bluuebunny/crossref_metadata_2025 huggingface dataset:
Minimierung von Abgasemissionen aus diskontinuierlichen Produktionsanlagen der chemischen Industrie
Authors: Simon Eberhard
Published: December 2004

Minimising Waste Gas Emissions from Batch‐Operated Production Plant in the Chemical Industry. In fulfilling legal obligations to limit waste gas emissions, the strategy of avoidance and reduction has to take precendence over waste gas cleaning. Fundamental disadvantages and limited possibilities of waste gas cleanning systems create a necessity to minimize waste gas emissions by substitution of process materials, or by better encapsulation of process systems. Reduction of process gas emissions is shown by the examples of gas feedback, avoidance of gas pressure cushions, and encapsulating of stirring systems as well as centrifuges. The problem of diffuse emissions from gaskets in separatable connections and from fitting casings is discussed. An example of chemical reaction in a strictly closed system is given. With regard to the reduction of exhaust volumes from open sources, bulk materials feed and sampling are discussed; centrifuges, pressure filters and continuous belt filters are shown as examples of closed systems in solid‐liquid‐separation.
Strukturwandel in der Ingenieurtechnik der chemischen Industrie – Wege zum Partner und Unternehmer
Authors: Francke Diethard , Ochel Klaus P. , Berger Walter , Sommer Ernst , Bode Henning
Published: December 2004

Structural Change of Engineering Units in the Chemical Industry – Ways of Becoming a Partner and Entrepreneur. Structural change must not be misunderstood as only observing staffing levels or methods of organisation. On the contrary, the cost/benefit‐relation is much more important. A balanced relation of a company's own personnel and the contractor's has to be considered. Structural change means also change of mind set: The task of management is nowadays to implement a culture of operational profit instead of a culture of demands. It is becoming more and more important to cooperate in a team. This cooperation starts early in defining the project aims, includes analysing all functions, looking for alternatives regarding cost/benefit‐aspects and is based on a clear, structured analysis of the problem instead of quick solutions.
Rechnergestützte Konfigurierung von RI‐Fließbildern am Beispiel von Pumpen
Authors: Blitz Helmut , Engelke Jochen , Sonnenschein Raymund , Schmidt‐Traub Henner
Published: December 2004

Knowledge‐based Design of PI Diagrams Exemplified for Pumps in Chemical Plant. To date, computer‐aided design for flow‐sheets has focussed on drawing procedures and reports extracted from these drawings. Today's software technology offers important potential which has still not been fully exploited, e.g. for the design of PI diagrams as front‐end application of CAD systems. PI diagrams for process units can be designed by means of knowledge‐based systems. The input information which has to be supplied by the process engineer comprises e.g. physico‐chemical properties, process conditions and start‐up and shut‐down procedures. The results are PI diagrams as well as the documentation of the design criteria and operating instructions if manual operations on site are necessary. The potential of knowledge‐based computer‐aided design of PI diagrams is demonstrated in the case of pumps in chemical plant.
DIN‐Norm‐orientierte Standard‐Spezifikationen für Rührwerke
Authors: Simon Eberhard
Published: December 2004

DIN Standard‐Oriented Specifications for Stirring Systems. Stirring as a unit operation is characterised by universal application possibilities for material and energy transmission in process industries. DIN standards provide an overview of the wide variety of equipment in technical use and define the conditions for low‐cost, exchangeable standard stirring systems. In many cases important process parameters are fixed only for a limited time. Possible operation time should be long, therefore performance reserves are justified; they will be useful for later tasks as well as for improving safety of existing processes. Engineering of such stirring systems requires definition of standard stirring tasks. This article deals with economic aspects, defines standard stirring tasks as well as design conditions and shows the principal engineering data of standard stirring systems for stainless steel vessels up to 20 m3 by means of pictures, tables and nomograms. In conclusion, adequate processing of construction materials as well as surface finishing and practical work with standard specifications for stirring systems are discussed.
Nichtbiologische Reinigung organisch verschmutzten Wassers
Authors: Mersmann Alfons , Kutzer Stephan , Kajszika Holger , Wintrich Hans
Published: December 2004

Non‐Biological Removal of Organic Pollutants from Water. Contaminants present in waste water, seepage water and ground water include salts, heavy metals and organic compounds of low biodegradability. This paper considers the wide range of physico‐chemical processes available for separation of such compounds from water and points out their optimal and economic range of application. Main subjects are desorption processes (air/steam stripping), adsorption processes (activated carbon, polymeric resins) and membrane separation processes. Alternative water treatment technologies (evaporation, distillation, liquid‐liquid‐extraction, oxidation, flocculation and precipitation) and combined processes are presented and discussed.
Anwendung der Molchtechnik in der chemischen Industrie
Authors: Mühlthaler Wolfgang
Published: December 2004

