Precession Vortex Flowmeter
Author:vacorda Source:www.vacorda.com Date: 2020-06-22 10:59:00
The precession vortex flowmeter is a new type of gas flow meter with advanced micro-processing technology, which has the advantages of strong function, wide flow range, simple operation and maintenance, easy installation and use, and the main technical indicators reach the advanced level of similar foreign products.
The main purpose
The precession vortex flowmeter is widely used in petroleum, chemical, electric power, metallurgy, urban gas supply and other industries to measure various gas flows. It is currently the first choice for oil field and urban natural gas transmission and distribution measurement and trade measurement.
1. No mechanical moving parts, corrosion-resistant, stable and reliable, long life, no special maintenance required for long-term operation;
2. Mechatronics has been realized, and the daily measurement process does not require manual duty;
3. The process installation conditions are not harsh, and the straight pipe sections upstream and downstream of the instrument can be greatly shortened compared with the orifice plate and vortex flowmeter;
4. The measurement accuracy of the system can meet the current trade measurement requirements (≤1.5%);
5. The flow measurement range is wide (qmax / qmin = 15 ～ 20), and it can work effectively in some small flow areas where the orifice plate and vortex flowmeter cannot reach;
6. Small size and light weight, offline calibration is more convenient;
7. The measurement signal can be displayed on the spot or remotely transmitted as required;
8. Instrument management personnel do not need professional training, and measurement parameters such as flow, pressure and temperature can be directly read from the meter head, and conversion conversion is not necessary;
9. Only need to regularly replace the battery (micro power consumption) and the parameters of the measured medium.
10. Large pressure loss;
When the circulating medium is gas, the pressure loss is about 3 to 4 times of the vortex flowmeter
When the fluid passes through a vortex generator composed of spiral blades (see Figure 1), the fluid is forced to rotate violently around the body axis, forming a vortex. When the fluid enters the diffusion section, the vortex flow is affected by the backflow and starts to make a second rotation, forming a gyroscopic vortex precession. The precession frequency is proportional to the flow rate and is not affected by the physical properties and density of the fluid. The detection element measures the precession frequency of the second rotation of the fluid and knows the flow rate.
Precautions for installation of precession vortex flowmeter
The sensor can be installed in vertical, horizontal or any inclined position according to the flow direction sign;
When the pipeline is long or close to the vibration source, support should be installed upstream and downstream of the flowmeter to eliminate the impact of pipeline vibration;
The installation site of the sensor should have enough space to facilitate the inspection and maintenance of the flowmeter, and should meet the environmental requirements of the flowmeter;
Avoid interference from strong external magnetic fields;
When installed and used outdoors, there should be coverings to avoid sun exposure and rain erosion, which will affect the service life of the instrument;
During the pressure test of the pipeline, pay attention to the pressure measurement range of the pressure sensor equipped with the intelligent flowmeter to avoid damage to the pressure sensor due to overpressure.
Pay attention to the influence of installation stress. The upstream and downstream pipelines of the flowmeter should be coaxial, otherwise shear stress will occur. The thickness of the gasket should be considered when installing the flowmeter, or an elastic expansion joint should be installed on the downstream side.
Before installing the flowmeter, remove the welding slag and other debris in the pipeline.
When it is put into operation, the upstream and downstream valves of the flowmeter should be opened slowly to avoid the sudden flow of air and the spinner being damaged.
When the flowmeter needs to have remote signal transmission, it should be strictly connected to the external power supply (8 ~ 24) VDC according to the "electrical performance index" requirements, and it is strictly prohibited to directly connect the 220VAC or 380VAC power supply at the signal output port;
The user shall not change the wiring mode of the explosion-proof system and twist each output lead connector at will;
When the flowmeter is running, it is not allowed to open the back cover to modify the parameters of the instrument, otherwise it will affect the normal operation of the flowmeter;
Check the leakage of the flowmeter flange regularly.