digitalYEWFLO Vortex Flowmeter

The digital YEWFLO vortex flowmeter combines the field proven sensor and body assembly used in more than 450,000 units installed worldwide with a unique and powerful combination of digital technology that includes spectral signal processing (SSP), a Yokogawa innovation. The digitalYEWFLO vortex flowmeter is accurate and stable, even in harsh process conditions, and has a highly reliable and robust design that delivers improvements in plant efficiency and reduced operating costs.

About OpreX

OpreX is the comprehensive brand for Yokogawa’s industrial automation (IA) and control business and stands for excellence in the related technology and solutions. It consists of categories and families under each category. This product belongs to the OpreX Field Instruments family that is aligned under the OpreX Measurement category.

Details

digitalYEWFLO Vortex Flowmeter Standard Type can measure flow rate of liquid, gas and steam.
A simple and robust structure with no moving parts provides high reliability and durability, and supports a wide range of applications.

 

Can Be Used in a Wide Range of Applications

digitalYEWFLO Vortex Flow Meter - Can Be Used in a Wide Range of Applications

It can measure the flow rate of liquid, gas and steam.
Installation at piping is easy because there are only two upstream and downstream connections.
The sensor detects frequency, and at zero flow rate it outputs frequency zero. Therefore, no zero adjustment is required.

 

Durability

Durability through simple design and construction.

digitalYEWFLO Vortex Flow Meter - Durability

 

Specifications / Functions

Refer to the General Specification sheet located under the Downloads tab for detailed specifications.

Model ・DY type vortex flowmeter (Integral type, remote type detector)
・DYA type remote type converter
Specification Standard specification
Measurement Fluid Liquid, gas, saturated steam, superheated steam (avoid multi-phase flow and adhesive fluid)
Process Temperature -29 to 250 °C
Process Pressure -0.1 MPa according to flange rating
Diameter Wafer 15 to 100 mm
Flange 15 to 400 mm
Accuracy Liquid ± 0.75 % of reading (depends on Reynolds number)
Gas, Steam ± 1.0 % of reading (depends on the flow velocity)
Output Signal Analog output, transistor contact output (simultaneous output possible)
Communication Type HART 7 / HART 5, BRAIN, FOUNDATION fieldbus
Explosion Protected Type TIIS Ex d, FM Ex d / Ex ia, ATEX Ex db / Ex ia, CSA Ex d / Ex ia, IECEx Ex db / Ex ia

 

digitalYEWFLO Vortex flowmeter Reduced Bore Type is a vortex flowmeter in which the main body of the vortex flowmeter and the reducer (reduction pipe and expansion pipe) are integrated into a casting.
Suitable for lines with large fluctuations in flow rate depending on the season, such as steam supply lines.
Since the reducer and the vortex flowmeter are integrated, it is not necessary to prepare a reducer and a short pipe for securing the straight pipe length.
This not only simplifies installation and reduces costs, but also improves safety by reducing the number of connection points.

Reduced Bore Type - Integrated construction allowsfor bore size reduction of up to 2 sizes.

 

Realize Simple Instrumentation

As an example of a vortex flowmeter application, a reducer may be used to measure low flow.
In this case, as shown in the figure below, it is necessary not only to connect the reduction pipe and the expansion pipe, but also to connect short pipes to secure the straight pipe length upstream and downstream respectively. As a result, not only is the installation process complicated and difficult, but also the installation cost increases. Furthermore, with six connections, the risk of fluid leakage increases.

digitalYEWFLO Vortex Flow Meter Reduced Bore Type - Realize Simple Instrumentation - Conventional Instrumentation

The Reduced Bore Type has a concentric reducer. Therefore, there is no need to install not only the reduction pipe and the expansion pipe, but also the short pipe for securing the straight pipe length.
Furthermore, the reduced number of connections brings reducing the risk of fluid leakage and installation costs.
The measurement lower limit value is expanded by 2 to 3 times, and a low flow rate can be measured with a pipe diameter size flowmeter.

digitalYEWFLO Vortex Flow Meter Reduced Bore Type - Realize Simple Instrumentation - New instrumentation

The line that used to change the two orifice plates according to the amount of flow fluctuation has no need to be changed by installing the Reduced Bore Type.
For lines that require yearly or long-term flow control, there is no need to stop the line when making changes. In addition to the high-temperature and high-pressure fluid that Vortex Flowmeter is originally good at, the vibration resistance and self-diagnosis function using the SSP function unique to digitalYEWFLO Vortex Flowmeter, the quality of flow control is upgraded using various functions.

