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Water flow meter selection of the vortex flowmeter

Jan 01, 2017

General  for the flowmeter selection we will first think of electromagnetic flowmeter and open channel flowmeter, but sometimes very pure medium  conductivity is low, or the installation site does not meet the  installation requirements of the open channel flow meter how to do it?  We have One option - the VNLUGB Worm Street Flowmeter.
The  vortex flowmeter has the advantages of simple structure, convenient  installation and maintenance, low pressure loss, wide measuring range,  long service life and stable performance. The instrument coefficient is  not affected by the temperature, pressure, viscosity and composition of  Reynolds number range The impact of change and other characteristics, has become more and more people of all ages.

For thevortex flowmeterselection must grasp the four selection  parameters, namely the pipe diameter; recent and long-term maximum,  minimum and common instantaneous flow; measured medium design pressure;  measured medium temperature.

1. Caliber selection

Vortex  flow sensor diameter is not necessarily the same diameter with the  process pipe, according to the flow rate, flow to a reasonable choice. Vortex  flowmeter diameter selection mainly to consider the lower limit of  flow, the general measurement of water velocity lower limit of 0.5m / s,  the normal flow is best in the measurement range of 1 / 2-2 / 3. Such as

2. Signal output selection

According  to the requirements of the acquisition signal to select a different  output form, when the need to accumulate flow can be selected pulse  output type, when you need to control can choose analog (4-20mADC)  output type. In general we will do 4-20mA signal output to the user.

3. Meter installation

Vortex water flowmeter should be installed in the insulation,  ventilation, easy to maintain the place, as far as possible away from  the vibration source and electromagnetic interference strong place where  the vibration must be the use of vibration reduction devices to reduce  the pipeline by vibration.

Vortex flowmeter in the pipeline can be horizontal, inclined or vertical installation. Installation location Be aware that liquid media must flow from the  bottom up when installed vertically: Temperature, pressure sensors, and  regulators should be installed downstream of the meter when a  temperature, pressure sensor, or flow control valve needs to be  installed on the pipe.

Vortex  flow meter must be long enough before and after the straight pipe, pipe  diameter must also be consistent with the vortex flow transmitter  internal diameter, and pipe connected to the inner diameter of the  gasket than the sensor diameter slightly larger, can not be projected  into the pipeline gasket Inside.

4. Parameter setting

Meter meter coefficient is calibrated under laboratory conditions, field use, the instrument coefficient should be amended.

5. Routine maintenance

In order to ensure the long-term work of the instrument accuracy,  reliability, to avoid accidental outage and data loss, in the flow meter  into operation after the need to strengthen the instrument itself and  the flow of all aspects of daily management and periodic maintenance.

6. Vortex Street Flowmeter limitations

Vortex  flowmeter is essentially a fluid vibration-type flowmeter, it is the  external vibration, fluid flow is particularly sensitive to the state. Pipeline  vibration, pipeline fluid impact force and due to changes in fluid  pressure, the resulting random pulse pressure and so on will have a  greater impact on the instrument measurement. Especially  in the small flow measurement, the smaller the lateral flow of small  lift, the detection signal is weak, vulnerable to shock and vibration of  fluid vibration and pipeline vibration noise.