抄録
To protect tuyeres from failures which were mainly caused by burn-out, their thermal states and burn-out were studied. The temperature and heat flux distributions in tuyeres and cinder notches were measured in operation, and burn-out tests were also made on water-cooled Cu-plates on which molten steel was poured.
The results obtained are as follows;
1. In normal operation, measured temperatures of a tuyere are about 200 in the upper portion of its nose; and about 100° in the lower one and its inner wall. The heat flux is 40-400×101 kcal/m2 hr in the tuyere nose.
2. In normal slag-tapping operation, temperatures of a cinder notch are ranged from 140 to 190° in its nose and ranged from 110 to 150 in its inner wall. The heat flux in its nose indicates the maximum value, about 200×104 kcal/m2. hr.
3. From the experiment of burn-out of Cu-plates, burn-out heat flux (Bo) is derived as a function of the temperature and velocity of the cooling water. In the case of inlet water at 27° and 1 m/sec, qBo of Cu-plate with 20 to 30 mm in thickness is about 750×104 kcal/m2·Ehr.
4. The burn-out heat flux of actual tuyeres is estimated above 400-700×104 kcal/m2·hr, which is obtained only during contact with a great amount of molten metal. Hence, it is assumed that burn-out of a tuyere in operation occurs only when it contacts with a great amount of pig iron.