Use of Pigging in the Chemical Industry. Use of piggable pipework systems can lead to dramatic savings in investment costs and to high efficiency of the installed pipework. Emptying and washing operations are no longer necessary. Moreover, losses of valuable raw materials and finished products are avoided, the contamination waste water needing treatment, and hence the environmental burden, is reduced. A small number of pipes suffices for transport of many different substances with a high degree of separation. Pipework systems with pigging equipment in regular operation remain free from deposits. Complete automation eliminates the possibility of operating errors. However, it should not be forgotten that such a system also generates operating and maintenance costs which vary according to product. A decision to introduce a pigging system must ultimately depend upon the economics and availability of the plant.
Olechemie – Chemieprodukte auf der Basis nachwachsender Rohstoffe
Authors: Breucker Christoph , Jordan Volkmar , Nitsche Michael , Gutsche Bernhard
Published: December 2004

Oleochemistry – Chemical Products Based On Renewable Raw Materials. Because of the increasing demand of consumers and industry for “green” products, the importance of the oleochemistry will grow in the future. This paper shows that the modern oleochemistry has developed from „soapboiling”︁ to a part of the chemical industry which requires all elements of chemical engineering. A wide and pretentious area of activities concerning unit operations and reaction technology is offered to the chemical engineer. The thermal sensitivity of raw materials and products results in high demands in the production process.
Thermodynamische Modelle zur Analyse der Verfahren für die thermische Entsorgung von Müll
Authors: Barin Ihsan , Igelbüscher Andreas , Zenz (Fh) Franz‐Rudolf
Published: December 2004

Evaluation of processes for thermal disposal of residual waste according to technical, economic, and ecological criteria has long been a topic of discussion in specialist circles. A basis for such evaluation is provided by material and energy balances determined by operational measurements and supplementary calculation. Thermodynamic process simulation can be regarded as a powerful engineering tool in preparing such balances; its use enhances the objectivity in analysis of various procedures and their comparison with the aid of material, energy, and entropy balances. However, this requires practically relevant calculation models. In this connection, the software used must be able to cope with the states of materials as completely as possible with due attention to technical boundary conditions. Practical knowledge is of decisive importance for the quality of process simulation. In the present work this was permitted by the collaboration of industrial companies arranged by the State Environmental Office of North Rhine‐Westphalia.
Technikfolgenabschätzung und ihre Bedeutung für die Tätigkeit des Ingenieurs
Authors: Stephan Karl
Published: December 2004

This special event held at the 1996 Annual Meeting of the GVC addressed the bright and the dark sides of technological forecasting. The review article on pp. 44 to 54 presents the content of a lecture delivered by Prof. Dr. ORTWIN RENN, Baden‐Württemberg Academy for Assessment of the Consequences of Technology. As an introduction to the assessment of the consequences of technology, Prof. Dr.‐Ing. KARL STEPHAN, University of Stuttgart, examined the significance of the assessment of the consequences of technology for the professional activities of the engineer. In this issue we publish extracts from his lecture.
Ingenieurkeramik in der Verfahrenstechnik — Alternativen für konventionelle Werkstoffe
Authors: Gugel Ernst , Leimer Gerhard
Published: December 2004

The use of ceramic materials in chemical engineering is on the increase. They have a number of advantageous properties which prove technically and economically beneficial. Realization of these benefits requires cooperation between component manufacturers and users, with due attention to appropriate design. Example of successful use are discussed.
Praxisorientierte Aufbereitung des Ermüdungsfestigkeitsnachweises für Komponenten der Druckbehälter‐ und Kraftwerkstechnik
Authors: Rudolph Jürgen , Weiss Eckart
Published: December 2004

The importance of the detailed analytical proof of fatigue strength of pressure vessel components is steadily growing in order to ensure safe long term operation of chemical plant and power stations. The state of the art is represented by the notch stress oriented concept of the proof of fatigue strength. It is implemented according to increasing quality requirements within pressure vessel codes and guidelines for analysis such as the German AD‐Merkblatt S 2. The main problem of its practical application is the stress analysis for fatigue including fatigue crack initiating notch stresses. Currently, only numerical instruments of analysis such as the finite elements method (FEM) allow for detailed modelling and analysis according to these needs. General results for standard pressure vessel components such as vessel‐to‐nozzle connections can be derived from parametric studies based on the finite elements method in case of swelling cyclic loading (start‐up and shutdown procedures). These results can be further processed within computer programs enabling the engineer as a user to carry out the detailed proof of fatigue strength for minimum expenditure.
20 Jahre Entwicklung einer bipolaren Membranzelle für die Alkalichlorid‐Elektrolyse vom Labor bis zur weltweiten Anwendung
Authors: Bergner Dieter
Published: December 2004

First samples of perfluorinated cation exchange membranes were obtained in 1971. They were tested for use in the diaphragm process as a replacement for asbestos diaphragms. However, the special features of these membranes led to the decision to develop special new membrane electrolysis cells. A patent was sought for the first new cell design in 1975. After extensive material testing and many improvements, the HOECHST bipolar membrane cell was produced, consisting of an electrolyzer made up of individual elements, i.e. individual sealed electrolysis cells. Starting in 1982, this cell type was developed further in cooperation with UHDE GmbH. In 1983 it was installed for the first time in an industrial electrolysis plant. Despite strong competition, the bipolar HOECHST‐UHDE membrane cell has now gained an important market share. In 1998 it will be installed worldwide in 43 electrolysis plants, with a total NaOH capacity then amounting to 2.5 million mtpa.
Experimentelle und theoretische Untersuchungen zur Filtration mit überlagerter Sedimentation in Drucknutschen
Authors: Bothe Clemens , Esser Ulrich , Fechtel Thorsten
Published: December 2004

