Applied Mechanics and Materials Vol. 832

Abstract: The main goal of this article is to analyze the distribution of primary and secondary combustion air in a combustion chamber. The fuel for the combustion chamber is biomass and the main characteristics the combustion chamber must meet is to be simple, reliable, cheap and ecological. A brief summary of the importance of primary and secondary air is made and then it is compared with the results from the numerical model. The numerical model is based upon a simplified chamber geometry and the results are computed for laminar and turbulent flow. From the comparison are determined flaws of the design of the combustion chamber and outlined possible solutions for their removal and further direction of the study.

Abstract: This article explains the physical features of various methods of compaction, primarily for end of life vehicle (ELV) bodies coming from ELV processors. By EU directive 2000/53/EC it is mandatory for all EU members to meet the reuse of 95 % of the old vehicle weight. It means that the vehicles have to be decomposed completely – metal shells freed from all the components like interior trim, rubber sealing, glass, all the liquids, seats tanks and other hard metal components like drive-train, engine etc. It follows that pressing machines used for compressing whole vehicles today, are overpowered, with high energy demand, robust structures and heavy weight. Hence it makes sense to concentrate on comparison of pressing methods and choosing the most energy efficient one and the designing a new device, if necessary. This device is aimed for operation in Slovak Republic but also usable in other countries with same or similar requirements such as optimized system for processing of car bodies, mobile concept and modularity of the whole mobile modular disintegration complex consisting of a pressing machine, shears and shredder. Car body structure

Abstract: This paper deals with a use of CFD modelling for optimization of supply of secondary combustion air in the two-chamber biomass boiler combusting very wet biomass (capacity ca. 200 kW). Objective of the analyse is to observe the impact of diameter of a secondary air supply pipe and air flow velocity on mixing of the secondary air with flue gas in the combustion chamber. The numerical model of the experimental boiler was build up for subsequent utilizing of CFD computation based on finite element method. The commercial code STAR-CD was used for carried out parametrical studies. Series of calculations were carried out for four different diameters of air distribution pipes and for 3 different air velocities in distribution orifice. Quality of air dispersion in flue gas flow was assessed in the vertical cross section lead in the end of the combustion chamber. The results of calculation were verified on the experimental installation of the boiler. Influence of secondary air mixing on emission production was measured and analysed. Emissions of pollutants for recommended air distribution comply with emission limits stipulated in the most stringent class 5 according to ČSN-EN 303-5 as well as with emission limits under Regulation No. 405/2012 Sb.