bluuebunny/crossref_metadata_2025 huggingface dataset:
Phasengrenzflächen in Blasenströmungen – Teil 3: Koaleszenzhemmung
Authors: Millies Marco , Mewes Dieter
Published: December 2004

The first part of this contribution [1] presents the population balances, i.e., balance equations for the numerical density of the bubbles in the individual bubble fractions. They are solved approximately by an analytical approach. There results a straightforward balance equation for the average bubble volume. This equation can be solved analytically for simple fields of flow. For complex fields of flow it has to be solved by a numerical approach. The result obtained is the bubble volume at any time and place averaged from the size distribution of the bubbles. This permits calculation of the local size distribution of the bubbles with the aid of the approximate analytical solution. In the second part of this contribution [2], this balance equation is extended to cover large gas volumes. Large bubbles and gas plugs then occur. These possess a very small interfacial area relative to their volume. They have high rise velocities and thus short residence times in the flow. They therefore participate to only a slight extent in mass and energy transfer and have to be considered, for example, in calculation of the conversion on a chemical reaction or the mode of action of an evaporator. The calculations are performed for pure liquids and compared with the authors' own and other experimental results. The liquids used industrially are generally mixtures of substances. In such liquids the coalescence behavior deviates significantly from that in pure liquids. The influence on coalescence and thus on the interfacial area is examined in the present paper.
Fettpolymere – Herstellverfahren und Eigenschaften
Authors: Behr Arno , Ritter Wolfgang , Zauns‐Huber Rudolf
Published: December 2004

The radical polymerization of esters of acrylic, methacrylic or crotonic acid with fatty alcohols proved to be an efficient method for production of polymers with hydrophobic moieties. By co‐polymerisation with hydrophilic co‐monomers ‐ such as maleic anhydride ‐ copolymers with a broad spectrum of properties can be designed. As an example the copolymerisation of fatty crotonates with maleic anhydride was studied in detail. The reaction was carried out as bulk polymerisation in a semi‐batch process. By this method the compatibility problems of the two monomers, which have very different hydrophilicities could be overcome. The product acts as a very effective fat liquoring agent in leather treatment: the maleic moieties cause an outstanding fixing of the agent on the leather and the fatty crotonate moieties create a very smooth leather. Terpolymers of fatty acrylates, hydrophilic monomers and terpenes could also be synthesized in a similar way. These terpolymers proved to be useful as dispersing agents for pigments in paints and varnishes.
Planungs‐ und Simulationssysteme in der Prozeßindustrie
Authors: Heydecke Jens , Kovriguin Oleg V.
Published: December 2004

Efficient scheduling systems are able to enhance production flow and production times in process industry. Scheduling, in this case, means simulation with alternatives of resources and/or activities. The result will be the exact time of output for each activity and the resulting profiles of capacity vectors concerning the recommended resources. In contrast to this, common planning systems add only the user defined production time of activities. Especially for flexible plants with batch production and a variable spectrum of products, as weil as for plants in the stage of design or enlargement, scheduling systems can be very helpful in identifying bottlenecks and over‐capacities. Therefore, reduction of costs in a significant extent and additional benefits can be realized, provided that the individual conditions and objectives have been taken into account.
Glanz und Elend technischer Prognosen
Authors: Renn Ortwin
Published: December 2004

People depend upon technology, at work and in everyday life. Without organisational and technological intervention in nature humankind would never have been able to maintain the population densities encountered today or uphold an ethical claim to an individual livelihood in dignity. At the same time, however, technology creates new risks. The extent to which the risks arising are balanced by the desired benefits often evades prediction since many consequences of the application of technology are uncertain and are also judged ambivalently by the persons affected. Forecasts can only predict probable or possible developments, but cannot overcome the genuine uncertainty surrounding the future. For this reason assessment of the consequences of technology cannot reveal all negative effects, or even promise the certainty of a positive cost‐benefit balance. Instead, it is the task of assessment of the consequences of technology to initially establish the potential positive and negative consequences according to the best available knowledge and on the basis thereof to harmonize the possibilities of modifications and conditions of introduction with the developers and users of technology. The most suitable approach utilizes discursive procedures in which scientists, manufactures, users, and other affected persons together have to assess the possible consequences.
Einsatz von korrosionsbeständigen Stählen in der chemischen Industrie — Bedeutung, Erfahrungen und zukünftige Anforderungen
Authors: Heinke Günter , Korkhaus Jürgen
Published: December 2004

Corrosion resistant steels – especially the austenitic and the ferritic‐austenitic “duplex” grades – represent basic materials of construction for the chemical industry. They serve in cryogenic and high temperature applications, but are most often used in aggressive highly acid to alkaline, frequently aqueous media. The criteria for the selection of corrosion resistant steels are governed not only by the corrosion resistance requirements, but also may be dominated by product cleanline and other process requirements. The development and the market introduction of corrosion resistant steels is closely connected with developments in the chemical process industry. Service experience for corrosion resistant steels is reported, and critical failure mechanisms like pitting and stress corrosion cracking, and their avoidance by appropriate material selection, are mentioned.
Innovative Verfahren mit komprimierten Gasen
Authors: Bungert Bernd , Sadowski Gabriele , Arlt Wolfgang
Published: December 2004

