Study On The Damage Theory Of Converter Water Cooled Hoods

Converter vaporization cooling flue is the main device for the recovery and reuse of converter exhausting gas. Movable fume hood as an important part of the vaporizing cooling flue having long been in the environment of high temperature, high pressure and dust for a long time. The problem of leakage of water cooling pipes is often occurred, which seriously affects the economy and safety of converter steelmaking. By using macroscopic appearance, metallographic microscope and scanning electron to analysis the crack of the damaged water cooling pipes, the alternating thermal stress concluded as the main reason leading to the damage of movable fume hood.Based on the research of the broken water cooling pipe and reference to the operating conditions and production conditions of the 150 t converter vaporization cooling flue, the temperature, diameter, ring diameter, wall thickness and fin thickness conditions were studied by numerical simulation of ANSYS. The results show that the flue gas temperature is too high, which can lead to the increase of temperature difference between inside and outside of the tube so that the heating of the water cooling tube is more serious, the water cooling pipe is more easily damaged. The water cooling pipe with larger diameter of the lower part of the movable fume hood is more likely to be damaged than that with a smaller diameter of the upper part of the movable fume hood. The method of increasing the diameter of the water cooling pipe, reducing the wall thickness and increasing the flux of cooling water can reduce the damage caused by the thermal stress and prolong the service life of the cooling pipe. According to the fin structure in a movable fume hood and the use of the environment, when selecting the fin size is 4mm, water cooling pipe and fin heat stress is small, the use of the best. Through parametric study, the structure of water cooling pipe is put forward to optimize and reform measures to improve the service life of the active smoke cover, and provide important theoretical support for the safe production.