Tag Archive: commissioning

May
27

Commissioning PI Control – Integrating Process

Three Element Drum Level Control

When the control objective is to maintain the controlled parameter of an integrating process at setpoint under all operating conditions, then using PI (proportional-integral or proportional plus reset) controller, it is possible to automatically compensate for changes in disturbance inputs and maintain the controlled parameter at setpoint. However, the application of PI control to an …

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May
20

Surge Tank Control

Surge Tank Level Control

Intermediate liquid storage tanks (surge tanks) are commonly installed between processing areas of the plant. Under normal operating conditions, these storage buffers allow each process area to be operated independently of the other process areas. Any imbalance in the area production rates within a plant will be reflected by a change in level of the …

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Dec
19

Maximizing the Return on Your Control Investment – Part 2

As addressed in my December 12th blog posting, James Beall and I presented Part 1 of this presentation on Friday morning at Emerson Exchange, 2011 in a “meet the expert” workshop. Part 2 was not presentation at Emerson Exchange because of time limitation. In this continuation of the presentation we address when it is possible …

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Dec
12

Maximizing the Return on Your Control Investment – Part 1

Maximizing the Return on Your Control Investment

At Emerson Exchange, 2011, I had the pleasure of working with James Beall, Principal Control Consultant, Emerson Process Management to host a workshop that addresses how to get the maximum return from your control investment. The design and commissioning of the controls associated with a continuous or batch process directly impact plant operating efficiency and …

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Dec
05

Commissioning Highly Interactive Process

Commissioning Highly Interactive Process

At Emerson Exchange, 2011, I had the pleasure of working with Eric Chen, Research Associate, Pickle Research Center, University of Texas at Austin SRP and Willy Wojsznis, Senior Technologist, Emerson Process Management, to host a workshop that addresses commissioning of a skid process that is characterized by a high degree of process interaction. The size …

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Sep
05

Commissioning Control Systems – Closely Coupled Process

Flash Skid Process for CO2 Recovery

In a previous blog, I addressed some of the challenges of commissioning a multiple input/multiple output (MIMO) process that is characterized by process interaction. Also, in Chapter 12 of Control Loop Foundation – Batch and Continuous Processes  we address the special considerations associated with tuning an interactive process.  In such a process, each manipulated input may impact …

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Jul
11

Commissioning Control Systems – Input Filtering

Analog Input Card Processing

The method used to process analog inputs and outputs is unique to each control system.  Also, controller and IO bus design influence how often measurement and outputs are updated and thus dictate the control execution rate that is supported by the control system. Understanding the limitations imposed by the basic control system design (i.e., controller …

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Jul
04

Commissioning Control Systems

The long-term performance of a plant is directly impacted by the care with which the control system is commissioned. Establishing control loop tuning is an important part of the work needed to commission a new plant or an area of the plant in which measurement or control changes have been made. Such work can be …

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Feb
14

Split-range Control

A wide variety of processes may be described as having one controlled parameter and two or more manipulated process inputs. The challenge from a control perspective is that there is no unique set of input values that are required to maintain the controlled parameter at setpoint. One of the most common ways of addressing multiple …

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Jan
17

Tuning and Loop Performance

During the commissioning of feedback control based on the PID algorithm, the tuning parameters associated with the PID (that is, the proportional, integral and derivative gain) must be set to specific values to achieve the best controller response to setpoint and disturbance input changes. The PID tuning parameters are normally specified as positive, floating-point values …

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