Liquid mass flowmeter

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Liquid mass flowmeters measure the mass flow of liquids and gases directly in almost all application…

I. product overview

Zw-cmf series liquid mass flowmeter has two parallel u-shaped vibrating tubes inside the sensor, the middle part is equipped with a driving coil, and the two ends are equipped with a pickup coil. The flowmeter directly measures the mass flow of the medium through the flowmeter, and can also measure the density of the medium and indirectly measure the temperature of the medium. Due to its excellent performance, it has high measurement accuracy, low requirements for fluid state and small pressure loss. Instruments of various specifications can directly obtain the mass flow, volume flow, density and temperature of the measured liquid or slurry without manual calculation or estimation.

Can solve the difficult measurement of fluid measurement problems, such as high temperature, low temperature, high pressure, high viscosity, small flow, temperature and pressure fluctuations, user requirements response time is fast, high precision requirements for fluid measurement problems. At the same time, the flow meter can be used as a density meter, without the need for temperature, pressure, density, viscosity, etc. conversion correction compensation.

Ii. Structure principle

1. Principle

Zw-cmf series liquid mass flowmeters are designed with double curved pipes. The measuring principle is to detect the mass flow in the pipe by measuring the mass flow in the double curved pipes. In the process of industrial production, sometimes it is necessary to measure the mass flow of the fluid, such as the material balance of chemical reaction, heat balance, ingredients, etc., all need to measure the mass flow of the fluid. Mass flow is the mass of a fluid flowing through a section of a closed pipe in a unit of time. The instruments used to measure mass flow are collectively called mass flowmeters.

2. Structure:

The mass flowmeter is composed of sensor, transmitter and digital indicator accumulator. The sensor consists of sensing tube, electromagnetic driver and electromagnetic detector. The electromagnetic driver makes the sensor vibrate with its natural frequency, and the introduction of the flow rate makes the u-shaped sensor produce a kind of distortion under the action, in its left and right sides to produce a phase difference, the phase difference is proportional to the mass flow rate. The electromagnetic monitor converts the phase difference into the corresponding level signal and sends it to the transmitter. Convert to 4-20ma analog signals proportional to the mass and a range of frequency signals in two forms of output.

Iii. Application:

Zw-cmf series liquid mass flowmeter is mainly used to measure the mass flow rate and the total volume, density, at the same time, it can also measure the volume flow rate and the total volume, medium temperature, moisture content, alcohol alcohol, mixed more uniform two liquid concentration, raw material ratio in the process flow. It is mainly applicable to the following industries:

1. Oil industry, such as crude oil output measurement, water cut measurement, single well output measurement and crude oil transportation measurement;

2. Chemical industry;

3. Food industry;

4, paper industry, such as pulp measurement;

5. Textile printing and dyeing industry;

6, energy transmission measurement, such as liquefied gas measurement;

7. Environmental protection industry, such as sewage treatment; The slurry density was measured during desulfurization.

Iv. Main features:

1. Directly measure the mass flow of the fluid in the pipe:

High measurement accuracy, good repeatability, can be in a large range, direct measurement of fluid mass flow; The measurement accuracy is high. The mass flow measurement accuracy of the flowmeter is 0.2 grade.

2. Stable and reliable work:

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

3. Suitable width of the fluid medium:

In addition to the general viscosity of the uniform fluid, but also measured high viscosity fluid (honey, oil slurry, etc.); It can measure not only the fluid parameters of a single solution, but also the multiphase flow. It does not affect the measurement accuracy whether the medium is laminar or turbulent.

4. Wide application environment:

It is widely used in petrochemical, chemical, metallurgy, pharmaceutical, papermaking, food, energy and environmental protection industries.

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

In addition to mass flow, the density and temperature of the fluid can also be directly measured. Intelligent flow transmitter, can provide a variety of parameters display and control functions, is a set of multi-function as one of the flow measurement and control instrument;

6. Good scalability:

The company can specially design and manufacture quality flow meters with special specifications, models and functions according to the needs of customers. Also can carry on the remote monitoring operation and so on.

