1Selection of electromagnetic flowmetersummary:
MS-LD seriesElectromagnetic FlowmeterThe measurement principle is Faraday's law of electromagnetic induction, and the main components of the sensor are: measuring tube, electrode, excitation coil, iron core, and magnetic yoke housing. It is mainly used to measure the volumetric flow rate of conductive liquids and slurries in closed pipelines. Including highly corrosive liquids such as acids, alkalis, salts, etc. This product is widely used in industries such as petroleum, chemical, metallurgical, textile, food, pharmaceutical, papermaking, as well as in fields such as environmental protection, municipal management, and water conservancy construction. The MS-LD series electromagnetic flowmeter is a fully intelligent electromagnetic flowmeter developed using the most advanced technology at home and abroad. Its all Chinese electromagnetic converter core adopts a high-speed central processing unit. The calculation speed is very fast, the accuracy is high, and the measurement performance is reliable. The converter circuit design adopts international advanced technology, with an input impedance of up to 1015 ohms, a common mode rejection ratio of better than 100db, and a suppression ability of better than 90db for external interference and 60Hz/50Hz interference. It can measure fluid medium flow rates with lower conductivity. The sensor adopts non-uniform magnetic field technology and a special magnetic circuit structure, which makes the magnetic field stable and reliable, and greatly reduces the volume, reduces repetition, and makes the flowmeter small and flow oriented. Our company's mission is to provide customers with peace of mind when buying, worry free when using, and satisfactory service.
IISelection of electromagnetic flowmeterProduct features:
There are no movable parts or flow blocking components inside the pipeline, and there is almost no additional pressure loss during measurement.
The measurement results are independent of physical parameters such as flow velocity distribution, fluid pressure, temperature, density, viscosity, etc.
▲ The range can be modified online according to the actual needs of the user on site.
▲ High definition backlit LCD display, fully Chinese menu operation, easy to use, simple to operate, easy to learn and understand.
▲ Adopting SMD devices and surface mount technology (SMT circuits have high reliability).
Adopting a 16 bit embedded microprocessor, it has fast computing speed, high accuracy, programmable low-frequency rectangular wave excitation, improved stability of flow measurement, and low power consumption.
▲ All digital processing, strong anti-interference ability, reliable measurement, high accuracy, flow measurement range can reach 150:1
▲ Ultra low EMI switching power supply, with a wide range of power supply voltage changes and good EMC resistance
▲ There are three integrators inside that can display the forward cumulative amount and the difference cumulative amount respectively. There is also a non power down clock inside that can record 16 power down times
▲ It has digital communication signal outputs such as RS485, RS232, Hart, and Modbus.
IIIWorking principle of electromagnetic flowmeter
MS-LD seriesElectromagnetic FlowmeterThe measurement principle is based on Faraday's law of electromagnetic induction. The measuring tube of the flowmeter is a non-magnetic alloy short tube lined with insulating material. Two electrodes are fixed on the measuring tube by passing through the tube wall along the diameter direction. The electrode tip is basically flush with the inner surface of the lining. When the excitation coil is excited by two pulse waves, a working magnetic field with a magnetic flux density of B will be generated in the direction perpendicular to the axis of the measuring tube. At this point, if a fluid with a certain conductivity flows through the measuring tube. Induce an electromotive force E by cutting the magnetic field lines. The electromotive force E is proportional to the magnetic flux density B. Measure the product of the inner diameter d of the tube and the average flow velocity v. The electromotive force E (flow signal) is detected by the electrode and sent to the converter through a cable. After amplifying and processing the flow signal, the converter can display the fluid flow rate and output signals such as pulses and analog currents for flow control and regulation.
E=KBdv
In the formula: E - -------------- is the signal voltage between the electrodes (v)
B - ----------------- Magnetic flux density (T)
D --------------------------------------------------------------------------
V ---------------- Average flow velocity (m/s)
In the equation, k and d are constants. Since the excitation current is constant, B is also constant. Therefore, from E=KBdv, it can be seen that the volume flow rate Q is proportional to the signal voltage E -, that is, the signal voltage E induced by the flow velocity is linearly related to the volume Q. Therefore, as long as E is measured, the flow rate Q can be determined, which is the basic working principle of electromagnetic flow meters.
According to E=KBdv, parameters such as temperature, density, pressure, conductivity, and liquid-solid composition ratio of the measured flow medium will not affect the measurement results. As for the flow state, as long as it conforms to axisymmetric flow (such as laminar or turbulent flow), it will not affect the measurement results. Therefore, electromagnetic flowmeter is a true volumetric flowmeter. For manufacturers and users, the volumetric flow rate of any other conductive fluid medium can be measured without any correction as long as it is calibrated with ordinary water. This is a prominent advantage of electromagnetic flow meters, which is not found in any other flow meter. There are no active or obstructed components inside the measuring tube, so there is almost no pressure loss and high reliability.
