High pressure type electromagnetic flowmeter

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High pressure type electromagnetic flow meter is composed of sensors and switches, sensors installed…

Products overview:

ZW - LDE seriesHigh pressure type electromagnetic flowmeterThe mud is mainly used in oil field measurement, zui high pressure for more than 40 mpa!Electromagnetic flowmeter most failures are due to not be carried out in accordance with the specification requirements, general as long as the small changes can deal with!Electromagnetic flow meter price is mainly related to the electrode selection and table body material, so the price difference is bigger.High-pressure electromagnetic flowmeter can measure the conductive liquid and requirements for the temperature of the liquid, not higher than 180 degrees. Commonly used to measure such as water, sewage, mud and lime in order to have the corrosion of liquid, such as oil and cannot measure the organic solution. Because of the electromagnetic flowmeter measurement precision, convenient operation, long service life and wide application of all. Measuring no corrosive liquid, the temperature is below 80 degrees, generally USES the rubber lining. For corrosive medium adopt F4 lining. Select the different lining for different medium and electrode, electromagnetic flowmeter can ensure the long-term stable job.

Second, the working principle:
ZW - LDE seriesType high voltage electromagnetic flowmeter based on Faraday electromagnetic induction principle, with the sounding pipe axis and the magnetic field lines in the vertical tube wall installed on a pair of detecting electrodes, when conducting liquid along the measuring tube axis movement, conductive liquid cutting lines of magnetic force induced electric potential, the induction electric potential by two detection electrodes detection, numerical size and flow into a direct ratio, its value is: E = KBVD type:
E - induction electric potential;
K - factor related to the magnetic field distribution and the axial length;
B - magnetic induction intensity;
V - conductive liquid average flow velocity;
D - electrode gap;(the measuring tube diameter)
Sensor will be induced potential E as traffic signal, sent to the converter, amplifying, transform filter with a series of digital processing, USES dot matrix LCD display with backlight instantaneous flow and cumulative flow.Converter has 4 ~ 20 ma output, alarm output and frequency output, and is equipped with RS - 485 communication interface, and supports HART and MODBUS protocol.

Three, the structure form:
1, the sensor:
Sensor is mainly composed of measuring tube and electrode, excitation coils, iron core, magnetic yoke and shell.
A, measuring catheter: by stainless steel tube, the lining and the connecting flange, as the carrier of measured liquid measurement working conditions on site.
B, measuring electrode: installed in the measuring tube inside wall, and the axial direction perpendicular to a pair of electrodes to measure liquid signal generation.
: c, excitation coil in a magnetic field measurement of intraductal two excitation coil.
D, iron core and magnetic yoke: the excitation coil of the magnetic field generated import liquid, and the magnetic circuit.
E, the shell body: instrument packaging.
2, converter that is smart the secondary table, it will flow signal amplification processing, single chip microcomputer after the operation, can display flow, total amount, and can output pulse and analog current signal, used in the measurement or control of fluid flow.
3, product assembly form: it into a shape and size in two forms.
A, a shape: mounted sensors and switches.
B, size: separation installation sensor and converter, through the connecting cable form flow metering system.
C, in order to adapt to the measurement demands of the different medium, the lining of sensor and electrode materials can have many choices.

Four, applications:

ZW - LDE seriesHigh pressure type electromagnetic flowmeter specially used for geology, oil exploration, oil field measurement system under the condition of high pressure slurry, water slurry, high pressure water injection and water pump experiment and conductive liquid or solid-liquid two phase medium.Type high voltage electromagnetic flowmeter in addition to the general conductive liquid flow can be measured, can also be measured liquid-solid two phase flow, high viscosity fluid and salt, strong acid, strong alkali liquid volume flow.

