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Anayet Karim

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Course EvaluationCourse Evaluation

• Test 1Test 1• Test 2Test 2• Assignment 1Assignment 1• Assignment 2Assignment 2• Lab Module Lab Module • Final ExamFinal Exam

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Reference BookReference Book

Bartelt, “Industrial Control Bartelt, “Industrial Control Electronics: Devices, Systems Electronics: Devices, Systems

& Applications” 3/E, 2006& Applications” 3/E, 2006

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Topics Covered Topics Covered

• Flow ControlFlow Control

• Process Control MethodsProcess Control Methods

• Introduction to Programmable ControllersIntroduction to Programmable Controllers

• Introduction to PLC ComponentsIntroduction to PLC Components

• Fundamental PLC ProgrammingFundamental PLC Programming

• Motion ControlMotion Control

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Today’s Topic Today’s Topic

Flow ControlFlow Control

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SystemsSystemsConceptsConcepts

• Automated Automated systems that systems that control flow rates control flow rates or volume employ or volume employ the following the following components:components:– A SourceA Source– A PathA Path– A Control FunctionA Control Function– An ActuatorAn Actuator– A Measuring A Measuring

InstrumentInstrument

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Reasons for ControlReasons for Control

• To ensure the correct proportions of raw To ensure the correct proportions of raw materials are combined during the materials are combined during the manufacturing processmanufacturing process

• To ensure that ingredients are supplied at To ensure that ingredients are supplied at the proper rate during the mixing and the proper rate during the mixing and blending of the materialsblending of the materials

• To prevent a high flow rate than might To prevent a high flow rate than might cause pressure or temperatures to cause pressure or temperatures to become dangerous, overspills to occur, or become dangerous, overspills to occur, or machines to over speedmachines to over speed

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Flow Units of Flow Units of MeasurementMeasurement

• Common classifications used to Common classifications used to determine flow instruments are:determine flow instruments are:– Volumetric flow rate - in cubic feet, Volumetric flow rate - in cubic feet,

gallons, or liters per unit of time (this gallons, or liters per unit of time (this is an is an inferredinferred measurement) measurement)

– Mass flow rate - pounds, tons, grams, Mass flow rate - pounds, tons, grams, or kilograms per unit of timeor kilograms per unit of time

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Solid Flow MeasurementSolid Flow Measurement• Solid materials that are measured for mass flow Solid materials that are measured for mass flow

rate are typically small particles, powder, rate are typically small particles, powder, pellets, or crushed materialspellets, or crushed materials

• Conveyors are usually used to transport these Conveyors are usually used to transport these materialsmaterials

• Mass flow rate calculation:Mass flow rate calculation:

F =WS

L

F = Mass flow rate in lb/min

W = Weight of a material on a section of length

S = Conveyor speed in ft/min

L = Length of weighing platform

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Solid Flow Measurement-Solid Flow Measurement-Cont’dCont’d

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Fluid Flow MeasurementFluid Flow Measurement

• Important terms:Important terms:– Velocity - speed at which a fluid Velocity - speed at which a fluid

moves through a pipemoves through a pipe– Density - weight per unit volumeDensity - weight per unit volume– Viscosity - Ease of flow of a fluidViscosity - Ease of flow of a fluid– Pipe size - Diameter of the pipe Pipe size - Diameter of the pipe

carrying the fluidcarrying the fluid

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What Do You What Do You Understand?Understand?

• What is Flow Control?What is Flow Control?

• What is the purpose of Flow Control?What is the purpose of Flow Control?

• Flow units measurements HOW? (2 Flow units measurements HOW? (2 types)types)

• Solid Flow MeasurementsSolid Flow Measurements

• Fluid Flow MeasurementsFluid Flow Measurements

• What Elasticity & Viscosity?What Elasticity & Viscosity?