 

Two Lineups

The Reduced Bore Type is available in two reducer specifications (/R1 and /R2) so that it can be used depending on the application.
The nominal diameter of the detection part is reduced by 1 size down for /R1 and 2 sizes down for /R2 compared to the nominal diameter of flange piping.
The relationship between the nominal diameter of the flange piping and the nominal diameter of the detector is shown below.

digitalYEWFLO Vortex Flow Meter Reduced Bore Type - Tow Lineups

The Reduced Bore Type contributes to stable flow measurement at low flow rates that are difficult to measure with standard types.
An example of the measurable flow rate range is shown below for the standard type and two reducer specifications.

digitalYEWFLO Vortex Flow Meter Reduced Bore Type -  Two Lineups  - Flow Rate Range

In the standard type, the measurable flow rate range is 74 to 1,876 kg/h, which is ideal when the flow rate range to be measured is wide.
If you want to measure a low flow below 74 kg/h, the Reduced bore type R2 is suitable.
In addition, if you want to measure flow as wide as standard type as well as low flow rate area under 74 kg/h, Reduced bore type R1 specification is suitable.

 

Combination with Multi-Variable Type Possible

The Reduced Bore Type can be combined with the Multi-Variable Type.
The combination with the Multi-Variable Type enables temperature measurement and temperature correction for low flow rate.
Even at low flow rates, the mass flow rate of saturated steam can be directly output with one unit.

digitalYEWFLO Vortex Flow Meter Reduced Bore Type -  Combination with Multi-Variable Type Possible

 

Combination with High Temperature Version Is Possible

The Reduced Bore Type can be combined with high temperature version.
The combination with high temperature version extends the upper limit of applicable fluid temperature from the usual 250 °C to 450 °C.
Even at low flow rates, it is possible to measure the flow rate of high temperature fluid.

 

Durability

Durability through simple design and construction.

digitalYEWFLO Vortex Flow Meter Reduced Bore Type -  Durability

 

Specifications / Functions

Refer to the General Specification sheet located under the Downloads tab for detailed specifications.

Model ・DY type vortex flowmeter (Integral type, remote type detector)
・DYA type remote type converter
Specification Optional specifications
 1 Size down: /R1
 2 Size down: /R2
Measurement Fluid Liquid, gas, saturated steam, superheated steam (avoid multi-phase flow and adhesive fluid)
Process Temperature -29 to 250 °C
Process Pressure -0.1 MPa to flange rating
Diameter Wafer None
Flange R1: 25 to 200 mm (detection unit: 15 to 150 mm)
R2: 40 to 200 mm (detection unit: 15 to 100 mm)
Accuracy Liquid ± 1.0 % of reading (depends on Reynolds number)
Gas, Steam ± 1.0 % of reading (depends on the flow velocity)
Output Signal Analog output, transistor contact output (simultaneous output possible)
Communication Type HART 7 / HART 5, BRAIN, FOUNDATION fieldbus
Explosion Protected Type TIIS Ex d, FM Ex d / Ex ia, ATEX Ex db / Ex ia, CSA Ex d / Ex ia, IECEx Ex db / Ex ia

 

digitalYEWFLO Vortex Flowmeter Multi-Variable Type is a flowmeter most suitable for steam applications, with a built-in resistance temperature sensor (Pt1000) in a solid shedder bar (vortex generator).
Analog and pulse signals can be output simultaneously, and while displaying the flow rate on the display, it is also possible to display the fluid temperature as a temperature monitor function. It contributes to the total cost reduction and energy saving of the line using steam as the heat medium.

 

RTD Built into the Shedder Bar (Vortex Generator)

  digitalYEWFLO Vortex Flowmeter Multi-Variable Type - RTD Built into the Shedder Bar

Built-in temperature sensor housed inside the shedder bar.
Based on signals from the temperature sensor, which is protected by the shedder bar serving as a protector tube, the mass flow rate of saturated steam is calculated.

 

Temperature Display Function

  digitalYEWFLO Vortex Flowmeter Multi-Variable Type - Temperature Display Function

The built-in thermometer inside the shedder bar allows simultaneous display of instantaneous flow and fluid temperature.

 

Mass Flow Calculation Function

digitalYEWFLO Vortex Flowmeter Multi-Variable Type - Mass Flow Calculation Function

The Multi-Variable Type has a built-in steam table, so it can automatically calculate and directly output the mass flow rate of saturated steam from the measured fluid temperature.

Furthermore, with FOUNDATION Fieldbus communication type, Arithmetic (AR) function block expands the mass flow calculation function for the saturated steam, superheated steam, gases and natural gas by using external pressure/temperature input (/MV: internal temperature input) with a high accuracy. In combination with FSA120 Flow Navigator software brings to the high accurate mass flow calculation output using AGA No. 8 temperature correction calculation of natural gas or using physical property database (DIPPR) for general gas, natural gas, and liquids.

