PURPOSE: To control the gaseous flow in a blast furnace directly by providing a pipe which is opened at top and bottom and is made adjustable of sinking depth at the center of the peak part of the raw materials charged into the furnace then controlling the pressure drop in the central past of ascending gaseous flow.

CONSTITUTION: In a blast furnace having a large bell 1, a small bell 2, a movable armor 4, an ascending pipe 7, etc., the lower part of a pipe 8 which is opened at top and bottom is sunk by suitable length into the central part of the charging raw material layers consisting of an ore layer 5 and a coke layer 6. The pipe 8 is moved vertically by means of an elevating rod 10 and arm 9 inserted into the furnace via a sealing device 11 mounted by through a hole opened in a furnace shell 3, thereby changing the sinking depth (l) into the charging raw material layers. The central part of the gaseous flow ascending in the charging raw material layers has the pressure drop less than the peripheral parts by as much as (l), and the flow rate of the gases increase correspondingly; therefore it is possible to control the distributions of the top gases of the blast furnace by controlling the sinking depth (l).