1. KROHNE Ultrasonic Flowmeters
A complete range of solutions
2014

2. KROHNE Ultrasonic Flowmeters
Introduction
KROHNE’s Ultrasonic Family
Measuring Principle
Typical Applications
Conclusion
KROHNE Ultrasonic Flowmeters
A complete range of solutions
2014

3. Introduction Milestones
In the 1920’s Methods and devices for volume measurement of flowing liquids, gas and steam volumes
In the 1950’s Introduction of the first ultrasonic flowmeters
In the 1960’s First ultrasonic flowmeters with multiple paths with the differential transit time method
In the 1980’s Introduction of a multi-path flowmeters for measuring gases.
Today
1900
Today
1950
2000
Patent Oskar Rütten
We can look first at the historical development of ultrasonic flow measurement. The use of ultrasound in flow measurement began in the last century
when, in the 1920’s, Oskar Rütten patented his method and apparatus for measuring the volume of flowing liquids, gas and steam.
The first ultrasonic flowmeters were introduced in the 1950’s,
and in the 1960’s different companies developed the first ultrasonic flowmeters using the differential transit time method. At this time the first clamp-on ultrasonic flowmeter was also launched onto the market.
KROHNE has been developing inline ultrasonic flowmeters since the end of the 1970’s. The first multi-path ultrasonic flowmeters for measuring gases were finally introduced at the start of the 1980’s.
However the main breakthrough in ultrasonic flow measurement has come in the last 10 to 20 years, which have seen the breakthrough of digital measurement. The exact recording and analysis of transit times has become increasingly accurate, which of course has made the measuring device extremely interesting to industry.
Today there are several different technologies on the market for ultrasonic flow measurement, with a wide range of applications. But how does ultrasonic flow measurement function today ? What should we know and what are the essential characteristics?
3 | Ultrasonic flowmeters

4. KROHNE Ultrasonic Flowmeters
Introduction
KROHNE’s Ultrasonic Family
Measuring Principle
Typical Applications
Conclusion
KROHNE Ultrasonic Flowmeters
A complete range of solutions
2014

5. KROHNE’s Ultrasonic Flowmeter Family
liquid
gas
steam
clamp-on
OPTISONIC 6300
OPTISONIC 6400
in-line
OPTISONIC 3400
UFM 530 HT
OPTISONIC 7300
OPTISONIC 8300 F
custody transfer
ALTOSONIC III
ALTOSONIC V
ALTOSONIC V12

6. OPTISONIC 3400 Standard for the bulk of applications
Robust and compact construction
Wide diameter range: 1…120”
For conductive and non-conductive liquids
For all environments: incl. hazardous areas
FM or CSA Division 1 & 2
ATEX zone 1, IEC-Ex
For process conditions:
Liquid temperatures -45…+140/180 °C / -49…+284/356 °F
Viscosity up to 100 cSt
Bulk of applications include:
Hydrocarbons, solvents, purified-, surface-, ground water, cooling water, low viscous oils, kerosene, naphtha, acids, glycol, ammonia, warm water, diesel, jet fuel, Crude Oils, etc.
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OPTISONIC 3400

7. OPTISONIC 6300 Design Features and Benefits
All in one system
One or Two Paths
1 Pipe or 2 Pipes
More with less
Modular electronics

8. OPTISONIC 6300 Design Features and Benefits
End cap (die-cast aluminum)
fast screw
OPTIFLUX 5000 | key features
cover (extruded aluminum)
rail (extruded aluminum)
connector cap (die-cast aluminum)
screws (connector cap to rail)
Floating transducer
Strap Fixation & Snap unit (SS)
Metal strap (SS)
signal cable (dual coax)

9. OPTISONIC 6300 = OPTISONIC 6000 + UFC 300
FAE

10. Special constructions
High Pressure, Up to bar ( psig)
Heating jacket
Flangeless
or with special
connection

11. KROHNE Ultrasonic Flowmeters
Introduction
KROHNE’s Ultrasonic Family
Measuring Principle
Typical Applications
Conclusion
KROHNE Ultrasonic Flowmeters
A complete range of solutions
2014

12. vm = Flow velocity of the medium
Measuring principle: Ultrasonic Differential transit time – Medium independent 1/3 1
Distance
Velocity
Transducer A
Transit time (t) =
TBA -
TAB
~ vm vm
Transducer B
vm = Flow velocity of the medium
In order to understand the technical background, but without going too deeply into the construction of an ultrasonic flowmeter, we can look at the most important features:
The transducers, which are always in pairs and mounted under an angle, consist of a transmitting and a receiving transducer,
which we can call transducer A and transducer B. The two transducers act both as signal transmitter and signal receiver.
The time an acoustic wave needs to travel from transducer A to transducer B, that is in the flow direction of the medium,
is known as transit time T AB and
from transducer B to transducer A, that is against the flow direction,
T BA. The transit times T BA and T AB are measured continuously.
The difference in transit time T BA to T AB is directly proportional to the average flow velocity vm of the medium.
12 | Ultrasonic flowmeters