By exploiting thermodynamic phenomena in systems with compressed gases, the properties of products such as their morphology and the size of particles and fibers can be tailored to industrial needs. Separation of complex mixtures can be accomplished. Processes that are conventionally operated in a number of costly steps can be reduced to a few operations. This article gives a phenomenological classification of such processes and explains the underlying principles. Operations developed on a laboratory scale as well as those already established in industry will be discussed.
Anforderungen und Möglichkeiten bei der Verfahrensentwicklung in der Trocknungstechnik Ein Vergleich realisierbarer Vorgehensweisen bei unterschiedlichen experimentellen Möglichkeiten
Authors: Liedy Werner
Published: December 2004

For many products the drying step exerts a great influence on price and application properties. Therefore great effort should be invested in developing and optimizing drying processes. This paper presents a structured procedure for the development of drying processes. In the case of optimal experimental equipment an “ideal” method of proceeding is indicated. Furthermore it is shwon how to develop and optimize drying processes very successfully with little experimental equipment or even if there is no experimental equipment available. Papers published in this field treat only special aspects or presume optimal experimental equipment. This paper is specially interesting for users with limited experimental equipment.
Prozeßmodellierung bei der metallorganischen Gasphasenepitaxie
Authors: Dauelsberg Martin , Durst Franz , Kadinski Lew , Makarov Yuri N.
Published: December 2004

This article provides a brief survey of mathematical modelling of metalorganic vapour phase epitaxy (MOVPE), a step in semiconductor processing of III‐V compound semiconductors serving as basis for the production of electronic and optoelectronic components. The process model for MOVPE is based on the mathematical description of gas flow for a MOVPE reactor coupled with heat transfer and mass transport, including multicomponent diffusion, thermal diffusion, and homogeneous and heterogeneous chemical reactions. Several approaches to the description of multicomponent mass transport, of the modelling of heat transfer in terms of thermal radiation, and of the actual growth process on the growing semiconductor surface are considered. The process modell is applied to MOVPE of GaAs in an industrial multilayer reactor and the calculated results validated with the aid of experimental results.
Experimentelle und numerische Modellierung der Wirkung von Gas‐ und Staubexplosionen
Authors: Schumann Steffen , Rastogi Ashok Kumar , Fucke Wolfgang , Friehmelt Volker
Published: December 2004

Since the intensity of an explosion increases substantially on damming or as a result of turbulence‐generating obstacles, gas or dust explosions in industrial plant can cause considrable damage. In connection with various research projects, medium and largescale experimental studies on gas and dust explosions were undertaken in order to gain detailed information about the course and effects of explosions under realistic conditions and to assess possible means of improving safety precautions. Some typical experiments on expansion in dust explosions are presented on the basis of the measured explosive pressures and flame lenghts and compared with the calculated results obtained using the BASSIM CFD code developed by Battelle or by empirical modelling.
Die auf einer Stoffstromanalyse basierende Implementierung von vorsorgendem integrierten Umweltschutz
Authors: Schnitzer Hans
Published: December 2004

Properly implemented environmental protection can prove to be an economically sound and profitable approach for processing and manufacturing industry. This requires an integrated approach with a systematic consideration, and consequent reduction, of the formation of waste products and emissions. This paper proposes a system for categorisation of the starting materials of production and for classification of waste and emission flows, and an answering strategy based thereon. Avoid ance and reduction of emissions can be achieved in four ways: increasing efficiency, increasing effectiveness, utilisation of by‐products, and substitution of starting materials. Combination of material‐flow analysis with a complete plant environmental cost calculation helps to clarify the economic benefits of production‐integrated environmental protection. More than 100 case studies conducted within the framework of cleaner production programs in Austria demonstrated the soundness and feasibility of thes approach.
Stoff‐ und Energiewandlungen bei verfahrenstechnischen Prozessen
Authors: Fratzscher Volfgang
Published: December 2004

Mass and Energy Conversion in Processes of Chemical Engineering. Being the practice of chemical engineering, chemical industry is among the industrial branches with a high energy consumption. This is scientifically based on the unity of mass and energy conversion. Although theoretically well‐known these interconnections have only little influence on engineering investigations. That's why incomplete and untrue evaluations of the energetic conditions of chemical processes can occur. After a brief historical survey, a classification of the different kinds of energy for chemical processes will be proposed as a help in solving this problem. This classification facilitates a deeper understanding of the energetics of chemical processes. To increase these investigations the term cumulative exergy expenses can be used for the evaluation of chemical processes. This evaluation considers both the conversion of energy and the conversion of mass. These connections are discussed by one example. If these research purposes are generalised for strategic development, they will lead to a new generation of chemical and energetical plants.
Betriebsleittechnik – Funktionsumfang und Stand der Systeme
Authors: Kersting Franz‐Josef
Published: December 2004