Five, the main features:
1, the measurement is not affected by fluid density, viscosity, temperature, pressure, and the influence of the conductivity changes.
2, sounding pipe unimpeded flow components, low pressure loss, straight pipe requirements.
3 May bring the grounding electrode, sensor, realize the instrument well grounded.
4, sensors, advanced processing technology, the instrument has a good ability to resist negative pressure.
5, converter adopts LCD backlit display, can make the reflection of sunlight or in a dark room reading easier.
6, installed on the pipe and the standard into the 90 ° rotating screen to improve the visibility of the shape meter.
7, through infrared touch button to set parameters, under the harsh environment don't open the converter cover plate can also be set securely.
8 and converter with self-diagnosis alarm output, empty load detection alarm output, flow on the lower limit alarm output, the traffic between value alarm output, and other functions.
9, not only can be used in the process of general testing, also applies to pulp, pulp and paste liquid measurement.
Six, the technical parameters:
1, the nominal diameter: DN25 ~ DN250mm;
2, nominal pressure: 6.3, 10, 16, 25, 32, 40, 70 mpa.
3, the accuracy of the essence: plus or minus 0.5% of value for optional value plus or minus 0.3% or + / - 0.2%;
4, lining: pu, F46;
5, electrode materials: molybdenum stainless steel, hartz titanium alloy, hartz alloy C, B;
6, the structure form: the size and shape;
7, medium temperature: - 10 ~ + 160 ℃;
8, ambient temperature: - 25 ℃ ~ + 60 ℃;
9 and the conductivity of medium: p 5 mu s/cm;
10, explosion-proof marks: Exmb Ⅱ T4;
11, connection mode: flange;Oil nonyl type.

Seven,Installation requirements:
The choice of installation environment
1, should as far as possible away from strong electromagnetic field equipment.Such as big motor, transformer, etc.
2, the installation place should not have a strong vibration, environmental temperature change is not big.
3, easy to install and maintenance.
The choice of the installation position
1, sensors, flow mark on the direction of the measured medium flow and the pipe must be consistent.
2, installation location must ensure that the measuring tube in the book is full of measured medium.
3, and the choice of fluid flow pulse smaller places, which should be far away from the pump and local resistance (valve, elbow, etc.)
4, the measurement of two-phase fluid, should choose is not easy to cause the location of the phase separation.
A negative pressure, avoid installed in a tube of five places.
6, when makes the electrode measured medium, measure the tube inner surface adhesion, scaling, suggest the measuring tube flow velocity of no less than 2 m/s.
At this time can use reducing pipe diameter slightly smaller than the process.For uninterrupted flow in the process piping cleaning electrode and the measuring tube, sensor can be used parallel installations, and cleaning.
The choice of the installation site 
In order to make the transmitter work stability, when choosing the location should be paid attention to the following requirements: 
1, try to avoid strong ferromagnetic objects and concrete equipment of electromagnetic field (such as a big motor, transformer, etc.), so as to avoid the magnetic field of magnetic field effect sensor and traffic information. 
2, should be installed in a dry and ventilated place, should not be in damp, easy seeper place of installation. 
3, should try to avoid weathered, avoid environmental temperature is higher than 45 ℃ and relative humidity is more than 95.9%. 
4, choose to facilitate maintenance and convenient place. 
5, flow meter should be installed in the pump back end, never on the suction side of the installation;Valve should be installed in the downstream flow meters.

Pay special attention to
1, sensors installed upstream of point relatively close if equipped with valve, switch valve and affect the service life of the sensor is great, very easy to cause * sexual damage to the sensor.
2, sensors to avoid the overhead of very long pipe installed on the sensor, so that over time, as the drop sensor is very easy to cause between the sensor and the flange seal leakage, if necessary when installation, must be set separately in the upstream and downstream of sensor 2 d pipe clamp device.
Eight, notable matters of installation:
1, the flow sensor should be installed vertically, and fluid flows from bottom to top, in order to meet the solid and liquid two is in a state of mixed.The reason is that if there is solid in the medium (sand, gravel particles, etc.) are prone to precipitation.Have fish and weeds in another line of fish swimming in the pipeline, will cause the flowmeter output swing;Hang back and forth near the electrode weeds can also cause the output of the meter is not stable.Set at the entrance of upstream flow meter metal screen blocking fish and weeds into the measuring tube.
2, flow meter to prevent negative pressure pipe set improper operation will cause negative pressure sensor inside.When closed, downstream of the valve in the flow meter at the same time, if the temperature is higher than the temperature of the fluid.Contraction after cooling, the pipe pressure is in danger of forming negative pressure.The negative pressure caused by the lining and metal vessel, cause leakage electrode.
3, near the flowmeter and negative pressure to prevent valve, open the valve on atmospheric pressure, in order to prevent to produce negative pressure in the sensor.Electromagnetic flowmeter downstream by a vertical line, if use flow upstream of the valve to close or adjust the flow sensor, the sensor will form a negative pressure measuring tube.In order to prevent negative pressure, need to add back pressure or use downstream to adjust and close the flow valve.
4, proper maintenance space, large diameter flowmeter are often installed in instrument well, for pipe installation, wiring, inspection and maintenance convenience, need to have the appropriate space.For observation, connection and maintenance convenience, instrument installation should have a certain height from ground, in order to facilitate cleaning, installation.

