Lecture 1

Industrial Process ControlEL 4223

Instructor:Prof. Azhar Hussain ShahEngr. Nabeel Khalid

Saturday, March 05, 2011

Engr. Nabeel Khalid Lecturer FOE,UCP

Lecture 1


Engr. Nabeel KhalidLecturer FOE,UCP

OutlineIntroduction

Recommended Text

Grading Criteria

What is Process Control

Automatic Process Control

Process Control Loop

Feed Back Process Control Loop

Types of Processes



Recommended Text Measurement and Control Basics By Thomas A. Hughes

Fundamentals of Final Control Elements By Helen Beecroft Ken MacDonald

Industrial Process Control Systems By Dale Patrick & Stephen Fardo

Process Control Instrumentation Technology By Curtis D. Johnson

Fundamentals of Industrial Instrumentation and Process ControlBy William C. Dunn



Grading CriteriaTheory (2 Credit Hrs.)

Mid Term 25%Final Term 50%Sessional 25%Total 100%

Note: Announcements will be available on

http://online.ucp.edu.pk Office Hours: Mon & Wed 0900-1100 hrs E-mail: [email protected]



http://online.ucp.edu.pk/�

What is a Process Control? Observing a parameter, comparing it to some desired

value, and initiating a control action to bring the parameter as close as possible to the desired Value” this is known as process control. e.g. use of fire to regulate the temperature of room.



What is an Automatic Process Control? Automatic control of an output variable by sensing the

amplitude of the output parameter from the process and comparing it to desired or set level and feeding an error signal back to control an input variable.

Process control will automatic, when there will be no human intervention in that process and all the action will take place automatically.e.g. use of Air Conditioner to regulate the temperature ofroom.



What is a Automatic Process Control? Figure (a) shows manual control system in which valve is

controlled manually by a human being after sensing the temperature of water.

Figure (b) shows automatic process control in which sensor senses the temperature of the water and controller generates a signal towards actuator to control the temperature of water heater.



Process Control loop



Feedback path in a Process Control Loop



Process Control with Flow Regulator



Example Figure shows the block diagram of a closed-loop flow

control system.

Identify the following elements: (a) the sensor, (b) thetransducer, (c) the actuator, (d) the transmitter, (e) thecontroller, (f) the manipulated variable, and (g) themeasured variable.



Presenter

Presentation Notes

Example 1.1 Solution: (a) The sensor is labeled pressure cell in the diagram. (b) The transducer is labeled converter. There are two transducers—one for converting pressure to current and the other for converting current to pressure to operate the actuator. (c) The actuator in this case is the pneumatic valve. (d) The transmitter is the line driver. (e) The controller is labeled PLC. (f) The manipulated variable is the differential pressure developed by the fluid flowing through the orifice plate constriction. (g) The controlled variable is the flow rate of the liquid. Simple and ideal process-control systems have been discussed. In practical process control the scenarios are much more complex with many scenarios and variables, such as stability, reaction time, and accuracy to be considered.

Different Process Control systems Systems that respond to changes in pressure are one of

the largest divisions in process control field. These systems include

Hydraulic sPneumaticsSteam or vapor systems Liquid distribution systems.



Hydraulic Systems This type of system is commonly found in automatic

machinery control and in material forming operations.

Popularity of this system can be attributed to the following thingsOperational simplicitySmoothness of operationReliabilityAdaptability



Double-acting Hydraulic System



Pneumatic Systems This type of system commonly found their

applications in powering of hand tools and lifting and clamping of products during machining operations.



Static Pressure Systems This type of system commonly used in industry to

distribute liquids in a variety of processing applications.

This type of systems utilizes pressure that is developed as a result of the source being elevated above other system components.



Steam Pressure Systems This type of system develops pressure by

transforming liquid into vapor when heat is applied. The resulting pressure occurs when steam or vapor is

forced to pass through the resistance of confined pipes or tubes.



Temperature Systems

These systems must perform following actionsGenerate heat provide path for its distributionInitiate some type of controlUtilize this energy to do workRecord the value of temperature through precise measurement.

For measurement of temperature, RTD (Resistance Temperature Detector), noncontact infrared thermometer etc can be used.



Level Determination Systems These systems are used to evaluate the amount of

material in a tank, bin, or hopper that is available for accomplishing a particular process.

These systems are often considered as control function that applies to a variety of different processes.

Sensing element detects change in level.



Flow Process Systems These systems are used to monitor and control water,

natural gas, solvents, chemicals and an infinite variety of other materials.

Operation of these systems is based on the followingsActual material that is flowingDensity of the materialVolume being processedAccuracyType of control required

Measurement and control of flow are the major functions of a flow process.Where flow rate is the evaluation occurs at specific instantWhere totalizing flow is the total amount moves part a given

point during specific period.



Flow Process Systems A. Flow measurement with in pipe flow dead pressure

Principal.Differential pressure =flow.

B. Electromagnetic principal. C. Target principal.



Flow Process Systems Laminar flow:

Flow that means in a straight line.



Figure: Laminar Flow meters

Flow Process Systems

Figure: Liquid vortex flow meters



Any Questions……..



Lecture 1

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