Process Control Engineering – Function and State of the Art of the Systems On considering material flow in a chemical engineering company it is possible to identify associated business processes whose support by appropriate information processing systems will permit efficient control of material flow and material conversion as production goal. Such consideration indicates not only the principal functions of information processing but also the necessary integration of process‐oriented information systems such as those relating to formulation, production planning, and operating data processing. Various concepts are currently under discussion for such integration.
Prozeßführung
Authors: Schuler Hans
Published: December 2004

Process Management The concept of “process management” is being increasingly used as a complement to similar concepts such as process automation, process control, etc. Such terms are defined within a framework of more general conceptional trends, which can be characterised by terms such as integration and holistic. Considerable potential exists with this framework for fruitful joint development of the main disciplines contributing to process management, viz. process engineering and automation engineering. Such developments remain inaccessible to the individual disciplines. The present article considers this concept from an industrial viewpoint.
Thermodynamische Grundlagen der Reaktivdestillation
Authors: Frey Thomas , Stichlmair Johann
Published: December 2004

Thermodynamic Fundamentals of Reactive Distillation Reactive distillation means the simultaneous implementation of reaction and distillation in a counter‐current column. The effective phase equilibrium is very complex since the chemical equilibrium is superimposed on the vapor liquid equilibrium. The paper focuses on the calculation and presentation of this equilibrium using so called reactive distillation lines. This leads to a clear explanation for the existence of reactive azeotropes and to a simple method for the determination of the concentration of these azeotropes. The effectiveness of this method is demonstrated on several mixtures with different reaction mechanisms.
Expedition ins Datenreich: Wie kann man Informationen in Produkt‐ und Prozeßdaten umfassend erschließen?
Authors: Estler Manfred , Hilpert Ralf , Soravia Sergio
Published: December 2004

Exploring the Data World: How Can We Extract the Maximum Information from Product and Process Data? In various areas of the chemical industry a wealth of product and process data of various kinds is generated and recorded. In the majority of cases these data have only been evaluated fragmentarily and not systematically in terms of their information contained. Following the acquisition and possible short term visualization they end up in regular “data graveyards”. Furthermore, these data often stem from different sources such as distributed control systems (DCS), laboratory information and management systems (LIMS), or shift logs. There is a great potential for an improvement of product quality, process control, and plant safety, as well as for a reduction of inspection costs in the compilation and systematic analysis of these data. In addition to classical statistical methods, new data analysis techniques are increasingly used. After a brief explanation of the procedure used in data analysis projects and a presentation of several methods, an example illustrates which results can be obtained from an approach to data analysis that is not yet widespread in the process industry.
Eine Querschnittstechnologie drängt zum Markt: Die Möglichkeiten der modernen Biotechnologie
Authors: Marquardt Rüdiger
Published: December 2004

The Scope of Modern Biotechnology Any attempt to explain the term “modern biotechnology” and to distinguish it from classical biotechnology soon reveals that the boundary is anything but distinct and frequently disappears in a terminological fog. Things only become easy when modern biotechnology can be defined as using the methods and processes of genetic engineering. This is indeed often the case, but not always. Modern biotechnology embraces advances in process engineering as well as new developments in equipment; it depends on monoclonal antibodies and new cell culture techniques, it benefits from advances in embryonal transfer in the animal kingdom and also from cloning; it is taking over large areas of environmental engineering. This list could be continued. Processes of classical biotechnology are always involved in the production of a modern biotechnological product. It is ultimately irrelevant to the engineer whether a fermenter contains genetically engineering microorganisms or not; or to the farmer whether the potatoes he grows are genetically modified or not. There can be no modern biotechnology without classical biotechnology – and the reverse will soon also be true.
Prozeßtechnische Aspekte der Produktion mit myzelbildenden Mikroorganismen
Authors: Schügerl Karl , Seidel Guido
Published: December 2004

Process Engineering Aspects of Production with Mycelium‐Forming Microorqanisms This review deals with process engineering aspects of biosynthesis, morphology and rheology of myceliumforming microorganisms, which produce secondary metabolites and proteins in semisynthetic and complex cultivation media. The interrelation of biosynthesis, morphology and rheology are discussed. Mathematical models for the biosynthesis and the morphological structures are presented. The investigations indicate that the results obtained with microorganisms cultivated in semisynthetic media cannot be directly transferred to systems with the same micro‐organisms cultivated in complex media.
GVC‐Fachausschuß „Kristallisation”︁
Authors: Gahn C. , Rauls M.
Published: December 2004

