【摘要】 采用理论推导和模拟实验相结合的方法,并应用《回归最优设计理论》进行实验设计,得出了既包含决定性相似准数又包含喷枪倾角的计算潜入侧吹气体流股在液体熔池中的穿透总长度和直段长的公式。更多还原

【Abstract】 The purpose of this article is to find out a mathematical formula to express the penetration length of a side-blown oxygen jet by an immcrged lance in molten steel bath in terms of the dicisive criterion of similitude (Archimedes criterion) and the inclined angle of lance.It is worthy to be considered for the gradually spreaded application of side-blown gas jet and it is useful for several steelmaking processes.Some existing investigations show that the essential forces for a gas jet are its inertial force and the buoyancy force of liquid steel acting on it.As for the viscous force and the surface tension of liquid,as a whole,they are playing the secondary roles in the system.Neglecting the actions of these forces,theoretically,the dimensionless penetration length of a side-blown gas jet L1 may be simplified and expressed aswhere Ar is Archimedes criterion and 0 the inclined angle of lance,and L1 the real length measured.Greater errors should unavoidably take place when such an expression to be calculated in practice.The explanation lies in the negligence of viscous force and surface tention and so it is inappropriate in practice.Modification to this expression has need to carry out by means’ of a cold model experiment according to the theory of optimal regression design.Thus,an expression relatively geared to actuality has been obtained aswhere L2——the length of straight part of the conical gas jet of whichthe inertial force is gaining the dominance over other forces,dimensionless; Ar——Archimedes criterion,pg and ρ1——density of gas jee and liquid in bath;ψ0——initial velocity of gas jet at lance exit;g——gravitational acceleration;d0——diameter of lance.It is found to be in agreement with the experimental results.更多还原