Sedimentation superimposed on industrial cake filtration leads to longer filtration times and often has a detrimental effect on subsequent process steps such as washing and demoisturing. The influence of sedimentation is seldom recognised in laboratory filtration experiments. Methods are presented for evaluation of pressure filter experiments with superimposed sedimentation which avoid the error made in the usual evaluation methods. For the case of zone sedimentation the article presents a graphical evaluation and a numerical method of modelling permitting scale up to any desired cake height. In superimposed classifying sedimentation simultaneous measurement of filtrate volume and cake height provide information about local variation in filter cake resistance. It is shown for a model system that, owing to sedimentation, the cake resistance shows a minimum at mean cake height and increases rapidly towards greater heights. The local cake resistance corelates with particle size distributions measured for layers of a horizontally cut filter cake. The method of evaluation presented permints determination of the flow resistance of the uppermost layers of a cake and hence estimation of the gas pressure necessary for demoisturing. The profiles of local filter cake resistance show that the relative cake layering is largely independent of the level of suspension filling. A scale‐up model is presented for use in those cases where classifying sedimentation cannot be suppressed.
Altanlagen – Sanierung nach TA Luft durch Kombination von Verbrennung und Absorption
Authors: Simon Eberhard , Jaenicke Ottmar
Published: December 2004

A waste‐gas cleaning system was constructed for a group of drug production plants. The chemical – synthetic processes taking place there are characterized by inevitable emissions, mainly of vapours of organic solvents. Their concentrations vary within a wide range and at any given moment in principle remain unknown. This paper describes the initial situation and the requirements for the waste gas cleaning process, including the calculation of the gas volume flow capacity. The polluting substances were divided into two groups; for critical substances only thermal oxidation was found to be adequate, whereas for non‐critical, water‐soluble material, water‐fed absorption columns were chosen; on one hand to avoid full exhaustion of the capacity of the thermal waste‐gas system and on the other hand to offer additional possibilities in the case that this system should be out of action. The criteria for this decision as well as for the combination of one central with several decentralised cleaning units are discussed in detail. The equipment of the waste‐gas emitting plants for feeding the cleaning units and the technical details thereof are described as well as the safety design. At last, experience gaine during preparation of the systems and considerations concerning further use of the thermal cleaning system are discussed.
Das Leitbild Nachhaltigkeit und das Konzept Technikbewertung
Authors: Jischa Michael F.
Published: December 2004

Sustainable Development and Technology Assessment. Changes in the environmental consciousness of wealthy western societies began t o appear in the 1960s. These changes manifested themselves in three ways. First, in the mid‐1960s the term “Technology Assessment” (TA) was coined in the USA. The TA discussion in Germany – as well as in other comparable countries – lead t o growing TA activities and the opening of institutions connected with Technology Assessment. Secondly, in 1968, the Club of Rome was founded, which in 1972 brought out its first study “The Limits to Growth”. Thirdly, the sustainability debate followed and intensified with the report in 1980 “Global 2000” and the Brundtland report in 1987 “Our Common Future”, which formulated the concept of sustainable development. Debates intensified further in 1992 with the “Agenda 21”. the closing document of the Rio Conference for Environment and Development. The following will show both that the diffuse idea of sustainability can be operationalised with the technology assessment concept; and – as has recently taken place at the TU Clausthal – that technology assessment should be established in research and teaching at the university level.
Bestimmung der fluidelastischen Instabilität in querangeströmten Rohrbündeln
Authors: Gelbe Horst , Schröder Kai
Published: December 2004

For the design of tube bundle heat exchangers avoiding tube bundle damage caused by vibration, fluidelastic instability is the most important vibration excitation mechanism. In order to present a guideline in the VDI‐Wärmeatlas the existing recommendations of CHEN, WEAVER and FITZPATRICK and PETTIGREW and TAYLOR were examined. They differ in the suggested equations for calculating critical velocities for single phase crossflow. With an extensive evaluation and test of consistency of the these and newly available data on this topic, better correlations could be derived. Consistent definitions of critical flow velocity, damping, natural frequency and hydrodynamic mass are used; their values are to be determined in the still fluid with the density ρ. Confident documented data show only a small scatter. The other data deviate more, but mainly to the safe side.
Neue Materialien – Was kann die Synthesechemie heute?
Authors: Herrmann Wolfgang A.
Published: December 2004

Materials of construction will exert a greater influence on cultural developments on all continents than in the past, meaning that research in materials science will have to be given a high interdisciplinary priority in countries with the right scientific and technological background. Particularly in the case of this developing area, science will have to emerge from its classical compartmentalization because further progress will require joint consideration of chemical, physical, and where appropriate biological aspects, while paying due attention to the creative scope of engineering. It will become more important than ever to combine science and engineering and to derive an innovative materials architecture from the more contemplative discipline of materials science.
Analyse nichtlinearer Phänomene bei verfahrenstechnischen Prozessen
Authors: Mangold Michael , Mohl Klaus‐Dieter , Kienle Achim , Gilles Ernst Dieter
Published: December 2004

