Practical Process Instrumentation and Automatic Control

Introduction

Globalization has placed increasing demands on modern process control in terms of quality, safety, flexibility, and costs. However, more efficient control can only be achieved through better measurement when the process instrumentation provides the correct information.

The field of process measurement and control is changing at a dramatic rate. Measurements and accuracies that would have been thought of as impossible to achieve are now commonplace.

Further, for many years chemical measurement has remained the preserve of the analytical chemist. More and more, however, on-line analytical measurement is being applied in process control and is increasingly becoming the responsibility of the instrumentation and control technologist.

This course, PRACTICAL Process Instrumentation a Measurement and Sensors, is designed to provide engineers and technicians with the basic theoretical and practical knowledge involved in the selection, application, installation, and commissioning of industrial instrumentation and on-line analytical instrumentation.

Although the subject of many hundreds of articles, books, and courses, the basic elements of automatic process control are still widely misunderstood. Worse, the majority of control systems are misapplied. Research carried out by ISA and other bodies indicate that up to 75% of all loops will oscillate when operated in automatic.

Objectives

On successful completion of this course delegates will be able to:

• Understand the major technologies used in the measurement of flow, temperature, pressure, and level
• Review the construction and operation of the most important process instruments
• Evaluate and select the appropriate instrumentation system
• Install process equipment correctly
• Optimize control with effective selection and installation of your process equipment
• Calibrate and troubleshoot instrumentation systems
• Isolate and rectify instrumentation faults
• Appreciate the basics of chemistry and how to read the chemical formula
• Understand how analytical chemistry is applied in industry
• Review the construction and operation of the most important analytical instruments
• Value the science and capabilities of on-line analytical chemistry
• Troubleshoot problems in the measurement of pH,
• Conductivity, turbidity, dissolved oxygen, chlorine, etc.
• Implement procedures for testing and calibration of analytical instruments
• Understand the basics of process analysis using IR spectroscopy and chromatography
• Understand the fundamentals of Process Control
• Define such terms as process lag, capacitance, and resistance
• Gain an insight into the process reaction curve
• Appreciate the effects of 1st and 2nd order reactions
• Avoid incorrect sensor placement
• Distinguish the effect of span on the system performance
• Appreciate the effects of different valve characteristics on the loop performance
• Analyze such problems as valve hysteresis, stiction, and non-linearities
• Fully appreciate the effects of proportional, integral and derivative control
• Correctly apply both open and closed Loop Tuning according to Ziegler Nichols
• Apply Lambda Tuning
• Appreciate the effects on loop tuning using a software-based loop analysis program
• Understand the effects of aliasing
• Realize the effects of filtering on loop performance
• Understand cascade and feedforward control
• Appreciate the rationale for using Ratio control and Adaptive control systems
• Identify and correct problems with process dead time

Target Audience

• Professionals involved in designing, selecting, sizing, specifying, installing, testing, operating and maintaining process instrumentation and control systems
  • Automation Engineers
  • Chemical Engineers
  • Consulting Engineers
  • Design Engineers
  • Electrical Engineers 
• • Electricians
  • Installation and Maintenance Technicians
  • Instrument and Process Control Engineers and Technicians
  • Instrument Fitters
  • Maintenance Engineers
  • Mechanical Engineers and Technicians
  • Operations Engineers
  • Process Engineers
  • Process Operators
  • Production Professionals
  • Project Professionals
  • System Integrators
• Professionals with little to moderate production facility design and/or operations background
• Other professionals who want a better understanding of the subject matter

Instrumentation & Process Outline

The course covers the following topics:

Overview

• Purpose of instrumentation
• Location of control functions
• Variables measured and controlled
• Final control elements
• Instrument operating medium

Basic measurement concepts

• Measured and controlled variables
• Performance terms and specifications
• Measurement terminology
• P&ID symbols

Flow measurement

• Basic fluid properties
• Reynolds number
• Flow measurement
• Positive Displacement Meters
• Inferential meters
• Oscillatory Flow Meters
• Differential Pressure Meters
• Electromagnetic Flowmeters
• Ultrasonic Flowmeters
• Coriolis meters
• Thermal mass meters
• Open Channel Flow

Temperature measurement

• Basic principles
• Scales
• Expansion systems
• Thermocouples
• Resistance thermometry
• Thermistors
• Radiation thermometry
• Installation considerations

Pressure measurement

• Basic principles
• Manometers
• Deadweight testers
• Bourdon tubes
• Bellow elements
• Diaphragm elements
• Electrical displacement sensors

Level measurement

• Basic principles
• Visual gauging systems
• Float systems
• Displacement systems
• Conductive level detection
• Capacitive level measurement
• Hydrostatic head measurement
• Ultrasonic level measurement
• Radar gauging
• Nuclear level measurement
• Point level measurement
• Load cells

Basic chemistry

• Elements, compounds, and mixtures
• Properties of elements
• Formation of ions
• Bonding
• Chemical formulae and equations
• Atomic weight
• Molar concentrations
• Acids and bases

Electrochemical cells

• Electrode potentials
• Simple voltaic cell
• Polarisation
• Daniell cell
• Electrolytic bridges
• Electrochemical series

On-line analytical measurement

• Measurement of pH
• Measurement of Redox
• Conductivity measurement
• Dissolved oxygen measurement
• Chlorine measurement
• Turbidity measurement
• Hygrometry
• On-line colorimetry and titration
• Infrared Spectroscopy
• Gas chromatography

Basic process considerations

• Definition of terms
• Process lag, capacitance, and resistance
• Process reaction curve
• 1st and 2nd order reactions
• Process measurement
• Instrumentation cabling
• Filtering
  • Aliasing
  • Reaction masking
• Sensor placement
• Correct PV
• Effect of span

Final control element

• Choked flow
• Pressure recovery
• Flashing and cavitation
• Valve construction
• Valve characteristics
  • Inherent
  • Profiling
  • Installed
  • Cavitation control
• Actuators
  • Diaphragm
  • Cylinder
  • Electric
• Valve positioners
• Dead band and hysteresis
• Stick-slip
• Testing procedures and analysis
• Effect of valve performance on controllability

Fundamentals of Process Control

• ON/OFF control
• Proportional control
• Proportional band vs. proportional gain
• Proportional offset
• Reset
• Integral action
• Integral windup
• Stability
• Bode plot
• Nyquist plot
• Derivative action
• PID control
• Control algorithms
• Load disturbances and offset
• Speed, stability, and robustness

Fundamentals of Tuning

• Basic principles
• Open-loop reaction curve method (Ziegler-Nichols)
• Default and typical settings
• Closed-loop continuous cycling method (Ziegler-Nichols)
• Lambda tuning
• Fine-tuning
• Tuning for load rejection vs. set-point rejection
• Tuning according to Pessin
• Tuning for different applications
• Speed of response vs. robustness
• Surge tank level control

Automated tuning systems

• Self-tuning loops
• Adaptive control

Advanced control algorithms

• Cascade systems
  • Feedforward and combined systems
  • Ratio control
  • Adaptive control systems
  • Deadtime compensation
• Fuzzy logic control