Vortex flowmeter analysis and solution
3. Reasons for parameter setting direction. The instrument is incorrectly indicated due to a parameter error. The parameter error makes the secondary meter full frequency calculation error, and the reason for this is mainly related to questions 1 and 3. The full-scale frequency is similar, indicating that the long-term inaccuracy is indicated. The full-scale frequency of the actual full-scale frequency and large-dry calculation indicates that the range is fluctuating and cannot be read. The inconsistency of the parameters on the data affects the final determination of the parameters, and finally passes. Recalibration combined with mutual comparison to determine the parameters solves this problem.
4. The secondary instrument is faulty. There are many faults in this part, including: when the instrument board is disconnected, the range setting has individual bit display bad, and the K coefficient setting has individual bit display bad, which makes it impossible to determine the range setting and K factor setting. Part of the reason is mainly related to questions 1, 2. The problem is solved by fixing the corresponding fault.
5, Four-way line connection problem. On the surface of some circuits, the line connection is very good. Check carefully. Some connectors are actually loose and the circuit is interrupted. Some connectors are tightly connected, but the fastening screws are fastened to the wire due to the secondary line problem. Interruption, this part of the reason is mainly related to question.
Third, the spiral vortex flowmeter measurement characteristics
The spiral vortex flowmeter is a flowmeter that began to appear in the 1970s. Its working principle is: the gas that enters the gas swirling vortex flowmeter is first forced by the spiral spinner to accelerate the rotation to form a vortex, the center of the vortex. For the vortex core. The accelerated vortex enters the enlarged section and then decelerates sharply. The pressure rises to produce a recirculation. Under the action of the recirculation, the vortex core makes a spiral precession around the axis of the flowmeter. The flow rate Q can be derived by measuring the vortex precession frequency f by sensing the sensitive component.
Fourth, gas turbine flowmeter and spiral vortex flowmeter measurement difference
The gas turbine flowmeter has a small pressure loss and can be suitable for gas metering in low pressure conveying applications. Gas-injected vortex flowmeters have a slightly higher pressure loss, and gas metering in low-pressure delivery situations sometimes has problems.
Gas turbine flowmeters require high media cleanliness and can be damaged if used improperly. The gas swirling vortex flowmeter gas swirling vortex flowmeter requires no gas turbine flowmeter and is not damaged.
Gas turbine flowmeters are highly accurate. It is the most accurate of all flow meters. The gas spiraling vortex flowmeter is not as accurate as the former.
Installation of plug-in electromagnetic flowmeter
The plug-in electromagnetic flowmeter sensor installation upstream straight pipe section is not less than 5D (D means pipe diameter), the downstream straight pipe section is not less than 2D:
1. Vertical installation. When the sensor is inserted into the pipeline, it should be less than 5° from the vertical diameter of the pipeline section. It is suitable for measuring the cleaning medium with small vibration of the pipeline.
2, inclined installation, the axis of the sensor and the axis of the pipe to be tested is 45 °, suitable for large pipe diameter and measuring the flow of liquid containing other impurities in the medium, the installation method is small, not suitable for entanglement.
There are two ways to insert the insertion point of the electromagnetic flowmeter sensor: one is inserted into the central axis of the pipe to be tested (ie 1/2 times the diameter of the pipe); the other is inserted into the inner wall of the pipe at 1/4 of the pipe.
Sensor installation:
1. Clean the welding slag and burrs of the base of the pipe to be tested.
2. Turn off the upstream flow control valve or use low pressure water supply.
3. Install the DN50 ball valve on the mounting base. Pay attention to the long cavity of the ball valve. Check whether the ball valve can be fully open and fully closed. Install the screw seat, compression nut and rubber sealing ring onto the ball valve and loosen the positioning nut. Insert the sensor into the rod through the ball valve and insert it into the pipe to be tested. At the same time, it should be noted that the direction of the sensor direction indicator rod should be consistent with the flow direction of the fluid. Ordering Information Please specify the name of the tested medium, working pressure, medium temperature, flow rate (flow rate) range, pipe diameter and the pipe network to be tested.