In this paper, heat transfer and magnetic fields in a vacuum INDUCTION melting FURNACE have been studied numerically. To solve the coupled equations of thermal and magnetic INDUCTION heating, the finite element method has been used. An INDUCTION FURNACE model is simulated using an industrial geometry. The studies indicate that the effect of the geometry of the crucible and the coil on the melting time has not been thoroughly investigated and requires more indepth studies. It is attempted to improve the shape of the INDUCTION FURNACE, so that in less time aluminum is melted in a small scale FURNACE. The effect of the diameter-to-height ratio of the crucible on the duration of melting has been investigated. By decreasing the diameter-toheight ratio, the temperature reaches melting temperature in a shorter time. The results show that for the diameter-to-height ratio of less than 0. 4, there will not be a significant change at the average temperature. 10% reduction in the distance between the coils leads to an increase in the average temperature of the working material inside the FURNACE. With considering the constant density of the coil current and the constant induced current in the heated material, the effects of the number of coil turns on the temperature distribution and magnetic flux are investigated. In this way, the accuracy of the model is also checked by INDUCTION heating concepts. The effect of frequency on temperature has been investigated in different coil lengths. The results show that an increase of 4 times in the frequency caused an increase of 1. 7 times in the average temperature.

With a yearly use of about 2000000 pieces of triangular blades for mowers, binders and combines in Iran, their fabrication seemed economically feasible. The major problem, however, is the blade hardening. Only the edges of blades should be hardened leaving the rest softened in order to withstand shocks. Among all methods of hardening; the traditional and modern; the method of case hardening using a frequency stove, served the purpose the best. The various components for the hardening method consisting the rectifier, head and frequency changer as well as hardening depth and hardening time were calculated. The peripherals, that is; the flow rate for the stove head cooler was determined. An economical coast analysis was given for a piece of hardened blade.

In previous studies on the use of steel slag in asphalt mixtures, no comparison has been made between different types of slags produced in steel factories in Iran. In this research, in order to evaluate the mechanical properties of asphalt mixtures containing different amounts of steel slag and to compare their effects on mixture behaviors, two types of slags – BOF and EAF – were replaced with 25, 50, 75 and 100 percent of coarse part of aggregates. After characterization of limestone aggregates and steel slags using X-ray fluorescence equipment (XRF) and scanning electron microscope (SEM), Marshall mix design method was used to determine the optimum bitumen content. Moreover, the mechanical properties of mixtures using resilient modulus testing at different temperatures and indirect tensile strength testing in both dry and saturated conditions were evaluated. The results showed that the use of steel slag in asphalt mixtures could result in a significant improvement of asphalt mixture properties. Furthermore, moisture sensitivity of mixtures containing steel slags was less than the control mixture.

Steel industry presents one of the highest energy demand of all the industrial sector. Foundries have a really relevant role both in economical terms and as regards the energy demand. The cost of energy represents several percentage points of the overall costs of a foundry.The electricity demand is very high, particularly for the INDUCTION melting FURNACEs. A large amount of thermal energy is obtained both from natural gas combustion and from the coal needed for the process of formation of cast iron in cupolas. Moreover, the plant services must be considered: one very energy consumer is compressed air production. Every factory is different from another so that the proposal of actions of energy savings or thermal recovers requires a detailed study of each plant considering the lay out and analysing the single processes with related energy needs and thermal levels. The co-operation of the University of Padua with the Centro Produttivita` Veneto allowed to plan a series of energy audits in some foundries located in Vicenza province. The experiences of the first facilities surveys and audits recommendations demonstrated both potential advantage of energy savings and the related difficulties, often due to the high investment costs.Anyhow the joint work of auditing between the university experts and the foundry technicians produced a better awareness on the critical points of the plant and a higher rationality level in the evaluation of investments for the renewable of the machinery. Here, the method of performing the energy audits is described together with the very first results in terms of proposals for energy savings evaluated technically and economically.

This paper analyzes how feasible it is to use electric arc FURNACE slag as coarse aggregate, and blast FURNACE dust as fine aggregate in the manufacture of hot asphalt concrete for roads. Three mixtures were designed using the Ramcodes methodology, the M1 mixture of control with conventional materials, the M2 mixture replacing 50% and the M3 mixture replacing 100% of the conventional aggregates, which were submitted to tests to evaluate the susceptibility to moisture damage and plastic deformation, as well as others to determine the resilient modulus and the fatigue laws for each type of mixture. The mixtures with EAF and BFD presented better mechanical characteristics than the mixture with natural aggregates, met the acceptance requirements and the results of the performance tests are within the required requirements.

Voltage flicker and harmonics are the power quality problems which are introduced to the power system as a result of behavior of the arc FURNACE operation.To analyze harmonic and flicker generated by an arc FURNACE, accurate arc FURNACE models are needed. In this paper, different arc FURNACE models with different level of complexity are reviewed.In the first part of this paper a new developed time domain static model based on a piece-wise linear approximation of the V-I characteristics of the arc FURNACE is presented.In the second part of the paper, dynamic model for an arc FURNACE using MATLAB (Simulink) is presented. In addition to this, the novelty of this simulation technique lies in the fact that the variation of power transmitted to the load by the arc FURNACE during the cycle of operation is considered, thus making the proposed model more accurate and dependent on the operating conditions of the load.Finally recommendations are made for the application of some of these models and the accuracy of the presented model to other models from the practical point of view by using MATLAB is shown.

In recent years, lots of research has been done on effective usage of natural gas; the first step in these processes is conversion of natural gas to Syngas. Natural gas reforming process by refomer FURNACE is commonly used for syngas and hydrogen production. In this paper, windows based software, RIPI-RefSim, is introduced. By using proper heat, mass, kinetic and thermodynamic models as well as effect of catalyst shape, the software has been developed for the reformer FURNACE simulation for syngas and hydrogen production. RIPI-RefSim could be used in three different modes (Rating, Simulation and Design) and provides user a detailed understanding of FURNACE performance, product characteristics, temperature, reaction rates and pressure drop profiles, heat loss, effect of catalyst shape, and etc.

Due to the high efficiency and low switching losses of resonant power convertors in comparison with switching convertors, nowadays there is a growing trend towards these convertors. However, because of the high frequency of switching in such convertors, it is quite difficult to present an efficient control method. In this paper, based on the state feedback method and using pole placement technique a control strategy is developed which controlling delay time in the converter’s switching to minimize losses in the INDUCTION and hardening FURNACEs. In the propose method, the input voltage is isolated from output load. Moreover, fewer number of elements are employed in the control circuit which will be caused lower costs and small dimensions for control system. As a result, the proposed controller is more economical in comparison with the conventional ones. To show the effectiveness of propose controller, simulation circuits using PSIM software and an experimental setup are provided and the results are reported.

In this study, Exergy and energy analysis of processes of the steel production in Bouyersanat steel industry that contains three stages, melting in INDUCTION FURNACE, preheating and continuous casting is carried out. After doing exergy and energy balance of three stages separately, amount of energy transferred with different way and their shares, exergy losses for each stage and their shares and energy and exergy efficiency are calculated, and finally the overall process has been evaluated.By discussion of the results solutions among preheating of input materials to EIF, Increasing of amount of deoxidization materials like Coke and High carbon ferro manganese, and drafting a proper lid for preheating process are suggested.