 

Mechanism of Saturated Steam Density Calculation

The Multi-Variable Type has the saturated steam curve that is a curve that represents the saturation point of the steam. The mass flow rate is calculated by calculating the density based on the measured fluid temperature and the saturated steam curve.
This is why digitalYEWFLO vortex flowmeters can perform mass flow calculations by tracking changes in fluid temperature. In the case of superheated steam, the density is calculated from the steam table with the pressure kept constant.
Using the integration function, the energy consumption of steam can be recorded at regular intervals, so it can be used as a material for energy saving improvement plans.

digitalYEWFLO Vortex Flow Meter Multi-Variable Type -  Mechanism of Saturated Steam Density Calculation

 

Combination with High Temperature Is Possible

The Multi-Variable Type can be used in combination with High Process Temperature Version.
The combination with the High Process Temperature Version extends the upper limit of applicable fluid temperature, usually from 250 °C up to 400 °C.

Model Code DY025 to DY100: Wafer Type
DY025 to DY200: Flange Type
Option Code /MV /HT/MV
Function Temperature Indication / Output Temperature Range -29 to 250 °C -29 to 400 °C
Saturated Steam Mass Flow Rate Calculation Temperature Range 100 to 250 °C 100 to 330 °C
Superheated Steam Mass Flow Rate 100 to 250 °C 100 to 400 °C
Gas Volume Flow Rate -29 to 250 °C -29 to 400 °C
Liquid Mass Flow Rate -29 to 250 °C -29 to 400 °C

 

Combination with Reduced Bore Type Possible

The Multi-Variable Type can be combined with the Reduced Bore Type.
The combination with the Reduced Bore Type enables temperature measurement and temperature correction even at low flow rates.

digitalYEWFLO Vortex Flow Meter Multi-Variable Type -  Combination with Reduced Bore Type Possible

 

Durability

Durability through simple design and construction.

digitalYEWFLO Vortex Flowmeter Multi-Variable Type - Durability

 

Specifications / Functions

Refer to the General Specification sheet located under the Downloads tab for detailed specifications.

Model DY type vortex flowmeter (Integral type, remote type detector)
DYA type remote type converter
Specification Optional specifications: /MV
Measurement Fluid Liquid, gas, saturated steam, superheated steam (avoid multi-phase flow and adhesive fluid)
Process Temperature -29 to 250 °C
Process Pressure -0.1 MPa to flange rating
Diameter Wafer 25 ~ 100 mm
Flange 25 to 200 mm (custom specification: 250 to 400 mm)
Accuracy Liquid ± 0.75 % of reading (depends on Reynolds number)
Gas, Steam ± 1.0 % of reading (depends on the flow velocity)
Output Signal Analog output, transistor contact output (simultaneous output possible)
Communication Type HART 7 / HART 5, BRAIN, FOUNDATION fieldbus
Explosion Protected Type TIIS Ex d, FM Ex d / Ex ia, ATEX Ex db / Ex ia, CSA Ex d / Ex ia, IECEx Ex db / Ex ia

 

digitalYEWFLO Vortex Flowmeters High Process Temperature Version can be measured up to 450 °C, Cryogenic Version can be measured down to -196 °C.

 

Ideal for Measuring High Temperature Steam, Liquid Nitrogen, Etc.

digitalYEWFLO Vortex Flowmeter High Process Temperature Version / Cryogenic Version - Product Image

Supports a wide range of fluid temperatures compared to the standard types.
It has the same face-to-face dimension as the standard type, so replacement is easy.
It is a simple structure that is easy to keep warm and cool.

 

Combination with Multi-Variable Type Possible (High Process Temperature Version Only)

For the High Process Temperature Version, combination with the Multi-Variable Type is possible.
The combination with multiple variable type allows temperature measurement and correction up to 400 °C.

Model Code DY025 to DY100: Wafer Type
DY025 to DY200: Flange Type
Option Code /MV /HT/MV
Function Temperature Indication / Output Temperature Range -29 to 250 °C -29 to 400 °C
Saturated Steam Mass Flow Rate Calculation Temperature Range 100 to 250 °C 100 to 330 °C
Superheated Steam Mass Flow Rate 100 to 250 °C 100 to 400 °C
Gas Volume Flow Rate -29 to 250 °C -29 to 400 °C
Liquid Mass Flow Rate -29 to 250 °C -29 to 400 °C

 

Combination with Reduced Bore Type Possible (High Process Temperature Version Only)

For the High Process Temperature Version, combination with the Reduced Bore Type is possible.
In combination with the Reduced Bore Type, flow measurement can be performed up to 450 °C even in the low flow.

 

Durability

Durability through simple design and construction.

digitalYEWFLO Vortex Flowmeter High Process Temperature Version / Cryogenic Version - Durability

 

Specifications / Functions

Refer to the General Specification sheet located under the Downloads tab for detailed specifications.

