2018 Flow Festival Open Channel Area Velocity Flow …• Rags • Damage • Calibration –...
Transcript of 2018 Flow Festival Open Channel Area Velocity Flow …• Rags • Damage • Calibration –...
HESCO
2018 Flow FestivalOpen Channel Area Velocity Flow Measurement
Rick DeyKey Account ManagerFlow Meter Products
Teledyne, Isco
Agenda
– Review of basics of Area Velocity flow measurement
– Latest advancements in flow technologies
– When and where to use each– Continuous Wave Doppler– Pulse Doppler– LaserFlow Non-contact
The right product for the application
Isco Flow Measurement Laboratory
Equipment Options
Flexibility Smart Device
2150 Area Velocity Flow Module
Modularity• Up to 4 modules• Set up and
interrogate with 1 connection
• Together today• Separate tomorrow• Redundant system
Battery Powered
Area Velocity Flow Measurement
• Q = A x V– Q is Flow– A is Area
• Level Measurement– Pressure sensor– Ultrasonic
– V is Velocity• Doppler
– Contact – 2150/350 AV Sensor– Non-contact - LaserFlow
Doppler Velocity Measurement
Q = A x V
A = Pressure V = Doppler
Return Spectrum
CWD Velocity Measurement
24" Pipe 0.25% 1780 gpm 8" 4.507 ft/s2150 201K01367 v1.12 Probe 203F00288
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500
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-400 -200 0 200 400 600 800 1000
Frequency
Sig
nal S
treng
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Continuous Wave Doppler• Advantages
– Works well in depths lower than 24” typically
– 5 – 10% normally– Shotgun pattern
• Good approximation of fluid velocity
– Low power consumption
– Portable– Lower cost
• Disadvantages– Sensor in fluid
• Debris• Rags• Damage• Calibration
– Shotgun pattern• Velocity accuracy
degrades >24”• Better for smaller
pipes
ADFM (Large Pipe)
Acoustic Doppler – Range Gating
Teledyne Isco is proud to present…..
• AccQpulse!
accQPulse Sensor
Velocity Diagnostics
Signal StrengthCorrelation-
Similar to 2150 spectrum
Velocity Bins
Pulse Doppler• Advantages
– Works well in depths above 5” typically
– 2% flow accuracy– Velocity profiling
• Discrete velocity measurement
• Up to 20’ water depth
– Portable or permanent– Non-drifting ultrasonic
level sensor– No calibration
• Disadvantages– Sensor mounted on
the bottom of the channel
• Debris• Rags• Damage
– Needs >5”– Cost– Power– Installation in large
pipe flow
Why use a non-contact flow sensor?
• Safety• Maintenance
Unlock the door to a successful flow monitoring
program
oLaserFlow
Theory of operation
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LaserFlow Sensor
Return DopplerSignal Light
Flowing Water Stream
V
Below Surface
Ultrasonic Principle of Operation
• Sensor angle prevents moisture accumulation
• Deflector Plate– Dead Band
inside sensor– Zero Dead Band
• Range 0 – 10 feet
0-10 ft
Off-axis reflected energy is weak and misdirected.
On-axis reflected energy is directed back to the sensor. However, the unfocused energy is very weak.
On-axis and focused reflected energy is directed back to the sensor with much intensity.
The frequency shift between the transmitted indicates the flow direction. The magnitude of the shift indicates the velocity.
Theory of Operation
Below the surface
5000 Spectral Velocity Readings
Point of Convergence
In 2 seconds!
Laser Velocity Spectrum
5000 Spectral Samples
Doppler Shift
5000 Spectral Samples
Doppler Shift
Signal
Noise
Doppler Power
Minimum of 1,000
Reading Stored in Memory
Measurement of reading quality
Velocity Diagnostics
Ultrasonic Level Measurement
Laser Velocity Measurement
Multi-point/Multi-depth Velocity Method
Signature Velocity Grid
Sanitary Sewer
Overflow
Pumps turned off created surcharge
Laser was under 15’ of water
Submerged Laser
LaserFlow Fully SubmergedCWD sensor reading velocity
Pressure Sensor reading depth
Typical applications• Collection systems
– Large Pipes (>36”)– Small Pipes (<36”)
Lab Tests
Accuracy
• Current published specification– 4% of Reading
• 3rd Party Tests Results• ITRC (Irrigation Training and Research Facility)
Cal Poly San Luis Obispo, CA– 1.8% Absolute Error
• Alden Research Lab– 2.7% Absolute Error
Acoustic Doppler – Range Gating
LaserFlow vs Pulse Doppler 2%
Multipath Transit Time
LaserFlow vs Transit Time 2%
Installation in front of flume
LaserFlow vs Flume
Low Level/High Velocity
• 1/2”Minimum depth for velocity!
• 15 ft/second maximum velocity!
High Velocity
Slow Velocity
Slow Velocity
Extreme Monitoring
Below 1”
From 6ft/sec to
2ft/sec
2912 Doppler Power
supportreading
Less than 1 GPM
Water level drops as it exits the pipe creating 2 level plains
Application Challenge: Drop Pipe
Remote Ultrasonic Level Sensor
X
Allows LaserFlow to adapt for elevated discharge
Improves performance and flow accuracy
Application Challenge: Rotating Bar Screen Blockage
Pump Station Flow
Storm Water
Laser Doppler• Advantages
– Non-contact flow measurement
– 5,000 readings in 2 seconds
– Multipoint Velocity– Large or small pipes– 4% flow accuracy– Works well in depths
from .5” up to 120” with no decrease in accuracy
– Lowest velocity measurement <.5ft/sec
– Portable or permanent– Non-drifting ultrasonic
level sensor
• Disadvantages– Cost
• > Continuous Wave
• < Pulse Doppler
– Power• DC Applications
– May not work in steam, foam or fog applications
Applications
• Continuous Wave Doppler– I & I Studies– Remote low power applications
• Pulse Doppler– High accuracy billing– Irregular velocity profile
• LaserFlow– High accuracy large or small pipe– Dangerous site conditions– Good hydraulic velocity profile
Summary
• One size doesn’t fit all• Multiple technologies may be required for a
successful monitoring program• Understanding the application is as
important as the technology itself
Teledyne Isco Flow Meters
Questions?