Papers by Keyword: Soot

Abstract: Research results of modified composites which consist of isolated layers with different properties and their practical usages are represented in this article. A structure of the composite material is considered. The structure is combined of few layers; external layers are made of corrosive resistance material with dielectric behavior while the internal part of the composite is made of electrically conductive material with high conductive and mechanical properties. Conductive properties of each layer have been measured as well as their mechanical properties and structure. Also, the features of the joints between layers in terms of structure and properties were defined. More than that, varieties of mixtures and their possible usage are considered. Conductive properties of composite materials and ways of their adjustment have been described as well. For the first time, the measuring scheme of conductive properties for each layer was offered and heat shrinkable tubes and copper electrodes were used for it. Efficiency of modified composites and its behavior when electrical current applied can be measured by using the scheme.

Abstract: This paper presents a study on improvement of performance characteristics of small diesel direct injection engine with power of 16.5HP using the re-design of intake manifold. With help of simulation tools like AVL BOOST, the proposed measures for improvement of intake manifold were analyzed. The simulation results indicated that two best intake manifolds were recommended for experimental purposes. These manifolds were experimentally used to benchmark to the current intake manifold of engine. In experiments, the important performance characteristics of engine (like volumetric efficiency, brake power, brake torque, fuel consumption, NOx, Soot, and CO) were analyzed. Moreover, the flow pattern of intake air was experimentally observed using a transparent cylinder.

Abstract: The object of the research work was coal fines and processes of enrichment of Ekibastuz coal to produce fuel briquettes with increased calorific value and less ash content. Research, scientific substantiation of technology for obtaining high-calorific coal briquettes from fines of Ekibastuz coal, using various binders and the possibility of further coking, designing and manufacturing equipment for the implementation of technology, was made. The standard methods of theoretical and experimental research widely used in metallurgy, machine building, computer systems, etc. were used in the work. The characteristics of briquettes on bio-binding and on petroleum pitch with enrichers in the form of rubber-technical soot and anode dust of electrolysis cell for aluminum production have been established. It is revealed that the calorific value of briquettes is higher than that of Ekibastuz coal (Pavlodar region) by 20-40%, and the heating value is the highest for briquettes with an enrichment agent in the form of anode dust and a binder in the form of petroleum pitch (-NH combustion = 6840.8 kcal / kg). Briquettes on petroleum pitch with an enrichment agent in the form of anodic dust of aluminum electrolysis can be used as industrial briquettes for further use in metallurgy.

Abstract: The scales of porous carbon materials usage are constrained by their considerably high cost. Therefore, development of new methods for production of porous carbon with the necessary complex of properties from cheap raw materials is actual. Also, porous carbon materials can be used for growth of carbon nanotubes as a matrices of catalyst particles. Herein, the method of fabrication porous carbon materials from waste of oil industry and their use as a matrices of catalyst particles to growth of CNT was developed. CNTs was synthesized by CVD using as hydrocarbon source - propan-butane gas mixture, as catalyst - Ni particles at 650°C, 700°C, 750°C, 800°C. Obtained carbon materials was investigated by Raman spectroscopy and by scanning electron microscope. Investigations on the properties of the obtained porous materials show soot particles sedimented in pores reduce well nanoparticles of metals from salts which act as nuclei for the growth of multiwall carbon nanotubes during pyrolysis of hydrocarbons by CVD method.

Abstract: Particulate matter (PM) is one of the major pollutants emitted by diesel engine which have adverse effects on human health. Accordingly, many researches have been done to find alternative fuels that are clean and efficient. Biodiesel is preferred as an alternative source for diesel engine which produces lower PM than diesel fuel. However, the manufacturing cost of biodiesel from vegetable oil is expensive. Therefore, using waste cooking oil (WCO) for biodiesel would be more economical and sustainable solution. The characteristics of direct injection diesel engine in term of the PM have been investigated experimentally in this study. The experiments were conducted using single cylinder diesel engine with different speed (1200 rpm, 1500 rpm, 1800 rpm, 2100 rpm, 2400 rpm) at constant load. PM emission of WCO B100 and diesel fuel was compared and the effect of PM components such as soluble organic fraction (SOF) and soot were studied. The result showed WCO B100 reduces the PM emission at all engine speed. Furthermore, both fuels showed highest reduction of PM concentration at moderate engine speed of 1500 rpm.

