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FLOW MANAGEMENT, NAIF SHAHMI BIN SUKHAIMI(2018679698) - Coggle Diagram
FLOW MANAGEMENT
Primary devices(quantity meter)
Measure the amount of fluid in terms of mass or volume that flows past a given point in a definite period of time.
Used device
Nutating Disc Meter
Application : Domestic water system
Mechanism : 1. The liquid entersthe left side of the meter, alternatelyabove and below the disc
Forcing it to nutate in circular path
The liquid from the inlet causes the disc to nutate
Small spindle attached to the sphere tracesa circular path and used to drive the mechanical counter
Sliding-Vane-Type Meter
Application : DIspensing petrol in the fuel filling station
Mechanism : 1. The metered liquid entering the inlet revolves the rotor
2.The vanes around a cam causing the vanes to move radially
3.The nearest inlet port begins to move outwards and fully extended at point A
4.The vane at point B is already fully extended and measuring chamber is fomed between the two vanes and the meter body.
continuous series of chamber at the rate of 4 per revolution are formed which deliver flow at the outlet.
Lobed-impeller Meter
Application : Metering of gas and refined petroleum products
Mechanism : 1. The incoming fluid is trapped between the two rotors and is conveyed to the outlet as a result of rotation rotors.
For every rotation, the swept volume corresponding to twice the area A. passed through the meter.
The number of revolutions of the rotor gives an indication of volumetric flow.
Method
Volumetric
Fluid flowing in flow meter diverted into a tank
When tank is filled, this volume is compared with the integrated volumetric quantity
Gravimetric
Fluid flowing in flow water diverted into a vessel
When tank is filled, this volume is compared with the integrated gravimetric quantity
Advantages : Simple, economic, accurate.
Secondary Devices(rate meter)
Variable head meter-Pitot Tube
Commonly used
Know as the air-speed indicator used in aircrafts
Invented by Henri Pitot in 1732
Advantages
Simple & low cost
No pressure loss
Easily inserted to small hole
Useful in checking the mean velocities
Drawbacks
Sensitive to misalignment
Not suitable for highly fluctuating velocities
Not suitable for measuring low velocities < 5 m/s
Mechanism : 1. Pitot tube pointing directly into fluid flow
As this tube contains fluid, pressure can be measure.
The moving fluid is brought to rest (stagnates) as there is no outlet to allow flow to continue
Formula 1 : Pt(Total Pressure) = Ps(Static Pressure)+( p(density) u(velocity)^2 / 2 )
Formula 2 : h2-h1 = (P2-P1) / pg
Example : Aircraft
NAIF SHAHMI BIN SUKHAIMI(2018679698)
