No abstract available

[en] The authors demonstrate the interest of the utilization of a pressurized-graphite/water/oxygen mixture in the incineration of irradiated graphite. The aqueous phase comes in the form of a three-dimensional system that traps pressurized oxygen, the pulverulent solid being dispersed at the liquid/gas interfaces. These three-phasic formulations give the following advantages: reduction of the apparent viscosity of the mixture in comparison with a solid/liquid mixture at the same solid concentration; reduction of the solid/liquid interactions; self-pulverizability. thus promoting reduction of the flame length utilization of conventional burners; reduction of the flue gas flow rate; complete thermal destruction of graphite. (author)

[en] The injection of non fuel materials (iron ores, flux s, slags, ilmenite sands), siderurgical wastes, plastics, and others, both in single form and in mixture with pulverized coal, is analyzed. As the characteristics of the injected materials, variations in the operation of blast furnace can be introduced. (Author) 47 refs

[en] This study describes that particle technology can be applied to the steam generation in the fossil and nuclear power plants

[en] PSI Energy's Engineering, Operating, and Maintenance personnel are committed to operational improvements through a program of problem identification and implementation of corrective action. Fuel system performance on Unit number-sign 5 at Wabash Power Station has proved, over the years, to be a major factor in limiting boiler performance during certain operating conditions. Meetings between PSI Energy and Riley Stoker identified several system deficiencies which, if addressed along with other modifications, would enhance PSI's goal of improved capacity, performance, and heat rate. This paper discusses the following aspects of the project: (1) evaluation of the existing equipment performance pinpointing where system improvement needs were; (2) the arrangement and design basis for system improvements that were ultimately chosen for implementation; (3) evaluation of performance of modifications including: capacity and ability of the system to handle wet coal; emissions; and coal fineness. Major modifications that were a part of this project included new crusher/dryers, mill bypass circuits, cyclone classifiers, low NO_x burners, mill level controls, and replacement of mill seals

[en] In mechanical alloying (MA) processing, alcohol, acetone and other organic solvents are often added as dispersants in order that powders will not stick to a vessel. It has been however considered that these organic solvents are simply additives. Enough attention has not been paid to the role or reaction of these dispersants. Recently, it was found that these organic solvents could react with some metals. For example, the authors reported that NbC is obtained by a reaction between Nb and methanol in the preparation of Al₃Nb intermetallics by the MA method. Niobium hydrides are obtained by milling of Nb powders in hydrocarbon. In this paper, the authors discuss the reaction between Nb powder and hexane (C₆H₁₄) or methanol (CH₃OH) during mechanical grinding (MG) processing

[en] Main properties of brown coals in Karazhyra open pit upper and lower packs are determined. Characteristics of these coals briquette-ability are evaluated. A conceptual possibility to obtain high-quality briquettes from open pit coal fines is shown. (author)

[en] Forming of beryllia ceramics through dry pressing requires the agglomeration of the powder through spray drying. To produce high quality fired ceramics it is necessary to disperse/grind the primary powder prior to binder addition. Size reduction of the powder is accomplished using an aqueous system in Vibro-Energy mills (VEM) charged with beryllia media to minimize contamination. Two VEM mills of different size were used to characterize the grinding operation. Details of the grinding kinetics are described within the context of the Macroscopic Population Balance Model approach. Spray drying of the ceramic slurry was accomplished with both a centrifugal atomizer and a two fluid nozzle atomizer. Two different spray dryers were used. Important operating parameters affecting the size distribution of the spray dried powder are discussed

[en] Quantitative profiling of pulverized fuel flow in a pneumatic conveying pipe is essential to balance the fuel distribution and improve the operation flexibility of a coal-fired boiler. In this study, an electrostatic sensing head comprising square-loop shaped electrodes and strip-shaped electrodes is used to characterize the particle flow in a square-shaped pipe under various flow conditions. Cross-correlation and data fusion algorithms are also proposed to process and combine the multi-channel signals from the sensor arrays in the sensing head. Dynamic characteristics of the particle flow in a vertical square-shaped pipe on an experimental platform are presented. Experimental results demonstrate that the cross-sectional profiles of the velocity and volumetric concentration of particles in a square-shaped pneumatic conveying pipe are highly non-uniform. (paper)

[en] Coal, in spite its abundance availability in Pakistan, is a neglected source of energy. Its role as fuel is not more than five percent for the last four decades. Some of the coal, mined, in used as space heating in cold areas of Pakistan but more than 90% is being used in brick kilns. There are 185 billion tonnes of coal reserves in the country and hardly 3 million tonnes of coal is, annually, mined. Lakhra coal field is, presently, major source of coal and is considered the largest productive/operative coal field of Pakistan. It is cheaper coal compared to other coals available in Pakistan. As an average analysis of colas of the country, it shows that most of the coals are lignitic in nature with high ash and sulfur content. The energy potential is roughly the same but the cost/ton of coal is quite different. It may be due to methods of mining. There should be some criteria for fixing the cost of the coal. It should be based on energy potential of unit mass of coal. (author)