Apparatus for feeding flour iron ore to blast-furnaces.

Application filed April 8, 1908. Serial No. 425,954.

To dll whom it may concern:

Be it known that I, Edward L, Harper, Jr., a citizen of the United States, and a resident of Big Stone Gap, in the county of Wise 5 and State of Virginia, have invented new and useful Improvements in Apparatus for Feeding Flour Iron Ore to Blast-Furnaces, of which the following is a full, clear, and exact description.

This invention relates to certain improvements in the apparatus for feeding of flour iron ore, that is, ore in an extremely fine state of subdivision, to blast furnaces, in such a manner that it will not be blown out imme15 diately by the blast, but will become amalgamated with the molten or fused mass in the bosh of the furnace.

In the ordinary type of blast furnace, ore, fuel and limestone are fed to the furnace 20 through the hopper at the upper end thereof, upon the opening of the bell, but due to the strong blast of air forced into the furnace at the lower end thereof and the strong current of gas escaping through the gas outlet pipe or 25 down-take, a large portion of the fine ore is . blown out of the furnace and cannot be smelted. In. fact, such a large quantity of this fine ore or dust is blown out of the furnace, that it is necessary to provide dust 30 catchers, wherein this fine ore or dust may separate from the blast furnace gases. It is needless to return this dust or flour ore to the hopper for re-charging in the furnace, for as soon as it enters the furnace it will be imme35 diately blown out again. This dust accumulates in enormous quantities, and even though it is very rich in iron, yet at the present day it is considered of no value, due to the inability to economically smelt the same.

In the working of my invention, I remove the flour ore from the dust catcher and return the same to the furnace at such a point that it cannot be blown out again. That is, I return it directly to the zone of fusion, where it 45 is immediately amalgamated or, melted before the blast can remove it through the down-take.

My invention consists in the means employed for forcing the flour ore above referred 50 to directly into the air pipe connecting the bustle pipe and twyer and above the peep hole, the forcing means being so constructed that the rate at which the ore is fed may be varied at will or may be stopped entirely , 55 without air escaping through the ore-delivery means.

Reference is to be had to the accompanying drawings, showing a blast furnace in vertical section with my improved mechanism connected thereto^ 60

My improved mechanism may be used in . connection with any blast furnace whatsoever, but for purposes of illustration I have shown an ordinary type of blast furnace, having a crucible 10, a bosh 11, and a stack or 65 column 12. The stack is supported by suitable columns 13, and is fed at its upper end through a hopper 14, which may be closed by a vertically-movable bell 15. Adjacent the hopper is a suitable platform 16, along which 70 the ore may be conveyed for dumping into the hopper, and there is provided suitable mechanism, including a lever 17, for operating the bell.

Surrounding the furnace, adjacent the 75 bosh, is an air-distributing pipe or bustle pipe 18. Below the bosh any suitable number of twyers 19 may be provided, each of which is connected to the bustle pipe by a conduit, including a horizontally-disposed 80 portion or blow pipe 20 and an inclined or leg pipe 21. The air which is delivered from the bustle pipe to the twyers comes into contact with the molten material and serves to support the combustion of the fuel. The 85 nitrogen in the air and the gases generated within the furnace, rise through the material in the stack, carrying all dust and finely subdivided ore to the upper end and force them out of the furnace through a gas outlet 90 or down-take 22. The down-take leads to a dust catcher, not shown, where the dust is separated from hot gases before the latter are conducted to burners, engines, or storage tanks. . 95

None of the features thus far described, constitute any portion of the invention hereinafter claimed, inasmuch as they may all be constructed in accordance with common practice. loo

In the specific mechanism illustrated for carrying out my invention, I provide a conduit, casing, or shell 23, having a rotary conveyer 24, mounted therein, and having one end thereof in communication with the leg 105 pipe 21 leading from the bustle pipe 18. At .or adjacent the rear end of the casing or conduit 23, there is provided an entrance opening 25, through which the fine flour ore or dust is received from a hopper 26. The screw con- 110 veyer 24 may be operated in any suitable manner, as, for instance, by a worm 27, en:,830 a rate as to be conveyed into the furnace be-, low the upper limits of the zone· of fusion. The flour ore here immediately amalgamates with the molten or semi-molten material, and its passage upward through the bosh and 35 stack with the gases, is prevented.