Fission plug-in electromagnetic flowmeter

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Fission plug-in electromagnetic flowmeter using the constant current low-frequency rectangular wave …

Products overview:
ZW - LDEC seriesFission plug-in electromagnetic flowmeterAdopting the new technology.Points are electromagnetic flowmeter is composed of sensors and switches, sensors installed on the measuring pipe, converter is installed within 100 meters of within 30 meters away from the sensor or occasions, between the shielded cable connection, used to measure the conductive liquid volume flow.Is in the pipeline on the basis of electromagnetic flowmeter developed a kind of new type of fluid flow meter.It on the basis of retain the advantages of pipeline electromagnetic flowmeter, electromagnetic flowmeter for pipeline to install on a great difficulty and cost big defects, such as using electromagnetic method by measuring the average flow velocity of the fluid, the volume of fluid flow is achieved.

Second, the working principle:
ZW - LDEC seriesFission plug-in 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.

Applications:
ZW - LDEC seriesFission plug-in electromagnetic flowmeter is mainly used to measure volume flow of conducting liquid and slurry in the closed pipeline.Especially suitable for medium and large diameter pipeline in the liquid liquid measurement, is widely used in petrochemical, steel, metallurgy, water supply and drainage, irrigation, water treatment, environmental protection sewage total amount control, paper making, medicine, food and other industrial and agricultural departments of flow measurement and control of production process.

Four, the main components:
Electromagnetic flowmeter is composed of sensors and switches, sensors installed on the measuring pipe, the converter can be connected to the sensor combination together referred to as electromagnetic flowmeter, a size converter is installed within 100 meters of within 30 meters away from the sensor or occasions, are connected by a shielded cable is called separation between type electromagnetic flow meter.Corrosion is the main component of the electromagnetic flowmeter sensor: the measuring tube, electrode, excitation coil, magnetic yoke iron core and shell.
Five, the main features:
1, the layout is easy, no moving parts, long service life;
2, small volume, light weight, convenient to install, small amount of maintenance.
3, a cut-off valve fission plug-in can be installed, the electromagnetic flowmeter realizes does not block the disassembly, easy maintenance, hone;
4, measurement is not affected by piping material under test;
5, unnecessary lining, unnecessary grounding ring.
Six, the technical parameters:
1, the precision instrument: pipeline 0.5 on the Richter scale;Plug in 1.5 on the Richter scale;
2, measuring medium: conductivity is greater than 5 mu S/cm of various liquid and liquid-solid two phase flow;
3, velocity range: 0.2 ~ 8 m/s;
4, work pressure: 1.6 MPa;
5, environmental temperature: - 40 ℃ ~ + 50 ℃;
6, medium temperature: ptfe lining 180 ℃ or less.
7, rubber lining, 65 ℃ or less;
8, explosion-proof marks: Exmibd Ⅱ BT4;
9, explosion-proof number: GYB01349;
10 and outside magnetic interference: 400 a/m or less;
11, the output signal: 4 ~ 20 ma DC, 0 ~ 750 Ω load resistance;
12, communication output: RS485 or CAN bus;
13, electrical connections: M20 x 1.5 internal thread, phi 10 cable hole;
14, power supply voltage: 90 ~ 220 v AC, 24 V.D C + / - 10%;
15, z big power consumption: 10 or less va.