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Reynolds’ NumberReynolds’ Number

• A numerical scheme that A numerical scheme that represents the four preceding represents the four preceding factors on fluid flow (R number)factors on fluid flow (R number)

R =VDp

u

V = Velocity

R = Reynolds’ Number

D = Pipe inside diameter

p = Fluid density

u = Liquid viscosity

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Application of Reynolds’ Application of Reynolds’ NumberNumber• The R-number is used to identify the type of The R-number is used to identify the type of

flow likely to occur in a process: flow likely to occur in a process: laminar laminar flow,flow, turbulent turbulent flow, orflow, or transition transition flowflow

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Fluid Flow meter Fluid Flow meter ClassificationClassification• One method of classifying flow One method of classifying flow

meters is to divide them into the meters is to divide them into the following categories:following categories:– Differential PressureDifferential Pressure– Positive DisplacementPositive Displacement– VelocityVelocity– Direct Reading MassDirect Reading Mass

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Differential Pressure Flow Differential Pressure Flow metermeter

• Most common type of flow meterMost common type of flow meter• A restriction called an A restriction called an orifice orifice is placed is placed

on the flowon the flow• An orifice plate has a specified size hole An orifice plate has a specified size hole

bored through it, through which the bored through it, through which the liquid must flowliquid must flow

• Using Bernoulli’s Principle, the Using Bernoulli’s Principle, the differential pressure is measured across differential pressure is measured across the restriction and flow rates may be the restriction and flow rates may be calculatedcalculated

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Flow Restrictor TypesFlow Restrictor Types

• Conventional orifice plate

• Flow nozzle restrictor

• Venturi tube restrictor

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RotameterRotameter

• Also known as a Also known as a variable area flow variable area flow metermeter

• The float, when no The float, when no flow is present, flow is present, settles at a location settles at a location in the tube with the in the tube with the same diameter as same diameter as has the tubehas the tube

• As flow increases, As flow increases, the float raises to a the float raises to a higher level in the higher level in the tubetube

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Positive Displacement Positive Displacement MethodsMethods

• Rotary instruments that mechanically Rotary instruments that mechanically make direct measurements to the make direct measurements to the fluid by separating the fluid into fluid by separating the fluid into segments of known valuessegments of known values

• Two types of PD flow meters are Two types of PD flow meters are rotary-vane rotary-vane and and lobed impellerlobed impeller

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PD Flow PD Flow metersmeters

Rotary-vane Flow meter Lobed impeller flow meter

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Velocity Velocity MetersMeters

• Velocity meters measure the velocity of fluids directlyVelocity meters measure the velocity of fluids directly

• The most common type of velocity meter is the The most common type of velocity meter is the turbine flow turbine flow metermeter

• Essentially, the turbine flow meter is a flow-powered generatorEssentially, the turbine flow meter is a flow-powered generator

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Electronic Electronic SensorsSensors• Several electronic flow meters are Several electronic flow meters are

available at this time:available at this time:– The coriolis meterThe coriolis meter– The rotor flow detectorThe rotor flow detector– The electromagnetic flow detectorThe electromagnetic flow detector– The thermal flow meterThe thermal flow meter– The vortex flow meter The vortex flow meter – The ultrasonic flow meterThe ultrasonic flow meter– The time-of-flight meterThe time-of-flight meter

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• Built around a U-shaped tube that liquid flows throughBuilt around a U-shaped tube that liquid flows through

• The tube is caused to vibrate by induction of The tube is caused to vibrate by induction of fluctuating currentsfluctuating currents

• Flow through the tube causes it to twist proportionally Flow through the tube causes it to twist proportionally to the flow. The distortion of the tube is detected by to the flow. The distortion of the tube is detected by magnetic sensors and the resultant signal is magnetic sensors and the resultant signal is conditioned and sent to control equipmentconditioned and sent to control equipment

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What Do You What Do You Understand?Understand?

• What is REYNOLD’s Numer?What is REYNOLD’s Numer?

• What is the application of R Number?What is the application of R Number?

