SQLDEThe intelligent electromagnetic flowmeter is a fully intelligent electromagnetic flowmeter developed by our company using the most advanced technology at home and abroad. Its all-Chinese electromagnetic converter core uses a high-speed central processor. The calculation speed is very fast, the accuracy is high, and the measurement performance is reliable. The converter circuit design adopts internationally advanced technology, and the input impedance is as high as10¹⁵Ohms, the common mode rejection ratio is better than100db, for external interference and60Hz/50HzInterference suppression capability is better than90db,It can measure the flow rate of fluid media with lower conductivity. Its sensor adopts non-uniform magnetic field technology and special magnetic circuit structure. The magnetic field is stable and reliable, and it greatly reduces the volume, reduces duplication, and makes the flow meter small and flow-oriented. Our company's purpose is to make customers "buy with confidence, use without worry, and provide satisfactory service".

Features:

▲There are no moving parts or flow-blocking parts in the pipeline, and there is almost no additional pressure loss during measurement.

▲The measurement results are independent of flow velocity distribution, fluid pressure, temperature, density, viscosity and other physical parameters.

▲The measuring range can be modified online on site according to the actual needs of the user.

▲High definition backlightLCDDisplay, full Chinese menu operation, easy to use, simple to operate, easy to learn and understand.

▲AdoptionSMDDevices and Surface Mount (SMTThe circuit reliability is high.

▲Adoption16The embedded microprocessor has fast operation speed, high precision, programmable frequency, low-frequency rectangular wave excitation, improved flow measurement stability and low power consumption.

▲Fully digital processing, strong anti-interference ability, reliable measurement, high accuracy, flow measurement range up to150:1

▲Ultra lowISwitching power supply, using a wide range of power supply voltage changes,EMCgood

▲There are three internal totalizers that can display the positive cumulative amount and the difference cumulative amount respectively. There is a non-power-off clock inside to record16Power-off time

▲WithRS485、RS232、HartandModbusAnd other digital communication signal output.

▲With self-checking and self-analysis functions

1  Overview

How it works

The measuring principle of the current meter is based on Faraday's law of electromagnetic induction. The measuring tube of the flow meter is a short tube of non-magnetic alloy lined with insulating material. Two electrodes are fixed on the measuring tube through the tube wall along the tube diameter. The electrode heads are basically flush with the inner surface of the lining. When the excitation coil is excited by a double-wave pulse, a magnetic flux density ofBAt this time, if a fluid with a certain conductivity flows through the measuring tube, the magnetic lines of force will be cut to induce an electromotive force.AND. Electromotive forceANDProportional to the magnetic flux densityB, measuring tube inner diameterdWith average flow ratevThe product of.AND(Flow signal) is detected by the electrode and sent to the converter through the cable. After the converter amplifies the flow signal, it can display the fluid flow rate and output pulses, analog current and other signals for flow control and regulation.

E=KBdv

Where:AND---------------is the signal voltage between electrodes (v） 

    B-----------------Magnetic flux density (T）

      d------------------Measuring tube inner diameter (m）

   v-----------------Average flow rate (m/s）

In the formulak, dis a constant. Since the excitation current is a constant current,Bis also a constant, thenE= KBdvIt can be seen that the volume flow rateQWith signal voltageAND-Proportional to the signal voltage of flow velocity sensingANDWith volumeQTherefore, as long as the measuredANDTo determine the flowQ, this is the basic working principle of electromagnetic flowmeter.

Depend onE=KBdvIt can be seen that the parameters such as the temperature, density, pressure, conductivity, and liquid-solid ratio of the measured flow medium will not affect the measurement results. As for the flow state, as long as it conforms to the axisymmetric flow (such as laminar flow or turbulent flow), it will not affect the measurement results. Therefore, the electromagnetic flowmeter is a real volume flowmeter. For manufacturers and users, as long as it is calibrated with ordinary water, the volume flow of any other conductive fluid medium can be measured without any correction. This is a prominent advantage of the electromagnetic flowmeter, which is not available in any other flowmeter. There are no moving and flow-blocking parts in the measuring tube, so there is almost no pressure loss and it has high reliability.

Application Areas

Because electromagnetic flowmeters have their unique advantages, they are widely used in chemical fiber, food, papermaking, sugar making, mining, water supply and drainage, environmental protection, etc.It is used in industrial fields such as water conservancy, steel, petroleum, and pharmaceuticals to measure the volume flow of conductive liquid media such as various acids, alkalis, salt solutions, mud, ore pulp, paper pulp, coal-water slurry, corn slurry, fiber slurry, grain slurry, lime milk, sewage, cooling raw water, water supply and drainage, brine, hydrogen peroxide, beer, wort, various beverages, black liquor, green liquor, etc.

2 Main technical parameters

Common medium conductivity table

3. Electromagnetic flowmeter selection code
HXLDE- - - - - -

        Diameter      Conversion Type    Electrode Materials    Lining material      pressure   Upper limit flowm3/h

（am） 1, one1,Stainless steel1,rubber0.6         

2, split2, Hastelloy2, Polyethylene1.0

3,titanium3, polytetrafluoroethylene1.6

4、Tantalum Ethylene4.0

Example:HXLDE-80-233-1.6-80

Description: Wuxi Hengxin intelligent electromagnetic flowmeter,DN80, split type, titanium electrode, polytetrafluoroethyleneSecondOlefin liner, pressure rated1.6MPa, upper limit flow rate 80m3/h.
If customers have other requirements, please specify them in detail when placing an order, such as communication, shell material, meter body, flange, material, whether there is a grounding ring, power supply method220VAC or 24VDC, etc.