Model DY type vortex flowmeter (remote type detector)
Specification Optional specification
 High Process Temperature Version: /HT
 Cryogenic Version: /LT
Measurement Fluid Liquid, gas, saturated steam, superheated steam (avoid multi-phase flow and adhesive fluid)
Process Temperature -29 to 450 °C( /HT )
-196 to 100 °C( /LT )
Process Pressure -0.1 MPa to flange rating
Diameter Wafer 15 to 100 mm
Flange 15 to 400 mm
Accuracy Liquid ± 0.75 % of reading (depends on Reynolds number)
Gas, Steam ± 1.0 % of reading (depends on the flow velocity)
Output Signal Analog output, transistor contact output (simultaneous output possible)
Communication Type HART 7 / HART 5, BRAIN, FOUNDATION fieldbus
Explosion Protected Type TIIS Ex d, FM Ex d / Ex ia, ATEX Ex db / Ex ia, CSA Ex d / Ex ia, IECEx Ex db / Ex ia

 

Remote

digitalYEWFLO Vortex Flow Meter Remote type

Remote electronics allows you to locate the indicator away from the process measurement point and to more convent visible area. Remote digitalYEWFLO vortex flowmeters are available in a number of different sizes ranging from 1/2-inch to 16-inch. Available with wafer style or flanged style (ANSI Class 150 to ANSI Class 900). digitalYEWFLO has the size you need.

The picture left shows a Stainless Steel housing. The SS housing is available option on all Yokogawa digitalYEWFLO Vortex Flowmeters.

 

High-Pressure

High-Pressure digitalYEWFLO is designed to take your toughest high-pressure steam and water applications. The High-Pressure digitalYEWFLO is available with ANSI 900#, 1500#, and 2500# flange connections. Quality, dependability, and now pressure ratings to 5000 psi!

digitalYEWFLO Vortex Flow Meter High-Pressure type

 

Dual Sensor

digitalYEWFLO Vortex Flow Meter Dual Sensor type

When your application requires the highest safeguards for personnel and process, the digitalYEWFLO dual sensor design offers total redundancy and is available in a broad range of sizes and pressure ratings.

 

High-Purity

High-Purity digitalYEWFLO meets the standards set forth in ASTM G93-6 Level B and ANSI B40.1 Level IV. Electropolished to a 15Ra or better finish and double bagged, the High-Purity digitalYEWFLO accurately measures critical high purity steam, water, and gas applications.

digitalYEWFLO Vortex Flow Meter High-Purity type

From Sensing to Sensemaking

YOKOGAWA supports the entire lifecycle of products.
Combining reliable technology with superior field knowledge, Yokogawa has insights into the lifecycle of the device that provides added value to the user.

 

digitalYEWFLO Vortex Flow  - Total Insight - Overview

digitalYEWFLO offers valuable information throughout the devices’ lifecycle.

Sensing Selection - Engineering and Procurement -
Simple lineup and a wide range of international approvals help the customer select the right product.

Easy Installation - Configuration and Commissioning -
Various ways of configuring devices contribute to reduced installation and configuration time.

Rich Information - Operation and Observation -
Valuable diagnostic information leads to improved process efficiency.

Expert Solution - Maintenance and Service -
Providing timely maintenance information contributes to reduced maintenance cost.

Image Zoom

 

Product Finder

digitalYEWFLO Vortex Flow  - Total Insight - Model Selection (Product Finder)

By using Product Finder, a product selection support tool that operates on our website, you can select the most suitable product for the purpose and conditions of flow measurement.
In addition, by using the specification selection support tool PF configurator, you can check the specifications more easily in comparison of specifications and inquiries.

Try Product Finder now

 

Worldwide Approvals

With the rapid globalization of markets, numerous international standards and approvals are becoming necessary; therefore, Yokogawa instruments have acquired various international certifications including explosion proof, electromagnetic compatibility (EMC), and communication protocols.

 

1. EMC Standards (EMC Standards)

Standard name Standard Type Reduced Bore Type Multi-Variable Type High Process Temperature Version and Cryogenic Version
CE Marking European EMC Directive Yes Yes Yes Yes
RCM Mark Australia and New Zealand
Electrical Equipment Safety Standards
Yes Yes Yes Yes
KC Mark Korea electromagnetic wave conformity standard Yes Yes Yes Yes

 

2. Explosion Proof Standard

Standard name Standard Type Reduced Bore Type Multi-Variable Type High Process Temperature Version and Cryogenic Version
TIIS Flame proof Yes Yes Yes Yes
IECEx Flame proof Yes Yes Yes Yes (for High Process Temperature Version only)
Intrinsically safe Yes Yes Yes Yes
ATEX Flame proof Yes Yes Yes Yes (for High Process Temperature Version only)
Intrinsically safe Yes Yes Yes Yes
FM Flame proof Yes Yes Yes Yes
Intrinsically safe Yes Yes Yes Yes
CSA Flame proof Yes Yes Yes Yes
Intrinsically safe Yes Yes Yes Yes

