Swirl Flowmeter Working Principle
The flow profile of the flow sensor is similar to that of a Venturi tube. A set of spiral guide vanes is placed on the inlet side.
When the fluid enters the flow sensor, the guide vanes force the fluid to produce a violent vortex flow.
When the fluid enters the diffusion section, the vortex flow is affected by the backflow and begins to rotate twice, forming a gyroscopic vortex precession phenomenon.
The precession frequency is proportional to the flow rate and is not affected by the physical properties and density of the fluid. By measuring the secondary rotational precession frequency of the fluid using the detection element, good linearity can be obtained within a wide flow range.
The signal is amplified, filtered, and shaped by the preamplifier and converted into a pulse signal proportional to the flow rate. Then together with the detection signals such as temperature and pressure, they are sent to the microprocessor for integration processing. Finally, the measurement results (instantaneous flow, accumulated flow, temperature, and pressure data) are displayed on the LCD screen.
What is the difference between a swirl and vortex meter?
Although both precession vortex flowmeters and vortex vortex flowmeters use the principle of fluid oscillation, the details are different.
- Different structures:
The generators of vortex flowmeters and precession vortex flowmeters are immovable parts and are usually called vortex generators.
But the vortex generators of the two are different. The vortex generator of the vortex street is triangular prism-shaped. The vortex generator of the precession vortex is similar to the impeller of a turbine. - Different measurement principles:
The principle of the vortex flowmeter is to set up a triangular prism-shaped vortex generator in the fluid. The gas flows through the vortex generator and alternately generates regular vortices from both sides. This vortex is called a Karman vortex street. By measuring the frequency of vortex street occurrence to calculate the measured medium flow rate.
The measurement principle of the precession vortex flowmeter is that when the fluid passes through the vortex generator composed of spiral blades, the fluid is forced to rotate violently around the generator axis to form a vortex.
When the fluid enters the diffusion section, the vortex flow is affected by the backflow and begins to rotate twice, forming a gyroscopic vortex precession phenomenon.
Both generate vortices. The vortex of the vortex flowmeter is generated alternately on both sides. The vortex of the precession vortex flowmeter is gyroscopic. - The measurement media are different:
Vortex flowmeters can measure gases, liquids and vapors, while precession vortex flowmeters can only measure gases. - Measuring pipe diameter:
The measuring diameter range of the vortex flowmeter is larger than the diameter of the precessing vortex flowmeter. When measuring gases with the same diameter, the flow ranges are different. Which flow meter is more suitable should be selected based on the actual application conditions on site.
What are the differences between gas turbine flowmeter and precession vortex flowmeter?
Both flowmeters, gas turbine flowmeter and precession vortex flowmeter, are considered to be the most accurate and stable flowmeters for measuring gas flow. Both flowmeters are widely used to measure natural gas, compressed air, and carbon dioxide. wait.
Gas turbine flow meters are only suitable for measuring gases with few impurities and no moisture in the medium, such as natural gas. In addition, please note when installing that it requires a 10DN straight pipe distance before and after.
The precession vortex flowmeter can measure gases containing moisture, such as biogas, compressed air, etc.
Based on the cost-effective analysis of the two models, the gas turbine flowmeter is more expensive and is suitable for high-standard gas measurement such as trade settlement.
The price of the precession vortex flowmeter is relatively moderate. It is suitable for internal assessment. It can measure gases containing moisture, and it has a long service life.
