Utilização de trocadores de calor de placas em espiral em processos da indústria siderúrgica

Stricter environmental policies are shown necessary to ensure an effective pollutant emission control. It is expected for the present year of 2015, that Brazil will assume, at the 21th United Nation's Climate Change Conference (COP21), implementation of commitment to a low carbon economy. This positioning affects the industrial environment, so that is deemed necessary to search for new technologies, less aggressive to the environment, so the adequacies to the new emission policies do not cause a negative effect on production. Almost all of the processes performed in the steel industry demand burning fuel and, therefore, flue gases are sent to the atmosphere. In this present work is discussed the utilization of heat exchangers so, by recovering part of the available heat from the flue gases of certain industrial process, the combustion air is preheated. The combustion air preheat results in less energy requirement, i.e., less need of fuel consumption and, in addition, minor amount of pollutants to be emitted. Due to better fitting to the process, it is studied the utilization of spiral plate heat exchangers. The heat exchanger dimensioning is made by an iterative method implemented in the software Microsoft Excel. Subsequently are analyzed the gains in terms of process's thermal efficiency improvement and the percentage of fuel saving. The latter implies in reduction of the same percentage of greenhouse gases emission

Gás natural no panorama brasileiro e um estudo de caso no setor automotivo

The intended purpose of this paper is to present the main aspects of natural gas applied to the public transportation as well as the environmental, economical and technical impacts in this sector. Also it is given specific information to be considered when comparing natural gas to other fuels, specially the diesel. At this point is presented the types of internal combustion engines (Otto and Diesel cycle) and which type is used in each vehicle. Moreover, it is presented the main standards pollutant emission (Euro, US and Proconve) with a brief explanation of the tests made in order to approve the engines. This paper is focused on heavy duty vehicles. Also in this paper is exposed the economic impact due to the natural gas use in the public transportation fleet. In addition is presented a real case (of Berlin) and an estimative to a Brazilian city, presenting the potential of natural gas as vehicular fuel in Brazil, as well as financial and environmental aspects of the substitution

Pesquisa, projeto e construção de um sistema de ignição sem distribuidor

This work intends to know the most types of ignition systems, studying its history, the way it works, applications and some examples. The assembly of a distributor less ignition system is also required. All vehicles powered by internal combustion engines need an ignition system that allows this engine to ignite the air-fuel mixture using its ignition system in the best possible manner. The main goal of an ignition system is to obtain a spark having enough energy to start the chemical reaction of the oxygen and the fuel. It took a study dealing with the various types of ignition systems since their creation at the beginning of the last century until 2015. The work starts studying the high tension magneto ignition system and later together with the low tension ignition system, going on with the conventional ignition system and finally accomplishing with the various types of electronic ignition systems. It was studied and implemented an electronic circuit to power a double spark ignition system also known as wasted spark ignition system. This circuit was assembled with an electric pulse generator and powered mechanically by a dc electric motor of the variable rpm type