Simulation of iron rods combustion in oxygen with the drop detachment

Abstract

The present article is a part of the research program to study the combustion of steel in oxygen at high pressure. A fundamental understanding of iron and steel combustion in oxygen is important to the selection and specification of safe materials for oxygen production, storage and transport technologies.In the article a standard upward-burning ignition model was considered for cylindrical iron rods in oxygen with non-flowing test conditions. A combustion model with the drops separation to investigate influence of different burning factors on the combustion process was presented. The model results were compared with the NASA experiments to clarify the values that were introduced parametrically. The present model allows to calculate and visualize such combustion parameters as burning velocities, the period of droplet detachment, temperatures and stoichiometric compositions of melt droplets, etc. The Wolfram Mathematica 9.0 program was used for simulation.

Numerical Model for the Combustion of a Thermal Lance

“…The burning velocities reported in Wilson et al range from 0.2 to 1.6 cm s –1 for different rod diameters and oxygen pressures in the chamber. Similar velocities between 0.4 and 1.4 cm s –1 for diameters between 0.7 and 0.2 cm and 70 bar of oxygen pressure in the chamber are also reported in the literature (see ref as in ref ).…”

“…They concluded that the molten material can detach from the solid rod before it has time to completely oxidize, and that when the molten material remains attached to the lance tip for a longer time, the tip temperature increases because a higher extent of oxidation of the molten iron into iron oxide can be achieved. 3 Wilson et al 2 analyzed experimental data 9,10 of the combustion of iron rods also in an enclosed, oxygen-filled chamber at pressures varying between 3 and 100 bar. Figure 2 shows their results.…”

“…However, Shabunja et al observed that for experiments of combustion of iron rods of diameters between 2 and 7 mm and for atmospheric oxygen pressure, despite most of the molten material consisting mainly of iron oxides, it could also contain molten iron that did not have time to react completely before being detached. They concluded that the molten material can detach from the solid rod before it has time to completely oxidize, and that when the molten material remains attached to the lance tip for a longer time, the tip temperature increases because a higher extent of oxidation of the molten iron into iron oxide can be achieved …”

“…Models for the operation of thermal lances are not abundant in the literature. Shabunja et al 3 presented a mathematical model describing the combustion and melting of an iron rod in a stagnant oxygen atmosphere. They calculate the melting velocity with an expression that accounts for a difference in temperature between the melt and the drop.…”

“…Models for the operation of thermal lances are not abundant in the literature. Shabunja et al . presented a mathematical model describing the combustion and melting of an iron rod in a stagnant oxygen atmosphere.…”