1. 1 Anayet Karim

2. 2 Course Evaluation Test 1Test 1 Test 2Test 2 Assignment 1Assignment 1 Assignment 2Assignment 2 Lab ModuleLab Module Final ExamFinal Exam

3. 3 Reference Book Bartelt, “Industrial Control Electronics: Devices, Systems & Applications” 3/E, 2006

4. 4 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

5. 5 Today’s Topic Flow Control

6. 6 Systems Concepts Automated systems that control flow rates or volume employ the following components: Automated systems that control flow rates or volume employ the following components: –A Source –A Path –A Control Function –An Actuator –A Measuring Instrument

7. 7 Reasons for Control To ensure the correct proportions of raw materials are combined during the manufacturing process To ensure the correct proportions of raw materials are combined during the manufacturing process To ensure that ingredients are supplied at the proper rate during the mixing and blending of the materials To ensure that ingredients are supplied at the proper rate during the mixing and blending of the materials To prevent a high flow rate than might cause pressure or temperatures to become dangerous, overspills to occur, or machines to over speed To prevent a high flow rate than might cause pressure or temperatures to become dangerous, overspills to occur, or machines to over speed

8. 8 Flow Units of Measurement Common classifications used to determine flow instruments are: Common classifications used to determine flow instruments are: –Volumetric flow rate - in cubic feet, gallons, or liters per unit of time (this is an inferred measurement) –Mass flow rate - pounds, tons, grams, or kilograms per unit of time

9. 9 Solid Flow Measurement Solid materials that are measured for mass flow rate are typically small particles, powder, pellets, or crushed materials Solid materials that are measured for mass flow rate are typically small particles, powder, pellets, or crushed materials Conveyors are usually used to transport these materials Conveyors are usually used to transport these materials Mass flow rate calculation: Mass flow rate calculation: 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

10. 10 Solid Flow Measurement-Cont’d

11. 11 Fluid Flow Measurement Important terms: Important terms: –Velocity - speed at which a fluid moves through a pipe –Density - weight per unit volume –Viscosity - Ease of flow of a fluid –Pipe size - Diameter of the pipe carrying the fluid

12. 12 What Do You 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 types) Flow units measurements HOW? (2 types) Solid Flow Measurements Solid Flow Measurements Fluid Flow Measurements Fluid Flow Measurements What Elasticity & Viscosity? What Elasticity & Viscosity?

13. 13 Reynolds’ Number A numerical scheme that represents the four preceding factors on fluid flow (R number) A numerical scheme that represents the four preceding factors on fluid flow (R number) V = Velocity R = Reynolds’ Number D = Pipe inside diameter p = Fluid density u = Liquid viscosity

14. 14 Application of Reynolds’ Number The R-number is used to identify the type of flow likely to occur in a process: laminar flow, turbulent flow, or transition flow The R-number is used to identify the type of flow likely to occur in a process: laminar flow, turbulent flow, or transition flow

15. 15 Fluid Flow meter Classification One method of classifying flow meters is to divide them into the following categories: One method of classifying flow meters is to divide them into the following categories: –Differential Pressure –Positive Displacement –Velocity –Direct Reading Mass

16. 16 Differential Pressure Flow meter Most common type of flow meter Most common type of flow meter A restriction called an orifice is placed on the flow A restriction called an orifice is placed on the flow An orifice plate has a specified size hole bored through it, through which the liquid must flow An orifice plate has a specified size hole bored through it, through which the liquid must flow Using Bernoulli’s Principle, the differential pressure is measured across the restriction and flow rates may be calculated Using Bernoulli’s Principle, the differential pressure is measured across the restriction and flow rates may be calculated

17. 17 Flow Restrictor Types Conventional orifice plate Flow nozzle restrictor Venturi tube restrictor

18. 18 Rotameter Also known as a variable area flow meter Also known as a variable area flow meter The float, when no flow is present, settles at a location in the tube with the same diameter as has the tube The float, when no flow is present, settles at a location in the tube with the same diameter as has the tube As flow increases, the float raises to a higher level in the tube As flow increases, the float raises to a higher level in the tube

19. 19 Positive Displacement Methods Rotary instruments that mechanically make direct measurements to the fluid by separating the fluid into segments of known values Rotary instruments that mechanically make direct measurements to the fluid by separating the fluid into segments of known values Two types of PD flow meters are rotary-vane and lobed impeller Two types of PD flow meters are rotary-vane and lobed impeller

20. 20 PD Flow meters Rotary-vane Flow meter Lobed impeller flow meter

21. 21 Velocity Meters Velocity meters measure the velocity of fluids directly Velocity meters measure the velocity of fluids directly The most common type of velocity meter is the turbine flow meter The most common type of velocity meter is the turbine flow meter Essentially, the turbine flow meter is a flow-powered generator Essentially, the turbine flow meter is a flow-powered generator

