Effect of Silica and Carbon-reducing Agents on Ni and Ti iImpurities During Silicon Production

The Ni and Ti contents of industrial silicon has a significantly affect the of organic silicon. On the basis of large specific production data, the chemical component of silica and the carbon-reducing agent effect of the Ni and Ti contents of silicon were investigated using statistical techniques. Two furnaces were also studied—an 8.5 MVA furnace and a 12.5 MVA furnace. The effects of TiO2 and NiO impurities on the power consumption of both furnaces were also evaluated using the correlation of the TiO2 and NiO impurities in raw materials with specific power consumption. The consumption of raw materials exhibited a high negative correlation with the TiO2 and NiO impurities in industrial silicon, as determined by linear regression—that is, 82% < |r| < 99%. The influence of Ni on industrial silicon production was also stronger than that of Ti. With an increase in Ni, the power consumption of the 8.5 MWA furnace significantly decreased, whereas that of the 12.5 MWA furnace is increased. Adjusting the content of Ni content can reduce the power consumption of industrial silicon production in the large furnace.

Superplastic Forming of a Complex Shape Automotive Component with Optimized Heated Tools

Superplastic forming (SPF) commonly requires industrial presses with an integrated large furnace able to uniformly heat the tools and the blank. In this work the feasibility to form via SPF an automotive component using a different heating approach was investigated. The heat is localized only where it is really needed embedding electric heating elements directly in the forming tools. Preliminary numerical simulations of the heating phase were aimed at calculating the electrical power and at choosing a suitable positioning of the heating elements. Further forming simulations were run to calculate the pressure profile. SPF experiments were finally conducted and sound components were obtained saving energy costs and using a common industrial press with lower investment costs.

New-Generation Sealing Slurries For Borehole Injection Purposes

The development of techniques and technologies thanks to which parameters of the ground medium can be modified makes specialists look for new recipes of geopolymers – binders for the reinforcing and sealing of unstable and permeable grounds. The sealing slurries are expected to meet a number of strict requirements, therefore it is important to find new admixtures and additives which could modify the fresh and hardened slurry. Special attention has been recently paid to the fluid ash – a by-product of the combustion of hard coals. However, the use of this additive is associated with the application of appropriate superplastifier. Laboratory analyses of rheological parameters of fresh sealing slurries and the ways of improving their liquidity by a properly selected third-generation superplastifier are presented in the paper. The slurries were based on Portland cement CEM I, milled granulated large-furnace slag and fly ash from fluidized-bed combustion of hard coal.

Acoustic Temperature Profile Measurement Technique for Large Combustion Chambers

Measurement of times of flight of sound waves can be used to determine temperatures in a gas. This paper describes a system, based on this principle, that is capable of giving the temperature profile in a nonisothermal gas volume, for example, prevalent in a large furnace. The apparatus is simple, rugged, accurate, and capable of being automated for process control applications. It is basically an acoustic waveguide where the outside temperature profile is transferred to a chosen gas contained inside the guide.

Analysis of Solar-Furnace Performance in Mechanical Testing at Extremely High Temperatures

The use of the solar furnace for investigating properties of materials has received increased attention. However, such work has been limited to determining physical properties of refractory materials. Analyses of performance, related to such work, have been confined to investigations of flux distribution and temperature on flat-plate, hemispherical, and cavity receivers at the focal spot. Heat conduction away from the focal spot usually has not been considered. The present investigation is concerned with the analysis of fluxes and temperatures that can be attained in tensile specimens undergoing mechanical tests. Account is taken of heat loss by conduction and reradiation. It is shown that, (a) attainable temperatures are considerably lower than those reached in flat-plate receivers, (b) with normal low-aperture furnaces (i. e., 60 deg) a large furnace is necessary to reach high temperatures with adequately large specimens, and (c) furnaces best-adapted to mechanical testing would have larger apertures (120 deg) than are now commonly conceived.