Das diesjährige Treffen des GVC‐Fachausschusses „Kristallisation”︁ fand auf Einladung der SCHERING AG vom 22. bis 24. März in Berlin statt. Die Sitzung wurde vom scheidenden Vorsitzenden des Fachausschusses Prof. WINTERMANTEL, BASF AG, geleitet. Der Vorsitz des Fachausschusses geht in den kommenden Jahren auf Prof. KIND, Universität Karlsruhe, über. Prof. MERSMANN, TU München, scheidet als berufenes Mitglied aus dem Fachausschuß aus. Seine wissenschaftlichen Leistungen sowie sein Engagement als Mitglied und Vorsitzender des Fachausschusses wurden von Prof. Wintermantel gewürdigt.
GVC‐Fachausschuß „Aus‐ und Fortbildung in der Verfahrenstechnik”︁
Authors: Molzahn Martin
Published: December 2004

Am 1. Dezember 1998 fand in Ludwigshafen eine interne Arbeitssitzung des GVC‐Fachausschusses „Aus und Fortbildung in der Verfahrenstechnik”︁ statt. Auf der Basis von insgesamt zehn Vorträgen diskutierten 32 Teilnehmer aus Hochschule und Industrie u. a. über die Einführung gestufter Studiengänge mit Bachelor‐Masterabschluß, über neuere Trends in der Ingenieurausbildung in Großbritannien, über Qualitätssicherung und Qualitätskontrolle an in‐ und ausländischen Hochschulen, über neue Studiengänge an Universitäten und Fachhochschulen sowie über Konsequenzen der Globalisierung des Bildungsmarktes.
Möglichkeiten zur Vorausberechnung von Verweilzeitverteilungen
Authors: Platzer Bernd , Steffani Katharina , GroßE Stefan
Published: December 2004

Possible Approaches to the Prediction of Residence Time Distributions Although the experimental determination of residence time distributions is based on a black‐box method, the signal shape also permits certain conclusions to be drawn about the internal conditions. However, if it is to provide a sole basis for elucidating process steps in a plant this method is soon overtaxed. A deeper theoretical penetration of the pertinent transport processes opens up the way ahead. However, since residence time distributions are based on mass‐oriented considerations, substantial advances in fluid mechanics, where location‐based considerations predominate, have not led to improved predictive capability. Yet the computer power now available offers a variety of ways of calculating residence‐time distributions for a known flow profile, thus permitting a step in the direction of better predictability of residence time distributions. This article presents utilisable methods and evaluates them with regard to their demands on time and effort and their predictive power. Problems arising in connection with the models are discussed.
Elektrothermische Regeneration von Adsorbern – Ein Überblick über den Stand von Forschung und Entwicklung
Authors: Bathen Dieter , Schmidt‐Traub Henner
Published: December 2004

Electrothermal Regeneration of Adsorbers ‐ Survey of Research and Development This article surveys the current state of the art in research and development in the area of electrothermal processes for the regeneration of spent adsorbers. In addition to processes based on the induction of electrical current in adsorber beds the paper considers processes in which the required desorption energy is supplied to the system by microwaves.
Elektrische Doppelschichten: Elektrostatik und Elektrodynamik
Authors: Lyklema Johannes
Published: December 2004

Electrical Double Layers: Electrostatics and Electrodynamics Dispersions of solid particles in aqueous solutions almost invariably bear a surface charge which is compensated by an opposite charge in the solution. An electrical double layer is formed. The surface charge can sometimes be determined by titration. In practice, the electrokinetic potential or zeta potential is usually measured. This potential is a characteristic quantity for stability, rheology, sedimentation, etc., of disperse systems. This paper addresses the question of the relation of the electrokinetic potential to the static double layer parameters. To this end the author provides a detailed account of electrokinetic shear processes. In addition, new results obtained with the aid of molecular dynamics are also presented.
The use of analytical peak profile functions to fit diffraction data of planar faulted layer crystals
Authors: Estevez‐Rams E. , Penton A. , Martinez‐Garcia J. , Fuess H.
Published: December 2004

The implication of the use of particular peak profile functions in the fit of diffraction data on the nature and density of stacking faults in layered solids is studied. Common type of profile functions are studied: Gauss, Lorentz, pseudoVoigt and Pearson VII. An additional peak profile is introduced. For each profile function the decaying term of the probability correlation function is determined and the expression for the correlation length is deduced. The form of the asymmetric component of each profile is also reported. Experimental data is fitted using each profile and the results are discussed. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Untersuchungen zu Steifigkeitskennwerten von Mauerwerkwänden im Zustand I
Authors: Steinbach Frank , Pfeifer Matthias
Published: December 2004

Mauerwerk hat in den letzten Jahrzehnten einen rasanten Wandel hin zu einem hochspezialisierten Baustoff vollzogen. Für einige Disziplinen – z.B. den Wärmeschutz – kann man von einem “Hightech”‐Produkt sprechen. Auch die Modelle für die Bemessung von Mauerwerk werden differenzierter. Besonders im Hinblick auf die Vielfalt der angebotenen Steinsorten und Formate wurde in den letzten Jahren versucht, die Bemessung der individuellen Mauerwerkssorte anzupassen. In den Arbeiten [3] und [10] wurde verstärkt die Steingeometrie in die Bemessungsmodelle für Schubversagen bzw. Stabilitätsversagen einbezogen. Andere Arbeiten, darunter [11], haben das Stabilitätsversagen einachsig gespannter Wände unter Berücksichtigung der unterschiedlichen Spannungs‐ Dehnungsbeziehungen verschiedener Stein‐Mörtelkombinationen beleuchtet.

