Energy audit experiences in foundries

Abstract

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 Produttività 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.

Energy efficiency opportunities in the production process of cast iron foundries: An experience in Italy

“…The residual heat could be used for pre-heating the combustion air of the post-combustion unit. Waste gas must then be cleaned in a bag filter at a required temperature around 160 C. The electrical power and the electrical efficiency that could be reached, considering an air excess of 100% in the post combustion unit, is evaluated around respectively 1 MW and 27% ( [6]). …”

“…Literature data report that the melting and metal treatment process are the main energy consumption stages during the cast iron production process: For the cupolas the percentage of furnace consumption on total foundry consumption is about 50% [6], for the induction furnaces it can be up to 70% [7]. Depending on the type of cast iron, melting is obtained at about 1450e1500 C. The following tapping and pouring phases can be automatic or manual respectively from the melting pot into the ladles and from the ladles to the moulds.…”

“…[6], consumes energy; this paper considers the energy performances and proposals for energy savings in cast iron foundries concerning the production process. Energy efficiency in service plants (i.e.…”

Enhancement of a Short-Term Forecasting Method Based on Clustering and kNN: Application to an Industrial Facility Powered by a Cogenerator

“…Solid oxide fuel cells and electrolyzers have been suggested for energy generation in industrial facilities producing hydrogen [32]. In [33,34], some energy audits in industrial facilities have been performed to analyze the main inefficiencies, and to define which improvements are required. The main scope of this study is to define a method for improving the performances of short-term forecasting and, consequently, to use it in order to improve the operation strategy of the energy generation plant of an industrial facility.…”

Development of tool framework for rapid cleaner production assessment (CPA) coupling to energy savings: a case study of metal production industry

“…Ngoài ra, ngành sản xuất kim loại là ngành tiêu thụ nhiều năng lượng cũng như có nhiều tác động tới môi trường. Trong thời gian qua đã có nhiều nghiên cứu về ngành này điển hình như từ chia sẻ kinh nghiệm kiểm toán năng lượng [10] đến đánh giá phát thải CO2 [11][12][13] và đánh giá hiệu quả sử dụng năng lượng [13,14] cũng như các khía cạnh tác động môi trường [15]. Các kết quả nghiên cứu cho thấy Mỹ và Trung Quốc là hai nước phát thải CO2 nhiều nhất trong lĩnh vực kim loại [16].…”