In addition to the correct instrument selection and installation according to the user’s given process parameters, and the installation meets the specified requirements, on-site adjustment is also a key issue.
1.On-site installation is completed and the inspection before power-on and current flow
(1) There should be no leakage in the flanges, valves, pressure measuring holes, temperature measuring holes and joints on the main pipeline and the bypass pipeline; (2) The vibration of the pipeline should comply with the specifications; (3) The installation of the sensor should be correct, and the electrical connection of each part should be good.
2. Power on static debugging
The flow totalizer should have no output when the power is not flowing, the instantaneous flow indication is zero, and the accumulated flow does not change. Otherwise, first, check whether the signal line is shielded or grounded poorly, or the pipeline vibration is strong and the interference signal is introduced. If it is confirmed that it is not for the above reason, you can adjust the potentiometer in the flow totalizer to reduce the amplifier gain or increase the trigger level of the shaping circuit until the output is zero.
3. Flow dynamic debugging
Close the bypass valve and open the upstream and downstream valves. After the flow is stable, the flow totalizer will output continuous pulses with uniform pulse width. The flow indicator is stable without jumps. Adjust the valve opening and the output will change accordingly. Otherwise, you should carefully check and adjust the potentiometer until the meter output is neither falsely triggered nor missing pulses.
4. The influence of the sharp edge wear of the vortex generator
The two edges of the front flow surface of the vortex flowmeter vortex generator are sharp under normal conditions, but if the measured fluid contains solids, the sharp edges are easily worn and become arcs, although the flow coefficient K The sharpness of the edge is not as sensitive as the orifice flowmeter, due to changes in geometry and size, the bleed air flow coefficient will also change. The impact of the blunt edge of the vortex generator on the flow coefficient was tested, and it was found that the flow coefficient of the vortex flowmeter increased with the increase of the sharp edge radius r under the same arc radius. The relationship between the radius of the sharp-edged arc and the flow coefficient is shown in Figure 2-17
Choosing a material with good resistance to buildup is a positive way to improve wear. Once wear is found, the flow coefficient of the meter should be re-calibrated, when the wear is serious and the flow coefficient changes too much. Should consider replacing the generating body.