Industrial Production Plants Research Articles

Interactions entre les risques des produits, des processus de fabrication, des ressources par l'utilisation du concept de typologie. Application à une usine de recherche et de production de semi-conducteurs

This paper deals with links between product, process and tool risks analysis, in a manufacturing environment. It presents business links through a specific model and its correlated links in the risk space. We propose in this paper a model for risks' links and we present its use for mastering process control and return of experiments in an industrial production plant.

A Win-Win Strategy to Energy Financing Challenges—Performance Contracts

ABSTRACT Energy users such as industrial production plants, public service entities, hospitals, universities, and others may desire to upgrade their energy system, often including such things as HVAC, lighting, furnaces, cooling towers, etc. These energy users are referred to as “clients.” “Performance contracts” provide a unique financial arrangement between a “client” and an energy service company (ESCO) that allows the client to replace its aged and inefficient equipment and upgrade its energy system, while investing relatively little money. With a performance contract, the client can get significant energy savings and assume little risk. The ESCO takes the responsibility of leasing / purchasing the system from the manufacturer / vendor, installing the equipment, and ensuring maintenance, for which they are paid a portion of the client's energy savings/revenues throughout the contract. As such, the performance contract presents a win-win strategy for all parties involved, including the client, the ESCO, and even related parties such as the equipment manufacturer, the maintenance organization, and the utility. The article is divided into three parts. First, the fundamentals of performance contracts are introduced. Second, the implementation process of a typical performance contract is outlined. Finally, a case study is provided to show the financial interactions and to present the economic analysis for each party involved.

‘You Just Have to See It’: Exploring the Forms of Expert Pattern Recognition in the Development of Chemical Technology

This paper contributes to discussion on the forms of adaptive learning by exploring how chemistry professionals interact with and in different physical settings—laboratory, pilot plant, and industrial production plant—while developing new chemical technology. More particularly, the study examines how chemistry professionals analyse information in these three physical settings and how they transform this information from one physical setting necessary in a chemical scale-up process to another. The presented empirical evidence suggests that expert pattern recognition mediates learning between different physical settings. The study identifies different kinds of seeing as a particular form of this expert pattern recognition. Processing contextual knowledge through seeing helps chemistry professionals extract clues about the underlying issues and problems in specific physical settings, thus enhancing learning in and across those settings. Furthermore, this study examines formation of such expert pattern recognition.

Using Process Simulators for Steady-State and Dynamic Plant Analysis: An Industrial Case Study

Process simulation tools are widely adopted for the design and optimization of chemical processes. However, for quite a long time their use has been confined within research centres and highly specialized technical groups. This is especially true for dynamic simulation software, long regarded as a very specific tool requiring considerable expertise. In this work we intend to demonstrate the benefits that process engineers working on the plant may receive from an appropriate use of commercial software currently available for steady-state and dynamic simulation. A case-study concerning the purification section of an industrial plant for vinyl chloride monomer production will be considered. First of all, a steady-state simulation will be considered. Primarily, the simulation will allow a better judgement of the plant operating conditions; then it will be illustrated that sensitivity studies may produce great benefits in the general economy and productivity of the plant. Secondly, it will be shown how a dynamic model suitable for practical needs can be derived from the steady-state model. This model can be used as a powerful tool to assess the performance of the control system in handling standard operational disturbances as well as abnormal events. Simple improvements of the control system design will be also simulated and commented on.

Modeling of Radial Flow Reactors of Oxidative Reheat Process for Production of Styrene Monomer

AbstractStyrene plays an important role in industrial production plants due to its increasing use in the production of various products. Thus, availability of a simulating program for styrene monomer reactors is of major importance in reducing the problems of a styrene unit. In oxidative reheat technology, styrene monomer is produced from ethylbenzene dehydrogenation in radial flow reactors in the presence of the generated heat from hydrogen oxidation reaction. In this article mass, energy and momentum equations on radial direction are developed for styrene monomer reactors. Required kinetic rates and parameters have been adopted from the literature [1,2]. Then, by means of experimental data from industrial reactors and sequential quadratic programming (SQP) methods, suitable kinetic parameters are obtained. Comparison of simulator prediction data with industrial ones show that the simulation has been achieved adequately.

Heat-treated wood and its development in Europe

Efficient use of timber is a vital concern problem, especially in these regions where the forestry coverage ratio is decreasing. Studies on physical modification of wood have been taken more attention due to the increasing attentions on environmental protection. Thermal modification is emphasized and developed quickly in developing countries, especially in European countries. A large number of researches have been conducted and some industrial production plants have been built. This paper reviewed the history of heat treatment, exemplifies the industrial developments in several European countries, summarized the basic principle of heat treatment and describes the environmental characteristics. The properties of heat-treated wood and its usage are also summed up.

