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Vortex flowmeter

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This sandbox is in the article namespace. Either move this page into your userspace, or remove the {{User sandbox}} template. Vortex flowmeter is a flowmeter for measuring fluid flow rates in an enclosed conduit.[1]

Composition of vortex flowmeter

A vortex flowmeter comprising: a flow sensor operable to sense pressure variations due to vortex-shedding of a fluid in a passage and to convert the pressure variations to a flow sensor signal,in the form of an electrical signal;and a signal processor operable to receive the flow sensor signal and to generate an output signal corresponding to the pressure variations due to vortex-shedding of the fluid in the passage.[2]

Working principle

When the medium flows through the triangular cylinder at a certain speed,an alternately arranged vortex belt is generated behind the sides of the triangular cylinder,called the"Carmen vortex".Since both sides of the vortex generator alternately generate the vortex,the pressure pulsation is generated on both sides of the generator,which makes the detector produce alternating stress.The piezoelectric element encapsulated in the detection probe body generates an alternating charge signal with the same frequency as the vortex,under the action of alternating stress.The signal is sent to the intelligent flow totalizer to be processed after being amplified by the pre-amplifier,realizing displaying instantaneous flow and cumulative flow of fluid,communicating and controlling of flow data and the microcomputer system.

In certain range of Reynolds number(2×10^4~7×10^6),the relationship among vortex releasing frequency f,fluid velocity V and vortex generator facing flow surface width d can be expressed by the following equation:

              f=Sr×V/d   V=f×d/Sr

In the equation,f-releasing frequency of Carmen vortex,Sr -coefficient(called the Strauss number),V-velocity ,d-width of the triangular cylinder.[3]

Industrial applications

Vortex flowmeter is a broad-spectrum flow meter which can be used for metering,measurement and control of most steam,gas and liquid flow for a very unique medium versatility,high stability and high reliability with no moving parts,simple structure and low failure rate.And The flowmeter is relative economical because of its simple flow measurement system and easy to maintain,widely used in petroleum,chemical industry,metallurgy,food,paper,electricity, industry boiler,urban pipeline heating,water supply,coal gas and other industries.

References

Category:Flow meters

Vortex flowmeter introduction