Chemical Vapor Deposition (CVD) is one of the most important methods for producing Carbon Nanotubes (CNTs). In this research, a numerical model, based on finite volume method, is investigated. The applied method solves the conservation of mass, momentum, energy and species transport equations with aid of ideal gas law. Using this model, the growth rate and thickness uniformity of produced CNTs,...

A recently developed model was used to study the CO/CO2 ratio inside a burning pulverized coal particle, to better understand the effect of bulk gas composition on the equilibrium partial pressure of reduced metal species at the surface of ash inclusions. The motivation was to improve the ability to model submicrometer particle formation by ash vaporization, as a function of furnace conditions....

Effects of rapid heat transfer using a fluidized bed on the heat-treating response of Al-Si-Mg alloys (both unmodified and Sr modified) were investigated. The heating rate in the fluidized bed is greater than in conventional air convective furnaces. Particle size analyses of eutectic Si showed that the high heating rate during fluidized bed solution heat treatment causes faster fragmentation an...

The kinetics of brittle phase transformation in cast duplex stainless steels CD3MN and CD3MWCuN was investigated under continuous cooling conditions. Cooling rates slower than 5 °C/min. were obtained using a conventional tube furnace with a programable controller. In order to obtain controlled high cooling rates, a furnace equipped to grow crystals by means of the Bridgman method was used. Samp...

The incineration of municipal waste under existing legislative and operational boundary conditions is a very complex process. An optimisation in the emissions is possible by a splitting up of the combustion air into primary and secondary air. The mixing of the secondary air into the furnace is the most important feature in order to reach uniform oxygen, temperature and velocity distributions. T...

A practical active disturbance rejection control (ADRC) solution is proposed for the furnace temperature system. Employing a linear reduced-order model with optimized parameters, the practical ADRC is simple to use, easy to tune and energy-efficient in dealing with the uncertainties and disturbances in plant dynamics. Through the order reduction in both the plant model and the state observer, w...

Scale up of microwave sintering for high temperature stable non-oxide ceramics, such as SiC, Si3N4, and dispersion ceramics, like SiC-MoSi2 is still difficult, mainly because of lack of an affordable equipment. For air atmosphere sintering different furnaces were developed, like e.g., gas-microwave hybrid heated tunnel kilns [1] or microwave sintering using an adiabatic casket in tunnel kilns [...

The purpose of this research is to investigate the mechanical and electrical properties of nano structured cordierite. Nano grain size powders were synthesized through mechanical activation by high-energy ball milling of the starting powders containing 34.86 wt% Al2O3, 51.36 wt% SiO2, and 13.78 wt% MgO. Samples were prepared by conventional and microwave sintering at 1390°C. SEM observations il...

ABSTRACT:A mathematical model for the performance prediction of an industrial glass furnace with six ports on each side was developed. This model comprises of two main sub-models for the combustion chamber and glass-melting tank. The first sub-model consists of the models for the combustion and the heat transfer model including, radiation, convection and conduction. The fuel combustion in a...

Large grain polycrystalline silicon wafers have been subjected to post~annealing (900 °C/45 ruin) after POCI3 pre-diffusion at different temperatures. For the first time we have investigated the effect of the furnace starting and quenching temperature on the gettering efficiency. The optimisation of thermal cycle parameters include the determination of the best combination of starting temperatu...