真空精錬における吹精酸素ガスの噴流特性
1976 年 62 巻 14 号 p. 1795-1802
詳細
1976 年 62 巻 14 号 p. 1795-1802
In order to find suitable lance to blow oxygen stably at the vacuum refining of stainless steels, the total pressure of oxygen jet ejected into vacuum from various kinds of nozzles were investigated and the following results were obtained:
(1) The total pressure of jet from the pipe, which is used as oxygen lance ordinarily, is comparatively low, and this tendency becomes remarkable especially at low vessel pressure.
(2) By using the Laval nozzle which is designed by Mach number corresponding correctly to the vessel pressure, it becomes possible to increase remarkably the total pressure of jet.
(3) It is possible to keep the total pressure of jet high by using such a Laval nozzle that becomes insufficiently divergent when the vessel pressure decreases during the refining.
By applying the Laval nozzle designed on the bases of these results to the 50t ladle furnace, it became possible to blow oxygen from the lance height more than twice of that from the pipe. Accordingly, as the erosion of oxygen lance can be prevented, the refining process becomestable remarkably.