Non-asbestos Diaphragms in Chlor-Alkali Electrolysis

For decades in diaphragm electrolysis, asbestos containing diaphragms have been utilized to separate the anode and cathode compartments. Due to the harmful characteristics of asbestos, its world-wide prohibition in diaphragm manufacturing is expected. The objective of this work was focussed on the development of a diaphragm with sufficient mechanical and chemical stability to substitute the modified asbestos diaphragm currently used. Suitable materials for the manufacture of non-asbestos diaphragms were identified and a deposition technology was developed which fulfils the requirements of industrial production plants.

Detection of process abnormality in food extruder using principle component analysis

Early detection of process abnormality is an important issue for manufacturing industry, particularly for an industry which is predominantly using manual operation. The result of early detection could reduce manufacturing cost due to unsatisfactory product quality. This paper reports a detection of process abnormality in food extruder using principle component analysis. To demonstrate the effectiveness of the procedure, an experiment is designed and performed on a pilot plant where we simulate the abnormality that might occur in an industrial production plant. Specifically, we target the variations of moisture content in feed materials. The experimental data are analyzed for detection of abnormality in the product.

Fuzzy decision support for the control of detergent production

AbstractThis paper describes a fuzzy decision support system (DSS) for the control of a detergent production process. The application has been carried out at a real‐world, large‐scale industrial production plant in the Netherlands, where a large variety of powder‐based detergents for industrial users are produced in a spray drying process. The system consists of several fuzzy rule bases that model the control actions of experienced process operators in response to different quality deviations of the product. A hierarchical architecture of the fuzzy system is introduced to cope with the complexity. A fuzzy supervisor is used to deal with process constraints and to activate the applicable rule bases when control actions are needed. In this way, a system is obtained that enables the control of the process within stricter quality bounds than those applied by human operators alone. During in‐production evaluation, the average improvement in the quality parameters for all product classes was above 30 percent. Copyright © 2001 John Wiley & Sons, Ltd.

Flexible working time systems--the process of design and implementation.

Examples of the design and implementation processes of flexible working time systems are derived from a counselling project in North Rhine-Westphalia, Germany. The practical cases shown represent a diversity of variable or flexible working time systems according to different branches and different anticipated aims to reach with flexibility. For companies flexibility should improve or at least consolidate their economic situation, and for employees flexibility should result in a beneficial effect on health, family and social life. Three examples of counselling practice are reported in this paper, each case representing a different approach to flexibility in working time. To avoid overtime an industrial production plant expanded the weekly operating time without increasing the employees working time. For this purpose shifts off had to be planned. To provide a continuous service one department of a service company changed from duty on call to regular shifts on weekends. Responsibility in handling the new working times was assigned to the team. In an old people's home working times were designed according to the irregular demands throughout the day, in combining full and part-time jobs adequately.

Supervised Real-time Control with PLCS and SCADA in Ceramic Plant

Abstract This paper describes the design of an automatic control system in an industrial ceramics production plant of the latest generation. The automatic control is implemented on PLCs and is monitored through a powerful package of SCADA software. A PC supervisory real-time system is designed and installed to optimise the adaptive control devices to their intended purposes, or to take complete control of the automation if it detects system failures. In addition, a supervisory system captures the most significant control parameters, for later off-line analysis. Furthermore, a telecontrol system allows taking total control over the real-time automation via modem.

Numerical modelling of the growth of electrodeposited chromium on corner-shaped cathodes

In this paper, we propose the numerical simulation of the internal Cr-plating process of bored gunbarrels, displaying corner-shaped features. The growth of the Cr layer over a machined step is simulated by modelling the current density distribution under mixed activation and mass-transport control and correlating the local instantaneous current density to the growth rate. The problem with non-linear and time-dependent boundary conditions is solved by the FDM method in an iterative scheme. Experimental kinetic data were used to obtain an analytical form of the boundary conditions (relating local overvoltage to local current density); original routines were devised in order to achieve efficient convergence with realistic cathodic kinetics. Experimental parameters from an industrial production plant were used to model the hydrodynamic effects on the growth of the coating. Predictions of Cr-coating growth profiles were compared with experiments.

A real-world software project

In an industrial glass production plant, the manufacturing process can be described as follows. There is a closed vat that contains a thin layer of liquid tin. At the head of this vat, the glass paste is deposited onto the tin. After a mechanical process of extension, glass sheets of various thicknesses are obtained at the other end. This towing process, while necessary, also causes defects in the glass sheets. The reason is the tin currents created by the glass as its pulled along the layer. These currents create multiple paths for the molten glass to take as it heads toward the other end. These currents also generate different levels/patterns of thermal energy within the vat. The thermal patterns lead to heat imbalances and, thus, plastic deformations. Until now, these processes were controlled by human expertise. But to improve quality, a computer-based methodology must be implemented. The goal is to control the different mechanical and optical glass features to obtain optimal quality. The fluid-dynamic problem is debugged through simulation.

