The new investigation method of the kinetics of the gas emission from moulding sands used for moulds and cores is presented in this paper. The gas evolution rate is presented not only as a function of heating time but also as a function of instantaneous temperatures. In relation to the time and heating temperature the oxygen and hydrogen contents in evolving gases was also measured. This method was developed in the Laboratory of Foundry Moulds Technology, Faculty of Foundry Engineering, AGH. Gas amounts which are emitted from the moulding sand at the given temperature recalculated to the time unit (kinetics) are obtained in investigations. Results of investigations of moulding sand with furan resin are presented - as an example - in the paper.
The paper deals with the problem of multiple remelting influence on AlSi6Cu4 alloy modified by antimony on chosen mechanical characteristics, microstructure and gas content. This foundry alloy is used mostly in automotive industry. Foundry Aluminum-Silicon alloys are also used in number of industrial weight sensitive applications because of their low weight and very good castability and good mechanical properties. Modifiers are usually added to molten aluminum-silicon alloys to refine the eutectic phase particle shape and improve the mechanical properties of the final cast products and Al-Si alloys cast properties.
This article presents changes in the operating parameters of a combined gas-steam cycle with a CO2 capture installation and flue gas recirculation. Parametric equations are solved in a purpose-built mathematical model of the system using the Ebsilon Professional code. Recirculated flue gases from the heat recovery boiler outlet, after being cooled and dried, are fed together with primary air into the mixer and then into the gas turbine compressor. This leads to an increase in carbon dioxide concentration in the flue gases fed into the CO2 capture installation from 7.12 to 15.7%. As a consequence, there is a reduction in the demand for heat in the form of steam extracted from the turbine for the amine solution regeneration in the CO2 capture reactor. In addition, the flue gas recirculation involves a rise in the flue gas temperature (by 18 K) at the heat recovery boiler inlet and makes it possible to produce more steam. These changes contribute to an increase in net electricity generation efficiency by 1%. The proposed model and the obtained results of numerical simulations are useful in the analysis of combined gas-steam cycles integrated with carbon dioxide separation from flue gases.