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FLOW MEASUREMENT & MEASUREMENT OF LIQUID LEVEL - Coggle Diagram
FLOW MEASUREMENT & MEASUREMENT
OF LIQUID LEVEL
FLOW MEASUREMENT
Elements needs to consider during FLOW
MEASUREMENT
4) laminar or turbulent
5) pressure
3) hazardous/corrosive or safe
2) wet or dry
1) Clean or dirty
6) temperature
7) flow rate
A technique used in any process requiring the transport of a
material from one point to another.
measuring devices categories
Secondary devices (rate meter)
Variable head meter
pitot tube
advantages
No pressure loss in the flow system.
Easily inserted to a small hole.
Simple and low cost.
useful in checking the mean velocities.
know as the air-speed indicator used in
aircrafts.
static pressure + dynamic pressure = total pressure
(Ps + ρ x (V^2)/2 ) = P1
Primary devices (quantity meter)
Measure the amount of fluid in terms of mass or volume
Advantages: Simple, economic and extremely
accurate.
commonly used device
Nutating Disc Meter
application: domestic water system.
desccription of process
1) water flows directly into meter housing
2) water flows through the meters internal
strainer before it enters measuring chamber
3) strainer do protects measuring chamber
due to debris in the water
1 more item...
Sliding Vane Type Meter
application: dispensing petrol/diesel in the
fuel filling station.
is vane type of positive displacement flow meter, creating high accuracy management and low pressure loss by decreasing rotation resistance
due to small revolution resistance, it gives large volume management with low pressure loss
Lobed Impeller Flow Meter
application: metering of gas and
redefined petroleum products
A type of positive displacement meter in which a fluid stream is separated into discrete quantities by rotating, meshing impellers driven by interlocking gears
Bernoulli Equation
P1 + (ρv1)^2 /2 + ρgh1 = P2 + (ρv2)^2 /2 + ρgh2
Re = (ρ u2) / (μ u / L)
If Re < 2000 = laminar flow.
If Re > 4000 = turbulent flow.
If 2000<= Re <= 4000 = Critical zone between
laminar & turbulent.
