Software for calculations of heat and mass exchange in torch guniting

The wide introduction of torch guniting in metallurgy provides a tremendous saving and therefore at present metallurgists of many countries of the World are displaying active interest in it. However, until now the theory of the guniting process has been developed very weakly and in essence has a fragmentary character. The many publications on torch guniting contain essentially a presentation of specific production experience and descriptions of narrowly specific results of experimental production investigations, the basis of which is practical experience and experience in the study, including theoretical, of similar or related phenomena and processes and also intuitive concepts of the rules of torch guniting. Some publications have been devoted to theoretical investigations but as a rule they consider only individual particular problems in a simplified setting. The need for development of the theory of guniting and, in particular, of the theory of the heat- and mass-exchange processes composing the essence and determining the effectiveness of torch guniting has been maturing for a long time. An experimental solution of these problems is difficult because of the difficulty and complexity in the development and use of a large flame stand (with a flame carrying the solid phase) and also the large variety of technological, geometric, and other characteristics of metallurgical equipment causing in turn wide variation in the conditions of repair of points of wear of the lining. In connection with this, in the State Institute for the Design of Nickel Industry Plants and the All-Union Institute for Refractories an attempt has been made to develop a universal physicomathematical model and software for the common system computer for calculation of a combination of complex heat and mass exchange processes which are the basis of torch guniting of metallurgical equipment. Below is given a brief description of the model developed and individual practical significant results obtained during computer experiments with it. The general model consists of three particular physicomathematical models. The first describes the temperature and velocity field of the gaseous and solid (polydisperse) phases of the guniting flame, the second the conditions of heat exchange of the portion of the lining being gunited with the external in relation to it medium, and the third the temperature field of the lining and the gunite coating being applied. The model for calculation of the temperature and velocity fields of the guniting jet was constructed on the basis of an analysis of a free axisymmetric nonisothermal subsonic turbulent stream with a high concentration of polydispersed solid impurity~ Taken into consideration were the relationship of the thermophysical properties of the gaseous phase to temperature and the impact of the solid phase particles. The content in the guniting compound of particles of different materials is assumed. The particles may differ in dimensions and thermophysical characteristics.