V. technical parameters:

1. Accuracy: [0.2% + (zero stability/instantaneous mass flow 100%);

2. Repeatability: (1/2) [0.2% + (zero stability/instantaneous mass flow 100%);

3. Density range: 0.2g /cm3 ~ 3.5g/cm3;

4. Density accuracy: 0.002g/cm3;

5, temperature range: 60 ℃ ~ + 200 ℃;

6, temperature accuracy: + / - 1 ℃;

7. Current output: 4mA ~ 20mA;

8. Frequency output: 0Hz ~ 10kHz;

9. Contact capacity of batch control relay: 24V/ 0.1a;

10. Contact form of batch control relay: normally open (user's instruction when ordering, can be changed to normally closed);

11, fluid temperature: - 40 ℃ ~ + 200 ℃;

: 12, working environment temperature 0 ℃ ~ + 40 ℃.

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

14. Atmospheric pressure: 86kPa ~ 106kPa;

15. Power supply requirements of the transmitter: AC (220 10%) V or (50 5%) Hz of the intrinsically safe power supply voltage, and 24 10%) V of the composite power supply voltage;

Power: < 15W.

Vi. Main functions:

1. Measurement function

It can directly measure the instantaneous mass flow rate of the liquid medium, the total cumulative mass flow rate, the total volume flow rate, the total volume volume, the temperature, the density, the concentration of the two-component liquid and so on. Can display, output, store and remote transmission; Modify the flow meter parameters.

2. Current output

With current signal output function, the current output is 4mA ~ 20mA, which can meet the control requirements of industrial instruments.

3. Frequency output

With frequency signal output function, the frequency output is 0KHz ~ 10KHz, which can meet the control requirements of industrial instruments.

4. Batch control

Volume control relay contact capacity: 24V/ 0.1a, the contact form is normally open (when the user orders, can be changed to normally closed), this function can meet the flow volume control of industrial equipment.

5. Communication function

This product has the data communication function, may pass the RS-485 communication, completes the data communication with the computer, may realize the computer network control.

6. Safe and explosion-proof

The company's mass flowmeter has been double explosion certificate.

Vii. Installation requirements

Mass flow meter is a high-precision measuring instrument. In order to ensure the accuracy of measurement, environmental requirements for installation shall be ensured:

1. The sensor (primary table) and transmitter (secondary table) shall not be installed in the area with strong magnetic interference, otherwise it will affect the circuit signal, thus affecting the measurement accuracy;

2. There shall be no other vibration interference in the pipeline installed by the sensor (primary table);

3, for the need to be installed in the outdoor situation, pay attention to the zui high and low ambient temperature, zui should consider wind and rain protection measures, avoid wind and rain, in order to improve the working life of the flow meter;

4. The ampere type flow meter transmitter (secondary meter) should be installed in a safe area or an appropriate control room;

5. The sensor of the ampere type flow meter (primary meter) and the transmitter (secondary meter) are connected by a 10-core shielded cable;

Viii. Installation method and precautions

1. Installation of horizontal pipeline

With the main body facing down, measure the liquid, and the outlet must be more than 0.8 meters high;

2, the main upside down

Self-emptying, measure the slurry containing solids, and the outlet must be more than 0.8 meters above the zui high point of the flow meter;

3. Flag installation (test mounting)

Self emptying, measuring of liquid or slurry, liquid must flow from bottom to top.

Ix. Fault treatment of flow meter:

In general, there will be no failure, it does not matter if there is a failure, careful analysis of the cause can make the problem solved, such as the working condition has not changed, there is no air, is not just check back to use and so on, the following briefly introduce several kinds of fault and treatment:

1. Hardware failure:

If the error is too large, the display of the integrator is not bright or value-added, the display is blank, etc., the reasons are as follows:

A. Improper installation can directly lead to zero drift of the flow meter. For example, the mass flow meter is installed near the pump outlet, the support strength of the sensor is not enough, the connection flange is welded improperly to generate stress signal, and the cable is subjected to electromagnetic interference.

B. Connection problem

If the display is not bright, should check the integrator power line, if the fuse is burned, should confirm the input voltage and standard voltage nominal value, ac and dc form is consistent. If the integrator does not increase with the flow, you should check the connection of the integrator, if the integrator is equipped with a positive/reverse program, you should check the flow meter connection, because the flow meter connection is not correct, will make the integrator in the reverse flow does not increase.