13. Measuring principle: Ultrasonic Differential transit time – Medium independent 2/3
TBA
Transit time (t) =
TAB
~ vm - 1
Distance
Velocity
Transducer A L v D 2
L CAB + v * cos a
Transit time of the signal from A to B
TA B = α
v • cos α
Transducer B 3
L CBA - v * cos a
TB A =
Transit time of the signal from B to A
Let’s see why ultrasonic flow measurement is completely independent of the medium.
As we can see in equation 1, the transit time of a signal is
the distance between transducer A and transducer B
divided by the velocity which the acoustic signal needs to travel from one transducer to the other.
Equations 2 and 3 describe the time the acoustic signal needs from transducer A to transducer B
and from transducer B to transducer A. The transit time of the signal is measured and then used with other variables to calculate the flow. Although the signal travels in a straight line,
it is travelling at an angle, Alpha, to the pipe axis. Equations 2 and 3 define the flow rate between transducer A „upstream“ and B „downstream“.
The transit time is shorter when the acoustic signal is transmitted „downstream“, that is in direction of the flow of the medium, equation 2,
than when it is transmitted „upstream“, that is against the direction of the flow, equation 3. The transit times are measured in rapid succession, tens of times a second.
In practice we can assume that since neither the temperature, nor the pressure, nor the composition of the medium will change in these intervals, that is within milliseconds, they remain constant. So, during the transit time period, the velocity of sound can also be seen as constant.
v = Flow velocity of the medium
L = Length of the acoustic path
C = Velocity of sound of the medium
Temperature, pressure and consistency of the medium = constant
13 | Ultrasonic flowmeters

14. Introduction Ultrasonic flowmeters: Typical advantages
Low Cost of Ownership
No moving parts
No wear
No maintenance
No recalibration
Very robust and reliable
Universal, works with any medium
Bi-directional
No obstructions in the pipe
No pressure loss
Excellent low flow sensitivity, starts measuring from zero flow on up
transducer A
transducer B D
The difference in transit time is proportional to the mean flow velocity of the medium
OPTISONIC 3400

15. Reynolds Number & Flow Profile
Measuring Principle
VAVG
Laminar flow
VAVG = Vm * 0.66
Reynolds Number & Flow Profile
SINGLE Beam through pipe axis….
Accuracy: 1-2% for Re > 10,000 – 20,000
Highly dependent on flow profile
Error from laminar to turbulent flow can be as high as 33% Vm
Turbulent flow
VAVG = Vm * 1.00
VAVG Vm

16. Reynolds Number & Flow Profile
Measuring Principle
Reynolds Number & Flow Profile
VAVG
Three Chordal Measurement Beams
More information on flow profile
Three individual line velocities, VL1-3 are integrated together using constants K1-3;
VAVG = K1*VL1 +K2*VL2 + K3*VL3
High accuracy over complete Reynolds range
Better performance with non-symmetric and distorted flow profiles
Accuracy: +/- 0.3% of rate VL
VAVG VL

17. Measurement Principle
Restriction for UFM
Effect Guideline
1. Gas bubbles Reflections Vol.%  2%
2. Solids Reflections Vol. %  5%
Reflection of acoustic signal due to gas bubbles or solids

18. KROHNE Ultrasonic Flowmeters
Introduction
KROHNE’s Ultrasonic Family
Measuring Principle
Typical Applications
Conclusion
KROHNE Ultrasonic Flowmeters
A complete range of solutions
2014

19. UFM 3400 Water & Wastewater Measurement of: Wastewater Demi water
Cooling water
Boiler feed water
Potable water
Produced water
Seawater
Raw water
Irrigation water
… many more

20. Ultrasonic Flowmeters Target markets
Oil and Gas:
Crude oil: on- and offloading, transportation, storage, allocation, blending
LNG
Oil and Gas
Chemical industry:
Feedstock, intermediate and end products
Solvents
Liquid polymers
Cooling water
Chemical industry
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OPTISONIC 3400
Slide 20

21. Ultrasonic Flowmeters Target markets
Petrochemical industry and refineries:
Crude oil
Refined hydrocarbons
Petrochemical industry and refineries
Energy:
Crude oil
Feed water, condensate, heated water, penstock water
Energy
Water industry and utilities:
De-mineralized water
Raw water
Heated water
Water industry and utilities
OPTISONIC 3400
Slide 21

22. KROHNE Ultrasonic Flowmeters
Introduction
KROHNE’s Ultrasonic Family
Measuring Principle
Typical Applications
Conclusion
KROHNE Ultrasonic Flowmeters
A complete range of solutions
2014

23. Benefits of Ultrasonic Flowmeter
Comparison Table
Flow meter
Technology
Non conductive
Liquids
Viscosity
Corrosion resistance
Solids, Bubbles
Low flow
Pressure loss
Dynamic range
UFM ++
+/-
Coriolis
mass + --
EMF
DP meter -
Vortex
PD meter
Turbine
+ = positive, - = negative

25. Thank you for your attention!