Nine, correct selection:
Choose what kind of electromagnetic flowmeter should be based on user's technological process, physical properties and chemical properties of the measured liquid medium, install and use the environment to determine the influence factors, such as, making the structure of the electromagnetic flowmeter, size, flow range, lining and electrode materials and the installation environment and other factors, such as the output signal to determine, which makes the structure of the electromagnetic flowmeter, size, flow range, lining and electrode materials and installation environment, to meet the requirements of measurement parameters such as output signals.For reasonable selection of flow meter, can be used according to specific situation from the following several aspects to consider.
1, the sensor diameter because of its influence and the flow velocity is an important consideration, in order to ensure that the medium velocity sensor measurement, often need to choose the larger or smaller than the connection pipes electromagnetic flowmeter, guidance for selecting the conventional velocity range is given in the table.
2, as the electromagnetic flowmeter, you first need to determine its size and measurement range, which determine the scope of the sensor measuring the flow velocity of fluid inside.Flow meter range range of choice to improve the reliability and precision of the flowmeter work has a lot to do, according to the principle of zui flow quantity is not lower than expected choose full range, the normal flow is generally not exceed 50% amount of full range that you can gain high accuracy of measurement.

Ten, the main technical data:

1, the whole machine and the technology of sensor data:

2, converter technology data:

3, the choice of the lining:

4, import protection flange and the choice of grounding flange ring (or ground) :

5, the choice of electrode:

11, correct selection:

Instrument selection is very important work in instrumentation, relevant data show that the instrument in two-thirds of faults in the practical application is instrument error caused by selection or wrong installation, please pay special attention to.

1, collect data:

By measurement of body composition;
Large flow, small flow;
Z high work pressure;
, z z high temperature low temperature;

2, range scope confirmation:

General industrial use measured medium velocity of electromagnetic flowmeter with 2 ~ 4 m/s advisable, under special circumstances, z low velocity should not be less than 0.2 m/s, high z should be not more than 8 m/s.If the medium containing solid particles, commonly used flow rate should be less than 3 m/s, prevent excessive friction lining and electrode;For viscous flow, the velocity can choose more than 2 m/s, larger velocity help eliminate electrode automatic on the effect of viscous material, to improve accuracy of measurement.

Under the condition of the range of Q have been identified, according to the velocity V can be decided to the size of the flow meter diameter D, the range of the values calculated by the next type:

Q = PI D2V / 4
Q: flow (㎡ / h) D: pipe diameter V: velocity (m/h)

Electromagnetic flow meter range of Q zui flow value should be greater than expected, the flow of the normal value in a full scale slightly greater than the flowmeter calibration 50 is advisable.

3And the reference flow range:

4, selection of code:

Twelve, design selection and ordering information:

1, the measured medium: name, composition, status, electrical conductivity and electrical conductivity;

2, working temperature (℃);

3, work pressure (Mpa);

4, the pipe diameter (DN), the smallest, normal, scope of quantity (m3 / h);

5, corrosion resistance, wear resistance, whether there is a negative pressure;

6, installation requirements and the environment: a body or fission, signal output, communications, power supply;

7, installation environment: protection grade and explosion-proof requirements.

After-sales service commitment:

1, from the date of signing of the contract, I in the way provided for products of the company offers free maintenance and maintenance service, commitment to lifelong maintenance service;

2, jiangsu wei measurement and control instrument co., LTD. Sales manager will be in regular contact with customers, understand the usage of products, and solve the problems of the customers to use in the process of produce, free of charge to provide technical support;

3 the man-made damage is found, the warranty period, our company is responsible for the maintenance, and the resulting maintenance fee;

4, product quality problems or are not satisfied with product, the user can choose unconditional return, wei tt&c don't charge any fees, appear quality problem, bear the freight back and forth.