Common faults and maintenance methods of vortex flowmeter

1) It is widely known that vortex flowmeters are not suitable for installation in places with strong vibrations. However, in places where the magnetic field changes frequently, the vortex flow sensor will measure a signal output higher than the normal value. Practice has proved that in a site without gas flow, when the vortex flow sensor is in a changing magnetic field, at the moment of magnetic field change, the vortex flow sensor will sense an error signal and output it. When the change ends and the instrument is in a stable magnetic field, the instrument will output a normal signal.

2) Coke oven gas has high temperature and high humidity when it leaves the factory, so there will be moisture in the gas transportation process. The gas flow drives the water to fluctuate back and forth, thus forming a pulsating flow. When the vortex flow sensor is in this fluid state, the output data fluctuates, and it cannot reflect the production status at all.

3) Because coke oven gas has many impurities and is easy to crystallize, the impurities condense on the sensor head, resulting in inaccurate measurement. When the temperature rises, the impurities volatilize, the sensitivity increases, and the signal is enhanced; on the contrary, it decreases. This causes unstable data.

4) The wire pressure is not solid during the instrument wiring process, resulting in intermittent signals during the transmission process.

5) The instrument grounding wire does not meet the specification requirements, so that the 50Hz interference in the strong current enters. When the normal signal is higher than 50Hz, a normal signal is output, otherwise an error signal will be output.

Solution:

1) During the installation and connection of the instrument, every link should be ensured to be accurate, including the site inspection before installation, instrument wiring during installation, system grounding wire, etc., so as to ensure that the real data is detected and can be accurately output.

2) For the metering system in operation, the "dual-track metering control engineering network copyright, comparison confirmation" method and the "substitution method" can be used to confirm and eliminate the faults of the metering instrument in operation.

3) Regularly clean the instrument as a whole, and if necessary, purge the sensor head of the instrument to avoid condensation of impurities at the sensor head. In cold seasons, adding a heating device to the metering straight pipe section and the instrument part is also beneficial to alleviate the condensation of impurities at the metering instrument.

4) Regularly drain the pipeline, especially the water in front of the straight pipe section. According to the specific situation, assign a dedicated person to regularly drain the water, reduce the water in the metering pipe section as much as possible, and eliminate the pulsation in the fluid to the maximum extent.

5) Strengthen the management of the vortex flowmeter metering system data, set up a timed printing function, and analyze the operation of the instrument based on the printed data combined with the production status.