(english) A vertical shaft type smelting furnace in which an air blast is used, usually hot, for producing pih iron. The furnace is continuous in operation using iron ore, coke, and limestone as raw materials which are charged at the top while the molten iron and slag are collected at the bottom and are tapped out at intervals.

 ภาพประกอบ (english) A vertical shaft type smelting furnace in which an air blast is used, usually hot, for producing pih iron. The furnace is continuous in operation using iron ore, coke, and limestone as raw materials which are charged at the top while the molten iron and slag are collected at the bottom and are tapped out at intervals.