Hot:18702013-09-01 23:41:23 From: FTD Automation Instruments
Vortex flow meter applied in coke oven gas measurement
Some problems can appear when Vortex flow meters are used in the measurement of coke oven gas, let's analyze these problems and solution to fix these problems.
The reasons of Field measurement system problem can be divided into two factors; one is the flow meter and its associated equipment problem;
The second factor is from environment or system error, these kinds of reasons are hard to find.
Technical personnel in addition to be familiar with flow meters, wide knowledge and rich field experience to carry on the analysis, reasoning, various test are also required.
Some errors are still unexpected.
If the flow meter itself is in good condition, but the output signal is unstable,
According to the practical experience, output signal unstable reasons are the following when the vortex flow meters are measuring coke-oven gas.
1, vortex flow meters are not suitable to be installed in strong vibration situation, but in frequent-change magnetic field, vortex flow sensor can also be interfered, and the measured signal is higher than actual figures.
Practice has proved that when the vortex flow meter is in changing magnetic field, The vortex flow sensor will output a wrong signal, when the changing magnetic field is over, the vortex flow meter will return to normal condition.
2, coke oven gas contained water when it is from factory high temperature and high humidity procedure.
Gas together with the water reciprocating fluctuates, pulsating flow is generated.
Vortex flow sensor is in this fluid state, output data is changing a lot, and it cannot reflect the production status.
3, due to the coke oven gas impurities, easy crystallization, impurity condensation in sensing head; it can result in flow meter measuring error.
When the temperature raises, the impurity volatile, sensitivity increases, the signal enhancement;
Otherwise the signal sensitivity is lower; Which Resulting in data is not stable.
4, the improper flow meter wring can also lead to intermittently signals.
5, instrument grounding line is not in conformity with the specification requirements. When the high voltage 50 Hz interference in, if the normal signal is higher than 50Hz, the output signal is normal; otherwise, the output signal is wrong.
1, when installation flow meter, technicians should take on site investigation, wiring and earthling grounding should be right.
2,In measurement system, we can take double measurement and comparing to ensure the accuracy.
3, Vortex sensor should be cleaned regularly, when necessary, sensor part should be blowing to avoid impurity condensate in flow sensor.
In cold season, heating devices are needed in straight pipe section and instrument parts to avoid impurity condensation in the flow meter sensor.
4, regular pipeline drainage, especially front straight section is required to decrease pulsating fluid in the pipeline.
Edit by FTD Automation Instruments (www.ftdinstruments.com)