• Bernoullis Principles Bernoullis Principles

• What is RotameterWhat is Rotameter

• Positive Displacements methodsPositive Displacements methods

• Electronic SensorsElectronic Sensors

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Electromagnetic Electromagnetic Flow DetectorsFlow Detectors

• Electromagnetic flow Electromagnetic flow detector is a transducer detector is a transducer that converts the flow rate that converts the flow rate of a conductive substance of a conductive substance into a voltageinto a voltage

• Based upon Faraday’s law Based upon Faraday’s law of inductionof induction

• Used for difficult and Used for difficult and corrosive liquids and corrosive liquids and slurriesslurries

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Thermal Flow Thermal Flow metersmeters• Liquid in the flow stream carries Liquid in the flow stream carries

away heat from the thermistor, away heat from the thermistor, thereby raising its resistance, thereby raising its resistance, which unbalances a bridge circuitwhich unbalances a bridge circuit

• Thermal flow meters use a Thermal flow meters use a thermistor inserted into the flow thermistor inserted into the flow streamstream

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Figure Thermal flowmeter

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• A blunt object is placed A blunt object is placed in the flow path of the in the flow path of the liquid, and as liquid is liquid, and as liquid is forced around the forced around the object, vortices are object, vortices are formedformed

• The number of vortices The number of vortices formed downstream is formed downstream is directly proportional to directly proportional to the flow rate; the the flow rate; the vortices cause a vortices cause a change in the pressure change in the pressure at the vortices’ at the vortices’ location, which is then location, which is then measuredmeasured

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Ultrasonic Flow Ultrasonic Flow metersmeters

• Using the Using the Doppler EffectDoppler Effect, ultrasonic , ultrasonic flow meters measure flow by analyzing flow meters measure flow by analyzing the frequency shift of induced sound the frequency shift of induced sound waves in a flow process. The frequency waves in a flow process. The frequency shift is directly proportional to the flow shift is directly proportional to the flow rate of the liquidrate of the liquid

• This method is only used on liquids that This method is only used on liquids that have particles present, not for clear have particles present, not for clear liquidsliquids

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The Doppler ultrasonic flow meter

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Time-of-Flight Flow meterTime-of-Flight Flow meter

• For clear liquid flow measurements For clear liquid flow measurements using ultrasonic principles, the time-using ultrasonic principles, the time-of-flight flowmeter is usedof-flight flowmeter is used

• It is based upon the principle that the It is based upon the principle that the speed of sound transmitted in the speed of sound transmitted in the direction of flow will increase, and direction of flow will increase, and decrease if transmitted against the decrease if transmitted against the flowflow

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Time-of-Flight flow meter

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• Is the fluid a gas or a Is the fluid a gas or a liquid?liquid?

• Is the fluid corrosive?Is the fluid corrosive?• Is the fluid Is the fluid

conductive or not?conductive or not?• Does the fluid contain Does the fluid contain

a slurry or large a slurry or large solids?solids?

• What is the viscosity What is the viscosity of the fluid?of the fluid?

• Will the fluid density Will the fluid density or viscosity change?or viscosity change?

• Is there a need for a Is there a need for a noninvasive noninvasive approach?approach?

• What is the cost?What is the cost?

When selecting a flow meter, the following issues need to be considered:

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• What is Electromagnetic Flow DetectorsWhat is Electromagnetic Flow Detectors

• What is Thermal Flow MeterWhat is Thermal Flow Meter

• What is Vortex Flow MeterWhat is Vortex Flow Meter

• What is Ultrasonic Flow MeterWhat is Ultrasonic Flow Meter

• What Factors need to consider 4 Selecting Flow What Factors need to consider 4 Selecting Flow MeterMeter

What Do You Understand?What Do You Understand?

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•Is it clear all the topics for Is it clear all the topics for everybody everybody

•Anything doubtsAnything doubts

•Feel free to ask meFeel free to ask me

Want to Summarize Want to Summarize

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THANK YOU THANK YOU

OROR

TERIMA KASIHTERIMA KASIH