Die Plattentragwirkung einer Mauerwerkwand wird wesentlich durch ihre Steifigkeiten in zueinander orthogonalen Richtungen beeinflußt. Die Unterschiede in der Fugenausbildung sowie in Steinform, ‐art und ‐format führen zu unterschiedlichen Steifigkeitsverteilungen, die bisher nur unzureichend bei der Schnittkraftermittlung und Nachweisführung berücksichtigt werden.

Im Rahmen von ersten Tastversuchen wurden für ausgewählte Steine die Elastizitätsmoduln und die Querdehnzahlen in den beiden wesentlichen zueinander orthogonalen Wandrichtungen bestimmt. Die Stoßfuge wird i. allg. als statisch nicht mitwirkend angesetzt, weil sie entweder nicht ausreichend oder gar nicht vermörtelt ist. Dies führt zu einer Anisothropie, die sich sowohl bei der Scheibenbeanspruchung als auch bei der Plattenbiegung im Zustand I mit den ermittelten Kennwerten auf einfache Art berücksichtigen läßt.
High temperature oxygen index studies of halogenated polyester thermosets containing antimony and molybdenum oxides
Authors: Das M. , Haines P. J. , Lever T. J. , Skinner G. A.
Published: December 2004

A study has been made of the effect of antimony and molybdenum oxides on the temperature‐critical oxygen index relationship of halogenated polyester thermosets. The polyesters were prepared from maleic anhydride, phthalic anhydride and propylene glycol, using either tetrachlorophthalic anhydride, tetrabromophthalic anhydride or chlorendic anhydride as the halogen source. Marked differences were observed in the effect of the two oxides. The critical oxygen index values of the halogenated polyesters containing maoybdenum (VI)oxide decreased with increase in timperature, which is in accordance with what is normally found for organic polymers, with and without additives. In contrast to this, the critical oxygen index values of the formulations containing antimony(II)oxide increased with increased with increase in temperature to reach a maximum value at around 100–150 °C. These results indicate that antimony(II)oxide is a better flame retardant than molybdenum(VI)oxide, since not only is it superior at the primary ignition stage but it shows enhanced activity at the higher temperatures which would be experienced by polymeric material in the early stages of a fire. It is concluded that higher temperature critical oxygen index studies provide a better guide to the flame retardant activity of additives than do ambient critical oxygen index determinations alone.
Some stochastic properties of fire plumes
Authors: Cox G. , Chitty R.
Published: December 2004

Reaction to fire tests are the main criteria used by legislators of fire regulations to determine the suitability of different materials for use in building construction. These do not always give reliable results, particularly when applied to new man‐made materials. Part of the explanation for this is the lack of detailed understanding of the heat and mass transfer processes occurring in fire. This is in part due to a lack of measurements of the fluctuating property field in the source plume. In this paper measurements of the probability density functions, spectra and mean square fluctuations of temperature together with the probability of combustion are reported for a stimulated fire plume. The results are consistent with the model of a fire comprising a series of narrow flame fronts oscillating at the flame flicker frequency (which for this system is 3 Hz). The effects of thermal inertia in thermocouples on the determination of mean and fluctuating gas temperature have been examined using the treatment of Ballantyne, Boon and Moss. The high‐frequency limitations of thermocouple and electrostatic probes have been discussed in the context of trubulent filed measurements in fires.
The formation of NOx from nitrogen containing materials in diffusion flames
Authors: Crowhurst D. , Simmons R. F.
Published: December 2004

The conversion of fuel‐N species to NOx in diffusion flames has been studied by adding acetonitrile to the fuel flow for a methane–Oxygen–argon diffusion flame burning in excess oxygen. It is shown that the conversion is significantly lower than that obtained in a ‘corresponding’ pre‐mixed flame, although the observed concentrations of NOx are still much higher than the appropriate thermodynamic equilibrium concentrations. The effect of initial concentration of acetonitrile, flame temperature and amount of excess oxygen on the conversion can all be explained in terms of the basic structure of a diffusion flame. This enables molecular nitrogen to be formed in the reducing atmosphere which exists on the fuel side of the flame through reaction of cyanide radicals with nitric oxide. The latter diffuses back from the oxygen side of the flame where it is formed, but the overall result is that a proportion of the fuel‐N is converted to molecular nitrogen before it can be converted to nitric oxide.
Combustion products of polymeric materials. 2—Test chamber CAB 650
Authors: Michal Jan
Published: December 2004

