Electromagnetic Flow Meter from China in Low Price
1. Introduction
The MLF electromagnetic flow meter is based on Faraday's law of
electromagnetic induction and consists of sensors and converters.
Used to measure the conductivity of a liquid or solid. In general,
its conductivity should be greater than 5μs/cm (tap water, raw
water conductivity of about 100 to 500μs/cm), can also be used to
measure acids, alkali, brine, pulp or pulp and other media.
However, these media must not contain large amounts of magnetic
substances and bubbles.
MLF electromagnetic flow meter is an instrument for measuring
liquid flow. Widely used in metallurgy, chemical, paper,
environmental protection, petroleum, textiles, food, urban
management, water plants and other industries flow metering.
2.Working Principle
The principle of the sensor is based on Faraday’s law of
electromagnetic induction.
It is installed a pair of detection electrodes on the pipe
wall,where the measurement pipe axis and magnetic field lines are
vertical. When the conductive liquid cuts magnetic field lines and
produces induced electromagnetic force.Which can be measured by the
two electrodes on the
meter pipe.The result can be calculated by formula: Induced
electromotive force,(flow signal)E=KBDV
E——Induced electromotive force,V；
K——meter constant；
B——Magnetic flux density,T；
D——Internal diameter of measuring pipe,m；
V——Average velocity of pipe section,m/s.
1MLF Series Electromagnetic Flow Meter
Assume the volume of liquid as qv(m3/s),qv=πD2V/4),so in the
formula E=(4kB/πD)qv=kqv,
K is meter constant,K=4kB/πD.
Actually, the electromagnetic flow meter consists of two parts,
transmitter and sensor, the measuring electrodes inspect the
electromotive force, and transmit to the converter, the converter
provides excitation current.
E is usually called a flow signal, after processing the flow signal
by converter, output 4~20 mA/pulse(or frequency) signal which is
proportional to the flow rate, then the flow rate recording,
adjusting can be achieved.
3. Features
- MLF electromagnetic flowmeter is explosion-proof design.
- The function of low conductivity measurement.
- There are 9 language options to meet the needs of different
customers.
- There are self-regulating functions and self-checking.
- Different outputs are optional: Hart, RS485,Profibus, 4-20mA,
frequency, pulse.
4. Selection of Liner Material
| Liner Material | Main Performance | Application |
| PTFE | 1 It has the most stable chemical properties in plastics, resistant
to boiling hydrogen chloride and sulfuric acid, nitric acid, aqua
regia, strong alkali and various organic solvents, but not
resistant to chlorine trifluoride, high temperature nitrogen
trifluoride, liquid fluorine, and liquid oxygen And ozone
corrosion. 2 Low wear resistance. 3 Low negative pressure resistance. | 1. -25~140℃ 2. Strong corrosion medium, like strong acid and alkali 3. Healthcare medium |
| CR | Oil proof, solvent resistance, oxidatite resistance and the
resistance to the erosion of common medium like acid, alkali, salt,
etc. | 1. ＜80℃ 2. Be able to measure sewage and mud |
| PU | 1. Very good abrasive resistance, flexibility. 2. Low acid and alkali resistance. | 1. ＜65℃ 2. Neutral strong abrasion resistance medium |
| Hard Rubber | 1 Resistance to room temperature, hydrochloric acid, acetic acid,
oxalic acid, ammonia, phosphoric acid and 50% sulfuric acid, sodium
hydroxide and potassium hydroxide 2 Avoid strong oxidants | 1. ＜80℃ 2. General acid, alkali, salt solution |
| PFA | 1. Can be used for most corrosive medium like acides, alkalis, and
strong oxidant. 2. High material strength, resistance to aging, better than PTFE,
EFP in high temperature 3. Injection molding for higher negative pressure | 1. 40~180℃ 2. Strong corrosion medium, like strong acid and alkali 3. Healthcare mdium |
| FEP(F46) | 1. Hydrophobicity and non-viscous 2. Corrosion resistance is inferior to PFA 3. Negative pressure | 1. 40~180℃ 2. Strong corrosion medium, like strong acid and alkali 3. Healthcare mdium |
5. Selection of Electrode Materials
| Electrode Material | Main Performance |
| 316L | Good corrosion resistance to nitric acid, less than 5% corrosion of
sulfuric acid, acetic acid, alkaline liquid, sulfite, seawater and
acetic acid under certain pressure at room temperature, and can be
widely used in petrochemical urea, vinylon and so on |
| Hb | Good resistance to all concentrations below boiling point of
hydrochloric acid, but also resistant to non-oxidizing acids,
alkalis, sulphuric acid, phosphoric acid, hydrofluoric acid,
organic acid corrosion. |
| Hc | Corrosion resistance to oxidizing acids, such as nitric acid, mixed
acids. A mixture of chromic acid and sulphuric acid, oxidizing
salts, such as Fe3 plus, Q3 plus, and other oxidants, such as a
mixture of hyalphate solutions and seawater above normal
temperatures. |
| Ti | Resistant to corrosion of seawater, various chlorides,
hypochlorite, oxidizing acids (including fuming nitric acid),
organic acids or bases, but not pure reductive acids (e.g.,
sulfuric acid, hydrochloric acid) etc. but if the acid contains
oxidants (such as nitric acid, Fe3,Q3), the corrosion resistance
will decrease. |
| Ta | Good corrosion resistance similar to glass. Resistance to the
corrosion of chemical medium(including hydrochloric acid and
fumiing sulfuric acid), but can not be used for sodium hydromide
fluid. |
| Pt-Ir | Have good corrosion resistance of all acid, and can be resistance
to the corrosion of alkali, all salt except aqua regia, ammonium
slat and few other medium |
| Tungsten Carbide | For pulp and sewage, good resistance to solid particle
interference. |
6. Dimensional Sketches
a. Dimension of Converter
Divided Type
Integrated Type
Battery Powered Type
b. Dimension of Sensor
| Pipeline Diameter | Dimension |
| L | W | H |
| 15 | 160 | 95 | 130 |
| 20 | 160 | 105 | 137 |
| 25 | 160 | 115 | 150 |
| 32 | 160 | 135 | 160 |
| 40 | 200 | 145 | 175 |
| 50 | 200 | 160 | 185 |
| 65 | 200 | 180 | 205 |
| 80 | 200 | 195 | 215 |
| 100 | 250 | 215 | 235 |
| 125 | 250 | 245 | 275 |
| 150 | 300 | 280 | 300 |
| 200 | 350 | 335 | 355 |
| 250 | 400 | 400 | 405 |
| 300 | 500 | 455 | 460 |
| 350 | 500 | 515 | 520 |
| 400 | 600 | 575 | 580 |
| 450 | 600 | 635 | 630 |
| 500 | 600 | 710 | 685 |
| 600 | 600 | 835 | 795 |
| 700 | 700 | 905 | 910 |
| 800 | 800 | 1020 | 1030 |
| 900 | 900 | 1120 | 1120 |
| 1000 | 1000 | 1245 | 1250 |
| 1200 | 1200 | 1465 | 1470 |
