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

Based on fundamentals of the dynamics and thermodynamics of compressible fl uid flow as well as heat transfer, the basic equations and formulae for cha racterizing and calculating the gas flow properties in tubular and annular type tuyeres (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 tuyere are given. For the case of an a nnular-tube type tuyere used for an AOD (argon-oxygen decarburization) vess el of 18 t capacity, the distributions of the inner wall temperatures of th e tuyere and the gas stagnation temperatures along its length have been mor e reasonably determined. The friction coefficients of its main tuyere and s ubtuyere to the gas flows during injection refining have been fixed by comp arison of the pressure-flowrate (P-Q) experimentally measured in relationsh ip to the results of trial calculations.