Seven, installation requirements:
1, the choice of the installation environment:
A, should as far as possible away from strong electromagnetic field devices, such as big motor, transformer, etc.
B, the installation place should not have a strong vibration, pipe fixation.The environment temperature should be changed.
C, installation environment should be easy to install and maintain.
2, installation location choice:
A, always with the current position must ensure that the pipe body.
B, and the choice of fluid flow pulse small place.That should be far away from the pumps and valves, elbow and other local resistance.
C, measuring dual phase (solid, liquid or gas, liquid) fluid, should choose the place is not easy to cause phase separation.
D, should avoid to appear negative pressure at site.
E, easy be side pipe diameter or circumference measurements, and ovality should be smaller.
3, straight pipe length:
Sensors installed pipe straight pipe upstream side length should be greater than or equal to 10 d, downstream should be not less than 5 d.D for pipe size to be tested.
4, flow control valve and regulating valve:
Flow control valves should be installed in the sensor on the upstream side of pipe to be tested, flow control valves should be installed downstream of the sensor in side.Measurement, usually flow control valves should be in the fully open position.
5, installation pedestal welding requirements are as follows:
A, the axis of the install base 63 pipe with pipe axis perpendicular to be tested.The Angle is 90 °
B, using electrode welding.Guarantee after welding flange end face parallel to the pipe axis, weld a solid, can withstand the pressure 1.6 Mpa no leakage phenomenon.
C, measured pipe hole size and install the base hole diameter.
6, installation method:
A, vertical installation: sensors should be inserted into the pipe and pipe section vertical diameter less than 5 ° Angle, suitable for measuring the pipeline vibration small cleaning medium.
B, tilted installation: its the axis of the sensor and the axis of the pipeline under test Angle 45 °, is fit for measuring the medium or big diameter and other impurity is contained in the liquid flow measurement, small resistance of the installation of water, should not be bound to hang.
C, plug-in electromagnetic flow sensor insertion point there are two ways: one is inserted into the pipe to be tested on the central axis, the second is inserted into the pipe wall for the pipe of 0.25 D.
7, the installation of sensors:
A, clean up the measured pipe installation pedestal welding slag and burr.
B, turn off the upstream flow control valves or low pressure water supply.
C, will be installed (ball valve to the base.Pay attention to the the sky cavity up ball valve, check valve to fully open, fitted to press the compression screw, nut and rubber seal installed onto the ball valve.Loosen the nut.Insert the sensor rod through the ball valve is inserted into the pipe to be tested, at the same time should pay attention to the sensor direction pointing to the antenna should work in harmony with the direction of flow.
Eight, troubleshooting:
Due to all kinds of faults in the operation of flowmeter in can cause measurement is allowed to occur, generally in the electromagnetic flow meter of faults in the operation probably can be divided into two classes.Kind of fault for flow meter itself, component damage caused by fault;The change caused by the fault for external conditions, such as: the output flow instability, countless times, large error and so on.Here are some simple troubleshooting way:
A, the instability of the output: 1. The unstable flow field;2. Through the sensor of the gas in the liquid, solid block;3. The electrical connection in the empty pick up;4. Bad earth;5. The electrode leakage solution: 1. The transformation pipeline, or increase the false sensor installation;2. Normal phenomenon;3. Check the wiring, then good line;4. Good earthed;5. Repair sensors.
B, no liquid output: 1. Between the converter and signal transmission cable conductor by the two;2. Power did not pick up or poor contact;3. The sensor instrument piping, shell, end face has a leakage.Solution: 1. The thread;2. Connect the power supply, for maintain good contact;3. Repair sensors.
C, liquid flows have not output: 1. Between the converter and signal transmission cable connection circuit;2. Signal cable to the electrode connection circuit;3. The electrode surface contamination or sedimentary insulating layer;4. Bad earth or open circuit.The solution: 1. Connect the cable for;2. Open the sensor, in again;3. Wash electrode surface;4. Good earthed.
Too much d, error: 1. The zero point is too high;2. Not completely filled with liquid.3. Power supply distortion is too large;4. Bad earth.The solution: 1. To adjust the zero point;2. Improve the conditions of pipeline, sensor is always full of liquid.(3) improve the power supply condition, conform to the normal working conditions;4. Good earthed.

Nine, installation considerations:
1, the 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, to prevent the 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.Plug-in 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.

Ten, the 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;
Heavy traffic, z z 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, zui low velocity should not be less than 0.2 m/s, zui high 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.

3, reference flow range:

4, selection of code:

Eleven, 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.