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Steel Pipe (steel + pipe)

Distribution by Scientific Domains
Engineering50%

Selected Abstracts

Assessment of Protection Systems for Buried Steel Pipelines Endangered by Rockfall

COMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, Issue 5 2005
Bernhard Pichler
First, a gravel-based protection system (GBPS) is investigated, that is, a pipeline buried in sandy gravel is considered. To assess the load-carrying behavior of this structure when subjected to rockfall, a finite element (FE) model has been developed. The development and the validation of this structural model are strictly separated, that is, they are based on two physically and statistically independent sets of experiments. Subsequently, scenarios of rockfall onto a gravel-buried steel pipe are analyzed considering different boundary conditions and structural dimensions. Following the conclusions drawn from these numerical analyses, an enhanced protection system (EPS) is proposed. It consists of gravel as an energy-absorbing and impact-damping system and a buried steel plate resting on walls made of concrete representing a load-carrying structural component. The potential and the limitations of both protection systems are discussed in detail. [source]

Numerical calculations of erosion in an abrupt pipe contraction of different contraction ratios

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 1 2004
M. A. Habib
Abstract Erosion predictions in a pipe with abrupt contraction of different contraction ratios for the special case of two-phase (liquid and solid) turbulent flow with low particle concentration are presented. A mathematical model based on the time-averaged governing equations of 2-D axi-symmetric turbulent flow is used for the calculations of the fluid velocity field (continuous phase). The particle-tracking model of the solid particles is based on the solution of the governing equation of each particle motion taking into consideration the effect of particle rebound behaviour. Models of erosion were used to predict the erosion rate in mg/g. The effect of Reynolds number and flow direction with respect to the gravity was investigated for three contraction geometries considering water flow in a carbon steel pipe. The results show that the influence of the contraction ratio on local erosion is very significant. However, this influence becomes insignificant when the average erosion rates over the sudden contraction area are considered. The results also indicate the significant influence of inlet velocity variations. The influence of buoyancy is significant for the cases of low velocity of the continuous flow. A threshold velocity below which erosion may be neglected was indicated. Copyright © 2004 John Wiley & Sons, Ltd. [source]

Heat transfer to a moving packed bed of nickel pellets

THE CANADIAN JOURNAL OF CHEMICAL ENGINEERING, Issue 2 2008
M. H. I. Baird
Abstract Heat transfer between a bed of nickel pellets and a vertical section of electrically heated steel pipe has been measured, with the pellet bed inside the vertical pipe. Most of the data are for a 20.27 cm diameter pipe but some data were also obtained for a 10.23 cm diameter pipe. The effective thermal conductivity of the stationary pellet bed has been estimated approximately from the results of unsteady heating tests. Tests have been carried out with a downwardly moving bed, including the effect of air flowing upwards through the bed. Average values of the pellet-side heat transfer coefficient are between 72 and 135 W/(m2°C) depending on the mass fluxes of air and pellets, and have been expressed as an empirical correlation. Le transfert de chaleur entre un lit de pastilles de nickel et une section verticale d'une conduite d'acier chauffée électriquement a été mesuré, le lit de pastilles se trouvant à l'intérieur de la conduite verticale. La plupart des données ont été obtenues pour une conduite de 20,27 cm de diamètre, mais certaines données ont également été obtenues pour une conduite de 10,23 cm de diamètre. La conductivité thermique effective d'un lit de pastilles stationnaire a été estimée de manière approximative à partir des résultats de tests de chauffe en régime non stationnaire. Les tests ont été menés avec un lit en mouvement descendant, incluant l'effet de l'air circulant dans le sens ascendant dans le lit. Les valeurs moyennes du coefficient de transfert de chaleur du côté des pastilles sont comprises entre 72 et 135 W/(m2°C) selon les flux massiques de l'air et des pastilles, et sont exprimées en tant que corrélation empirique. [source]

Growth of Enterococcus mundtii ST15 in medium filtrate and purification of bacteriocin ST15 by cation-exchange chromatography

JOURNAL OF BASIC MICROBIOLOGY, Issue 6 2005
Monique Granger
Bacteriocin ST15 (bacST15), produced by Enterococcus mundtii ST15, inhibited the growth of a variety of bacteria, including exopolysaccharide (EPS)-producing strains isolated from biofilms in stainless steel pipes. Maximal production of bacST15 (51200 AU/ml) was recorded after 20 h of growth in MRS broth (Biolab), which was maintained throughout fermentation. Only 12800 AU/ml bacST15 has been recorded in MRS filtrate with components smaller than 8000 Da, suggesting that nutrients larger than 8000 Da are required for optimal bacST15 production. Cation-exchange chromatography yielded an active peptide, which is 3944.00 Da, according to electron-spray mass spectrometry and tricin-SDS PAGE. BacST15 is smaller than the 4287 Da reported for bacteriocins ATO6 and KS produced by E. mundtii . The iso-electric point of bacST15 is between 7 and 9, and similar to that reported for pediocin PD-1. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]