Causes of Vortex Flowmeter Instability in Coke Oven Gas Measurement

Vortex flowmeter measures the causes and solutions of coke oven gas instability HHWJ series digital intelligent vortex flowmeter, it breaks through the limits of traditional analog processing vortex signal, through the modern method of processing of the digital signal to identify and filter the signal from the vortex probe, so as to obtain the normal flow signal, which greatly improves The anti-seismic performance of the vortex street has basically solved the problem that the vortex street has not been anti-seismic for decades. It is widely used in water, salt and wind flow in petrochemical, light industry, thermal power, papermaking and other industries. Vortex flowmeters are still widely used in the measurement of coke oven gases, but there are also some issues. Let\'s talk about the causes and solutions of these problems: The reasons for the failure of the system ofon-site counting can be summarized in two major reasons. Control Engineering All rights reserved, one is caused by the flow encountered or its associated equipment. The second is reasons unrelated to the flow meter, that is, the flow meter is normal, but environmental or system reasons cause failures, and these reasons are difficult to find. In addition to requiring technicians to be familiar with the performance of the instrument, they must also have extensive knowledge and rich field experience for analysis, reasoning and multi-party testing before they can be confirmed. Some outages are caused by unexpected events. For instrument failures other than flow, the output signal is often unstable. According to practical experience, when the vortex flowmeter measures the coke oven gas, the reasons for the unstable output signal are as follows:

1) The flowmBeing vortex is not suitable for installation in places subject to strong vibrations. It is well known, but in the case of frequent changes in the magnetic field, the vortex flux sensor will measure an output signal higher than the normal value. Practice has proved that in a scene without gasflow, when the vortex flux sensor is in a changing magnetic field, the moment the magnetic field changes, the vortex flux sensor will induce an error signal and output it. When the change is completed, the instrument is in a stable magnetic field, the meter will output a normal signal.

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

3) Since coke oven gas contains many impurities, it is easy to crystallize, and the impurities condense on the sensor head, resulting in inaccurate measurement. When the temperature increases, the impurity volatilizes, the sensitivity increases and the signal increases; on the contrary, it decreases. Therefore, the data is unstable.

4) In the process of wiring the instrument, the pressure line is not strong, which causes the signal intermittent during the transmission process .

5) The ground wire of the instrument does not meet the requirements of the specification, so that the 50Hz interference in the strong current enters. When the normal signal is over 50Hz, the normal signal is output, otherwise it will output an error signal.

Solution:

1) When installing and connecting the instrument, make sure that each Accuracy of alink includes site inspection before installation, instrument wiring during installation, system grounding wire, etc., to ensure that the actual data can be detected and output precisely.

2) For the measurement system in operation, the method of \"copyright, comparison and confirmation of the dual-way measurement control engineering network\" and the \"surrogate method\" can be used to confirm and eliminate faults in the measuring instrument during operation.

3) Regularly clean the whole instrument and, if necessary, purge the sensing head of the instrument to avoid the condensation of impurities at the level of the sensing head. During the cold season, adding a heater to the measuring straight pipe section and the instrument part is also beneficial to alleviate the condensation of impurities at the measuring instrument.

4) Drain the pipe regularly, especially the water before the straight section of the pipe. According to the specific situation, install a special person to discharge it regularly, reduce the water in the section of the metering pipe as much as possible, and eliminate the pulsation in the fluid as much as possible.

5) Strengthen the data management of the measurement system, set the synchronization printing function, and analyze the operation of the instrument according to the printing data combined with the production status .

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