Share
VIDEOS 1 TO 50
What is Process Control
What is Process Control
Published: 2016/03/23
Channel: Deacom, Inc.
1. Introduction - Process Control Instrumentation -
1. Introduction - Process Control Instrumentation -
Published: 2016/03/07
Channel: Yokogawa: Industrial Automation
Process Control Fundamentals
Process Control Fundamentals
Published: 2014/03/10
Channel: Convergence Training
Day in the Life: process control engineer
Day in the Life: process control engineer
Published: 2017/04/19
Channel: Chevron
What is PROCESS CONTROL? What does PROCESS CONTROL mean? PROCESS CONTROL meaning & explanation
What is PROCESS CONTROL? What does PROCESS CONTROL mean? PROCESS CONTROL meaning & explanation
Published: 2017/03/30
Channel: The Audiopedia
Process Control Loop Basics
Process Control Loop Basics
Published: 2016/10/14
Channel: Pete Vree
Process Control and Instrumentation
Process Control and Instrumentation
Published: 2016/11/20
Channel: Ammonia technicians cafe
Mod-01 Lec-01 Lecture-01-Introduction to Process Control
Mod-01 Lec-01 Lecture-01-Introduction to Process Control
Published: 2012/07/06
Channel: nptelhrd
Second Order Systems in Process Control
Second Order Systems in Process Control
Published: 2015/10/19
Channel: APMonitor.com
PID Control - A brief introduction
PID Control - A brief introduction
Published: 2012/12/14
Channel: Brian Douglas
Meet Mike Gardner,  Process Controls Engineer Co-op
Meet Mike Gardner, Process Controls Engineer Co-op
Published: 2013/01/17
Channel: DTEEnergyCompany
Applied Process Control for Chemical Engineers
Applied Process Control for Chemical Engineers
Published: 2012/11/06
Channel: APMonitor.com
Introduction To Process Control
Introduction To Process Control
Published: 2009/06/10
Channel: IDCTechnologies
Instrumentation and Process Control System - The Plant at School – LabVolt Series 3531
Instrumentation and Process Control System - The Plant at School – LabVolt Series 3531
Published: 2012/02/08
Channel: Festo Didactic – LabVolt Series
The Control Process by Charbel El Khoury
The Control Process by Charbel El Khoury
Published: 2015/10/24
Channel: Interactive Teaching
PROCESS CONTROL INSTRUMENTATION TRAINING
PROCESS CONTROL INSTRUMENTATION TRAINING
Published: 2017/02/18
Channel: Instrumentation and Control Training
Process Control Systems
Process Control Systems
Published: 2014/01/27
Channel: Analog Devices, Inc.
What is SPC (Statistical Process Control)?
What is SPC (Statistical Process Control)?
Published: 2010/12/26
Channel: sixsigmamoneybelt
Complexity Made Simple - Why Statistical Process Control (SPC)
Complexity Made Simple - Why Statistical Process Control (SPC)
Published: 2015/11/30
Channel: Paul Allen
Georgia-Pacific Careers: Process Control Engineer
Georgia-Pacific Careers: Process Control Engineer
Published: 2014/02/21
Channel: Georgia-Pacific
Basic Process Control: The Piping & Instrumentation Diagram
Basic Process Control: The Piping & Instrumentation Diagram
Published: 2016/05/23
Channel: Arjay Automation, Inc.
Statistical Process Control (SPC) in Hindi – (Part 1). SPC  हिंदी में सीखे।
Statistical Process Control (SPC) in Hindi – (Part 1). SPC हिंदी में सीखे।
Published: 2017/08/12
Channel: Quality HUB India
Quality (Part 1: Statistical Process Control)
Quality (Part 1: Statistical Process Control)
Published: 2017/03/08
Channel: Infinity MFG
Process Control Block(PCB) | User and System(Kernel) Modes of Execution
Process Control Block(PCB) | User and System(Kernel) Modes of Execution
Published: 2017/02/27
Channel: Easy Engineering Classes
C Batch Process Control System - Basic Video
C Batch Process Control System - Basic Video
Published: 2011/11/26
Channel: CBatchChannel
Introduction to Statistical Process Control
Introduction to Statistical Process Control
Published: 2015/06/18
Channel: Russell Hills
iSpani 7 - Episode 10: Process control & instrumentation technician