Abstract: This paper presents the experimental results of smoke opacity and exhaust gas measurements due to the oxidation of soot at different microwave power levels to the exhaust gas. The experiment attempts to ascertain the soot oxidation capability of using microwave in reducing smoke from the diesel engine. The exhaust gas from a diesel engine was directed into the microwave generator system which then flows through the chamber assembly that contains the soot trap. Three different microwave power levels of 0.5, 1.0 and 1.5 kW were generated and exposed to the soot at different exposure time. The results showed that when the power level of the electromagnetic waves was increased, the amount of smoke opacity reduced between 32 to 65 % depending on the microwave power levels. Due to the oxidation of the carbon particles of the soot, CO₂ gas increased in corresponding to the decreased in the smoke opacity. The experimental work also found that NOx gas was also reduced due to the breaking down of NOx at the localised high temperature of the soot trap. Hence, the microwave generator system has proven its capability as an in-situ soot oxidation device for deployment in diesel vehicles.

Abstract: Radial Basis Function (RBF) interpolation and trilinear interpolation techniques are compared in the soot particle tracking inside the cylinder of a direct injection engine. The interpolation techniques are used separately in an efficient routine written in Matlab codes which is developed to track the movement or pathline of soot particles in the engine operation cycle ranged from inlet valve closing (IVC) to exhaust valve opening (EVO). Soot particles are treated as a massless body and in spherical shape which will move under the influence of bulk gases flow inside the cylinder. Movement of soot particles are examined through the selection factors of particle's initial coordinate (r,Ɵ,z) and soot concentration level at different instant crack angle. Results obtained from both interpolation techniques are compared and good agreement is achieved with some minor relative difference. However, RBF interpolation has wider applications potential where it can be applied to variety type of mesh geometry as compared to trilinear interpolation which is best used in mesh with hexahedral shape.

Abstract: The severe legislation regarding pollution from actual time determine us to find new alternative solutions for diesel engine fuelling. This paper objective is the use of LPG as alternative fuel at a diesel engine in the purpose of pollutant emissions level decreasing in general and especially of NO_x and smoke emissions. Is difficult to use LPG as single fuel at the diesel engine because it has an high auto ignition endurance (CN = -3). There are many fuelling methods of the diesel engine with LPG, but the authors of this paper used the diesel-gas method for a 1,5 l engine fuelling. The research followed the establishment of the optimal LPG cyclic dose and the diesel engine adjustments for different engine operating regimen. The paper presents results of some theoretical and experimental investigations of the LPG fuelled diesel engine. Three substitute ratios of diesel fuel with LPG were taken into account for full load and 2000 rpm engine speed. Thus, the NO_x emissions decreased with 20-28 % for different substitute ratios of diesel fuel with LPG. The smoke emission decreased with 35-47% for same substitute ratios. LPG fuelling represents a very good solution for a cleaner environment.

Abstract: The results of analyses of coloured plasters are given in the paper. The samples come from traditional folk earth houses from SE and Central Moravia and were chosen so as all of the most common colours of the Central European folk architecture are present among them: red, yellow, blue, green, and black. The analyses were conducted by the means of light microscopy, which is also a powerful tool for stratigraphical analyses, X-ray diffractometry, Raman spectrometry, end electron microanalysis. Hematite of industrial origin was identified as the red pigment, the yellow one was formed by yellow earth, which also may be a precursor for traditional production of red dye. The widest used blue pigment was ultramarine in the 19th and the first half of 20th century in Moravia. The analysed green pigments were formed by an organic dye of green earth and the black one consisted of soot. Based on the sort and composition of pigment and plaster, the age of the material is also discussed.

Abstract: The mathematical model of soot dynamical evolution process is built based on the discrete particles population balance theory, including particle nucleation, collision coagulation, oxidation and surface growth processes; a corresponding numerical model is established using Lagrange interpolation method of moments. Based on the perfectly-stirred reactor combustion model, coupled the numerical model with detailed chemical kinetic model. The computing platform of soot particle growth evolution is established. Meanwhile, three nucleation models are built for the soot nucleation in this paper. Two chemical reaction mechanisms are used to study different fuels combustion process. The related information of soot particle growth evolution is obtained, the effect of different nucleation model on other dynamical events such as coagulation, oxidation and surface growth processes is discussed.