Technological and structural calculation of the recuperator for air preheating on the cupola furnace

Scientific paper - Original scientific paper

• Author: Ladislav Lazić
• Author: Ivan Jandrlić
• Author: Marin Pomahač
• Author's institution: University of Zagreb; Faculty of Metallurgy
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Metallurgy

Abstract (english)

In cases of melt preparation for larger tonnage production, the most common melting method used in iron casting plants is the cupola furnace. The main advantages of cupola furnaces compared to electric ones are: less sensitive to low quality charge materials and contaminants, oxidation and reduction reactions take place within and above the melt zone during cupola melting, which allows the use of highly oxidized and low quality scrap material, lower prices of alloys and non-metallic additions. The metallurgical process in the cupola furnace can be intensified by preheating the air that is blown into the working space of the furnace through nozzles. In addition to increasing aggregate productivity, reduced coke consumption and higher melt temperatures are also achieved. For this purpose, tubular recuperators are usually used, which exploit the enthalpy of the output cupola gases, and in some cases also the enthalpy of natural gas combustion gases. For the cupola furnace with a capacity of 3 t/h, the technological and construction calculation of the recuperator sections was carried out. The calculation is based on the experimental data of furnaces and recuperators that are used in practice. It consists of the calculation of the combustion of natural and cupola gases and the calculation of the construction of three recuperator sections. In the first section, which is connected to the nozzles, i.e. in the zone of the highest temperatures of the combustion gases, the final heating of the air is achieved before entering the cupola furnace, in the second section the cupola gases are reheated before its combustion, while in the third section the air is heated from the initial ambient temperature. The design of the tubular heat exchanger with counter-flow of flue gases and air, composed of steel U-tubes, was adopted.

• Keywords (english): cupola furnace; air preheating; recuperator
• Language: english
• Publication type: Scientific paper - Original scientific paper
• Publication status: Published
• Peer review: Peer review - international
• Publication version: Published version
• Publication title: 63rd IFC Portoroz 2023 : conference proceedings
• Numbering: 20
• ISBN: 978-961-94793-8-4
• URN:NBN: urn:nbn:hr:115:245404
• Publication: 2023
• Conference: Title: 63nd IFC PORTOROZ 2023; Location: Portorož, Slovenia; Organizer: Slovenian foundrymen society; Start date: 2023-09-13; End date: 2023-09-15; Assembly type: Lecture
• Type of resource: Text
• Publisher: Slovenian Foundrymen Society
• Publishing place: Ljubljana
• Access conditions: Open access
• Created on: 2024-04-25 09:21:41