The technical report concerns with some technical aspects of air separation plants widely installed and operated in Iron and Steel Industries for the purpose of making iron and steel in a blast furnace, an open hearth, and an oxygen converter and besides processing stainless steel in a furnace so as to strengthen its mechanical properties. As an introductory explaining, the statistical data shows the co-relation between said industry and industrial gases manufacturing industries especially concerned with oxygen gas and points out the remarkable developement stages of both of them. It is then described that iron and steel making processes have been developed with the utilization of oxygen, nitrogen and argon gases and the processes have stood most important position of the industries after the second war. A tonnage oxygen gases supply system with pipings is then described, which is newly developed according to the enormous growth of the industry in order to meet tonnage oxygen gas demand in steel making process in a oxygen converter and the system needs large scale air separation plants because of producing said gases or liquids of them with rather reduced production cost in comparison with the conventional types of the plants on the basis of lower power requirements, reduction of operators with applying more advanced instrumentation and automation to the plants, and rather simple procedures of operation. Then several types of said air separation plant is shown in the following. There are four types of the plants, producing (1) high purity oxygen and nitrogen gases, (2) both of gases and liquids, (3) high purity argon with (1) or (2), and (4) rather lower purity oxygen such as 90vol.% especially breathed into a blast furnace. On the above mentioned four types of the plant their characteristics is technically explained with flow-sheets giving main apparatuses namely compressors, adsorbers, refrigerators in case of necessity, heat exchangers, tanks, purification adsorbers and rectification columns. Other wellknown types of the plant are added into said explanation. Some present status of large scale air separation plant is listed and shown, which are in operation in Iron and Steel Works in Japan and belong to on site-plant mostly.
This paper summarizes our works on newly-developed multifilamentary V3Ga and Nb3Sn compound superconductors, including their designing, processing, and characteristics such as mechanical and superconducting properties, and coil performances.