For the last few years, especially since the public revelation of Operation Aurora, the targeted successful intrusion into Google and two dozen other companies, I have often been asked by our worldwide customers if they should worry about such sophisticated penetrations themselves or if that is a concern only for government agencies, defense contractors, and […]
Systems
Distributed control system with benefits In this installment of What Works, a DCS upgrade enhances data acquisition and improves machine performance. When is a new equipment installation more than just implementing new devices? When it delivers benefits beyond and outside the areas you originally planned. When is a technical partnership more than just working […]
Sigurd Skogestad 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 […]
To achieve best overall plant operation, it is often necessary to coordinate the operation of equipment in multiple process areas. In Chapter 16 of Control Loop Foundation – Batch and Continuous Processes, some examples are given where multi-loop techniques may be effectively used for such coordination. One of the examples from this chapter is power […]
21 CFR Part 11 might really be called the Data Integrity Act. Here is a high-level look at what is needed to ensure compliance. By John Avellanet, Cerulean Associates, LLC Data integrity is critical to regulatory compliance, and the fundamental reason for 21 CFR Part 11. This article outlines and summarizes strategies and requirements. […]
Money spent to reduce deadtime (e.g. greater agitation, faster valves, faster measurements) will be wasted if the controller is not tuned faster. You may have wonderful process dynamics but loop performance will be lousy if the PID is not tuned to be commensurate with the opportunity. A loop with excessively slow tuning and low deadtime […]
By Terry Blevin Single-loop and multi-loop control may be used to address a wide variety of control requirements. However, if a process is characterized by extremely long process delays or by a high degree of process interaction, then other control techniques may be required. In Chapter 16 of Control Loop Foundation – Batch and Continuous […]
By Robert Cook This entry is part 5 of 5 in the series How to Interpret Piping and Instrumentation Diagrams With a Bit of Smoke, a Few Mirrors and a Degree in Hieroglyphics, Anyone Can Learn to Read a P&ID. From CheNected
By Robert Cook This entry is part 4 of 5 in the series How to Interpret Piping and Instrumentation Diagrams With a Bit of Smoke, a Few Mirrors and a Degree in Hieroglyphics, Anyone Can Learn to Read a P&ID. From CheNected
By Robert Cook This entry is part 3 of 5 in the series How to Interpret Piping and Instrumentation Diagrams With a Bit of Smoke, a Few Mirrors and a Degree in Hieroglyphics, Anyone Can Learn to Read a P&ID. From CheNected