The clamping type electromagnetic flowmeter

Products overview:
ZW - LDE/K seriesIs the domestic and foreign advanced technology development, the development of the intelligent flowmeter, and other manufacturers of traditional analog or non intelligent electromagnetic flowmeter has a very big difference, especially in the measurement precision, stability, reliability, use function and service life, etc.It is a kind of high performance, high reliability of electromagnetic flowmeter, adopted a new generation of special high quality lining technology, and using special mirror polishing PFA lining, especially suitable for measurement of viscosity pulp and gypsum slurry, the detachable electrode makes maintenance more convenient.
Second, the working principle:
ZW - LDE/K series clamping type 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 - LDE/K series clamping type electromagnetic flowmeter has a wide range of USES, in meet the field monitoring shows that at the same time can be output standard current signal (4-20 ma) in line with the HART communication protocol, for record, adjust, control;Can be widely used in chemical industry, environmental protection, textile, metallurgy, mining, pharmaceutical, paper making, feed, food, sugar, brewing and other industries in the process piping conductive medium liquid flow metering.
Four, 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.

Five, the main features:
1, the measurement is not affected by fluid density, viscosity, humidity, pressure, and the influence of the conductivity changes.
2, measuring pipe unimpeded moving parts, no pressure loss, low straight pipe requirements.
3, sensors, a new generation of use special high quality lining technology, and use the special mirror polishing PFA lining.
4, sensors, advanced processing technology, the instrument has a good ability to resist negative pressure.
5 with removable electrode, sensor, make the maintenance more convenient.
6, intelligent converter adopts LCD backlight LED display, even under strong light or night can clear reading.
7, intelligent converter can show the percentage volume flow at the same time, the instantaneous flow and cumulative flow measurement data.
8, installed on the pipe and standard into the 90 ° rotating screen to improve the shape meter or less visibility.
9, through infrared touch button to set parameters, under the harsh environment don't open the converter cover plate can also be set securely.
10 and converter with self-diagnosis alarm, empty load detection alarm, traffic flow on the lower limit alarm and poles value alarm output, and other functions.
Six, the technical parameters:
1, the nominal diameter: DN10 - DN200mm;
2, the accuracy of the essence: plus or minus 0.5% of value for optional value plus or minus 0.3% or + / - 0.2%;
Size: 3, medium temperature points - 10 ℃ ~ + 180 ℃;A body - 10 ℃ ~ + 80 ℃;
4, ambient temperature: - 25 ℃ ~ + 60 ℃;
5, medium conductivity: more than 20 mu s/cm;
6, line: in the PFA;
7, electrode materials: including molybdenum, hartz alloy stainless steel, titanium, tantalum, hartz alloy C B, platinum, iridium alloy;
8, electrode form: three electrode structure, two electrode structure, removable electrode structure;
Installation: the size and shape;
9, shell protection grade: sensor IP65, IP68 optional (IP65: dust tight, water proof, IP68: dust tight, can work under water for a long time).Converter IP67 (IP67: dust tight, can short time immersed);
10, explosion-proof marks: explosion-proof type sensor ExmIICT4, explosion-proof level for ExmdIIBT4.
Seven, flowmeter 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.

Eight, main advantages and disadvantages:

Main advantages are as follows:
1, the sensor structure is simple, the measuring tube has no moving parts, no obstacles to fluid flow throttling components.So when the fluid flow through timing does not cause any additional pressure loss, flow meter is running in one of the flowmeters zui low energy consumption.
2, measurable smudges medium, corrosive medium and clouding the liquid-solid two phase flow of traffic.This is due to internal unimpeded flow meter tube parts, and the measurement of body contact is sounding pipe lining and electrode, the materials can choose according to the nature of the current body.For example, made from poly three fluoride or ptfe lining, can measure all kinds of acid, alkali, salt and other corrosive medium.Adopt wear-resisting rubber lining, is especially suitable for measuring with solid particle slurry, water slurry, wear a large liquid-solid two phase flow and various liquid with fiber and pulp suspension.
3, is a kind of volume flow measuring instrument, in the process of measurement, it is not affected by the temperature of the measured medium, viscosity and density with conductivity (in a certain range.Therefore, electromagnetic flowmeter only after water calibration, it can used to measure the conductivity of liquid flow.
4, the output of the meter only is proportional to the average flow velocity of the measured medium, and under the symmetric distribution of flow state (laminar flow and turbulent flow).So the electromagnetic flowmeter range very wide range, the measurement range can be up to 100:1, some even up to 1000:1 working flow range.
5, no mechanical inertial electromagnetic flowmeter, responsive, can measure the instantaneous pulse flow, also can measure the rate of flow of positive and negative two directions.
6, industrial use very wide range of the calibre of the electromagnetic flowmeter, from a few millimeters to a few meters, and the domestic existing diameter up to 3 m's real flow calibration equipment, which laid a foundation for the application and development of electromagnetic flow meter.
Electromagnetic flowmeter is still the main deficiencies are as follows.
1, cannot be used for measuring gas, steam and liquid contains a lot of gas.
2, low cannot be used to measure the conductivity of liquid medium, such as the petroleum products or organic solvent such as medium, the electromagnetic flowmeter is powerless.
3, ordinary electromagnetic flow meter used in industry due to the measuring tube lined with the limitation of materials and electrical insulation materials, can not be used in measuring high temperature medium;If without special treatment, also cannot be used for the measurement of low temperature medium, in order to prevent the measuring tube condensation (frost) destruction of insulation.
4, the clamping type electromagnetic flowmeter is susceptible to the influence of the external electromagnetic interference.
Nine, installation considerations:
1, when moving and lifting sensor, should will sling set beside the sensor on both ends of the flange neck position, do not in the measurement, hoisting so as not to damage the lining tube inserted into the pipe to help.
2, before the installation, the sensor electrode with alcohol cotton in carefully erased due to causes such as hａnd touch the surface of the electrode material grease stain.
3, the inner diameter of the sealing washer when installation should be consistent with the sounding pipe lining inside.
4, must ensure that the terminal box is dry, otherwise the instrument measurement error may result.
The preparing work before ten, run:
1, put into operation after installation wiring should be checked again before the installation, wiring is correct.(the size)
2, before the bed bottom valve is opened, the sensor after the valve closed, let the sensor with the medium.
3, after the completion of the preparation, upstream of the valve to open the first sensor, then slowly open the downstream of the valve, observe the converter instantaneous flow display should be toward the direction of change, that signal lines in the right direction.Otherwise, will signal A and B connection swap position.(the size)
4, open the sensor before and after the valve, drainage for a few minutes, the gas discharge tube.
5, close the sensor downstream of the valve, then close upstream of the valve, the measured medium is inside the sensor.And then to form a complete set of adjustment.Sensor and converter matching coefficient of zero adjustment and instrument set converter specifications, please read them.

Eleven, packing details:
When users out of the box, according to the packing list, please check the sensor model, specifications and product code, and check whether there is any defect on the sensor.
Systematic include:
1, a set of stainless steel flowmeter;
Type 2, signal cable RVVP PVC insulation shielding sheath line 2 x 32/0.2 5 meters (body supporting);
3, excitation RVVP type PVC insulated cable shielding sheathed line 2 x 32/0.2 5 meters (body supporting);
4, the file using the 1;
5, installation instructions 1;
June 1, product certification;
7, product packing list 1, etc.

12, 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:

13, 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 z 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:

14, selection of coding:

15, 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.