 

3. Communication Protocol

Communication protocol Standard Type Reduced Bore Type Multi-Variable Type High Process Temperature Version and Cryogenic Version
HART 7 Yes Yes Yes Yes
5 Yes Yes Yes Yes
BRAIN Yes Yes Yes Yes
FOUNDATION Fieldbus Yes Yes Yes Yes

 

FSA120 Flow Configuration Software FlowNavigator

digitalYEWFLO Vortex Flow - Total Insight - Installation Setting - FlowNavigator

Flow Configuration Software FlowNavigator (FSA120) is a software package that provides various functions required to easily set mass flow parameters of field devices.

The flow calculation setting software consists of the following two programs.

  • EJXMVTool: for EJX910A / EJX930A multi variable transmitter
  • DYFMVTool: digitalYEWFLO Vortex Flowmeter for Fieldbus Communication Type


FlowNavigator uses FDT technology and operates on FieldMate Versatile Device Management Wizard and Plant Resource Manager (PRM).

Click here for details on the FSA120 FlowNavigator Flow Configuration Software
Click here for details on the FieldMate Versatile Device Management Wizard

 

Straight Pipe Length According to Installation Situation

Vortex flowmeters generally affect flow measurement accuracy when the flow velocity distribution in the pipe is biased.
Necessary straight pipe length and main points are shown along with typical installation examples.

Straight Pipe

Secure at least 10D upstream and 5D downstream.

digitalYEWFLO Vortex Flow  - Straight Pipe

 

Reducer Pipe

Secure at least 5D upstream and 5D downstream.

digitalYEWFLO Vortex Flow  - Reducer Pipe

 

Expander Pipe

Secure at least 10D upstream and 5D downstream.

digitalYEWFLO Vortex Flow  - Expander Pipe

 

Single Bent Pipe

Secure at least 10D upstream and 5D downstream.

digitalYEWFLO Vortex Flow  - Single Bent Pipe

 

Double Bent Pipe in the Same Plane

Secure at least 10D upstream and 5D downstream.

digitalYEWFLO Vortex Flow  - Double Bent Pipe in the Same Plane

 

Double Bent Pipe in Another Plane

Secure at least 20D upstream and 5D downstream.

digitalYEWFLO Vortex Flow  - Double Bent Pipe in Another Plane

 

Valve Position and Straight Pipe Length

Install the valve on the downstream side of the flowmeter. The upstream straight pipe length dependent on the element located on the upstream such as reducer/expander, bent and etc., refer to description as above. Keep 5D or more for downstream straight pipe length.
In case the valve has to be installed on the upstream of the flowmeter, ensure the upstream straight pipe length to be 20D or more, and the downstream straight pipe length be 5D or more.

digitalYEWFLO Vortex Flow  - Valve Position and Straight Pipe Length

 

Mounting Attitude

If the pipe is always filled with fluid, the mounting direction does not matter whether it is horizontal, vertical or inclined.
However, in the case of horizontal and inclined, be sure to install the terminal box or converter above the piping position in order to avoid flooding.

Horizontal Piping

digitalYEWFLO Vortex Flow  - Mounting Attitude - Horizontal piping

digitalYEWFLO Vortex Flow  - Mounting Attitude - Horizontal piping 2

 

Vertical Piping

digitalYEWFLO Vortex Flow  - Mounting Attitude - Vertical Piping Left                  digitalYEWFLO Vortex Flow  - Mounting Attitude - Vertical Piping Right

 

Inclined Piping

digitalYEWFLO Vortex Flow  - Mounting Attitude - Inclined Piping Left                  digitalYEWFLO Vortex Flow  - Mounting Attitude - Inclined Piping Right

Simple Indicator

digitalYEWFLO Vortex Flow  - Total Insight - Operation Monitoring - Simple Indicator

The digitalYEWFLO vortex flowmeter has a simple two-line display.
The upper part of the display shows the flow rate in selected engineering unit or % of the span, and the lower part shows the total flow rate or alarm number.

Furthermore, in the case of Multi-Variable Type, the upper part can display the % of the span of temperature, and the lower part can display the actual temperature.
Flow monitoring and temperature monitoring can be performed with one digitalYEWFLO Vortex Flowmeter.

In addition, when setting parameters using the keys, the setting item number is displayed in the upper, and the value of the parameter is displayed in the lower.
You can easily access the parameters as well as setup via communication.