Continuation methods combined with the concepts of stability and bifurcation theory are now widely accepted for the analysis of chemical engineering systems. Nonlinear analysis can lead to an improved process design or process operation. The integration of continuation methods into standard tools for dynamic process simulation opens a wide range of possible applications in chemical engineering. The first part of this paper gives a basic introduction into nonlinear dynamics. In the second part, that theory is applied to three different types of chemical engineering processes, which have been studied recently at the Institut für Systemdynamik und Regelungstechnik of the Universität Stuttgart.
Digitale Feldgeräte und deren Bedeutung für die Instandhaltung verfahrenstechnischer Analgen
Authors: Steinweg Andreas , Raab Helmut
Published: December 2004

Digital Field Devices and Their Importance for Maintenance of Chemical Plant The term “digital field device” is briefly discussed in order to demonstrate the extent to which digitalization has created conditions for increased and “new” functionality in the field. The body of the article then classifies and describes this functionality according to elementary, shifted, and extended measuring functionality and maintenance functionality. The ensuing advantages and disadvantages for chemical plant maintenance are considered. The key role of communication in the field becomes very clear. An attempt is also made to present some future prospects for digital field devices.
Strömungsvisualisierung mit Texturen
Authors: Loser Thomas , Mewes Dieter , Levy Yuval , Hesselink Lambertus
Published: December 2004

Visualisation of Flow with the Aid of Textures Many new methods of flow visualisation have been developed in recent years. One of the most promising approaches is the visualisation of flow with the aid of textures. Textures are graphic structures containing directional information. They can be calculated with the Line Integral Convolution (LIC) algorithm developed by Cabral and Leedom, according to which pixel‐oriented random entry fields are convoluted along integral lines. This paper uses the LIC algorithm for texture generation. Known procedures for texture generation and for spatial representation of textures are considered and extended by the authors' own work. Textures are compared with traditional approaches, which use flow lines and vector arrows for flow visualisation, and evaluated. In their presentation of the topic the authors use a easily comprehensible representation which the user can readily reproduce rather than an exact mathematical‐statistical analysis of texture generation.
GVC‐Fachausschuß „Prozeß‐und Anlagentechnik”︁
Authors: Bathen Dieter
Published: December 2004

Die Sitzung des GVC‐Fachausschusses „Prozeß‐ und Anlagentechnik”︁ fand am 25. und 26. Oktober 1998 in Kleve statt. Gemeinsam mit dem DECHEMA‐Ausschuß „Computeranwendungen in der chemischen Industrie”︁ und dem GVC‐Arbeitskreis „Produktionslogistik”︁ wurden aktuelle Problemstellungen aus der Industrie und neue Problemlösungsansätze aus der Forschung präsentiert und diskutiert.

In seiner kurzen Begrüßung erläuterte der Ausschußvorsitzende H. SCHMIDT‐TRAUB einerseits die Zielsetzung der Tagung und verdeutlichte andererseits den Teilnehmern die Ursachen und Konsequenzen des drastischen Rückgangs der Anfängerzahlen in den verfahrenstechnischen Studiengängen, was für Gesprächsstoff in den Pausen sorgte. Die anschließende Tagung umfaßte insgesamt 35 Vorträge in zehn Schwerpunktthemen.
Vorhersagegenauigkeit von Auslegungsmethoden für den Entlastungsquerschnitt bei durchgehender chemischer Reaktion
Authors: Friedel Lutz , Korfmann Steffen
Published: December 2004

Predictive Accuracy of Design Methods for the Relief Cross‐Sections for Runaway Reactions On the basis of calculations performed on the results of experiments conducted in reactors with volumes up to 10 m3 for so‐called vapour‐pressure producing (runaway) reaction systems, it is found that all simplified or steadystate methods regularly afford overdimensioned relief cross‐sections. As a consequence, unnecessarily large mass flows leave the reactor to enter the containment system. A balanced design of both plants components is possible only with the aid of transient methods. In the case of gas generating reactions simplified methods also lead to excessively large pressure relief cross‐sections. Design with the aid of a transient method for such a reaction system is rendered difficult by the fact that a conservative submodel cannot be used a priori for description of the expansion behaviour. A parametric study is then required.
Listeria's right‐handed helical rocket‐tail trajectories: Mechanistic implications for force generation in actin‐based motility
Authors: Zeile William L. , Zhang Fangliang , Dickinson Richard B. , Purich Daniel L.
Published: December 2004

