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M. Zajemska, H. Radomiak and A. Poskart

REFERENCES [1] W. Bialik, S. Gil, P. Mocek, Prediction of CFD processes of gaseous pollutants emission in high-temperature combustion chamber, Ęnvironment 11 , 3, 3-12 (2009). [2] R. Bilbao, M.U. Alzueta, A. Millera, V. Cantín, Experimetal study and modeling of the burnout zone in the natural gas reburning process. Chemical Engineering Science 50 , 16, 2579-2587 (1995). [3] A. Bogusławski, A. Tyliszczak, S. Kubacki, Numeryczne modelowanie procesów przepływowych, Materiały dydaktyczne Wydziału Inżynierii Mechanicznej i Informatyki, www

Open access

W. Longa

References W. Longa: The main paradigm used in the theory of calculation of the height and structure of combustion zone and melting zone in coke-fired cupolas. Polish Academy of Sciences Archives of Metallurgy and Materials. 54 , 4, 1207-1222 (2009). W. Longa: Calculation of height and structure of melting zone of coke cupolas. Polish Academy of Sciences Archives of Metallurgy and Materials 55 , 3, 669-682 (2010). W. Longa: Calculation of Combustion Zone Height in a Cupola Working

Open access

A. Poskart, H. Radomiak, P. Niegodajew, M. Zajemska and D. Musiał

REFERENCES [1] R.C. Flagan, J.H. Seinfeld, Fundamentals of air pollution engineering; Prentice-Hall: New Jersey, 2005. [2] D. Vallero, Fundamentals of air pollution. 4th edition. Library of Congress Cataloging-in-Publication Data. Academy Press, 2008. [3] C. Baukal, Oxygen enhanced combustion. Air Products and Chemicals Inc; CRC Press. Allentown: Pensylwania, 1998. [4] O. Marin, F. Châtel-Pélage, G.M. Usman, N.bPerrin, Low-oxygen enrichment in coal-fired utility boilers. Int. Tech. Conf. Coal Util. Fuel Syst., 27th, Clearwater, 2003

Open access

S.H. Choi, B. Ali, S.K. Hyun, J.J. Sim, W.J. Choi, W. Joo, J.H. Lim, Y.J. Lee, T.S. Kim and K.T. Park

Abstract

Combustion synthesis is capable of producing many types of refractory and ceramic materials, as well as metals, with a relatively lower cost and shorter time frame than other solid state synthetic techniques. TiO2 with Mg as reductant were dry mixed and hand compacted into a 60 mm diameter mold and then combusted under an Ar atmosphere. Depending on the reaction parameters (Mg concentration 2 ≤ α ≤ 4), the thermocouples registered temperatures between 1160°C and 1710°C · 3 mol of Mg gave the optimum results with combustion temperature (Tc) and combustion velocity (Uc) values of 1372°C and 0.26 cm/s respectively. Furthermore, this ratio also had the lowest oxygen concentration in this study (0.8 wt%). After combustion, DC plasma treatment was carried out to spheroidize the Ti powder for use in 3D printing. The characterization of the final product was performed using X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, and N/O analysis.

Open access

J. Cheng, X.P. Zou, G. Zhu, M. F. Wang, Y. Su, G.Q. Yang and X. M. Lü

In this paper, the effects of position of substrates in flames, preparation time, stability of flames and catalyst precursors on the synthesis of carbon nanofibers (CNFs) by ethanol catalytic combustion (ECC) were investigated. For investigating the effects of these influence factors on the synthesis of CNFs, several sets of controlled experiments were performed, such as preparation experiments with different position of substrates in flames, different preparation time, stable and unstable flames, and different catalyst precursors. In our experiments, the catalyst precursors were iron nitrate, cobalt nitrate, nickel nitrate, and iron chloride, cobalt chloride, nickel chloride. The as-synthesized products were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Raman spectroscopy. Our results indicate that the optimal position of substrates in flames is more than 1cm and less than 2.5cm, the optimal preparation time is more than 5min and less than 30min for massive yield, stable flames would be tent to synthesize CNFs with mainly single-type morphology and could improve the graphitization of CNFs, and the catalyst precursors obviously have effects on the synthesis of CNFs.