iSpani 7 - Episode 10: Process control & instrumentation technician
Published: 2016/05/05
Channel: SABC Education Shows
Statistical Process Control vs. Process Capability
Statistical Process Control vs. Process Capability
Published: 2016/03/14
Channel: Statisfaction
Mod-01 Lec-02 Lecture-02-Introduction to Process Control (Contd.)
Mod-01 Lec-02 Lecture-02-Introduction to Process Control (Contd.)
Published: 2012/07/06
Channel: nptelhrd
Linux Basic Process Control Command
Linux Basic Process Control Command
Published: 2014/06/17
Channel: Linux Tutorial
Laplace Transforms for Process Control
Laplace Transforms for Process Control
Published: 2015/10/08
Channel: APMonitor.com
Introduction to OPC for Factory Automation and Plant Process Control
Introduction to OPC for Factory Automation and Plant Process Control
Published: 2011/03/31
Channel: TheOPCFoundation
Programming Interview  Process Control Block in Operating system PCB
Programming Interview Process Control Block in Operating system PCB
Published: 2016/05/05
Channel: IncTutorial Education
Statistical Process Control Overview and Basic Concepts - What You Need to Know for the CQE Exam
Statistical Process Control Overview and Basic Concepts - What You Need to Know for the CQE Exam
Published: 2017/05/25
Channel: ASQStatsDivision
What is Process Control - A Galco TV Tech Tip
What is Process Control - A Galco TV Tech Tip
Published: 2017/10/20
Channel: GalcoTV
Video 7:-Process Management Introduction and Process Control Block PCB
Video 7:-Process Management Introduction and Process Control Block PCB
Published: 2016/07/16
Channel: GATE Lectures Computer Forum NCR
Statistical Process Control |  R-Chart (Control Chart for Ranges)
Statistical Process Control | R-Chart (Control Chart for Ranges)
Published: 2015/07/19
Channel: Joshua Emmanuel
SAP GRC Process Control Videos
SAP GRC Process Control Videos
Published: 2015/11/19
Channel: Ajay Videos
“Out of Control” in Statistical Process Control: Meaning and “Prevention” by Day Duong-Tran
“Out of Control” in Statistical Process Control: Meaning and “Prevention” by Day Duong-Tran
Published: 2016/02/02
Channel: GRCCtv
EE4265 Tutorial Chapter 7 MIMO process control (part 1)
EE4265 Tutorial Chapter 7 MIMO process control (part 1)
Published: 2014/10/28
Channel: Ultracer
STATISTICAL PROCESS CONTROL AND PROCESS CAPABILITY
STATISTICAL PROCESS CONTROL AND PROCESS CAPABILITY
Published: 2013/11/09
Channel: iimtnew
SPC - Statistical Process Control
SPC - Statistical Process Control
Published: 2014/02/04
Channel: Matrix Industrial Control Systems Inc.
PLC Level Process control
PLC Level Process control
Published: 2013/10/15
Channel: billkleitz
Process Control Charts
Process Control Charts
Published: 2012/11/29
Channel: Convergence Training
Industry 4.0 – Kistler Industrial Integrated Process Control for Maximum Efficiency
Industry 4.0 – Kistler Industrial Integrated Process Control for Maximum Efficiency
Published: 2017/06/14
Channel: Kistler Group
Valve Design for Process Control
Valve Design for Process Control
Published: 2014/09/24
Channel: APMonitor.com
Management part 4 of 4: Control Process & Principles in Hindi Under E-Learning Program
Management part 4 of 4: Control Process & Principles in Hindi Under E-Learning Program
Published: 2017/04/19
Channel: Dr. B. R. Ambedkar Govt. College Kaithal
Webcast of the Month: Process Control for Activated Sludge
Webcast of the Month: Process Control for Activated Sludge
Published: 2014/12/22
Channel: Water Environment Federation
Understanding Process Control System 3 : Direct & Reverse Acting
Understanding Process Control System 3 : Direct & Reverse Acting
Published: 2017/06/13
Channel: HAMDANI YUSUF
Simulink Process Control Exercise
Simulink Process Control Exercise
Published: 2013/09/14
Channel: APMonitor.com
NEXT
GO TO RESULTS [51 .. 100]

