http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Diesel Particulate Traps Regenerated by Catalytic Combustion
Fino, Debora,Fino, Paolo,Saracco, Guido,Specchia, Vito 한국화학공학회 2003 Korean Journal of Chemical Engineering Vol.20 No.3
The development of catalytic means for the regeneration of particulate-laden traps for diesel exhaust cleaning is the main topic of this paper. All the steps of the catalytic trap preparation are dealt with, including: the synthesis and choice of the proper catalyst and trap materials, the development of in situ catalyst deposition, and the bench testion of the derived catalytic traps. Two different traps were considered(i.e., silicon carbide and cordierite wallflow monoliths operating via a shallow-bed filtration mechanism), whereas the best catalyst selected was the perovskite LaCr_0.9O_3. The filtration efficiency and the pressure drops of the catalytic and non-catalytic monoliths were evaluated on a diesel engine bench under various operating conditions. On the basis of the obtained results the catalysed SiC converter was found to be the most satisfactorty converter to be placed on the exhaust line of the modern commonrail diesel-engine cars.
Mobile and Non-mobile Catalysts for Diesel-Particulate Combustion : A Kinetic Study
Fino, Debora,Russo, Nunzio,Badini, Claudio,Saracco, Guido,Specchia, Vito 한국화학공학회 2003 Korean Journal of Chemical Engineering Vol.20 No.3
One of the potential ways to solve the problem of diesel particulate emission from both stationary and mobile sources is the use of traps carrying a suitable catalyst for promoting particulate combustion as soon as it is filtered. A Cu-K-V based catalyst, considered among the most promising in the literature, the KVO_3+C_sCl and the K_0.7Cu0.3VO_3+KCl catalysts were prepared and investigated. Their performance was compared to a reference V_2O_5 catalyst. The superior performance of the Cu-K-V catalyst is based on the grounds of both microreactor(temperature programmed combustion) and catalytic trap tests. Based on experimental data and modelling calculations, this paper elucidates how the mobility of catalyst components is the main reason for such an outcome performance and is a prerequisite to achieve an activity sufficient for trap self-regeneration.
Al2O3-ZrO2 nanocomposites produced by solution combustion synthesis followed by ultrasonic milling
Sara Biamino,Elisa Paola Ambrosio,Diego Manfredi,Paolo Fino,Claudio Badini 한양대학교 세라믹연구소 2011 Journal of Ceramic Processing Research Vol.12 No.2
Zirconia toughened alumina materials (ZTA) have been produced by solution combustion synthesis (SCS). SCS has proved to be a rather rapid and simple method to produce nano-structured ceramic oxides powders. Its main drawback is a limited sinterability of the powder due to aggregation of the nanometric grains into larger particles characterized by irregular shapes. It was found out that when coupling the preparation of ZTA nanocomposites by SCS with ultrasonic milling it is possible to improve the powder sinterability. The effect of ultrasonic irradiation on the powders was observed by BET and SEM analyses,and by its effect on the final density.
Alessandro Carrozza,Federico Mazzucato,Alberta Aversa,Mariangela Lombardi,Federica Bondioli,Sara Biamino,Anna Valente,Paolo Fino 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.9
Directed energy deposition is an additive manufacturing technology which usually relies on prototype machines or hybridsystems, assembled with parts from different producers. Because of this lack of standardization, the optimization of the processparameters is often a mandatory step in order to develop an efficient building process. Although, this preliminary phaseis usually expensive both in terms of time and cost. The single scan approach allows to drastically reduce deposition time andmaterial usage, as in fact only a stripe per parameters combination is deposited. These specimens can then be investigated,for example in terms of geometrical features (e.g. growth, width) and microstructure to assess the most suitable processwindow. In this work, Ti-6Al-4V single scans, produced by means of directed energy deposition, corresponding to a total of50 different parameters combinations, were analyzed, focusing on several geometrical features and relative parameters correlations. Moreover, considering the susceptibility of the material to oxygen pick-up, the necessity of an additional shieldinggas system was also evaluated, by comparing the specimens obtained with and without using a supplementary argon flow. A process window, which varies according to the user needs, was found together with a relationship between microstructureand process parameters, in both shielding scenarios.
Productivity Enhancement in Directed Energy Deposition: The Oscillating Scanning Strategy Approach
Alberta Aversa,Alessandro Carrozza,Giulio Marchese,Stefano Felicioni,Michele De Chirico,Mariangela Lombardi,Federica Bondioli,Paolo Fino 대한금속·재료학회 2023 METALS AND MATERIALS International Vol.29 No.7
Directed Energy Deposition (DED) is an additive manufacturing process that enables the production of large metal componentsby melting the feedstock material while being deposited. An improvement of the production speed of this processwould further increase its applicability in many industrial fields. The DED building rate is strictly related to the buildingparameters adopted, in particular to the laser spot diameter, which also affects the build accuracy and the surface quality ofthe components. The possibility of using a variable laser spot would result in a significant increase in the production rate inbulky zones, while also providing a good surface quality where needed. In the present work, an oscillating scanning strategywas used to create a large apparent laser spot (+ 170% of the nominal value) to produce 316L stainless steel samples via DED. The optimisation of the DED parameters with the oscillating strategy was performed using the single scan tracks (SSTs)approach. The morphologies of the SSTs obtained with different process parameters were assessed and the geometrical featuresrelated to the melt pools were analysed in order to select the most suitable X and Z displacements for the production ofthe cubic samples. The analyses of the cubes revealed that, if the correct overlap among nearby scans is selected, it is possibleto obtain dense samples with all the oscillating diameters tested. Finally, comparing the building rate and powder efficiencyvalues confirmed that this method can accelerate the building process and improve its overall performance.