Abstract: In a blast furnace installation wherein raw material is changed in a blast furnace successively through a rotary hopper, an impeller and an inclined chute surrounding the impeller, the inclined chute is suspended from a carriage movable along rails so as to decrease the weight of the chute acting upon the blast furnace.

Abstract: In a blast furnace installation comprising a blast furnace and a raw material charging apparatus including a hollow inverted frustum shaped rotary hopper mounted above the blast furnace, conveyor means for supplying the raw material to the rotary hopper, a hollow disc shaped impeller located beneath the rotary hopper for receiving the raw material therefrom, stationary inclined chute means including an annular chamber member surrounding the periphery of the impeller for receiving the raw material discharged from the impeller, and an electric motor for driving the impeller, the gas pressure in the furnace top is accurately controlled by detecting the gas pressure in the annular chamber member at a plurality of circumferentially spaced points, comparing the mean value of the detected gas pressure with a preset furnace top gas pressure for producing a control signal proportional to the difference therebetween, and controlling the speed of the motor by the control signal thereby reducing substantially to zero the

Abstract: A hollow inverted frustum shaped rotary hopper is provided above the furnace top to receive the raw materials from a conveyor. Beneath the rotary hopper is disposed a hollow disc shaped impeller including a dish shaped central portion facing to the lower end of the rotary hopper and a plurality of wedge shaped vanes mounted on the periphery of the impeller for defining a discharge openings between adjacent vanes for throwing out the raw materials by centrifugal force. A stationary inclined chute means is provided including an annular hopper surrounding the impeller for charging the raw materials discharged by the vanes into the furnace top and inert gas is ejected into an annular gap defined between the covers of the impeller and the inclined chute means for preventing the gas in the blast furnace from leaking to the outside.