Unit �II Flow Meters1

Unit –II Flow Meters : 

Unit –II Flow Meters S.Vivekanandan Vivek_shanaras@yahoo.co.in

Factors Affecting the Flow Rate : 

Factors Affecting the Flow Rate Fluid Velocity Fluid Density Fluid Viscosity Fluid Friction in Contact with Pipes

Types of Flow : 

Types of Flow Laminar Flow Turbulent Flow Re<2000 Re>4000

Quantities to be measured : 

Quantities to be measured Volume Flow Rate Mass Flow Rate Fluid Velocity

Classification of flow meters : 

Classification of flow meters Head Type – Orifice, Venturi ,Flow nozzle Area Type – Rota meter, Piston type Mass Flow –Turbine, Calorimeter Coriolis, Thermal Electrical – Electromagnetic, Ultrasonic Vortex, Solid flow measurement techniques Positive displacement flow meters

Flow Sensors : 

Flow Sensors Volume flow rate sensors: Differential Pressure Orifice Nozzle Venturi Elbow Pitot Tube Wedge Positive Displacement Nutating Disk Oscillating Piston Oval Gear Diaphragm Gas Meter Turbine & Impeller Variable Area Movable Vane Rotameter

Mass flow rate sensors: : 

Mass flow rate sensors: Coriolis Mass Thermal Mass Heated Tube Immersion Probe Turbine Flow Meter Angular Momentum Electrical type

Flow Velocity : 

Flow Velocity • Ultrasonic Doppler Effect Transition Time • Magnetic • Vortex • Target

Positive Displacement Flow Meter : 

Positive Displacement Flow Meter

NUTATING DISK : 

NUTATING DISK

ROTATING VANE : 

ROTATING VANE

ROTATING LOBE (ROOTS) : 

ROTATING LOBE (ROOTS)

Piston type +ve Flow sensor : 

Piston type +ve Flow sensor

Oscillating Piston : 

Oscillating Piston Oil metering in motor test Proper for Dirty Liquids Solid size permitted :200”-74 mic

Rotameter : 

Rotameter Low Cost Easy Installation Linear Output

Turbine-Electrical Mass Flow meter : 

Turbine-Electrical Mass Flow meter

Turbine Flow meter : 

Turbine Flow meter It consist of a turbine on which a magnet is mounted.Each time magnet passes the pickup coil it produces output in form of pulse and these can be counted, or frequency to voltage converter can be used to measure the fluid flow.

Turbine –Angular momentum : 

Turbine –Angular momentum

CORIOLIS MASS FLOW METER : 

CORIOLIS MASS FLOW METER

Corio contd : 

Corio contd

Corio - contd : 

Corio - contd Flow rate is measured by Coriolis effect (1835) Mass flowrate, vol. flowrate, temp. and density are simultaneously measured. High Initial cost High accuracy Independent of Changes in Density Viscosity Pressure Temperature

Corio -contd : 

Corio -contd

Thermal mass (Heated tube) : 

Thermal mass (Heated tube) Independent of Changes in Density Viscosity Pressure Clear fluid Proper for low velocity fluids

Magnetic flow meters : 

Magnetic flow meters Based upon Faraday’s Law The fluid is the conductor, must be electrically conductive. E = B D V x 10-8 E=voltage, volts B=magnetic flux density, gauss D= length of the conductor, cm V=velocity of the conductor, cm/sec

Industrial Magnetic flow meter : 

Industrial Magnetic flow meter

Ultrasonic Flowmeters : 

Ultrasonic Flowmeters

Doppler effect : 

Doppler effect It is a non-contact method of finding instantaneous flow velocity of fluid. The fluid requires contamination for scattering of. It is based on Doppler shift phenomenon, in which the frequency of the scattered light from the moving object is different from that of incident beam by an amount proportional to the fluid velocity. Shift in frequency is determined by signal processing

Ultrasonic Doppler Effect : 

Ultrasonic Doppler Effect Obstruct less flow Clamp-on installation Proper for fluid with suspended particles Proper for corrosive liquids

Vortex Flow meter : 

Vortex Flow meter

Vortex Shedding Meter Principle : 

Vortex Shedding Meter Principle An ultrasonic beam, located downstream from a small strut, is transmitted through the vortex pattern. As the vortices travel through the beam, they modulate its carrier wave. This signal is immediately processed electronically which provides an exact reading of the flow rate. Because the number of vortices formed is directly proportional to the rate of flow, It provides a highly accurate and extremely useful method to determine flow in a wide range of application

Target Flow Meter : 

Target Flow Meter

Laser Doppler Anemometer : 

Laser Doppler Anemometer

Industrial Flow Meter Usage : 

Industrial Flow Meter Usage Orifice meter – 50.3% Thermal mass – 46.8% Turbine – 46.6

I appreciate your interest and attention : 

I appreciate your interest and attention