Basic equations and calculation procedure for analysis of gas flow properties in tuyère under the influence of heat source

Abstract

Based on fundamentals of the dynamics and thermodynamics of compressible fluid flow as well as heat transfer, the basic equations and formulae for characterizing and calculating the gas flow properties in tubular and annular type tuyères (constant cross‐sectional area lances) under the influence of a heat source are derived. The calculation procedures of the properties at different discharge states through a tuyère are given. For the case of an annular‐tube type tuyère used for an AOD (argon‐oxygen decarburization) vessel of 18 t capacity, the distributions of the inner wall temperatures of the tuyère and the gas stagnation temperatures along its length have been more reasonably determined. The friction coefficients of its main tuyère and subtuyère to the gas flows during injection refining have been fixed by comparison of the pressure‐flowrate (P‐Q) experimentally measured in relationship to the results of trial calculations.

Preliminary Investigation of Fluid Mixing Characteristics during Side and Top Combined Blowing AOD Refining Process of Stainless Steel

“…When using 5 tuyeres with an angle of 31.5°between each tuyere or 4 tuyeres with an angular separation of 45°between each tuyere at a gas side blowing rate corresponding to case III in table 2, the area occupied by the two-phase zone at the bath surface could come to about half of the surface area of the bath. These are different from those observed in the water modelling experiments for an 18 t AOD vessel with side blowing through two annular tube tuyeres [6]. This part of the liquid, then, moved downward along the side wall.…”

“…From beginning to end, the liquid in the bath underwent active agitation and circulatory motion during the blowing process, and there was no obvious dead zone anywhere in the bath. This behaviour is similar to that observed in the water modelling experiments for an 18 t AOD vessel with side blowing through two annular tube tuyeres [6]. It is exactly this kind of gas stirring and liquid flow pattern to ensure and provide the excellent mixing of the AOD process.…”

Physical Modeling Study on Combined Side and Top Blowing AOD Refining Process of Stainless Steel: Back-attack Phenomenon of Gas Streams with Horizontal Side Blowing and Its Influence on Erosion and Wear of Refractory Lining

“…Some measures, including improving the tuyere design according to the previous studies, [25][26][27] have been taken. The lining life has constantly risen.…”

Mathematical Modeling of Fluid Flow in Bath during Combined Side and Top Blowing AOD Refining Process of Stainless Steel: Mathematical Model of the Fluid Flow

“…The wall function method was utilized to treat the zones near the wall surfaces. For longitudinal symmetry plane: The gradients of the velocities and volumetric fractions of the two phases, as well as the turbulent kinetic energy and dissipation rate of the turbulent kinetic energy for the liquid phase at the normal direction of the symmetry plane were zero: For inlet zones: r 1 = 0, r 2 = 1. The turbulent kinetic energy and dissipation rate of the turbulent kinetic energy at the inlet zones were, respectively 17: For both the practical AOD converter of 120 t capacity and its water model unit, based on Wei's et al work 37–39, corresponding to the blowing operation of the main decarburization period, the outlet parameters of the gas side blowing streams from the tuyeres were determined with a series of treatments given in Ref. 4 in terms of heating friction flow and adiabatic friction flows, separately 8, 9.For the outlet parameters of a gas streams from a tuyere, the most usual method treated in the literature is to take the relevant values given from the state equation of an ideal gas under the bath temperature and the static pressure suffered at the tuyere outlet.…”

“…For both the practical AOD converter of 120 t capacity and its water model unit, based on Wei's et al work 37–39, corresponding to the blowing operation of the main decarburization period, the outlet parameters of the gas side blowing streams from the tuyeres were determined with a series of treatments given in Ref. 4 in terms of heating friction flow and adiabatic friction flows, separately 8, 9.…”