 

Diagnostics

digitalYEWFLO Vortex Flow  - Total Insight - Operation Monitoring - Diagnostics

The digitalYEWFLO Vortex Flowmeter displays alarm numbers such as sensor failure or temperature sensor abnormality in the lower part of the display. By checking the alarm number, you can easily grasp what is happening now.

Additionally, some errors which are difficult to check from the outside of the pipe, such as fluid flow error (CHECK Flow) and vibration abnormality (CHECK Vibration) are also displayed as the result of self-diagnosis.

 

Analog / Pulse Simultaneous Output

The digitalYEWFLO Vortex Flowmeter can output pulse output simultaneously with current output.
In the case of Multi-Variable Type, not only flow rate but also measured temperature can be output.

As an example, the connection method when using a shielded cable is shown.

digitalYEWFLO Vortex Flow  - Total Insight - Operation Monitoring - Analog / Pulse Simultaneous Output

 

Alarm Output, Status Output Function

The digitalYEWFLO vortex flowmeter outputs by the status output function when an alarm is generated as a result of self-diagnosis.

In addition, by sending this status output signal to the solenoid valve via a relay, an emergency cutoff operation can also be performed.

digitalYEWFLO Vortex Flow  - Total Insight - Operation Monitoring - Alarm Output, Status Output Function

 

Flow Switch Function

digitalYEWFLO Vortex Flow  - Total Insight - Operation Monitoring - Flow Switch Function

Status contact is on when the measured flow rate falls below the set threshold.
By detecting the flow rate drop early, stable flow rate can be continued.

Data Copy by FieldMate

You can use FieldMate to copy device settings to the same type digitalYEWFLO.
It is possible to reduce the time for start-up by preparing multiple devices with the same settings with a simple operation.

digitalYEWFLO Vortex Flow  - Total Insight - Maintenance Service - Data Copy by FieldMate

 

* Click here for details on the FieldMate Versatile Device Management Wizard

Vortex Flowmeters - Principle of Operation

Vortex Flowmeters use the Von Karman Effect to measure the rate of flow of a fluid or gas.

What is the Von Karman Effect?

Early in the 20th century, a Hungarian-American mathematician and physicist, Theodore von Karman, discovered that a fluid or gas flowing perpendicularly pass a bluff body would generate alternating vortices on both sides of the body. The path of these vortices is called the von Karman vortex street.

What is the Von Karman Effect?

Von Karman found that if the frequency of these vortices was measured, that the frequency is proportional to the flow velocity that is generating the vortices. This frequency is called the Karmen Vortex Frequency. The relationship of the frequency and the flow velocity can be mathematically expressed with the following formula:

Von Karman Effect Formula 01

From the equation, we can see that the frequency is proportional to the velocity. If we can measure the frequency (f), know the Strouhal number (St), know the shedder bar width (d); we can solve for v (velocity).

Von Karman Effect Formula 02

 

How do we measure the frequency of the vortices?

As vortices form and pass the shedder bar (the bluff body), they create a low pressure as compared to the rest of the fluid. This low pressure produces a differential pressure (dp) across the shedder bar. The high pressure side of the dp exerts stress on the shedder bar in the direction of the low pressure. As the location of the low pressure side alternates due to the vortices switching from side-to-side, the change in direction of the exerted force causes the shedder bar to oscillate. This oscillation is equal to the Karmen Vortex Frequency.

How do we measure the frequency of the vortices?

There are several methods in the marketplace to measure the oscillation. Diaphragms or capacitance sensors are two of the more common; but, the best method is the use of Piezo-electric crystal sensors. These sensors, when compressed, produce an electric signal that can be sent to the Flowmeter's electronics. Now that the Karmen Vortex Frequency is measured (and we know the St and d), the flowmeter electronics can do simple calculations to determine volumetric flow through the pipe.

What are the advantages of using Vortex Flowmeters?

High Accuracy
The accuracy of the vortex flowmeter is ±1% (pulse output) of the indicated value for both liquids and gases and is higher compared to orifice flowmeters. For liquids, an accuracy of ±0.75% is available depending on the fluid type and their conditions.

Wide Rangeability
Rangeability is defined as the ratio of maximum value to minimum value of the measurable range. It is broad rangeability the allows vortex flowmeters to operate in processes where the measuring point may fluctuate greatly.

Output is Proportional to Flow Rate
Since the output is directly proportional to the flow rate (flow velocity), no square root calculation is needed, while orifice flowmeters require square root calculations.

No Zero-point Fluctuation
Since frequency is output from the sensor, zero-point shift does not occur.

Minimal Pressure Loss
Since only the vortex shedder is placed in the pipe of the vortex flowmeter, the fluid pressure loss due to the small restriction in the flow piping is small compared with flowmeter a having an orifice plate.