Treatment and recycling of zinc hydrometallurgical wastes by self-propagating reactions

A novel technique for treating and recycling of a highly toxic solid waste from electrolytic zinc plants, i.e. goethite waste, is proposed. It consists of blending this waste with suitable amount of reducing agents (aluminum or aluminum and silicon) and ferric oxide, and igniting the resulting mixture so that a self-propagating reaction in the form of a combustion wave rapidly travels through the mixture without requiring additional energy. Reactants are converted into two solid products (P 1 and P 2) with different mass, composition and structure, and a gas constituted by SO 2. Aluminum and silicon should be preferred as reducing agents, since the reaction product P 1 obtained in larger quantity, is constituted by an amorphous glassy structure of alumino-silicates which embodies heavy metals, such as Pb and Cd. Leaching tests of the reaction products P 1 are also performed to verify the possibility of their disposal. The solid product P 2 on the other hand may be recycled in the roasting unit of the industrial zinc production plant. A waste treatment process is also proposed.

Design Strategies for Flow of Non-Newtonian Fluids Through Packed Beds

Flows through packed beds are well known in industrial production plants, e.g., distillation, rectification, filtering, tertiary oil recovery. The authors present results illustrating that this procedure using the flow of non-Newtonian fluids (shear thinning or shear thickening) through packed beds of spheres is an adequate method of predicting the pressure loss from measured volume flow rates.

Application of TQM Principles in the International Technology Transfer Process of Industrial Production Plants: A Conceptual Framework

This paper attempts to illustrate the application of the principles in Total Quality Management (TQM) to the International Technology Transfer (ITT) processes used in industrial production plants. Disaggregated analysis of the ‘technology transformation’ process is deployed to highlight the application of TQM. AT&T's ‘customer–supplier’ model of quality is introduced to explain the interactive roles of the parties involved. It argues that the existing literature deals inadequately with the issues raised and discussed in this paper. A conceptual ITT‐TQM model is proposed. Such a model should ensure proper assimilation of imported technology and permit continuous improvement of the processes leading to the customer satisfaction. It is suggested that the success of the model depends on the ‘win‐win‐win’ strategies of the supplier, the process owner and the customer. Examples from various sources are presented to reinforce the argument. In addition, international standards such as the ISO 9000 standard and frameworks for TQM such as the US Malcolm Baldrige National Quality Award and the European Quality Award (European Foundation for Quality Management) are posited as necessary to ensure quality technology transfer.

An Information System for Quality Data in Industrial Production Processes

In industrial production plants the availability of quality-oriented information has become a key factor for competitiveness nowadays. While there are proven models for structuring this information in an object-oriented way, there are no general implementations of such models available, which meet the broad range of requirements in process control engineering. This paper describes the requirements of a quality data information system, proposes its basic structures and presents an agent-based approach enabling the implementation of such a system in future.

A reusable iterative optimization software library to solve combinatorial problems with approximate reasoning

Real world combinatorial optimization problems such as scheduling are typically too complex to solve with exact methods. Additionally, the problems often have to observe vaguely specified constraints of different importance, the available data may be uncertain, and compromises between antagonistic criteria may be necessary. We present a combination of approximate reasoning based constraints and iterative optimization based heuristics that help to model and solve such problems in a framework of C++ software libraries called StarFLIP++. While initially developed to schedule continuous caster units in steel plants, we present in this paper results from reusing the library components in a shift scheduling system for the workforce of an industrial production plant.

Machinery selection ‐ process capability and product reliability dependence

Reliability of a product is highly dependent on the process capability index of the manufacturing process. Discusses a mathematical modelling technique for deriving the relationship between the product reliability strength and the process capability requirement to meet the product reliability strength for different types of external stress/load distributions which the product undergoes in the actual working environment. Considers four cases of external stress distributions: normal, log‐normal, expotential and Weibull. These techniques can be applied effectively in industrial production plants while selecting machines with required process capability to meet the product reliability strength demand.

Modelling of the Leavening Process in a Continuous Bread-Making Industrial Plant Using Neural Networks

In this paper we propose a model of the leavening process in an industrial plant for bread-making production. The model is implemented by means of a mix of neural networks and linear ARX systems. The model can be used by a human operator to predict the effect of manual control action: furthermore. it could be used to implement a predictive automatic control in order to achieve a certain mean quality of the products. The identification has been carried out by means of measurements on the plant and on experiments in laboratory: in operating mode the model needs of some measurements which can be easily acquired from the plant. The good fitting of the results shows that the proposed architecture is well suited for the considered plant.