WIKIPEDIA ARTICLE

From Wikipedia, the free encyclopedia
Jump to: navigation, search

Automatic process control in continuous production processes is a combination of control engineering and chemical engineering disciplines that uses industrial control systems to achieve a production level of consistency, economy and safety which could not be achieved purely by human manual control. It is implemented widely in industries such as oil refining, pulp and paper manufacturing, chemical processing and power generating plants,

There is a wide range of size, type and complexity, but it enables a small number of operators to manage complex processes to a high degree of consistency. The development of large automatic process control systems was instrumental in enabling the design of large high volume and complex processes, which could not be otherwise economically or safely operated.

In process control, there is process gain. Process gain is the relationship between the process control output and the process control input, and is defined as the change in input divided by the change in output. Positive gain is when both the input and the output are increasing, while negative gain is when the input increases, while the output decreases.

The applications can range from controlling the temperature and level of a single process vessel, to a complete chemical processing plant with several thousand control loops.

History of Process Control[edit]

Early process control breakthroughs came most frequently in the form of water control devices. Ktesibios of Alexandria is credited for inventing float valves to regulate water level of water clocks in the 3rd Century BC. In the 1st Century AD, Heron of Alexandria invented a water valve similar to the fill valve used in modern toilets [1].

Later process controls inventions involved basic physics principles. In 1620, Cornlis Drebbel invented a bimetallic thermostat for controlling the temperature in a furnace. In 1681, Denis Papin discovered the pressure inside a vessel could be regulated by placing weights on top of the vessel lid[2]. In 1745, Edmund Lee created the fantail to improve windmill efficiency; a fantail was a smaller windmill placed 90° of the larger fans to keep the face of the windmill pointed directly into the oncoming wind.

With the dawn of the Industrial Revolution in the 1760’s, process controls inventions were aimed to replace human operators with mechanized processes. In 1784, Oliver Evans created a water-powered flourmill which operated using buckets and screw conveyors. Henry Ford applied the same theory in 1910 when the assembly line was created to decrease human intervention in the automobile production process[3].

Major breakthroughs in process controls came in the 1920’s, when Nicolas Minorsky published a study on using proportional, derivative, and second-derivative controllers to steer ships. Minorsky also demonstrated that differential equations could be used to improve ship steering stability. In addition, Harry Nyquist developed a procedure for determining the stability of feedback systems. Throughout the next 3 decades, countless articles and papers on process control theory appeared. Most notably, the first text on process controls was published by AJ Young in 1954, followed by a second text from Norman Ceaglske in 1956. From this point onward, process controls became fundamental topic for chemical engineering students[4].


Hierarchy of process control[edit]

Functional levels of a manufacturing control operation.

The accompanying diagram is a general model which shows functional manufacturing levels in a large process using processor and computer-based control.

Referring to the diagram;

  • Level 0 contains the field devices such as flow and temperature sensors (process value readings - PV), and final control elements (FCE), such as control valves
  • Level 1 contains the industrialised Input/Output (I/O) modules, and their associated distributed electronic processors.
  • Level 2 contains the supervisory computers, which collate information from processor nodes on the system, and provide the operator control screens.
  • Level 3 is the production control level, which does not directly control the process, but is concerned with monitoring production and monitoring targets
  • Level 4 is the production scheduling level.

