Background. The task of sustainable use of energy and raw materials resources is becoming increasingly important due to growing industrial consumption of energy resources, decreasing raw material stocks on the planet, as well as growing environmental pollution with industrial waste. These problems are especially important for ferrous metallurgy enterprises that are the largest consumers of energy resources. One of the main processes of metal production is coke-chemical production, the technological process of which includes coke cooling-off, in particular by dry method. The main advantage of dry quenching is the utilization of the heat of the cooling coke and its increased quality at the output in comparison with wet quenching. However, a significant disadvantage of this technology is the decrease of the coke output due to its burnout. Thus, the goal of this study is the development of a technical solution to reduce coke burnout during dry quenching.
Materials and methods. The following analytical methods have been used in the course of the study: heat balance method to calculate the energy efficiency of a dry coke quenching unit; calculation of heat exchange parameters between coke and circulating gas; method of comparative analysis of coke burn-off when using different compositions of circulating gas (air, technical nitrogen); engineering methods of thermotechnical calculations, including determination of the amount of heat transferred to the coolant, heat losses through the unit body, steam capacity of the waste heat boiler, and economic efficiency of of the modified technology. Also, data from the literature and previous engineering developments have been used, including information on the composition of the gas mixture and the heat of combustion of coke.
Results. A description of the method of dry quenching of coke is presented. A method to reduce coke burn and a scheme describing its implementation have been proposed. Based on the scientific review, coke burn is assumed when nitrogen is used as a circulating gas. The results of the calculation of energy characteristics taking into account the proposed scheme have been presented. The capacity of the coke cooler plenum and the steam-production capacity of the waste heat boiler have been determined. An assessment of the economic effect of the implementation of the proposed technical solution has been carried out.
Conclusions. The results obtained allow us to talk about the expediency of implementing the proposed measure to replace circulating gas at industrial installations of metallurgical plants. The implementation process at industrial plants seems promising for further research, taking into account the possibilities of industrial production.