MS | -LD electromagnetic flowmeter related parameter table: |
Execution standards
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JB/T 9248—1999
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Nominal Diameter
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15. 20, 25, 32, 40, 50, 65, 80, 100, 125, 150, 200, 250, 300, 350, 400, 450, 500, 600, 700, 800, 900, 1000, 1200, 1400, 1600, 1800, 2000, 2200, 2400, 2600, 2800, 3000
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Maximum flow velocity
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15m/s
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accuracy
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DNl5~DN600
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Indication: ± 0.3% (flow rate ≥ 1m/s); ± 3mm/s (flow rate<1m/s)
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DN700—DN3000
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± 0.5% of the indicated value (flow rate ≥ 0.8m/S); ± 4mm/s (flow rate<0.8m/S)
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Fluid conductivity
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≥5uS/cm
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Nominal pressure of flowmeter
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4.0MPa
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1.6MPa
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1.0MPa
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0.6MPa
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6.3、10MPa
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DNl5~DN150
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DNl5~DN600
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DN200~DN1000
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DN700~DN3000
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Special Orders
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ambient temperature
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sensor
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-25 ℃ -+60 ℃
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Converter and integrated model
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-10 ℃ -+60 ℃
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Lining material
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Polytetrafluoroethylene, chloroprene rubber, polyurethane, perfluoroalkoxy (F46), mesh PFA
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Maximum fluid temperature
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- Body type
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70℃
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separated
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Polychloroprene rubber lining
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80℃; 120 ℃ (specify when ordering)
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Polyurethane lining
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80℃
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PTFE lining
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100℃; 150 ℃ (specify when ordering)
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Perfluoroethylene propylene (F46)
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Mesh PFA
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Signal electrode and ground electrode materials
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Stainless steel 0Crl8Nil2M02Ti, Hastelloy C, Hastelloy B, titanium, tantalum, platinum/iridium alloy, stainless steel coated with tungsten carbide
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Electrode scraper mechanism
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DN300—DN3000
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Connecting flange material
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carbon steel
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Grounding flange material
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Stainless steel 1Cr18Ni9Ti
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Imported protective flange materials
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DN65—DNl50
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Stainless steel 1Cr18Ni9Ti
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DN200~DNl600
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Carbon steel and stainless steel 1Cr18Ni9Ti
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Shell protection
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DNl5~DN3000 separable rubber or polyurethane lined sensor
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IP65 or IP68
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Other sensors, body type flow meters, and separate converters
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IP65
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Distance (separated type)
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The distance between the converter and the sensor is generally not more than 100m
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Selection of electromagnetic flowmeterSelection of lining
Flow meter lining material
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Performance
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Maximum medium temperature
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scope of application
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- Body type
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separated
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Polytetrafluoroethylene (F4)
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It is the most chemically stable plastic, capable of withstanding boiling hydrochloric acid, sulfuric acid, nitric acid, and aqua regia, as well as concentrated alkali and various organic solvents. Not resistant to corrosion from chlorine trifluoride, high-temperature chlorine trifluoride, high flow rate liquid fluorine, liquid oxygen, and auto oxygen.
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70℃
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100 ℃ 150 ℃ (special order required)
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1. Strong corrosive media such as concentrated acid and alkali. 2. Sanitary media.
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Perfluoroethylene propylene (F46)
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Same as F4, its wear resistance and negative pressure resistance are higher than F4.
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ditto
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Polyfluoroethylene (Fs)
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The upper limit of applicable temperature is lower than that of polytetrafluoroethylene, but the cost is also lower.
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80℃
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neoprene
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1. Has excellent elasticity, high tensile strength, and good wear resistance. 2. Resistant to corrosion in general low concentration acid, alkali, and salt media, but not resistant to corrosion in oxidizing media.
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80 ℃ 120 ℃ (special order required)
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Water, sewage, and weakly abrasive slurry.
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polyurethane
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1. Extremely strong wear resistance.
2. Poor corrosion resistance.
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80℃
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Neutral strong abrasion slurry, coal slurry, mud
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Selection of electromagnetic flowmeterSelection of electrodes
Electrode material
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Corrosion resistance and wear resistance
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Stainless steel 0Crl8Nil2M02Ti
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Used for weakly corrosive media such as industrial water, domestic water, sewage, etc., suitable for industrial sectors such as petroleum, chemical, steel, as well as municipal and environmental protection fields.
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Hastelloy B
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It has good corrosion resistance to all concentrations of hydrochloric acid below boiling point, as well as to non chlorinated acids, bases, and non oxidizing salt solutions such as sulfuric acid, phosphoric acid, hydrofluoric acid, and organic acids.
