Agenda
• Coriolis Flow Meter Theory of Operation
• Bunkering
• Marine Fuel Management
• Viscosity
• Questions
Coriolis Flowmeter Technology
Direct mass measurement is insensitive to fluid properties such as:
• Temperature
22 °C (40°F) Change
• Pressure
1027L
1000L
• Density
The same amount of fluid (1 Tonne)
looks like 2.7% (~$18) difference with
volumetric measurement
$54,000 difference on a
3000 Tonne bunker
1 Tonne
$654
Bunkers sold on mass but measured by inferred volume
2
Source: Bunkerworld, April 28th
1 Tonne.
$654
Theory of Operation
• The Coriolis effect is an inertia force.
• In 1835, Gustave-Gaspard de Coriolis showed that this inertia force must be taken
into consideration if the simple Newton’s Law of Motion of bodies are to be used
in a rotating frame of reference.
Gasparde de Coriolis
Coriolis Effect: The original path is deflected
westward by the rotation of the planet
Typical Components of a Coriolis Meter
Theory of Operation – Mass Flow
• In a Coriolis meter, the inertial force is provided by
vibrating the flow tubes. The tube twist or angle of
deflection from the vibration plane is measured and
converted into a mass flow measurement.
Micro Motion Confidential
Page 5
Theory of Operation – Mass Flow
•
Process fluid enters the sensor and flow is split with half the flow through each tube. The
sensor flow tubes are vibrated in opposition to each other by energizing a drive coil. Tubes
are oscillated at their natural frequency.
•
Magnet and coil assemblies, called pick-offs, are mounted on the flow tubes. As each coil
moves through the uniform magnetic field of the adjacent magnet it creates a voltage in
the form of a sine wave.
Micro Motion Confidential
Page 6
Theory of Operation – Mass Flow
•
•
During a no flow condition, there is no Coriolis effect and the sine waves are in phase with
each other.
When fluid is moving through the sensor's tubes, Coriolis forces are induced causing the
flow tubes to twist in opposition to each other. The time difference between the sine waves
is measured and is called Delta-T which is directly proportional to the mass flow rate.
Theory of Operation – Mass Flow
• The Flow Calibration Factor consists of 10 characters, including two decimal
points.
– The first five digits are the flow calibration factor. This calibration factor, multiplied by
a given Delta-T, yields mass flow rate in grams/sec.
– The last three digits are a temperature coefficient for the sensor tube material. This
coefficient compensates for the effect of temperature on tube rigidity (% change in
rigidity per 100°C).

Three wire platinum RTD measures tube
temperature on inlet side of sensor
–
–
Accurate to +/- 1.0oC
Available as additional process variable
Applies to liquid and
gas, and is linear
throughout the entire
range of the meter
RTD
Micro Motion Confidential
Page 8
Theory of Operation - Density
Theory of Operation -Temperature
Coriolis Multi-Variable Capability
Three process variables measured independently
Direct Mass
Flow
On-Line
Density
Temperature
Coriolis Technology
Multi-Variable Measurement Capability
• Density-dependant variables are also available as either;
– Standard Curves (Brix, API, HFCS, etc)
– Customer-specific Curves (% Mass, % Volume, Alcohol, etc)




Degrees API
Degrees Baume
Degrees Brix
Degrees Plato




% Solids
% Mass
% Black Liquor
Concentration




Specific Gravity
Alcohol
% HFCS
SCFM
Mass Flow
Volume Flow
Density
Specific
Gravity
% Solids
By Volume
Net Solids
Temperature
Temperature
% Solids
By Mass
Mass Flow
Theory of Operation - Volume
• Volumetric Flow is a calculated variable.
Volume Flow 
Mass Flow
Densit y
• Volume can be referenced to standard temperature
using the temperature input.
• Coriolis meters are preferred for volume
measurements.
–
–
–
–
Low pressure drop
Wide turndown
High accuracy
High degree of linearity
Coriolis Sensor Geometries
• All Geometries are not created equal
• Design trade-offs are made for such things as;
–
–
–
–
–
–
–
Flow sensitivity & turndown
Density accuracy
Fluid S.G. range (gas/liquid)
Materials of construction
Temperature effects
Drainability and Cleanability
Pressure limits
Why Coriolis – Volume Measurement
•
Coriolis meters are unaffected by flow profiles,
and provide higher turndown than a typical
Orifice plate, Vortex
Flow conditioner
or Turbine
velocity-based volumetric
meters
42 D
No straight run





6D
No Reynolds # Limits
No parts to wear out
Limits leak points/fugitive emissions
Lower life cycle costs
Low installed costs
Marine Industry Applications
• Fuel Bunkering
• Engine Fuel Control
• Fuel Viscosity
Navy Supply
Platform
Pleasure Cruise
Cargo Ship
Benefits of a 1% Measurement Improvement
•
Bunker fuel represents 50-70% of total ship operating expense
Example: Large container ship-7,750 TEU
– Summer 2010 $455/tn*200tn/day*200 days operating = $18.2M
– Winter 2011 bunkers $655tn*200tn/day*300 days operating = $39.3M
– Next summer ????
•
What does a 1% measurement improvement mean to you?
– Last summer $182K potential savings
– Now $393K potential savings
– Reduced billing discrepancies
The technology is here today that can benefit suppliers, barge operators and shipping
companies