Listeria monocytogenes forms right‐handed helical rocket tail trajectories during actin‐based motility in cell‐free extracts, and this stereochemical feature is consistent with actoclampin's affinity‐modulated, clamped‐filament elongation model [Dickinson and Purich, 2002: Biophys J 82:605–617]. In that mechanism, right‐handed torque is generated by an end‐tracking molecular motor, each comprised of a filament barbed end and clamping protein that processively traces the right‐handed helix of its filament partner. By contrast, torque is not a predicted property of those models (e.g., elastic propulsion, elastic Brownian ratchet, tethered ratchet, and insertional polymerization models) requiring filament barbed ends to depart/detach from the motile object's surface during/after each monomer‐addition step. Helical trajectories also explain why Listeria undergoes longitudinal‐axis rotation on a length‐scale matching the helical periodicity of Listeria's rocket tails. Cell Motil. Cytoskeleton 60:121–128, 2005. © 2004 Wiley‐Liss, Inc.
Investigations of the meteoritic mineral (Fe,Ni)3P
Authors: Geist V. , Wagner G. , Nolze G. , Moretzki O.
Published: December 2004

A survey is presented on some characteristic features of meteoritic (Fe,Ni)3P which is an abundant and important minor phase of most iron meteorites. This mineral (named schreibersite/rhabdite) plays a decisive role during the formation of the so‐called Widmanstätten pattern. Different transmission as well as scanning electron microscopic techniques have been applied to get more precise information about the real structure of the phosphide crystals, their chemical composition and the metal distribution across the phoshide/ kamacite interface. X‐ray crystal structure determinations have been performed for selected (Fe,Ni)3P ‐ cystals from various iron meteorites (Toluca, North Chile, Watson, Orange River, Morasko, Agpalilik, Odessa, Canyon Diablo). These experiments revealed a metal ordering, i.e. for the three non‐equivalent metal positions a different substitution of Fe by Ni has been found. The perfection of the brittle (Fe,Ni)3P samples differs appreciably and seems to be dependent on the thermal history of each individual meteorite. Moreover, inside Ni‐rich rhabdite crystals small monocrystalline inclusions of CrN (carlsbergite) have been detected. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Formation of diffusion‐hindering interlayers in metals in contact by dedicated thermal treatment
Authors: Meyer D. C. , Gorbunov A. , Pompe W. , Levin A. A.
Published: December 2004

Thermal evolution of the structure of Fe/Al multilayers (MLs) with nominal composition 5*(5 nm Al / 5 nm Fe) prepared by crossed‐beam pulsed laser deposition is studied by wide‐angle X‐ray scattering and X‐ray reflectometry after different temperature‐time procedures of thermal treatments under high‐vacuum conditions. In comparison to direct thermal annealing at temperatures of 250 °C and 275 °C, respectively, which results in nearly complete mixing of the MLs and formation of the FeAl intermetallic compound, quite different behaviour was found after dedicated thermal pretreatment. Annealing at successive growing temperatures before final annealing at temperatures mentioned, resulted in conservation of pronounced multilayer structure. From the results it is generalised, that also in the case of ML systems, the tendency of mixing a dedicated tuning of interface characteristics by thermal treatment allows for formation of diffusion‐hindering interlayers. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electron holographic material analysis at atomic dimensions
Authors: Lehmann M. , Lichte H.
Published: December 2004

In [110]‐oriented GaAs, both types of atomic columns can hardly be distinguished by conventional transmission electron microscopy (TEM) because of the small difference of atomic numbers for Ga and As with ZGa = 31 and ZAs = 33. Quantitative off‐axis electron holography allows unambiguously determining the structural polarity of GaAs in [110]‐orientation, where, besides lateral resolution, the sensitivity of the phase signal plays the most important role. In order to attribute the phase signal only to the different types of atoms, two holographic experiments were performed using the same wedge‐shaped GaAs‐crystal, where for the second experiment, the sample was inserted into the holder upside down yielding an inverse structural polarity of GaAs. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Überarbeitung der Flachsturzrichtlinie
Authors: Jäger Wolfram , Reeh Helmut
Published: December 2004

Die Bemessung von Flachstürzen wurde bisher vornehmlich auf der Basis der vom Deutschen Ausschuß für Stahlbeton herausgegebenen Flachsturzrichtlinie in ihrer Fassung von 1979 [1] durchgeführt. Diese nimmt Bezug auf die Stahlbetonnorm in der auf dem Konzept globaler Sicherheiten beruhenden Ausgabe (s. [2]) von 1988. Mit Ende des Jahres 2004 verliert diese Norm ihre Gültigkeit, so daß eine Neuregelung der Bemessung von Flachstürzen erforderlich ist. Es wird eine kurze Information zum Stand, zum zeitlichen Ablauf sowie zur Verfügbarkeit einer ersten überarbeiteten Version der Flachsturzrichtlinie gegeben.
Flame‐Retarded polypropylene: A comparison of large‐ and small‐scale tests
Authors: Abbott C. J.
Published: December 2004

This paper describes work carried out on flame‐retarded polypropylene comparing results on selected small‐scale laboratory fire tests with those obtained on a larger‐scale test designed to simulate the typical real life hazard situation. In the latter test a number of important parameters such as heat build‐up, Hame spread, smoke development and gas evolution were assessed. The results indicate that there is need to use both types of tests to gain a fuller understanding prior to using new materials. An assessment based on small‐scale tests alone could be misleading and allow the use of potentially hazardous material in the particular application involved.
A fire test device suitable for small‐scale testing of fire retardant coatings
Authors: Kay M. , Price A. F.
Published: December 2004