A chamber has been designed which allows total assessment of products formed during the thermal stressing of polymer material samples. The chamber is of oval shape and creates an infinite track for the movement of products formed in the course of the thermal degradation process. It allows the complete analysis of the products to be carried out to monitor the contents of the most important of them, to determine the oxygen content, to measure the optical density of smoke and to measure the temperature inside the chamber in the course of the experiment. The chamber was used for testing the combustion products of polyethylene, polypropylene, polystyrene and polyamide.
Comparative study of the toxicity of combustion products from flame retardant and untreated materials
Authors: Herpol Claire
Published: December 2004

Fire retardants improve reaction to fire characteristics such as ignitability and flame propagation. This paper presents the toxicological results of tests performed on eleven pairs of untreated and treated materials, including woods, synthetic materials and textiles (both natural and synthetic). It is shown that the effects of fire retardants on toxicity results can be variable. In addition, the problem of the use of toxicity results is discussed more generally.
Rate of heat release measurements with the Swedish box test
Authors: Holmstedt Göran
Published: December 2004

The Swedisn box apparatus was modified to include an oxygen analysis of the exhaust gases to be compared with the conventional exhaust gas temperature measurement. A slow‐burning material shows good correlation between the temperature measurement and the rate of heat release. A fast‐burning material, however, consumes all the available oxygen, and the temperature measurement becomes a measure of only the thermal properties of the material.
Predicting flash fire protection of clothing from laboratory tests using second‐degree burn to rate performance
Authors: Behnke W. P.
Published: December 2004

Laboratory tests have been developed that evaluate realistically the protective performance of clothing materials and garments. Test conditions are chosen to stress the high temperature resistance of materials in the same manner as in an industrial flash fire exposure. A second degree burn in human tissue is used as the criteria to ate performance of materials. Test results have been correlated between the small‐scale lab swatch test and a full‐scale instrumented manikin garment test, and these results related to industrial experience. The TPP lab test has been found useful in evaluating the performance of candidate materials as replacement for existing materials with known acceptable protective performance. It can be used to specify the level of protection needed in a garment when the intensity of the exposure hazard is known. Also, the test is especially useful for developing new materials and selecting candidates for additional field testing.
Specification of combustible materials for passenger train design
Authors: Allender Peter J.
Published: December 2004

The general nature of fire problems on energy‐conservative passenger trains is described, including a description of vehicle structures and lightweight design. Effects of high energy demand, tunnels and high maximum speeds on fire safety are outlined. The considerations used in design analysis are described, beginning with the development of a ‘worst‐case fire scenario’. Typical combustible materials are considered and some of the reasons for choices are given. Notes on cavity and chimney effects emphasize the importance of clear objectives. Structural fire resistance is examined, and the basis of conventional recommendations analysed. The application of British Standard 6336 guidelines on fire tests and hazard assessment is examined. Limitation of fire load density is described, and some problems of calorific value determination outlined. Sources of ignition and hazards from passengers are defined. Flammability and flame‐spread control are discussed, and rate of heat release is referred to in the context of fire behaviour. Problems of passenger escape linked to flashover, smoke and combustion gases are dealt with briefly.
Characterization of the burning behaviour of polymeric materials
Authors: Paul K. T.
Published: December 2004

Measurements of the limits of flaming and smoldering combustion and relative rates of burning under elevated temperatures and oxygen‐depleted conditions have been used to characterize the fire behaviour of polymeric materials using a semi‐empicical approach (based on scientific theory) in terms of Power Law Indices. The work was based on modified current tests; namely the Limiting Oxygen Index (ASTM D2863) at elevated temperatures and the Setchkin Flash and Self‐Ignition Test (ASTM D1929) modified to operate in oxygen‐depleted atmospheres and to record rate of weight loss. Results show that the relative flammability and rate of burning of materials can change markedly with fire environment, and confirms the need to test materials lunder conditions representative of those of the anticipated end‐use hazard.
Radiative ignition of thermoplastic and charforming materials
Authors: Clark Ferrers R. S.
Published: December 2004

Small samples of poly(methyl methacrylate), red oak and possibly low‐density polyethylene ignite under the influence of thermal radiation with a propensity that increases with the area irradiated, consistent with ignition requiring that the lower flammability limit of pyrolysis gases be reached. The time to self‐extinction of small samples of charring, burning materials (low‐density polyethylene, red oak and possibly polycarbonate) in the absence of external radiant flux increases with burning area, suggesting that the increased absorptivity of char increases the importance of radiative feedback.
Hazard assessment techniques used in the chemical industry and their possible uses elsewhere
Authors: Simmons R. F. , Tyler B. J.
Published: December 2004

The traditional methods used for the identification and assessment of hazards in the chemical industry are based on experience, but increased economic and environmental restrictions on its operations have required the development of other methods to ensure that an acceptable level of safety is maintained. The present paper briefly reviews the traditional methods, describes in mire detail the basis of the newer methods, namely hazard and operability studies and hazard analysis, and considers how they might be more widely used in assessing fire hazards.
A review of products evolved from heated coal, wood and PVC
Authors: Hurst Nichoas W. , Jones T. Alwyn
Published: December 2004

