Abstract
No difference in the quality of molten iron can be observed when the low sulphur coke (LSC coke) of 60∼80mm size and the Tekken Briquette Coke of 75mmH×75mmφ are mixed by the ratio of 50 : 50 and are used as the split coke in the case of melting the cast iron by the hot blast cupola (inside dia. 550mmφ, blast temperature 300∼350°C). The percentages of scrap in the past several years in our foundry and which due to a pin-hole defect appeared on the inside surface of the cylinder casting after machining finish with a honing machine are as follows:
Percentages of scrap in the duration of the melting was performed with the use of LSC coke alone: 4.9%.
Percentages of scrap in the duration of the melting was performed with the mixing use of LSC coke and the Tekken Briquette Coke: 4.2%.
No great difference was obtained in the percentages of scrap due to pin hole defect.
The mixing percentages of the Tekken Briquette Coke into the LSC coke reached to 28.5% in 1956 and the savings of fuel cost was attained to ￥. 200,000.
Even though the quality of molten iron was improved, the percentages of scrap could not be lessened for the last several years, but it was possible to lessen it down to 1∼2% by improving the molding sand or the casting conditions.
The automatic controlling apparatus was used to control the blast volume, so that the blowing quantity was maintained constant in this experiment.