A fire test device suitable for small‐scale, comparative testing as a first step in investigating the performance of fire retardant materials is described. The procedure developed is not intended to predict the performance of a given material in a real fire, since the local conditions can be extremely variable. However, the parameters in the device can be varied over a wide range to screen the performance of various materials in given situation. Typical results for an intumescent mastic consisting of epoxy resin, hardener and melamine phosphate are quoted, together with appropriate calibration curves. A method of estimating the thermal resistance of the developing char is also discussed.
Creep of structural steel in fire: Analytical expressions
Authors: Williams‐leir G.
Published: December 2004

Two models of creep, one proposed by Harmathy1, the other empirical, have been fitted to published measurements of creep in seven steels. The data have been selected so as to cover the range needed for predicting the survival of protected steel or reinforced concrete buildings exposed to fire.
Studies on the measurement of smoke propensity of UPVC
Authors: Martin K. G. , Burn L. S.
Published: December 2004

The smoke propensity of plastics as measured in the NBS Smoke Chamber method has been rationalized in terms of the influence of specimen thickness and resolved in a relation between mass optical density (MOD) and mass loss, which gives two parameters for characterizing behaviour, a maximum MOD for thin specimens and an asymptotic MOD for thicker ones. Data have been obtained for unplasticized piolyvinylchloride formulations and compared to that obtained by the Arapahoe Smoke Chamber and the Australian Standard method (AS 1530 Part 3). Although correlation coefficients between the methods were generally poor, the same formulations were ranked as the best performers in each method and the improvement over a standard formulation was potentially important in terms of wider acceptance under Australian building regulations.
The persistence of burning of textiles in different oxygen environments and the determination of the extinction oxygen index
Authors: Horrocks A. R. , Ugras M.
Published: December 2004

The influence that oxygen has on the burning behaviour of cotton single‐ and multilayered fabries has been determined by recording persistence of burning times as a function of oxygen concentration. For a given fabric subjected to a specified igniter application time, an extinction oxygen index parameter, EOI, may be determined. EOI is defined as the oxygen concentration expressed as a volume fraction in an oxygen‐nitrogen mixture, necessary to give a persistence of burning time equal to zero. For a given fabric, EOI is found to decrease as the igniter application time increases and two limiting EOI values may be observed, one corresponding to zero inginter application conditions and one for igniter application times greater than 10 s. At any given ignition time, the extinction oxygen index increases linearly with fabric area density and decreases linearly with the logarithm of the respective air permeability. Similar results are observed for nylon 6.6 and polyester single‐ and multilayered fabrics. The validity of the extinction oxygen index is discussed with reference to other published works.
Flammability limits of the polymer pyrolysates generated from flame retarded poly (ethylene terephthalate)
Authors: Day M. , Suprunchuk T. , Wiles D. M.
Published: December 2004

A device constructed and used to determine the flammability limits of pyrolysate–air mixtures as a function of percentage weight loss on pyrolysis has been employed to investigate the pyrolysate gases generated from poly (ethylene terephthalate) both in the presence and absence of chemical flame retardants. The chemicals tripropyl phosphate (TPP), dibromopropanol (DBP) and tris (2, 3 dibromopropyl) phosphate (TRIS) all influenced both the lower and upper flammability limits, with the largest effects being obtained when both phosphorus and bromine were present, followed by bromine only and then phosphorus only. The results indicate TPP has negligible condensed phase activity with only small gas phase action. DBP has no condensed phase activity but is a very active gas phase inhibitor. In contrast, TRIS has a detrimental effect upon the condensed phase reactions in that it is responsible for the formation of a more flammable pyrolysate gas mixture. Fortunately, its gas phase inhibition reaction is capable of reducing the overall flammability.
Combustion products of polymeric materials. 1—Test chamber CAB 4.5
Authors: Michal Jan
Published: December 2004

A test chamber for performing complete investigation of the dangerous effects of thermal degradation products of polymeric materials has been designed. The tow‐chamber system with separated combustion chamber and smoke chamber has a steep temperature gradient between both chambers and enables continuous analysis of combustion products of the tested polymeric material for carbon monoxide and carbon dioxide to be performed, to monitor the oxygen content in the chamber during testing and to perform tests of biological toxicity on mice as test animals. The function of the test chamber was verified on combustion of polyethylene, polypropylene, polystyrene and polyamide samples.
Combustion products from burning wool fabric
Authors: Hodgkin J. H. , Galbraith M. N. , Chong Y. K.
Published: December 2004

A Preliminary study of the thermal degradation of wool fabric was carried out under a wide range of oxidative degradation conditions including flaming combustion. Product collection methods and analysis conditions were designed to minimize secondary reactions. The degradation products obtained included a variety of organic nitriles and heterocyclic compounds as well as the usual aromatic and oxygenated products. Variations in moisture content and fire retardant level in the wool had little effect on the organic volatiles produced form the fabrics.
Test methods and standards. Fire performance of products
Authors: Becker W. H. K.
Published: December 2004