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Hastelloy C
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Can withstand corrosion from non oxidizing acids such as nitric acid, mixed acids, or mixed media of chromic acid and sulfuric acid, as well as corrosion from oxidizing salts such as Fe, Cu, or other oxidants such as hypochlorite solutions above room temperature and seawater
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titanium
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Capable of withstanding corrosion from seawater, various chlorides and hypochlorites, oxidizing acids (including fuming sulfuric acid), organic acids, and alkalis. Not resistant to the corrosion of relatively pure reducing acids (such as sulfuric acid, hydrochloric acid), but if the acid contains oxidants (such as nitric acid, Fc++, Cu++), the corrosion is greatly reduced.
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tantalum
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It has excellent corrosion resistance and is very similar to glass. Except for hydrofluoric acid, fuming sulfuric acid, and alkali, it can almost withstand corrosion from cutting chemical media (including boiling point hydrochloric acid, nitric acid, and sulfuric acid below 50 ℃). Dig in alkali; Corrosion resistance.
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Platinum/titanium alloy
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Almost capable of cutting chemical media, but not suitable for aqua regia and ammonium salts.
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Stainless steel coated with tungsten carbide
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Used for non corrosive and highly abrasive media.
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Note: Due to the wide variety of media and the complex factors such as temperature, concentration, and flow rate that affect their corrosiveness, this table is for reference only. Users should make their own choices based on the actual situation, and if necessary, conduct corrosion resistance tests on the selected materials, such as hanging plate tests.
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MS-LD series electromagnetic flowmeter instrument selection:
◆ Range confirmation
The flow rate of the medium measured by the general industrial electromagnetic flowmeter should be 2-4m/s. In special circumstances, the minimum flow rate should not be less than 0.2m/s and the maximum should not be greater than 8m/s. If the medium contains solid particles, the commonly used flow rate should be less than 3m/s to prevent excessive friction between the lining and the electrode; For viscous fluids, the flow velocity can be chosen to be greater than 2m/s. A higher flow velocity helps to automatically eliminate the effect of viscous substances attached to the electrode, which is beneficial for improving measurement accuracy.
Under the condition that the range Q has been determined, the size of the flowmeter diameter D can be determined based on the range of flow velocity V mentioned above, and its value can be calculated by the following formula:
Q=πD2V/4
Q: Flow rate (㎡/h) D: Inner diameter of pipeline V: Flow rate (m/h)
Electromagnetic FlowmeterThe range Q of the flow meter should be greater than the expected maximum flow value, and the normal flow value should be slightly greater than 50 of the full scale of the flow meter.
MS-LD seriesSelection of electromagnetic flowmeterReference flow range
Caliber mm
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Flow range m3/h
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Caliber mm
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Flow range m3/h
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φ15
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0.06~6.36
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φ450
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57.23~5722.65
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φ20
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0.11~11.3
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φ500
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70.65~7065.00
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φ25
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0.18~17.66
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φ600
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101.74~10173.6
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φ40
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0.45~45.22
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φ700
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138.47~13847.4
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φ50
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0.71~70.65
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φ800
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180.86~18086.4
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φ65
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1.19~119.4
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φ900
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228.91~22890.6
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φ80
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1.81~180.86
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φ1000
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406.94~40694.4
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φ100
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2.83~282.60
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φ1200
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553.90~55389.6
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φ150
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6.36~635.85
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φ1600
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723.46~72345.6
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φ200
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11.3~1130.4
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φ1800
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915.62~91562.4
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φ250
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17.66~176.25.
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φ2000
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1130.4~113040.00
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φ300
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25.43~2543.40
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φ2200
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1367.78~136778.4
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φ350
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34.62~3461.85
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φ2400
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1627.78~162777.6
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φ400
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45.22~4521.6
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φ2600
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1910.38~191037.6
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Selection of MS-LDE series electromagnetic flowmeter
model
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caliber
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MS-LD
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15~2600
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code
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Installation form
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Y
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Integrated
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F
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split type
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code
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Converter model
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ZA
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rotundity
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ZB
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square
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code
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output signal
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I.4
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4~20mA
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f
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Frequency 1KHz
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Rs
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Serial communication (485)
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C
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control output
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Code name
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Explosion proof requirements
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N
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No explosion-proof
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EX
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Explosion proof (only applicable to split type)
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code
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medium temperature
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T1
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≤65℃
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T2
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≤120℃
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T3
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≤ 180 ℃ (only applicable to split type)
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code
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Lining material
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NE
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Chloroprene rubber (≤ 65 ℃)
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PTFE
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Polytetrafluoroethylene (≤ 189 ℃)
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PVC
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Polyvinyl chloride (≤ 70 ℃)
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code
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Electrode material
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316L
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stainless steel
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HC
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Hastelloy C
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HB
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Hastelloy B
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Ti
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titanium
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Ta
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tantalum
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