Study of efficiency of thermal insulation of the outer surface of the blast furnace tuyere

At present, the problem of air tuyeres resistance increasing and heat loss decreasing through air tuyeres surface is solved in several ways. Simulation of tuyere’s thermal condition is appropriate for analysis of the techniques for further solving of this problem. The aim of the research was estimation of the tuyere’s thermal state while its interaction with liquid cast iron with using different kinds of heat insulation. Both computer simulation and experimental evaluation were carried out during research. DEFORM-3D Finite Element Method (FEM) software was used for computer simulation. Simulation results allowed thermal state estimation for different parts of the tuyere. Point-tracking option of the DEFORM-3D post-processor was applied for that purpose. Influence of thickness and thermo-physical properties of ceramics is studied. At that, ceramics is in the shape of sector with slip coating as a matter of blast furnace’s air tuyere burnout protection. Experimental data showed the necessity of combined protection: ceramic sector protects upper and lower part of inner cup and part of mug from cast iron; wear-resistant material surfacing protects the rest part of the mug from abrasion due dust-coal fuel. It is shown that usage of silica as heat insulation of tuyere outer surface allows decreasing heat loss due cooling water sufficiently. At that, increasing silica’s thickness allows increasing its resistance.