addition to uniformly viscous fluids, it can also measure high viscosity fluids such as honey and oil slurry; Not only can it measure the fluid parameters of a single solution, but it can also measure multiphase flow; Whether the medium is laminar or turbulent, it does not affect its measurement accuracy;

4. Wide range of application environments:

Suitable for industries such as petrochemicals, chemistry, metallurgy, pharmaceuticals, papermaking, food, energy, and environmental protection, it has been widely used in process detection and control, as well as trade handover measurement;

5. Multiple real-time online measurement and control functions:

In addition to mass flow rate, it can also directly measure the density and temperature of fluids. An intelligent flow transmitter that provides display and control functions for multiple parameters is a multifunctional flow measurement and control instrument;

6. Good scalability:

The company can design and manufacture quality flow meters with special specifications, models, and functions according to user needs; Remote monitoring operations can also be performed.

5、 Technical parameters of high-temperature Coriolis mass flowmeter:

1. Measurement accuracy: ± [0.2%+(zero stability/instantaneous mass flow rate x 100%);

2. Measurement repeatability: ± (1/2) × [0.2%+(zero stability/instantaneous mass flow rate × 100%);

3. Density measurement range: 0.2 g/cm3 to 3.5 g/cm3;

4. Density measurement accuracy: ± 0.002g/cm3;

5. Temperature measurement range: -60 ℃ to+200 ℃;

6. Temperature measurement accuracy: ± 1 ℃;

7. Current output: 4mA~20mA;

8. Frequency output: 0Hz~10kHz;

9. Batch control relay contact capacity: 24V/0.1A;

10. Batch control relay contact form: normally open (indicated by the user when ordering, can be changed to normally closed);

11. Fluid medium temperature: -40 ℃ to+200 ℃;

12. Working environment temperature: 0 ℃~+40 ℃;

13. Working environment humidity: ≤ 90% RH, non condensing;

14. Atmospheric pressure: 86kPa~106kPa;

15. Power supply requirements for transmitters: intrinsic safety power supply voltage AC (220 ± 10%) V or (50 ± 5%) Hz, composite power supply voltage (24 ± 10%) V;

Whole machine power: ＜ 15W.

6、 Main functions:

1. Measurement function

It can directly measure the instantaneous mass flow rate, cumulative mass total, volumetric flow rate, volumetric total, temperature, density, and concentration of two-component liquids of liquid media. Can display, output, store, and remotely transmit; Modify the parameters of the flowmeter.

2. Current output

It has a current signal output function, with a current output of 4mA to 20mA, which can meet the control requirements of industrial instruments.

3. Frequency output

It has a frequency signal output function, with a frequency output of 0KHz to 10KHz, which can meet the control requirements of industrial instruments.

4. Batch control

Batch control relay contact capacity: 24V/0.1A, contact form is normally open (indicated by the user when ordering, can be changed to normally closed), this function can meet the flow batch control of industrial equipment.

5. Communication function

This product has data communication function and can complete data communication with a computer through RS-485 communication, enabling network control of the computer.

6. Safe and explosion-proof

Our company's quality flowmeter has obtained dual explosion-proof qualification certificates.

7、 Installation requirements:

The installation environment requirements for quality flow meters are that they are high-precision measuring instruments. In order to ensure measurement accuracy, the installation environment requirements must be met:

1. Sensors (primary meters) and transmitters (secondary meters) must not be installed in areas with strong magnetic interference, otherwise it will affect the circuit signal and thus affect the measurement accuracy;

2. The pipeline where the sensor (primary meter) is installed must not have any other vibration interference;

3. For outdoor installations, attention should be paid to the highest and lowest ambient temperatures, and windproof and rainproof measures should be considered to avoid wind and rain to improve the working life of the flowmeter;

4. The intrinsic safety flowmeter transmitter (secondary meter) should be placed in a safe area or a suitable control room;

5. The intrinsic safety flowmeter sensor (primary meter) and transmitter (secondary meter) are connected by a ten core shielded cable;

8、 Installation method:

1. Horizontal pipeline installation

The main body is facing downwards, measuring the liquid, and the outlet must be at least 0.8 meters high;

2. Invert the main body upwards

Self emptying, measuring the slurry containing solids, the outlet must be at least 0.8 meters above the highest point of the flowmeter;

3. Flag installation (test installation)

Self emptying, measuring liquids or slurries, the liquid must flow from bottom to top.

9、 Fault handling:

Liquid mass flow meters generally do not malfunction, and it is not a big deal if they do. Careful analysis of the cause can solve the problem, such as whether the operating conditions have changed, whether there is air leakage, whether they have just been calibrated and used, etc. Below are a few types of malfunctions and their solutions:

1. Hardware malfunction:

If there is a large error, the integrator does not light up or increase in value, or the display shows kb * * * bits, the reasons are:

a. Improper installation can directly lead to zero drift of the flow meter, such as installing the mass flow meter close to the pump outlet, insufficient sensor support strength, improper welding of the connecting flange generating stress signals, and electromagnetic interference on the cable.

b. Wiring issues

If the monitor does not light up, check the power connection of the integrator. If the fuse is blown, confirm whether the input voltage is consistent with the nominal value of the standard voltage and whether the AC/DC form is the same. If the accumulator does not increase with the flow rate, the wiring of the accumulator should be checked. If the accumulator is equipped with forward/reverse programs, the wiring of the flow meter should be checked. Incorrect wiring of the flow meter can cause the accumulator to not increase in reverse flow.

c. Change in process medium

If the measuring medium exhibits phenomena such as gas entrapment, gasification, or two-phase flow, the transmitter will display an alarm, and in severe cases, the sensor will stop working.

d. The transmitter is malfunctioning.

e. Sensor failure.

f. Pipeline blowing problem.