Types of process control[edit]

Processes can be characterized as one or more of the following forms:

  • Batch – Some applications require that specific quantities of raw materials be combined in specific ways for particular duration to produce an intermediate or end result. One example is the production of adhesives and glues, which normally require the mixing of raw materials in a heated vessel for a period of time to form a quantity of end product. Other important examples are the production of food, beverages and medicine. Batch processes are generally used to produce a relatively low to intermediate quantity of product per year (a few pounds to millions of pounds).
  • Continuous – Often, a physical system is represented through variables that are smooth and uninterrupted in time. The control of the water temperature in a heating jacket, for example, is an example of continuous process control. Some important continuous processes are the production of fuels, chemicals and plastics. Continuous processes in manufacturing are used to produce very large quantities of product per year (millions to billions of pounds). Such controls use feedback such as in the PID controller A PID Controller includes proportional, integrating, and derivative controller functions.
  • Hybrid - Applications having elements of batch and continuous process control are often called hybrid applications.

Control loops[edit]

Example of a continuous flow control loop. Signalling is by industry standard 4-20 mA current loops, and a "smart" valve positioner ensures the control valve operates correctly.

The fundamental building block of any industrial control system is the control loop, which controls just one process variable. An example is shown in the accompanying diagram, where the flow rate in a pipe is controlled by a PID controller, assisted by what is effectively a cascaded loop in the form of a valve servo-controller to ensure correct valve positioning.

Some large systems may have several hundreds or thousands of control loops. In complex processes the loops are interactive, so that the operation of one loop may affect the operation of another. The system diagram for representing control loops is a Piping and instrumentation diagram.

Commonly used controllers are programmable logic controller (PLC), Distributed Control System (DCS) or SCADA.

Example of level control system of a continuous stirred-tank reactor. The flow control into the tank would be cascaded off the level control.

A further example is shown. If a control valve were used to hold level in a tank, the level controller would compare the equivalent reading of a level sensor to the level setpoint and determine whether more or less valve opening was necessary to keep the level constant. A cascaded flow controller could then calculate the change in the valve position.

Economic Advantages[edit]

The economic nature of many products manufactured in batch and continuous processes require highly efficient operation due to thin margins. The competing factor in process control is that products must meet certain specifications in order to be satisfactory. These specifications can come in two forms: a minimum and maximum for a property of the material or product, or a range within which the property must be.[5] All loops are susceptible to disturbances and therefore a buffer must be used on process set points to ensure disturbances do not cause the material or product to go out of specifications. This buffer comes at an economic cost (i.e. additional processing, maintaining elevated or depressed process conditions, etc.).

Process efficiency can be enhanced by reducing the margins necessary to ensure product specifications are met.[6] This can be done by improving the control of the process to minimize the effect of disturbances on the process. The efficiency is improved in a two step method of narrowing the variance and shifting the target.[7] Margins can be narrowed through various process upgrades (i.e. equipment upgrades, enhanced control methods, etc.). Once margins are narrowed, an economic analysis can be done on the process to determine how the set point target is to be shifted. Less conservative process set points lead to increased economic efficiency.[8] Effective process control strategies increase the competitive advantage of manufacturers who employ them.

List of techniques and mechanisms used in process control[edit]

External links[edit]

References[edit]

  1. ^ 2
  2. ^ 2
  3. ^ 2
  4. ^ 2
  5. ^ 1
  6. ^ 1
  7. ^ 1
  8. ^ 1

1. Smith, C. L., “Process Control for the Process Industries - Part 2: Steady State Characteristics,” Chemical Engineering Progress, pp. 67–73 (March 2017).

2. Svrcek, William Y., et al. “A Brief History of Control and Simulation.” A Real Time Approach to Process Control, John Wiley & Sons Inc., 2014, pp. 1–2.

Disclaimer

None of the audio/visual content is hosted on this site. All media is embedded from other sites such as GoogleVideo, Wikipedia, YouTube etc. Therefore, this site has no control over the copyright issues of the streaming media.

All issues concerning copyright violations should be aimed at the sites hosting the material. This site does not host any of the streaming media and the owner has not uploaded any of the material to the video hosting servers. Anyone can find the same content on Google Video or YouTube by themselves.

The owner of this site cannot know which documentaries are in public domain, which has been uploaded to e.g. YouTube by the owner and which has been uploaded without permission. The copyright owner must contact the source if he wants his material off the Internet completely.

Powered by YouTube
Wikipedia content is licensed under the GFDL and (CC) license