22. 22 Electronic Sensors Several electronic flow meters are available at this time: Several electronic flow meters are available at this time: –The coriolis meter –The rotor flow detector –The electromagnetic flow detector –The thermal flow meter –The vortex flow meter –The ultrasonic flow meter –The time-of-flight meter

23. 23 Built around a U-shaped tube that liquid flows through Built around a U-shaped tube that liquid flows through The tube is caused to vibrate by induction of fluctuating currents The tube is caused to vibrate by induction of fluctuating currents Flow through the tube causes it to twist proportionally to the flow. The distortion of the tube is detected by magnetic sensors and the resultant signal is conditioned and sent to control equipment Flow through the tube causes it to twist proportionally to the flow. The distortion of the tube is detected by magnetic sensors and the resultant signal is conditioned and sent to control equipment

24. 24 What Do You 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 Rotameter What is Rotameter Positive Displacements methods Positive Displacements methods Electronic Sensors Electronic Sensors

25. 25 Electromagnetic Flow Detectors Electromagnetic flow detector is a transducer that converts the flow rate of a conductive substance into a voltage Electromagnetic flow detector is a transducer that converts the flow rate of a conductive substance into a voltage Based upon Faraday’s law of induction Based upon Faraday’s law of induction Used for difficult and corrosive liquids and slurries Used for difficult and corrosive liquids and slurries

26. 26 Thermal Flow meters Liquid in the flow stream carries away heat from the thermistor, thereby raising its resistance, which unbalances a bridge circuit Liquid in the flow stream carries away heat from the thermistor, thereby raising its resistance, which unbalances a bridge circuit Thermal flow meters use a thermistor inserted into the flow stream Thermal flow meters use a thermistor inserted into the flow stream

27. 27 Figure Thermal flowmeter

28. 28 A blunt object is placed in the flow path of the liquid, and as liquid is forced around the object, vortices are formed A blunt object is placed in the flow path of the liquid, and as liquid is forced around the object, vortices are formed The number of vortices formed downstream is directly proportional to the flow rate; the vortices cause a change in the pressure at the vortices’ location, which is then measured The number of vortices formed downstream is directly proportional to the flow rate; the vortices cause a change in the pressure at the vortices’ location, which is then measured

29. 29 Ultrasonic Flow meters Using the Doppler Effect, ultrasonic flow meters measure flow by analyzing the frequency shift of induced sound waves in a flow process. The frequency shift is directly proportional to the flow rate of the liquid Using the Doppler Effect, ultrasonic flow meters measure flow by analyzing the frequency shift of induced sound waves in a flow process. The frequency shift is directly proportional to the flow rate of the liquid This method is only used on liquids that have particles present, not for clear liquids This method is only used on liquids that have particles present, not for clear liquids

30. 30 The Doppler ultrasonic flow meter

31. 31 Time-of-Flight Flow meter For clear liquid flow measurements using ultrasonic principles, the time-of-flight flowmeter is used For clear liquid flow measurements using ultrasonic principles, the time-of-flight flowmeter is used It is based upon the principle that the speed of sound transmitted in the direction of flow will increase, and decrease if transmitted against the flow It is based upon the principle that the speed of sound transmitted in the direction of flow will increase, and decrease if transmitted against the flow

32. 32 Time-of-Flight flow meter

33. 33 Is the fluid a gas or a liquid? Is the fluid a gas or a liquid? Is the fluid corrosive? Is the fluid corrosive? Is the fluid conductive or not? Is the fluid conductive or not? Does the fluid contain a slurry or large solids? Does the fluid contain a slurry or large solids? What is the viscosity of the fluid? What is the viscosity of the fluid? Will the fluid density or viscosity change? Will the fluid density or viscosity change? Is there a need for a noninvasive approach? Is there a need for a noninvasive approach? What is the cost? What is the cost? When selecting a flow meter, the following issues need to be considered:

34. 34 What is Electromagnetic Flow Detectors What is Electromagnetic Flow Detectors What is Thermal Flow Meter What is Thermal Flow Meter What is Vortex Flow Meter What is Vortex Flow Meter What is Ultrasonic Flow Meter What is Ultrasonic Flow Meter What Factors need to consider 4 Selecting Flow Meter What Factors need to consider 4 Selecting Flow Meter What Do You Understand?

35. 35 Is it clear all the topics for everybody Is it clear all the topics for everybody Anything doubts Anything doubts Feel free to ask me Feel free to ask me Want to Summarize

36. 36 THANK YOU OR TERIMA KASIH