A review is presented of the gaseous combustion and pyrolysis products evolved from coal, wood and PVC. Information has been collated on the range of products evolved, the temperatures of evolution and the effect of different ambient conditions (e.g. oxidizing of inert conditions). The data for coal have been subdivided into those from which rates of gas evolution have been or can be derived and those from which this is not possible. Probable decomposition routes for PVC and for wood are discussed. Although all three materials have been widely studied, the correlation between the work of different authors in not always good. The data obtained are dependent on the form of the experiment, and there are gaps in the information available, especially information on the rates of evolution of products of products as a function of temperature.
Analysis of gases evolved from heated coal, wood and PVC conveyor belt their effect on zinc oxide single‐crystal semiconductor gas sensors
Authors: Hurst Nicholas W. , Jones T. Alwyn , Mann Brenda , van Ewyk Robert L. , Walden Paul
Published: December 2004

An analysis, using gas chromatography and gas chromatography‐linked mass spectroscopy, of the major products evolved as a function of temperature from coal, wood and PVC conveyor belting is described. The effect of these products, both collectively and as individual species, on the electrical properties of zinc oxide gas sensors has been investigated: the conductance of the sensors was measured in air containing either the total products evolved from the heated materials or the individual products eluted from a gas chromatographic column. Thus, the products from the different materials which make up the total zinc oxide gas sensor response at different material temperatures were identified. For coal dust heated in air the sensors responded to aromatic hydrocarbons H2 and CO, which were evolved between 100° and 200°C. For coal heated in nitrogen the sensors responded to the aromatic hydrocarbons evolved between 100° and 170°C. For PVC conveyor belt heated in air, the low temperature response was to the low levels of HCl evolved below 200°C. Finally, for hardwood dust heated in air the sensors responded primarily to the acid vapour evolved between 170° and 200°C.
Flammability testing state‐of‐the‐art
Authors: de Ris John
Published: December 2004

Traditional material‐flammability tests are discussed in terms of their empirical foundation and oversimplified interpretation of fire phenomena. More recent rate of heat‐release tests overcome some of these problems by measuring a material's response to different levels of fire exposure. However, no existing small‐scale tests are sensitive to the radiant emission from the material's own flames. This radiant emission controls large‐scale fire hazards. As a result, existing flammability tests canot be xpected to adequately characterize large‐scale hazards. Some new approaches to this problem are discussed and a specific bench‐scale test method is suggested which may overcome the identified problems of existing test methods.
Modelling of furniture experiments with zone models
Authors: Blomqvist Jan , Andersson Berit
Published: December 2004

The Harvard Computer Fire Code Mark V has been used to simulate full‐scale furniture fires. Simulations were run with one sofa burning in the open and another burning in a small room. To obtain better agreement between experiment and simulation, changes were made in the code to include heating of the lower surfaces in the room. A simulation of a mattress test, conducted at NBS, is included. Comparison with a zone model using a different plume equation is also presented.
Acidic volatiles from overheated polymeric materials
Authors: Humphreys Hazel , Christopher A. J.
Published: December 2004

Previous work on the emission of smoke and fumes from overheated aircraft interior materials has included simple monitoring of acids and alkalies by means of a glass electrode in a water‐bubbler. In order to put these measurements on a quantitative basis and as part of an attempt to assess the significance of acidic or alkaline fumes in terms of irritant effects, a two‐way pH‐stat automatic titration apparatus is now used. A small sample of material is heated at a controlled rate to 500°C in a stream of flowing air. The effluent is bubbled through water and automatically titrated for acids or alkalies. The temperatures at which these emissions occur and their amounts can be measured. Good recoveries of acids, alkalies and of both evolved consecutively have been achieved. To assess the utility of the apparatus for actual materials, the acid evolved from various types of PVC was compared. The emissions from three different nylons and from a composite cable were also investigated. Reference materials with various known additives are now being examined by the method and comparisons with irritancy measurements are being made. Ion‐chromatography will be used to study the individual acid evolved.
A practical method for the calculation of the non‐steady temperature fields in solid bodies
Authors: Haksever Ataman
Published: December 2004

The load‐bearing capacity and deformation response of structural members in fire are mainly influenced by non‐steady temperature distributions in heated bodies. The determination of the temperature fields in these members is therefore the primary assumption for the further computational treatment of fire problems. In this study a new practical calculation method is presented by which the determination of the temperature fields in solid bodies in the case of non‐steady heating becomes easy, and even a simple calculator can solve the problem with sufficient accuracy for practical use. The calculation method is based on the principles of conformal transformations from applied mathematics whereby the Gauss error law is used for the description of unidimensional temperature fields. The efficiency of the method is shown by means of an example.
Quarter‐scale room‐fire tests of interior finishes
Authors: Lee Billy T.
Published: December 2004

