27-12-2012, 04:54 PM
Fluid Mechanics & Hydraulic machines
Fluid Mechanics.ppt (Size: 1.29 MB / Downloads: 155)
Flow measurement
Important variable in plant operation
Measured primarily for determining the amount of fluid flowing
Fluid types
Less or highly viscous
Clear or opaque
Clean or dirty
Wet or dry
Erosive or corrosive
Fluid flow – steam line
Occurs at low velocities
All parts flowing in one direction parallel to walls
Change in cross section means change in direction of flow
Pressure drop ∞ flow velocity
Types of flow meters
Head type meters
Rota meter (variable –area type)
Electromagnetic type
Mechanical type
Anemometer
Ultrasonic flow meter
Vortex flow meter
Orifice meters
Head type meter used for large &medium pipes
Orifice plate- inserted to pipe to create a partial restriction to flow
Pressure before orifice plate rises and pressure after it reduces but velocity increases
Types of orifice plate
If fluid contains suspended materials , particles tend to settle down in orifice,- to avoid this- segmented or ccentric type used