More than 700 standardized rules for fire testing are used round the world in order to assess the fire safety of materials, products and constructions in different technical fields. This article discusses the reasons for this variety of test methods and evaluation systems and the attempts to create systematic models in this special field of material testing, including new suggestions and developments in ISO and CIB for future approaches.
Effective thermal inertia in relation to normalized heat load
Authors: Williams‐Leir G.
Published: December 2004

Normalized heart load, obtained by dividing heat absorption by thermal inertia, is a quantity useful in building design for relating fire severity in fully developed compartment fires to fire severity in standard fire resistance tests. Harmathy has shown how normalized heat load may be used for determining required fire resistance in projected buildings. The present work describes how effective values of thermal inertia can be calculated for such important materials as brick and concrete, both normal and lightweight, for which thermal properties depend strongly upon temperature.
Some factors influencing fire spread over room linings and in the ASTM E–84 tunnel test
Authors: Quintiere James
Published: December 2004

An examination of the correlative relationship between room fire intensity (temperature) and flammability data for materials, ASTM E–84 flame ratings and energy release rate from calorimertry devices is presented for fire spread on lings. The results of the analysis show the significance of two modes of flame spread—wind‐aided and opposed‐flow spread. The factors important in these spread modes are considered from approximate solutions developed for turbulent flow. As the importance of energy release rate to flame spread in the tunnel test (E–84) and in upward or wind‐aided spread is illustrated. The results suggest a possible reason why the ASTM E–84 and in upward or wind‐aided spread is illustrated. The results suggest a possible reason why the ASTM E–84 ratings may not be applicable to the performance of low‐density combustible linings in wall fires. In the analyses, flame radiation has not been considered. Also the interpretation of energy release rate data for difference scale and orientation effects has been ignored. These two factors must ultimately be addressed.
Toxic gas and smoke measurement with the British Fire Propagation test. II: Hydrogen chloride evolution from UPVC building products
Authors: Brown S. K. , Martin K. G.
Published: December 2004

Extension of the British Standard Fire Propagation test (BS 476 Part 6) as a combustion mode for measuring smoke and toxic gas production from small panels of UPVC building products has been investigated. Hydrogen chloride gas concenatrations in the test room have been measured continuously with a method developed to ensure high collection efficiency from the fire gases. Using this method, the influences of test conditions (room temperature and humidity, room surface finish, reactivity of fire box interior) on HCl gas concentrations were examined to explain the fate of HCl gas after its evolution. The relative humidity (RH) in the room was the most critical factor influencing HCl gas concentrations during tests. Although HCl evolution early in the test was influenced little by RH and closely matched smoke production, maximum HCl gas concentrations in the room attained later varied markedly with RH. Generally, no more than one‐third of the HCl expected theoretically remained airborne under any test condition. Further investigations suggested that this loss and the effect of RH are associated with HCl plate‐out on room surfaces. Using test conditions set to minimize the influence of RH, HCl evolution from a series of UPVC building products was investigated. HCl concentrations in the test room did not exceed incapacitating levels for those products where less than a certain quantity of UPVC was combusted. This observation is discussed in relation to French regulations, which limit the total quantity of chlorine in some synthetic materials within building compartments.
Towards regulating toxicity of materials in building
Authors: Reichwerger Z. , Balbin J.
Published: December 2004

A method is presented for evaluating the toxic hazard resulting from the thermal decomposition of materials used in buildings or other closed structures. It was developed in conjunction with the current revision of Israel Standards pertaining to the behavior in fire of building materials. The method is based on the measurement and evaluation of those gases recognized as hazardous in fire situations. A ‘toxicity ratio’ of the materials is defined in terms of the sum of concentration ratios of all toxic gases monitored to the corresponding lethal threshold limit concentration levels. The ‘toxicity index’, a material property, relates the toxicity ration to the material quantity and the plenum volume. The toxicity index is found by experiment for specimens heated to their smoldering and flaming temperatures in a closed system. Fire hazard levels due to toxic gases emitted from different materials can then be compared using the toxicity ratio computed for the specified situation. The proposed method is compatible with Israel Standards IS 921, where allowable levels for buildings and compartments are defined.
Movement of destruction products through the carbonized layer upon combustion of polymers
Authors: Gibov K. M. , Shapovalova L. N. , Zhubanov B. A.
Published: December 2004

Penetration of the carbonized polymeric residues has been investigated and their influence on combustibility of polymers has been shown. It has been found that filtration of liquid and gas products of pyrolysis through the carbonized layer upon combustion is described by Darcy's law, the movement of liquids being due to the surface tension forces. It has been shown that the carbonized layer cannot be regarded as an important obstacle for passing of volatile and low‐viscous products into the gas phase, and that the polymeric melts can also rise through the coke due to the capillary forces. Phosphoric and some boric compounds have been found to cause a decrease in penetration of the carbonized residues, which can be one of the reasons of the flammability decrease of polymers when using such compounds.
Combustion products of polymeric materials versus heat released by polymer combustion in the CAB 650 chamber
Authors: Michal J. , Poková E.
Published: December 2004