A technique for estimating fire‐buildup in rooms with combustible interior finish is discussed. Use of the technique resulted in good agreement between fires conducted in one‐quarter‐scale rooms with a doorway opening and those performed in full‐scale rooms. The effects of burner location and heating rate on flashover in a well‐insulated room were also studied to help select a suitable ignition source size and placement for testing of interior‐finish materials.
Review of Interflam'85
Authors: Allender Peter J.
Published: December 2004

The International Conference Interflam'85 was held at the University of Surrey, Guildford, UK, on 26–8 March 1985. This third conference in the Interflam series was set up with the specific aim to bring together the 1985 state of the art of fire science and to show particularly how this information can be put to practical use in the saving of lives. Over 45 speakers, each specialists in their own field of work, some 15 different countries contributed papers. Dr Peter Allender, formerly of Metro‐Cammell and now with John Allen Associates, has seen the Conference both from the lecturing platform and from the audience. He has been invited to give his views about Interflam'85.
Molybdenum compounds as flame‐retardants and smoke‐suppressants in halogenated polymers
Authors: Skinner G. A. , Haines P. J.
Published: December 2004

The hazards resulting rom smoke emission were widely recognized in the early 1970s as a result of several major fire disasters. Since that time considerable interest has been shown in the development of smoke‐suppressants. This paper reviews some of the very promising results that have been obtained using molybdenuem comounds as flame‐retardants and smoke‐suppressantes in halogenated polymers. They have been shown to be effective in both rigid and flexible grades of PVC. In the rigid grades these compounds can reduce smoke emission by at least 80%. Reductions in excess of 50% have been observed with typical plasticized formulations, although the magnitude of the effect here depends on both the type and level of plasticizer. Comparisons of the results of different smoke tests suggest that the small‐scale tests commonly used do not fully reflect the true extent of the smoke‐reductions that are obtainable with these combounds. Significant reductions in smoke‐emission have also been obtained with halogenated polyester thermosets and chlorinated elastomer formulations. With the polyesters some of the best results occurred when molybdenum oxide was used in conjunction with alumunium trihydrate. In all cases these compounds proved to have significant flame‐retardant properties. Reference has been made in the paper to their mode of activity but the actual mechanistic investigations have not been discussed in detail.
Acrylonitrile–butadiene–styrene copolymers (ABS): Pyrolysis and combustion products and their toxicity—a review of the literature
Authors: Rutkowski Joseph V. , Levin Barbara C.
Published: December 2004

A review of literature was undertaken to ascertain the current knowledge of the nature of the thermal decomposition products generated from ABS and the toxicity of these evolved products in toto. The literature review encompasses English language publications available through June 1984. This literature surveyed showed that the principal ABS thermooxidative degradation products of toxicologic importance are carbon monoxide and hydrogen cyanide. The experimental generation of these and other volatile products is principally dependent upon the combustion conditions and the formulation of the plastic. The toxicity of ABS thermal degradation products has been evaluated by fire methods. The LC50 (30 min exposure + 14 day post‐exposure period) values for flaming combustion ranged from 15.0 mgl−1 to 28.5 mgl−1. In the non‐flaming mode of combustion, the LC50 values ranged from 19.3 Mgl−1 to 64.0 mgl−1. Therefore, no apparent toxicological difference exists between the flaming mode and the non‐flaming mode. The toxicity of ABS degradation products was found to be comparable with the toxicity of the thermal decomposition products of other common polymeric materials.
A simple mathematical model of flashover in compartment fires
Authors: Zdanowski M. , Teodorczyk A. , Wójicicki S.
Published: December 2004

The purpose of this work was to examine the phenomena which determine the possibility of flashover occurrence and progress in compartment fires. A number of experimental fire tests were performed aimed at simplifying the phenomenon in successive tests by eliminating the factors influencing the main mechanisms which determine the occurrence of flashover in compartment fires. A physical model has been proposed as well as mathematical description of the flashover, including a simplified first stage of fire development. A new method for mathematical description of chemical mechanisms of combustion in gas mixture was employed according to which the experiments were considered to be simplified kinetic tests permitting the derivation of a substitute formula for chemical change. A computer program was developed enabling computation of the dynamics of the pre‐flashover fire phase. By means of this program, extensive theoretical analysis was performed of the influence on fire development of a number of compartment factors, including fire load, ventilation and potential fire size.
Preliminary results from an examination of house survival in the 16 February 1983 Bushfires in Australia
Authors: Ramsay G. Caird , McArthur N. A. , Dowling V. P.
Published: December 2004

This paper describes a survey which was undertaken to ascertain those features of house design and construction which were important to the survival of house in the ‘Ash Wednesday Bushfires’ of 16 February 1983. The Otway Ranges are of Victoria was chosen and 1153 house, with varying degrees of damage, were included in the survey. Results of a preliminary analysis of data collected are given, together with observations made concerning the so‐called ‘exploding house’ phenomenon, the role of wind and the part that people played in house survival. Evidence for the ways that houses were ignited (i.e. by radiation, flame contact and wind‐blown embers) was also gathered. The importance of these ignition modes is discussed and examples given. Preliminary observations on the rebuilding process are also given.