1. Special installation requirements for electromagnetic flow meters
Strictly follow the installation requirements of the electromagnetic flowmeter and install the intelligent electromagnetic flowmeter on the top of the vaporizer as much as possible. Extending the front straight pipe section of the flowmeter is a good way to solve the pulsation caused by the operation of the coal slurry booster pump.
2. Special processing of electromagnetic flow meters
Measure the flange interface size of the electromagnetic flowmeter using professional measuring tools, calculate and design it, and process it into a protective erosion and wear sleeve for the interface flange using special materials such as 316 manganese complex alloy. The chamber of the electromagnetic flowmeter is coated with silicon carbide (which has a protective effect against electromagnetic interference) to prevent erosion and wear. The induction electrode of the electromagnetic flowmeter is coated with tungsten carbide protective erosion and wear film.
3. Suggestions for the use of electromagnetic flow meters
1) It is strictly prohibited to power on the electromagnetic flowmeter during the single machine test phase. First, take measures to protect the coal slurry circulation pipeline from wear and tear, and use coal water slurry to remove rust on the inner wall of the coal slurry pipeline. Otherwise, rust will be adsorbed near the electrode by the magnetic field on the inner wall of the electromagnetic sensor, causing polarization voltage interference on the electrode and causing fluctuations in the flowmeter. After the vaporization furnace is shut down, power off the electromagnetic flowmeter and clean the pipeline to avoid the magnetic field formed by the excitation inside the electromagnetic flowmeter sensor from causing the rust adsorbed near the electrode to not be washed away.
2) During normal operation, sudden fluctuations in the electromagnetic flow meter may cause interference as follows:
a. Possible fluctuation caused by the pump
There is an abnormality in one of the diaphragm working chambers of the coal slurry pump, and the change in flow rate may not be significant, but the flow field changes greatly, causing pulsation and increasing fluctuation. Timely observe whether the monitoring pressure gauge of each diaphragm working chamber of the coal slurry pump is balanced.
b. Possible fluctuation caused by coal slurry
The increase in the amount of metal particles in coal slurry accumulates near the electrode, causing polarization voltage interference to the electrode and causing fluctuations in the flow meter. Timely stop, dismantle, or flush the flow meter.
c. The output signal of the electromagnetic flowmeter suddenly experiences instantaneous pulse interference
If the instantaneous pulse interference caused by the friction of large metal particles or bubbles in coal slurry and the collision with electrodes occurs frequently, the quality of coal slurry should be checked. The sensor lining of the electromagnetic flowmeter is limited by its temperature resistance and cannot be used to flush the coal slurry pipeline with steam.
d. Parameter tuning of electromagnetic flow meters
When the electromagnetic flow meter sensor cannot be installed and used under better installation conditions, the damping time of the flow meter itself can be adjusted. Especially after the electromagnetic flow meter is used for a long time with high pressure flushing, the structure of the measuring equipment has undergone certain changes due to severe flushing. In order to better use the measurement accuracy, an angle grinder is needed to shape the silicon carbide protective film on the inner lining, especially the tungsten carbide protective film on the induction electrode. However, it is important to remember that after shaping the protective film, the parameters of the electromagnetic flow meter must be calibrated and adjusted through measurement calibration in order to accurately operate the electromagnetic flow meter and better leverage its inherent advantages and specialties in the coal water slurry industry.
Post time: 21-12-23