Process and Production Control Package

An ideal combination of process control and operation planning can reduce system cost and maximize economic and environmental benefits. This research proposed an integrated simulation-based process control and operation planning (IS-PCOP) system by using neural networks, genetic algorithm, multistage principle, and Monte Carlo simulation. It could well link process control and operation planning by simultaneously adopting different time-scales in computation. The hourly process control strategy forwarded the results to the operation planning module where long-term arrangements could be further evaluated. The use of ANN modeling also played a key role in predicting the nonlinear behavior of complex processes. In addition, Monte Carlo simulation yielded a better insight on uncertainties, which may arise from a number of different sources. A case study on marine wastewater management was carried out to demonstrate the efficacy of the proposed approach. Six different treatment standards (i.e., 5, 10, 15, 20, 25, and 30 μg L?1) were examined over a 20-day period and the 20 μg L?1 standard appeared to be the most economic option with a mean net cost of $18 per day. As compared to the traditional operation planning without process control, the integrated approach achieved more economically competitive results. By addressing the uncertainties and expressing the results in probability distributions, the decision makers would have more confidence in making decisions on both short- and long-term operations. It was concluded that the combination of process control and operation planning could help meet the economic objectives and ensure timely completion of the tasks.

Chapter 6 - Protecting Critical Infrastructure: Process Control and SCADA

The main objective of a 1986 survey of production and operations managers throughout New Zealand industry was to determine the extent of computer use. The survey explored the use of microcomputers, mini computers and mainframes by production managers. Job title and responsibilities of the manager responsible for the majority of production management functions were investigated. It appeared that information and decision making in production management was fragmented in most organisations. The survey examined the main uses of computer information and control systems in production planning and inventory control, the perceived benefits and problems. The main computer brands in use and types of software were also analysed. Comparisons were made with surveys of British companies and some work in the USA.

Computer systems for real-time process control and supervision A framework for education based on a systems-engineering approach

To meet the flexibility demands introduced by modern markets, process plants have to become more flexible themselves. To tackle this issue and to ease vertical integration of IT-systems in enterprises a service-oriented approach is promising. Despite the developments concerning service-oriented architectures there is no standardized interface for service systems in process control systems. Therefore, in this paper we lay a basis for service systems in process control. We propose a message format and a way to describe services. We show which actions of a service interaction sequence have to be done in the engineering phase and which can be done at runtime. This is needed to meet non-functional requirements of control applications. The overall aim of the service system is to enhance flexibility without creating new dependencies.

A program for handling multiple phases of the design cycle in process control system design

Process Control Algorithms for Microprocessors

In December of 1988 a joint venture led by Freeport Sulphur Company discovered a major brimstone deposit of 67,000,000 long tons twenty miles offshore in the Gulf of Mexico. At a production of 2 million tons of sulphur per year this facility will be in operation for the next 30 years. This paper will cover the process of automating the frasch sulphur mine including design and planning, redundancy, reliability, training and configuration. A description of system architecture which allows information for production to be gathered and handled at the facility from process control, production and drilling will be presented. The ability to monitor and control the offshore platform from an onshore facility via satellite communications and the ability to network the process control system with a local area network of host and personal computers will be discussed. INTRODUCTION Main Pass Block 299, is located (Fig. 1) in 210 feet of water, 20 miles east of the mouth of the Mississippi River in the Gulf of Mexico. The production facilities will incorporate the latest technology based upon previous applications, the company's expertise in offshore sulphur mining and on proprietary mining techniques that use seawater in sulphur mining. The offshore production facility will be installed on a series of offshore platforms (Fig. 2) linked together by more than a mile of bridges. The Main Pass facilities are scheduled for completion in late 1991 with sulphur production beginning soon thereafter. One of the greatest tools in assisting operations achieve high safety and efficiency goals is through production automation. Improved productivity as well as improved management of production information can be realized from a modern process control system. Through automation and remote monitoring, operating costs can be reduced and production revenues increased. The strategy was to implement a completely integrated information system - one that gives the association of the process operations data with management and business systems data. AUTOMATION PROCESS Planning There are a great number of factors to consider when developing a plan for plantwide process control and flow of information. The needs and requirements of production planning, engineering, maintenance, material handling, scheduling and overall management are unique when it comes to process control data and business information systems. The first step in the planning of the control system was assembling a team of people from the various areas listed above. The company had to make a decision to make available the best that the company has to offer in the areas of production, maintenance and engineering to be a part of the team. Because of their other responsibilities in construction of this facility as well as running existing facilities it is almost impossible for them to spend a majority of their time on process automation alone. Once a team was established then the next step was to set the criteria for controlling the process and the handling of production data.

The numerical modelling and process simulation for the fault diagnosis of rotary kiln incinerator were accomplished. In the numerical modelling, two models applied to the modelling within the kiln are the combustion chamber model including the mass and energy balance equations for two combustion chambers and 3D thermal model. The combustion chamber model predicts temperature within the kiln, flue gas composition, flux and heat of combustion. Using the combustion chamber model and 3D thermal model, the production-rules for the process simulation can be obtained through interrelation analysis between control and operation variables. The process simulation of the kiln is operated with the production-rules for automatic operation. The process simulation aims to provide fundamental solutions to the problems in incineration process by introducing an online expert control system to provide an integrity in process control and management. Knowledge-based expert control systems use symbolic logic and heuristic rules to find solutions for various types of problems. It was implemented to be a hybrid intelligent expert control system by mutually connecting with the process control systems which has the capability of process diagnosis, analysis and control.