Open access

K. Naplocha and K. Granat

activated combustion synthesis of titanium aluminides, Materials Science & Engineering A 394 , 385-392 (2005). [5] C.L. Yeh, W.Y. Sung, Combustion synthesis of Ni3Al inter-metallic compound in self-propagating mode, Journal of Alloys and Compounds 384 , 181-191 (2004). [6] K. Morsi, Review: reaction synthesis processing of Ni-Al in-termetallic materials, Materials Science & Engineering A299 , 1-15 (2001). [7] J.J. Moor, H.J. Feng, Combustion synthesis of advanced materials: part I. Reaction Parameters, Progress in Materials Science 39 , 243-273 (1995). [8] P

Open access

R. Tomoshige and H. Tanaka

Abstract

Hot shock compaction method was utilized for the consolidation of MAX phase composites consisting of Ti, Al and C. This paper presents the production of dense, crack-free composites by combining the combustion synthesis with explosive detonation. Another objective is to investigate various properties of the obtained shock-compacts. The shock compacted materials were post-annealed at 1173 K for releasing the shock-induced strain. As a result, these compacts had strong interparticle bonding strength and few macro cracks. Intermetallic compounds (TiAl, Ti2Al and Ti3Al) and non-oxide ceramics (TiC and Ti4Al2C2) were detected in as-synthesized and annealed materials by X-ray diffraction experiments. Also, lamella structures of Ti4Al2C2 phase were observed by SEM. It was known that the coefficient of thermal expansion increased with increasing temperature, and decreased with increasing TiC content.

Open access

Paweł Lisiak, Izabela Rojek and Paweł Twardowski

Abstract

The article describes a method of evaluating the reliability of groove turning for piston rings in combustion engines. Parameters representing the roughness of a machined surface, Ra and Rz, were selected for use in evaluation. At present, evaluation of surface roughness is performed manually by operators and recorded on measurement sheets. The authors studied a method for evaluation of the surface roughness parameters Ra and Rz using multi-layered perceptron with error back-propagation (MLP) and Kohonen neural networks. Many neural network models were developed, and the best of them were chosen on the basis of the effectiveness of measurement evaluation. Experiments were carried out on real data from a production company, obtained from several machine tools. In this way it becomes possible to assess machines in terms of the reliability evaluation of turning.

Open access

L. Chlubny, J. Lis, K. Chabior, P. Chachlowska and C. Kapusta

Abstract

Authors present results of works on the interesting new group of advanced ceramics called MAX phases – Ti-based ternary carbides and nitrides. They have an original layered structure involved highly anisotropic properties laying between ceramics and metals, with high elastic modulus, low hardness, very high fracture toughness and high electrical and heat conductivity. Using Self-Propagating High-Temperature Synthesis (SHS) in the combustion regime it is possible to prepare MAX phases-rich powders that can be used as the precursors for preparation of dense MAX polycrystals by presureless sintering or hot-pressing. Different novel Ti-based phases with layered structures, namely: Ti3AlC2 and Ti2AlC have been synthesized in a combustion regime. The possibility of controlling of combustion phenomena for obtaining near single-phase products is discussed in details as well as some of properties of the materials tested as structure and functional ceramics.

Open access

W. Longa

Massive, Volumetric and Energetic Effects of Coal Exchange between Coke and Exhaust Gases at Various Levels of Cupola Processing Stack

Formulas for the calculation of mass, volume and energetic effects bound with reaction CO2 + C = 2 CO have been derived in the paper. The effects occur in the charge coke, which pass from the upper boundary of the heating zone to the lower boundary of the combustion zone as well as in the cupola gases generated in the combustion area and moving through the charge material stack to the upper boundary of the heating region. The formulas include the effects at the lower levels and the maximum effects i.e. occurring between the lower boundary of the combustion zone and the upper melting region.

The presented example of calculations contains full information on the size of analyzed reaction effects and describes its energetic model.

The work contributes to the elaboration of so far inexisting theory of thermal zone and subzone balances of cupolas as well as the method of calculation of gas temperature at the sub- and zone boundaries followed by the kinetics of zone processes, which depend on the temperature of gases