Choice of protection level
The protection level of the electromagnetic flowmeter should be selected according to the actual situation. If the sensor is required to be installed below the ground and is often flooded, IP68 should be selected. If the sensor is installed above the ground, IP65 and IP67 should be selected. In any case, the display area of ??the electromagnetic flowmeter cannot be used with water or enter the water, which may cause damage to the electromagnetic flowmeter. As a chemical company, the workshop produces high humidity, but IP65 (IP65 is a water-proof type. The electromagnetic flowmeter sensor housing allows the faucet to spray water from the sensor in any direction of the sensor of the electromagnetic flowmeter. The pressure of the water spray is 30Kpa, the water output It is 12.5L/S and the distance is 3 meters.) The electromagnetic flowmeter of the protection grade fully meets the requirements of on-site measurement.
Choice of connection method
Electromagnetic flowmeters have threaded connections, flanged connections, clamps, etc. In the chemical industry, flange-connected electromagnetic flowmeters are generally used. The selection must be consistent with the process-flange engineering pressure and standards.
Conclusion, with the maturity of the domestic instrument industry, chemical companies such as lithium carbonate, boric acid and potash will also enter the market in line with the domestic market. As an important industrial flow measuring instrument, electromagnetic flowmeter should play its role in DCS control. The right selection is especially important to provide accurate measurement data, reduce labor costs and increase production efficiency.
Main features of vortex flowmeter
Measuring medium: nominal diameter of liquid, gas and steam: DN15-DN300 (non-standard products can be customized according to user requirements) Temperature range: -40°C~350°C Pressure specification: PN1.6Mpa; PN2.5Mpa; PN4.0Mpa, Higher pressure specifications can be customized to a specific range: normal range 1:10 Extended range 1:15 Pressure loss factor: Cd ≤ 2.6 System measurement accuracy: liquid, gas indication ± 1%, steam indication ± 1.5% plug-in flow The measured value is ±2.5% of the supply voltage: sensor +12VDC, +24VDC (optional) transmitter +24VDC.
On-site display type The meter comes with 3.6 lithium battery output signal: sensor pulse frequency signal 0.1~3000Hz low level ≤1V high level ≥6V.
Transmitter two-wire 4~20mADC current signal for vibration acceleration: Piezoelectric ≤0.2g Ambient temperature: -40°C~55°C (non-explosion-proof place) -20°C~55°C (explosion-proof place) Ambient humidity: Relative Humidity 5~85% signal remote transmission distance: ≤500m signal line interface: internal thread M20×1.5 explosion-proof grade: iaIICT2-T5 protection grade: ordinary IP65 submersible IP68 instrument material: converter shell is made of aluminum alloy, the body part is adopted 1Cr18Ni9Ti can also be made of special materials according to user requirements.
Vortex flowmeter analysis and solution
6. The connection problem between the secondary instrument and the subsequent instrument. Due to the problem of the subsequent instrument or the maintenance of the subsequent instrument, the mA output circuit of the secondary instrument is interrupted. For this type of secondary instrument, this part is mainly related to the problem 2. Especially for the subsequent recorders, in the case that the recorder cannot be repaired for a long time, it is necessary to pay attention to shorting the output of the secondary meter.
7. The circuit always has no indication due to the failure of the secondary instrument flat-axle cable. Due to long-term operation, coupled with the influence of dust, the flat-axle cable is faulty, and the problem can be solved by cleaning or replacing the flat-axis cable.
8. For the problem 7, the main problem is that the secondary instrument shows that the fixing screw of the meter head is loose, causing the head to sink, the pointer and the case friction are large, the movement is not working, and the problem is solved by adjusting the meter head and re-fixing.
9. Use environmental issues. In particular, the sensor part installed in the well is affected by the humidity of the environment, which causes the circuit board to be damp. This part is mainly related to questions 2 and 2. Through the corresponding technical improvement measures, the sensor part with large humidity is re-separated from the probe part and the conversion part, and the separate type sensor is used. Therefore, the working environment is good, and the instrument has been running well.
10. Due to the poor adjustment of the site, or due to the actual situation after the adjustment. Due to the on-site vibration and noise balance adjustment and sensitivity adjustment is not good. Or because of the re-allocation of the situation after a period of operation after the adjustment, causing the indication problem, this part of the reason is mainly related to questions 4 and 5. Use an oscilloscope, plus the combined process operation, and re-adjust.