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Chapter 5 INTC 1305 – 01
FLOW
Vern Wilson
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Innage/outage
Floats
Interface
Meniscus
Density and head
Chapter 5
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Pipeline Meter Run #117 avi
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These instruments measure FLOW
Fluid in motion
Always from hi to lo p
Molecules continually change
Laminar - streamline
Turbulent
Obstructions mess up smooth flow
Usually turbulent flow is consistent
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Identifies type of flow – turb or lam
R=vxdxϱ/μ
v = velocity
d = diameter
ϱ = density
μ = viscosity
> 4000 = turbulent
> 10,000 = fully turbulent
< 2,000 = laminar
Between 2,000 and 4,000 = transient
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Positive Displacement
◦ Measures absolute volumes
◦ Uses chambers of known volume
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Percentage flow
◦ Based on known flow at 100%
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Volumetric Flow
◦ GPM
◦ MCFD
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Mass Flow
◦ Pounds per time
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Differential Pressure
Bernoulli – page 109
As velocity increases the static pressure of
the fluid decreases
Flow devices: Orifice (differential flow
meters), Venturi, Flow Nozzles, pitot tubes,
Annubar tubes, rotameters, electromagnetic
meters, turbine meters, mass flow meters
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Simple pressure drop
Flat upstream – bevelled downside
Set in tapped flanges
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Higher cost but lower op costs
Smooth cone shaped
As speeds increase in the throat the pressure
is reduced according to Bernoulli
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Extended tapered inlet
Can be inserted into a flange
Allow higher flow then orifice plates - twice
Can handle slurries
Less $ than venturi but more than orifice
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Measures impinging pressure
Disadvantage – measures flow at only one
point
Can’t measure laminar flow
ANNUBAR or MULTI PORT
Pitot with several ports
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Based on gravity and impinging pressure
Tapered flow tube with a float
Flow tube calibrated to flow
Only give an estimate of flow
Float can be magnetized inside steel tube
Designed for specific small range
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Or Magmeters – no metal in body
Measures electrically conductive liquids
Generally water based
Obstruction free – noninvasive
Food and drug use
Based on Faraday’s law of induction – an
electrical potential is produced when a
conductor moves at a right angle through a
magnetic field
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Flow tube with free spinning turbine
One blade is magnetic
Induction pick up coil
Each pulse indicates a rotation of the turbine
Simply multiply a K factor times the number
of sensor pulses
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CORIOLIS METER
They measure density through temperature
and pressure
Tube vibrates and twists giving a velocity
difference which is converted to flow
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Most common
Responds to pressure
Flow is proportional to square root of dp
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FLOW MEASURED IN:
 GPM
 POUNDS PER MINUTE
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An injection program requires 100 barrels of
injection fluid per day.
How many GPM is equal to 100 barrels per
day?
First: There are 42 gallons per barrel
Second: Convert to GPM
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We are pumping mud that weighs 10.9
pounds per gallon at 4 barrels per minute.
How many pounds per minute are we
pumping?
First: Determine how many pounds are we
pumping – 4 barrels = 42 gals/barrel
Second: Determine how many pounds per
minute.