An effectiveness analysis of the pulsed resonant fuel combustion in the processes of steel­casting ladle drying and warming

Abstract

This paper reports a technique of the pulsed resonant fuel combustion in the processes of drying and heating steel-casting ladles, devised to save fuel. The research method is based on the initiation of pulsations when burning fuel at a frequency equal to the frequency of natural fluctuations within the working volume of the ladle, which leads to the resonance of pulsations. This study aimed to define a technique to effectively burn fuel and to confirm a decrease in fuel consumption in the process of the pulsed resonant combustion. The experimental and industrial studies involving 8 drying operations and 5 ladle heating operations have established the possibility to comply with the normative requirements in line with the technological instructions at the level of 80‒100 %. The possibility to search for the pulsed resonance frequencies under industrial conditions has been confirmed, despite the negative impact of high temperatures, acoustic interference, and inertia of the equipment. The feasibility of a pulsation unit has been determined, as well as the possibility to steadily maintain, during the drying process, the required resonance frequencies of gas pulsations. A more intensive course of the drying process has been observed, which makes it possible to shorten the process duration and, accordingly, to reduce fuel consumption. The high excitability of resonance frequencies in the ladle during heating has been detected, due to the short length and volume of the section of a gas pipeline between the pulsation unit and burner compared to the drying bench. The warm-up intensity was noticeably higher than that of drying due to the lower end temperature of the lining (777‒910 °C instead of 900‒1,120 °C) and the lack of moisture evaporation. Using the pulsed resonant fuel combustion mode at the posts of intensive heating of ladles for melting makes it possible to force the heating by the resonant pulsation of the torch. During pulsed resonant combustion, the usable utilization of fuel heat increases markedly, which leads to an increase in the drying and heating processes efficiency and corresponding fuel economy. The decrease in the consumption of natural gas when drying the ladles amounted to 2.7÷26.1 %; at the warm-up ‒ 19.5÷37.8 %. These data indicate the energy efficiency of the pulsed resonant combustion and the feasibility of implementing a burning technique in the processes of ladle drying and warming