4. Electromagnetic flowmeter selection instructions
   Correctly selecting the electromagnetic flowmeter is a prerequisite for ensuring good use of the electromagnetic flowmeter. The type of electromagnetic flowmeter to be selected should be determined based on the physical and chemical properties of the fluid being measured, so that the electromagnetic flowmeter's diameter, flow range, lining material, electrode material and output current can adapt to the properties and flow requirements of the fluid being measured.

Measurable fluids

   From the working principle of electromagnetic flowmeter, we know that the fluid that can be used to measure the flow rate of electromagnetic flowmeter must be conductive. Strictly speaking, except for high temperature fluid, as long as the conductivity is greater than5m/cmAny fluid should use the corresponding electromagnetic flowmeter to measure the flow rate, so non-conductive gas, steam, oil, acetone and other substances cannot use electromagnetic flowmeter to measure the flow rate.

Determination of sensor caliber

The flow meter is best used at a flow rate ofIn the range of 0.3-15m/s, the flow meter diameter can be selected to be consistent with the user's pipeline diameter.
Use flow rate lower thanWhen the flow rate is 0.3m/s, it is best to increase the flow rate locally at the instrument and use the tube reduction method:

★ The center cone angle of the reducer is not greater than 15^theC, the reducer can be regarded as part of the straight pipe section.

Choice of integrated or separate type

Integrated type: When the on-site environment is good, the integrated type is generally selected, that is, the sensor and converter are assembled into one.
Separate type: the sensor and converter are installed separately in different locations. Generally, the separate type is selected when the following situations occur.

⑴ The ambient temperature or the radiation temperature of the flowmeter converter surface exceeds 60^theC.
⑵ Occasions where pipeline vibration is large.
⑶ Situations that will cause severe corrosion to the aluminum shell of the sensor.
⑷ Where the site temperature is high or there is corrosive gas.
⑸ The flow meter is installed at high altitude or in places where it is inconvenient to debug downward.

When ordering, please specify the separation distance of the sensor converter, which should generally not exceed100m, the converter is wall mounted.

Selection of electrode and grounding ring materials

The material of the electrode should be selected according to the corrosiveness of the fluid being measured. Please check the relevant corrosion manual and conduct tests for special fluids.

Lining material selection instructions
The lining material should be selected according to the corrosiveness, abrasiveness and temperature of the measured medium.

Flow range selection

The maximum and minimum flow rates must comply with the numbers in the table below.

Selection of installation site
In order to ensure reliable and stable operation of the transmission line, the following requirements should be noted when selecting the installation site:

⑴Try to avoid ferromagnetic objects and equipment with strong electromagnetic fields (such as large motors, large transformers, etc.) to prevent the magnetic field from affecting the working magnetic field and flow signal of the sensor.
⑵It should be installed in a dry and ventilated place as much as possible, and should not be installed in a humid place or place prone to water accumulation.
⑶ Avoid exposure to sunlight and rain as much as possible, and avoid ambient temperatures above 60°C and relative humidity above 95%.
⑷ Choose a place that is easy for maintenance and convenient for activities.
⑸ The flow meter should be installed at the rear end of the water pump and never on the suction side; the valve should be installed on the downstream side of the flow.

Installation Requirements
In order to measure correctly, you should pay attention to the following requirements when choosing the position on the pipeline:
⑴The sensor can be installed on a straight pipe, or on a horizontal or inclined pipe, but the center line of the two electrodes must be in a horizontal state.
⑵The medium should flow through the pipe at the installation location to avoid the pipe being full and the gasThe body is attached to the electrode.
⑶ For liquid-solid two-phase fluid, it is best to adopt vertical installation to ensure uniform wear of the sensor lining and extend its service life.
⑷ When the medium does not fill the pipe at the flow meter installation location, you can take the method of raising the flow half of the rear end pipeline to make it full. It is strictly forbidden to install the flow meter at the highest point of the pipeline and the outlet. (See figure)
⑸Modify the installation method of the pipeline:
When the medium flow rate does not meet the requirements, a flow meter with a smaller diameter should be selected. At this time, a different-diameter cone tube should be used or part of the pipeline should be modified to make it the same diameter as the sensor. However, the front and rear straight pipe sections must at least meet the following requirements:≥5DN,Rear straight pipe ≥2DN(DNFor pipe diameter)
⑹The straight pipe section before and after is before the flow meter ≥5DN, backend ≥2DN

Flow meter wiring

▲If the signal cable is connected by split installation, a customized special cable should be used. The shorter the cable, the better.

▲Excitation cable is optionalYzMedium rubber sheathed cable, same length as signal cable

▲Signal cables must be strictly separated from other power sources. They cannot be laid in the same pipe, cannot be laid equally, and cannot be twisted together. They should be put in a steel pipe separately.

▲The signal cable and excitation cable should be as short as possible. Do not roll up the excess cables. Cut off the excess cables and re-weld the joints.

▲When the cable enters the sensor electrical interface, it is made at the portINThis prevents rain from penetrating into the sensor.