Microcomputer Control of a Printing Ink Plant

The synthesis of control systems for overall processes remains a challenge. Whilst a number of automated approaches have been explored academically, in practice systems are mainly synthesised using experience and intuition in conjunction with dynamic simulation software. An approach is presented in this paper for the systematic synthesis of overall process control systems which is simple, practical and appropriate for use at the undergraduate teaching level. Many potential problems can be identified and avoided in the synthesis of process control systems by ensuring that the control system can maintain a steady-state control of the overall mass, the mass of the individual components and, where necessary, multiple phases. Processes with recycles are vulnerable to process control problems when the overall mass balance of the system containing the recycle is not correctly managed. This can be overcome by self-regulation (perhaps involving process design changes) or by changing the structure of the control system. Achieving and maintaining the material balance are the main purposes of the majority of controllers in most chemical processes. Without robust delivery of material balance control, higher level control objectives (such as quality controls) are unlikely to be met reliably. This paper presents a step-wise approach to the synthesis of overall process control systems that avoids many potential problems by identifying which process parameters can be manipulated to achieve the intended process mass balance and designing the control structure accordingly.

Das funkenerosive Senken ist ein abbildendes Abtragsverfahren zur formgebenden Metallbearbeitung, das im wesentlichen auf der Ausnützung von elektrischen Feldeffekten zwischen ungleich gepolten Elektroden basiert. Der Abtrag wird durch Funkenüberschläge in Folge einer pulsförmigen Spannung zwischen der (meist positiv gepolten) Abbildungselektrode und dem auszuerodierenden Werkstück bewirkt. Werkstück und Werkzeugelektrode sind dabei durch einen sehr schmalen (5(µm-50µm) mit Dielektrikum gefüllten Spalt getrennt. Infolge Leitwertänderung des Dielektrikums durch Erwärmung in Verbindung mit einer Kontaminierung durch Abtragspartikel ändert sich die elektrisch wirksame Spaltweite praktisch von Funken zu Funken. Dies stellt für die Prozeßsteuerung im Hinblick auf Abtragsmaximierung und Abtragsgüte (Oberflächengüte und Abbildungsgenauigkeit) ein hochgradig nichtlineares und zeitkritisches Problem dar. Zur Beherrschung dieser Prozeßführungsaufgabe wurde eine hierarchisch kaskadierte Prozeßführung entwickelt, die auf sehr unterschiedliche Zeitkonstanten reagieren kann. Die integrierten Fuzzy-Bestandteile behandeln dabei die nichtlineare Prozeßcharakteristik. Die Aufgabenverteilung auf die einzelnen kaskadierten Stufen richtet sich dabei nach den zeitlichen und regelungstechnischen Anforderungen und nach der zu bewältigenden Datenmenge. Insgesamt wird eine Hochleistungs-Prozeßführung vorgestellt, die neben effizienter Datenerfassung und -Übertragung über einen Protokollierungsanteil verfügt, der es erlaubt, die Wirkungsweise der einzelnen Fuzzy-Komponenten genauestens zu untersuchen. Abschließend soll über eine eigens entwickelte Fuzzy-Hardware berichtet werden, die zu einer deutlichen Geschwindigkeitssteigerung in der Abarbeitung von Fuzzy-Algorithmen führt.

Research in automating the process level of machining operations has been conducted, in both academia and industry, over the past few decades. This work is motivated by a strong belief that research in this area will provide increased productivity, improved part quality, reduced costs, and relaxed machine design constraints. The basis for this belief is two-fold. First, machining process automation can be applied to both large batch production environments and small batch jobs. Second, process automation can autonomously tune machine parameters (feed, speed, depth of cut, etc.) on-line and off-line to substantially increase the machine tool’s performance in terms of part tolerances and surface finish, operation cycle time, etc. Process automation holds the promise of bridging the gap between product design and process planning, while reaching beyond the capability of a human operator. The success of manufacturing process automation hinges primarily on the effectiveness of the process monitoring and control systems. This paper discusses the evolution of machining process monitoring and control technologies and conducts an in-depth review of the state-of-the-art of these technologies over the past decade. The research in each area is highlighted with experimental and simulation examples. Open architecture software platforms that provide the means to implement process monitoring and control systems are also reviewed. The impact, industrial realization, and future trends of machining process monitoring and control technologies are also discussed.

Increasing operating costs and decreasing net revenues have greatly underlined the importance of optimizing production operations. The development of automation systems in the Petroleum Industry has become important in uniting isolated production facilities to form integrated systems. This paper briefly traces the history and development of remote and computer control systems for gas and oil production. It also describes the development of the remote control and monitoring system installation at Union Oil onshore and offshore production facilities in East Kalimantan. Emphasis is placed more on the description of the remote process system monitoring and control in the Attaka field. The wireless communication and process control system are being used to transmit alarm and flow metering, emergency shutdown, and paging functions between five satellite wellhead platforms and production platform central monitoring system at the Attaka field. Each producing facility is designed to be compatible with remote supervisory control. To obtain this compatibility and a high degree of safety, conditions in each portion of the process system are monitored. Paralleling the development of automatic control techniques were computer applications. A simple computer system are being used to control and monitor three gas dehydration towers which comprise a portion of the Union LEX Plant operation at Santan onshore facility. Expectations and development of future systems and evaluation of past experience are discussed in the conclusion.

A method is presented for process fault diagnosis using information from fault tree analysis and uncertainty/imprecision of data. Fault tree analysis, which has been used as a method of system reliability/safety analysis, provides a procedure for identifying failures within a process. A fuzzy fault diagnostic system is constructed which uses the fuzzy fault tree analysis to represent a knowledge of the causal relationships in process operation and control system. The proposed method is applied successfully to a nitric acid cooler process plant. >