Combining Noise Reduction and Spectral Signal Processing (SSP) to provide an accurate and stable measurement.

 

Signal Processing (SSP: Spectral Signal Processing)

digitalYEWFLO's SSP function provides enhanced vibration immunity and advanced diagnostics

digitalYEWFLO is a maintenance-free flowmeter. It has a circuit for analyzing the frequency of detected signal and allows only vortex frequency to pass through the segmented band-pass-filter, thereby accurately identifying and eliminating noise. The Spectral Signal Processing (SSP) function of digitalYEWFLO only outputs the appropriate vortex frequencies, even under fluctuating flow rate conditions.

Signal Processing (SSP: Spectral Signal Processing)

 

Noise Reduction

digitalYEWFLO Vortex Flow Meter Noise Reduction

Noise caused by strong piping vibration may affect the accuracy of the vortex frequency detection. The two piezoelectric elements installed in the digital YEWFLO are of a polarized structure, so they do not detect vibration in the flow or vertical directions. The noise in the lift direction vibration is reduced by adjusting the outputs of the piezoelectric elements.

Measurement of Air Supply to Reaction Tank

Background

A chemical company used an area flowmeter in the process of reacting the raw materials.
However, for the aging of the instrument and further improvement of productivity, the renewal of the instrument was considered. Also, because the area flowmeter did not carry out temperature correction, a temperature error of about 10% occurred. Therefore, temperature correction was also considered when updating the instrument.

Process Outline

In the process, if the air supply to the reaction tank is not properly performed, the yield of the reaction will be extremely degraded.
Since the previous area flowmeter did not carry out temperature correction of the supply air, the temperature change due to the season fluctuates the air supply, which affects the yield.

digitalYEWFLO Vortex Flow  - Application - Measurement of Air Supply to Reaction Tank - Process Outline

 

Applicable Product

digitalYEWFLO Vortex Flowmeter Multi-Variable Type has been adopted.

 

Merits of Introduction

Since the existing area flowmeter is a two-wire meter, if the mass flowmeter (four-wire meter) considered as a comparison target is adopted, there was a concern about the construction cost increases because the existing wiring cannot be used.
On the other hand, the digitalYEWFLO Vortex Flowmeter Multi-Variable Type is a 2-wire instrument, so wiring work and switchboard construction can be reduced, and the cost reduction nearly 25% compared to mass flowmeters has been achieved.

digitalYEWFLO Vortex Flow  - Application - Measurement of Air Supply to Reaction Tank - Merits of Introduction

 

Field Data

digitalYEWFLO Vortex Flowmeter Multi-Variable Type, correction with the built-in thermometer enables more accurate management of the amount of supplied air.
This is expected to improve productivity in the future.

digitalYEWFLO Vortex Flow  - Application - Measurement of Air Supply to Reaction Tank - Field Data

Measurement of Saturated Steam Flow Rate

Background

Conventional steam measurements required correction equipment such as thermometers and calculators to measure mass flow.

 

Process Outline

digitalYEWFLO Vortex Flow  - Application - Measurement of Saturated Steam Flow Rate - Process Outline

 

Applicable Product

digitalYEWFLO Vortex Flowmeter Multi-Variable Type has been adopted.

 

Merits of Introduction

digitalYEWFLO Vortex flowmeter Multi-Variable Type incorporates a thermometer in the shedder bar (vortex generator). Therefore, it is not necessary to install a thermometer on the piping.
Not only can it contribute to cost reduction because it can simplify construction, but it can also contribute to ensuring the safety of the plant because it can reduce the number of construction.

 

Field Data

digitalYEWFLO Vortex Flowmeter Multi-Variable Type calculate mass flow rate from the temperature value constantly measured with the internally held steam table.
It can be confirmed that the result of correction calculation output by external thermometer and pressure gauge with standard type and the output of digitalYEWFLO Vortex Flowmeter Multi-Variable Type almost match. digitalYEWFLO Vortex Flowmeter Multi-Variable Type measures the fluid temperature in real time, and responds instantly to sudden changes in temperature to achieve highly accurate output.

digitalYEWFLO Vortex Flow  - Application - Measurement of Saturated Steam Flow Rate - Field Data

Management of Steam Supply for Heating of Alumina Ceramic Line

Background

So far, they have been using the initial model of our vortex flowmeter YEWFLO series.
However, due to the influence of pipe vibration over the years, adjustment was necessary for low flow measurement.

 

Process Outline

digitalYEWFLO Vortex Flow  - Application - Management of Steam Supply for Heating of Alumina Ceramic Line - Process Outline

 

Applicable Product

digitalYEWFLO Vortex Flowmeter standard type has been adopted.

