キュポラに関する研究（第4報）

―操業状態の風の流れと炉内反応との関係―

抄録

  This study was carried out with the intention to know the foundation of cupola operation with surveying the relation between construction and reaction of cupola and their influences on melting condition. In the reports 1∼3, experiments and considerations were performed about the effects of cupola factors on the flow of wind in furnace and its fundamental character in the state of non combustion. In this report, melting rate, the properties of melts, gases distribution and the changes of wind pressure in the furnace were surveyed in the state of practical operation by using the same cupola.
  The results are summarized as follows :−
  In case of smaller tuyère, air distribution becomes ununiform especially with tuyère ratio of 25∼16, the furnace atmosphere is oxidizing, the melt is liable to be oxidized. Si loss is increased, eutectic graphite is apt to be produced and remarkable strength can not be obtained. On the contrary in the case of larger tuyère, the air distribution is uniform but both melting ratio and tapping temperature are decreased. In such a case, however, the blast pressure becomes larger with the increase of the blast volume and so the properties of the melts are improved.
  According to the above facts, the author considers that extremely large tuyère ratio is undesirable and should be reduced below 10.