A method has been developed enabling comparison of polymeric Materials on the basis of the heat evolved during combustion. The calculated heat index yields information on the heat capacity of the material compared with cellulose as a standard material.
Prediction model of CO, CO2 and O2 concentrations in compartment fires using wood fuel
Authors: Nakaya Ichiroh
Published: December 2004

A simple model for predicting as concentrations, temperature and heat release rate in a room fire was developed. The CO, CO2 yield rates and O2 yield rates and O2 depletion rate were calculated using this model for wood fuel. The calculated values were compared with the experimental ones and a fairly good accuracy was obtained. As this model can apply to any kind of fuel by replacing the assumption for the fuel pyrolysis, it may be useful for evaluating toxic hazards in a room fire.
An analysis of the potential economic impact on society due to the compliance with the fire service order. (Northern Ireland) 1985
Authors: Ewart K. , Shields J. , Silcock G.
Published: December 2004

The article outlines the analysis of data collected by questionnaire, inspection and detailed surveys of a selection of boarding houses in Northern Ireland. A statistical model is developed which enables a cost of compliance to be estimated for boarding houses having more than six bedspaces. Comparisons are also made regarding cost with previous studies in England and Wales for similar boarding houses/small hotels. Finally the cost of compliance for these houses and other buildings is given with an estimate of the impact of this cost on the building industry and the public at large in Northern Ireland.
Developments in inorganic phosphorus flame retardants
Authors: Stephenson J. E.
Published: December 2004

Difficulties encountered in bulk transportation of red phosphorus can be overcome by making an intimate blend with alumina trihydrate. The blend is suitable for direct use with more alumina hydrate in a synertistic flame retardant system for epoxy resin mouldings. The degree of observed synergism allows low loadings of the addivities and consequently the electrical and physical properties of the mouldings are only slightly affected.
Correlation between the hot plate ignition test and other laboratory‐scale flammability tests on rubber conveyor belts with fabric skeletons
Authors: Nakagawa Yuichi , Komai Takeshi , Kohno Makoto
Published: December 2004

The hot plate ignition test was conducted on ten different conveyor rubber belts with fabric skeletons. In this test, a 25 × 25 mm2 belt sample was placed on a stainless steel plate in an electric furnace and heated. The ‘ignition temperature’ was determined on each sample in almost the same way as proposed in Canada. The test results were compared with those from other laboratory‐scale flammability tests (i.e. the small‐scale flame tests, the Oxygen Index test and the laboratory‐scale gallery test). The calculated results of both sample and rank correlation coefficients imply that the ‘10 signition temperature’ in this hot plate ignition test has a correlation with the results from both the Oxygen Index test and the laboratory‐scale gallery test, but that it has very little or no correlation with those from the small‐scale flame tests. On the other hand, it is found that the ‘60 s ignition temperature’ in this test has a far better correlation both with the results from the small‐scale flame tests and with the time to ignition in the laboratory‐scale gallery test than the ‘10 s ignition temperature’.
Phospham—A stable phosphorus‐rich flame retardant
Authors: Weil Edwar D. D. , Patel Navin G.
Published: December 2004

Phospham is an iminophosphazene polymer of unusually high thermal stability. We have found that phospham imparts a substantial level of flame retardancy to nylon‐4,6, a high‐melting crystalline engineering thermoplastic. It did not appear to produce degradation of the polyamide in the processing temperature range. The flame retardant efficacy of phospham in nylon‐4,6 was similar to that of stabilized red phosphorus, when compared on an equal phosphorus basis. In nylon‐4,6, it did not display nitrogen–phosphorus synergism. Limited evidence from TGA suggested a condensed phase mode of action in nylon‐4,6. Phospham showed orders‐of‐magnitude better hydrolytic stability than did ammonium polyphosphate, and did not produce detectable phosphine on processing as did red phosphorus.
Christmas trees—what happens when they ignite?
Authors: Damant Gordon H. , Nurbakhsh Said
Published: December 2004

Burn tests were conducted on a number of Christmas trees commonly used in typical households. Trees were kept in room conditions for several weeks to dry out. Burn tests were also conducted on fresh and almost fresh trees to compare their burning behaviors wilth those of dry trees. Two trees were moistened and wetted prior to burn to observe the effects of water on burning of dry trees. The foremost objective of this work was to quantitatively demonstrate the potential fire hazard of Christmas trees by measuring the rate of heat release and room temperature during the burn.
Quantitative structure—property relationships for auto‐ignition temperatures of organic compounds
Authors: Suzuki Takahiro
Published: December 2004

Quantitative structure–property relationship techniques were applied to develop a predictive method for autoignition temperatures of a wide range of organic molecules, including hydrocarbons, alcohols, phenols, ethers, aldehydes, ketones, acids, amines, esters and halogenated compounds. Multivariate linear regression models in terms of easily available molecular descriptors or intrinsic molecular properties such as critical pressure, parachor, atomic charges, etc. were proposed. Principal component analysis on the set of descriptors employed uncovered the significant contributions of the polarity‐related factors to auto‐ignition temperatures. For the majority of the 250 compounds over an auto‐ignition temperature range of 170–630°C, good agreement between observed and calculated autoignition temperatures was confirmed. The method could be useful for assessing the flammability of new compounds.