Topic: Process Automation Systems

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Gas Chromatographs Rule
What Comes First--the Analyzer or the Analyzer Application?

Hooking Up the Plant and the Enterprise
Do You Know the Benefit From Connecting Process Plant Automation, Information Systems and Higher Level Computing Platforms?

Industrial Computers, Part 2. Data Processing Escapes the Enclosure
Whether It Happens on a Cloud-Based Service, Virtualized Server or Plain Old Wireless, Internet or Ethernet, It's Clear That Industrial Computing for Process Control Has Moved Beyond Its Old Laptops and Desktops. So How Can You Protect Such Far-Flung Data Processing?

Blending Controls Sweetens Soda Pop
Schweppes Australia Consolidates Process and Logic Controls in Its Syrup Room With a New Automation and Controls System

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White Papers: In Depth Research

A Systematic Approach To Plantwide Control
Author: Sigurd Skogestad, Norwegian University of Science and Technology (NTNU)
Posted: 01/25/2011
This paper summarizes Sigurd Skogestad's struggles in the plantwide control field.

A chemical plant may have thousands of measurements and control loops. By the term plantwide control it is not meant the tuning and behavior of each of these loops, but rather the control philosophy of the overall plant with emphasis on the structural decisions. In practice, the control system is usually divided into several layers, separated by time scale.

My interest in this field of plantwide control dates back to 1983 when I started my PhD work at Caltech. As an application, I worked on distillation column control, which is excellent example of a plantwide control problem. I was inspired by Greg Shinskey's book on Distillation Control, which came out with a second edition in 1984 (Shinskey, 1984). In particular, I liked his systematic procedure, which involved computing the steady-state relative gain array (RGA) for 12 different control structures ("configurations"); the DV-configuration, LV-configuration, ratio configuration, and so on. However, when I looked in more detail on the procedure I discovered that its theoretical basis was weak. First, it did not actually include all structures, and it even eliminated the DB-configuration as "impossible" even through it is workable in practise (Luyben, 1989). Second, controllability theory tells that the steady-state RGA by itself is actually not useful, except that one should avoid pairing on negative gains. Third, the procedure focused on dual composition control, while one in practise uses only single end control, for example, because it may be optimal economically to use maximum heating to maximize the recovery of the valuable product.

Understanding REACH
Author: Mike Levesque, Randy Elliott, Ariann Griffin and Michael Karg, C&M Corporation
Posted: 12/13/2010
Registration Evaluation Authorization and Restriction of Chemical Substances

It is certainly no secret to anyone that the past decade has placed a renewed focus on the environment and how all members of the world community, to include business organizations, affect it. Concerns about protecting the world in which we live have been the impetus behind such worldwide movements as recycling and renewable energy. From a manufacturing standpoint, RoHS (Reduction of Hazardous Substances) has impacted businesses as well as REACH, a more recent set of regulations that are becoming more significant to North American based manufacturing operations that are part of a supply chain that directly or indirectly supplies products into the European Union.

As with any new regulatory requirements, the initial exposure to the documentation can create a degree of uncertainty among those who will be asked to comply. From this perspective, REACH is no different from any of its predecessors. In an attempt to offer some understanding of the REACH regulations and some clarification of the requirements it places on manufacturers, C&M Corporation gathered Michael Karg, Director of Product Development, along with Randy Elliott, Regulatory Compliance Engineer, and Ariann Griffin, Regulatory Compliance Technician, to discuss some of the particulars of REACH and respond to some of the questions C&M has been discussing with members of its client base.

What is the purpose of REACH?

How A Biogas Processing System Manufacturer Identified the Best Flow Meter for Gas Measurement
Author: Fluid Components International, Achim Sprick, Managing Director, Klargastechnik Deutschland GmbH
Posted: 10/28/2010
Klargastechnik Deutschland GmbH's equipment and processes help customers address organic biomass fermentation and recovery while supporting electric power co-generation. The result is clean, green electric power that also reduces both solid waste and hazardous toxic gases such as carbon dioxide and methane, which pollute the environment and contribute to global warming.

In order to provide these benefits, the company's equipment and systems rely on highly precise and reliable flow measurement of process waste gases. Measuring biogas flow at several points in the system provides operators with critical information for optimal gas production, control, safety and reporting. However, Biogas applications present several challenges in selecting the proper flow meter.

Download this application note to learn how a biogas processinf system manufacturer can identify the best flow meter for gas measurements.

Real-Time Profit Optimization
Author: Invensys, Peter G. Martin, PhD, Invensys Operations Management
Posted: 10/25/2010
Distributed Control Systems (DCS) have been successfully utilized to help control manufacturing and production processes since the late 1970s. The primary function of these DCS systems has been the automatic feedback control of the various process loops across the plants and the human interfacing with plant operators guiding the production from control rooms. Although these systems have proven to be very successful at improving the efficiency of industrial operations as compared with earlier control technologies, the state-of-the-art has not grown significantly since their inception. Most plants still operate exactly as they did 40 years ago.

Considerable research and development has been invested in expanding the functionality of DCS's in the areas of advanced controls and advanced manufacturing execution software. Numerous industrial plants have started to employ advanced controls in critical or high-value process operations, with some venturing into the use of advanced application software packages, each typically designed to address a specific issue or challenge within the industrial operations. Entrepreneurial software companies typically developed the software at this level of operation, essentially between the automation and business levels, often referred to as the manufacturing execution software (MES).

Although some industrial operations implemented advanced control and advanced MES software, the vast majority of processes are still controlled by simple automatic feedback control. The efficiency and effectiveness of most plants is a function of the installed feedback control systems. As a result, many industrial managers have expressed concerns that, in spite of the huge investments made in automation systems and software, plants do not appear to be operating better than they had been 30 years ago. In some cases, the plants actually appear to be operating less efficiently, possibly due to the reduced and inexperienced work forces and aging equipment.

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