Split type electromagnetic flowmeter

Split type electromagnetic flowmeter

Overview

The measurement principle of the split electromagnetic flowmeter is based on Faraday's law of electromagnetic induction. The split electromagnetic flowmeter is composed of a sensor and a converter. The sensor is installed on the measurement pipe, and the converter is installed within 30 meters or 100 meters away from the sensor. The two are connected by shielded cables. The main components of the split electromagnetic flowmeter sensor are: measuring tube, electrode, excitation coil, iron core and yoke shell. It is mainly used to measure the volume flow of conductive liquid and slurry in closed pipelines. Such as water, sewage, mud, pulp, all kinds of acid, alkali, salt solution, food slurry, etc., are widely used in petroleum, chemical industry, metallurgy, textile, food, pharmaceutical, papermaking and other industries, as well as environmental protection, municipal management, water conservancy construction and other fields to measure the environment with high temperature, high humidity and inconvenient observation.

II. Product features:
1. Applicable to conductivity greater than 5 ц Volume flow measurement of s/cm conductive fluid
2. There are no moving and blocking parts in the measuring pipe, and the pressure loss is small
3. Linings and electrodes made of different materials have good corrosion resistance
4. It is not affected by medium, density, viscosity, temperature, pressure and conductivity
5. Low frequency rectangular wave excitation, not easy to be disturbed, stable and reliable
6. The converter has low energy consumption, simple and convenient installation, and users do not need to debug

Technical parameters:
Accuracy grade: ± 0.5%, ± 1%
Lining material: polyurethane, neoprene, PTFE, etc
Electrode material: stainless steel, Hastelloy, titanium, platinum iridium alloy, etc
Connection mode: flange clamping, flange connection, etc
Medium temperature: 0 ℃ ~ 70 ℃, 0 ℃ ~ 130 ℃ (0 ℃ ~ 180 ℃)
Nominal pressure: 1.0MPa ~ 32 MPa
Protection grade: IP65, IP68
Explosion proof sign: exibbt4
Working voltage: 220VAC, 24VDC
Installation conditions
Upstream straight pipe section >10 × DN
Downstream straight pipe section >5 × DN
Dn= nominal diameter of sensor

Precautions for installation of split electromagnetic flowmeter
The sensor of the split electromagnetic flowmeter shall be installed vertically, and the fluid shall flow from bottom to top to meet the mixing state of solid and liquid. The reason is that if there are solids (sediment, small gravel particles, etc.) in the medium, it is easy to precipitate. In addition, if there are fish and weeds in the pipeline, the fish swimming in the pipeline will cause the output of the flowmeter to swing back and forth; The back and forth swing of weeds hanging near the electrode will also cause the output of the flowmeter to be unstable. A metal filter screen is set at the upstream inlet of the flowmeter to prevent fish and weeds from entering the measuring pipe.
The improper operation of the pipeline setting of the split electromagnetic flowmeter to prevent negative pressure will cause negative pressure in the sensor. When the upstream and downstream valves of the flowmeter are closed at the same time, if the temperature of the fluid is higher than the air temperature, it will shrink after cooling, so that the pressure in the pipe is in danger of forming negative pressure. Negative pressure causes the lining to peel off from the metal conduit, causing electrode leakage.
Add a negative pressure prevention valve near the split electromagnetic flowmeter, open the valve and connect the atmospheric pressure to prevent negative pressure in the sensor. When a vertical pipe is connected downstream of the split electromagnetic flowmeter, if the upstream valve of the flow sensor is used to close or adjust the flow, a negative pressure will be formed in the measuring pipe of the sensor. In order to prevent negative pressure, it is necessary to add back pressure or use the downstream valve to adjust and close the flow.
Split electromagnetic flowmeter has appropriate maintenance space. Large diameter flowmeter is often installed in the instrument well. For the convenience of pipeline installation, wiring, inspection and maintenance, appropriate space needs to be reserved. For the convenience of observation, wiring and maintenance, the instrument shall be installed at a certain height from the ground to facilitate cleaning and installation.