2. Software issue:

Before installing and using a newly calibrated flowmeter, it is important to pay attention to zero calibration under the current operating conditions. It is necessary to ensure that the flowmeter is filled with medium and close the two end shut-off valves before zero calibration can be performed. There are many specific methods, such as panel operation, manual operation, and using ProLink II software.

a. Zero calibration error;

b. Parameter settings are incorrect;

c. Pulse fluctuations of power supply;

d. I/O configuration error (be sure to pay attention to the range);

e. Operation error.

10、 Installation and usage precautions:

1. General requirements for installation of flow sensors

Due to the differences in the shape and structural design of dry measuring tubes, the weight and size of sensors with similar flow ranges and different models vary greatly. For example, for a diameter of 80mm, the lighter sensor weighs only 45 tons, while the heavier sensor weighs 150-200kg. The installation requirements also vary greatly, so it is necessary to follow the installation methods and avoid prohibited items specified by the manufacturer. For example, some models of flow sensors can be directly connected to the pipeline, while others require the installation of support frames or foundations. To isolate the impact of pipeline vibration on instruments, sometimes a flexible pipe is used to connect the sensor to the pipeline, and a rigid straight pipe with supporting components fixed between the flexible pipe and the sensor is also required. Before making a purchase, it is necessary to obtain the installation and usage manual from the manufacturer who intends to purchase CMF for comparison and selection.

When installing and designing, try to ensure a long service life. To remove solid objects and mixed gases that cause premature wear and measurement errors, protective devices such as filters or gas separators should be installed upstream of the sensor according to fluid and pipeline conditions. If you want to calibrate instruments online on site, you should consider the drainage connection port and valve, as well as the corresponding space.

2. Installation posture and position of flow sensor

Residual solids, scaling, and stored gases inside the flow sensor measuring tube will all affect the measurement accuracy. Generally speaking, it is more ideal to install it in a vertical pipeline that flows from bottom to top; However, whether non straight measuring pipes are installed on vertical or horizontal pipes depends on the vibration conditions and application conditions of the pipes. The installation position must be * * * so that the measuring tube is filled with liquid. For example, if the fluid flows through a horizontal pipeline and is directly placed in a container without back pressure, the measuring tube often cannot be filled, which will cause the output signal to fluctuate violently.

3. Installation of globe valve and control valve

To set up shut-off valves upstream and downstream for zero adjustment and ensure no leakage. The control valve should be installed downstream to maintain the highest possible static pressure to prevent cavitation and flash evaporation.

4. Pulsation and vibration

To avoid the impact of mechanical vibrations during the process and external factors, inquire with the manufacturer about the resonance frequency range of the provided CMF to determine if the on-site pulsation or vibration frequency is close to the resonance frequency. We can provide on-site vibration condition consultation to the manufacturing plant to determine whether the following measures need to be taken, such as: 1) setting up pulsation attenuators, 2) setting up vibration attenuators or flexible connecting pipes, 3) installing special clamping and fixing equipment for flow address sensors, and so on.

5. Prevent mutual influence between CMFs

When two units of the same model are installed in series, or multiple units are installed in close proximity to each other in parallel (or in parallel), especially when installed on the same support platform, the vibration of the measuring tube will affect each other, causing interference and abnormal vibration, and in severe cases, the instrument may not work. Preventive measures should be taken during installation, such as proposing to the manufacturer to stagger the resonance frequency values close to the instrument; Open the distance between the flow sensors, do not set them on the same rack, and set up independent support racks; Installation of flow sensors in opposite directions; Methods such as setting up anti vibration materials for isolation between flow sensors.

6. Pipeline stress and distortion

When tightening the bolts connecting the flange to the pipeline flange, they should be evenly tightened to avoid stress (such as caused by the non parallel planes of the two flanges in the pipeline). If a short pipe of the same length is pre connected when laying the pipeline, it can prevent stress caused by poor pipe laying. During use, due to changes in process pressure and temperature, the pipeline may be subjected to axial or bending/twisting forces, which can affect measurement performance. Necessary fixing brackets should be provided.

7. The use of highly abrasive slurry

As mentioned earlier, for measuring highly abrasive slurries, a straight and single tube type should be used, and the measuring tube should be in a vertical position to avoid uneven wear on the tube wall and shorten its service life. However, the thinning of the pipe wall thickness will reduce the rigidity of the measuring pipe and change the flow measurement value. Therefore, regular monitoring should be carried out in the early stages of operation in such places to confirm the service life.

Scaling or sedimentation on the inner wall of the measuring tube can also affect measurement accuracy, so regular cleaning is necessary.

8. Zero drift and zeroing

Zero drift comes from the flow sensor part, mainly due to: 1) the asymmetry and attenuation of mechanical vibration; 2) Changes in density and viscosity of fluids. The factors that affect the former include: a) the influence of fixed stress at the pipe end; b) Change in stiffness of vibration tube; c) ****** Inconsistencies in resonant frequency; d) Internal attenuation of pipe wall material. The reason why the latter affects the zero position is due to structural imbalance. Therefore, even if the resonant frequency of the double tube is adjusted to be consistent during empty tube operation, zero drift may occur when it is filled with liquid. Similarly, vibration attenuation caused by dryness is frequency dependent, and zero drift may also occur during flow.

Zero adjustment must be carried out at the installation site. The flow sensor should exhaust the gas, fill the measured fluid, and then close the upstream and downstream valves of the sensor. Zero adjustment should be carried out under conditions close to the working temperature. When there are changes in installation or significant changes in temperature, adjustments need to be made again.
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