 

Merits of Introduction

The digitalYEWFLO Vortex Flowmeter has been further enhanced by the addition of the Spectral Signal Processing (SSP) function.
As a result, even at low flow rates, excellent results have been achieved, enabling more accurate measurement.
In addition to the long-term stability proven in the YEWFLO series, maintaining high precision contributes significantly to cost reduction and energy saving.

 

Field Data

The effect of vibration has been suppressed, and stable output has been achieved even in a constant flow range. With the introduction of the digitalYEWFLO Vortex Flowmeter standard type, the customer realized that the flow rate can now be grasped with high accuracy. It can also be expected to play a major role in the planning and implementation of future energy saving plans.

digitalYEWFLO Vortex Flow  - Application - Management of Steam Supply for Heating of Alumina Ceramic Line - Field Data

Control of Steam Supply to Plating Process and Clean Room

Background

At the Ome factory of Yokogawa Electronics Manufacturing, steam is supplied from two boilers for heating the 60 plating baths of printed circuit boards and for humidifying clean rooms. This plating baths has a flow fluctuation of about 100 to 850 kg/h at all times for temperature control. Until now, boilers have only been used to automatically manage the amount of steam, but as part of energy saving measures in the future, they have introduced the digitalYEWFLO Vortex Flowmeter as a model for controlling the flow of steam to reduce fuel and improve utilization efficiency.

 

Process Outline

digitalYEWFLO Vortex Flow  - Application - Control of Steam Supply to Plating Process and Clean Room - Process Outline

 

Applicable Product

digitalYEWFLO Vortex Flowmeter standard type has been adopted.

 

Merits of Introduction

Calculate annual loss amount and effect of yearly fuel saving amount when measuring steam with digitalYEWFLO Vortex Flowmeter with 1% accuracy and with orifice instrumentation with 2 to 5% accuracy, respectively. As a result, it turned out that they can save 335,000 yen a year.

  digitalYEWFLO Orifice instrumentation
Accuracy ± 1 % of reading ± 3 % of reading (average)
Diameter 40 mm
Flow rate 850 kg/h
Daily loss of steam due to error 204 [kg/day]
(= 850 [kg/h] × 0.01 × 24 [h/day])
612 [kg/day]
(= 850 [kg/h] × 0.03 × 24 [h/day])
Annual loss of steam (operating rate 90%) 67,014 [kg/year]
(= 204 [kg/day] × 365 [days/year] × 0.9)
201,042 [kg/year]
(= 612 [kg/day] × 365 [days/year] × 0.9)
Annual loss amount (steam unit price 2.5 [yen/kg]) 167,535 [Yen]
(= 67,014 [kg/year] × 2.5 [Yen/kg] × 1 [year])
502,605 [Yen]
(= 201,042 [kg/year] × 2.5 [Yen/kg] × 1 [year])
Annual fuel savings (vs. orifice instrumentation) -335,070 [Yen]
(=167,535 [Yen] - 502,605 [Yen])

 

Field Data

It also follows a sudden change in the amount of steam supply, achieving a stable output at all times.

digitalYEWFLO Vortex Flow  - Application - Control of Steam Supply to Plating Process and Clean Room - Field Data

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Overview:

Measuring energy consumption is an important factor in the quest to improve energy efficiency. Efficient and accurate metering is paramount to determining excess use, along with an accurate picture of where the steam is being used. The more accurate and reliable measurements that are made, the more informed decisions can be taken that affect costs and product quality. Traditionally the most common method of steam metering is the orifice plate and differential pressure transmitter technique. General areas of concern with this type of measurement are the orifice plate's susceptibility to wear introducing immediate inaccuracies, the relatively high permanent pressure losses introduced into the system by the orifice place and the small measuring range, typically 3:1.

Yokogawa's digitalYEWFLO Reduced Bore Type Vortex Flow meter features a cast stainless steel body and a concentric reducer and expander that enable stable flow rate measurements in low-flow conditions. This expands the range of measurements that can be performed, from the higher flow rates down to the lower end of the flow span, which is normally difficult for Vortex Flow meters, and ensures stable and accurate flow rate output.

Industries:
Overview:

It is estimated that almost two thirds of oil discovered in the United States lies unrecovered trapped in porous formations. There are approximately 500,000 abandoned wells containing such oil. Because of this fact oil companies are constantly pursuing methods for the recovery of this oil.

Yokogawa Technical Report
Overview:

Progress in digital signal processing and network technologies has enabled advanced functions which cannot be achieved by traditional field devices with 4-20 mA signal, to be implemented on field devices. Standardization of international fieldbus specifications, notably the FOUNDATION™ Fieldbus, has enabled users to build optimum field networks comprised of freely chosen field devices from various device vendors.

Overview:

Vortex flow meters utilize a fluid phenomenon in which frequencies of Karman vortex streets released from a shedder bar inserted in a flow are proportional to flow velocities.

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