US972126A - Continuous-twyer furnace. - Google Patents

Description

G. W. MUNSON'.

CONTINUOUS TWYER FUBNAOE.

APPLIOATIoN FILED man1, ma.

972,126. Patented oem, 1910. A

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UNITED STATES PATENT OFFICE.

CORYDON W. MUNSON, OF TOLEDO, OHIO, ASSIGNOR, BY MESNE ASSIGNMENTS, TO MARY OWEN MUNSON.

CONTINUOUS-TWYER FURNACE.

Specification of Letters Patent.

Application filed March 7, 1908.

Patented Oct. 4, 1910. seran No. 419,696.

To aZZ whom t may concern:

Be it known that I, CoRYDoN lV. MUNsoN, a citizen of the United. States, residing at Toledo, in the county of Lucas and State of Ohio, have invented certain new and useful Improvements in Continuous-'lwyer Furnaces, of which the following is a specification.

This invention relates to apparatus for the application of the principles embodied in modern practice of smelting pyrites or sulfid ores or artificial sulfites carrying gold, silver, copper or other metal values, the purpose and object being to utilize the fuel elements of sulfur and iron in the ores to furnish the heat to smelt themselves with the use of but little or no extraneous fuel.

The usual method of smelting practice is a reducing or melting down of the ores; but it is well known that the hot-blast smelting of sulfid ores is an oxidizing process, where a large volume of heated air is driven into the ore body in the furnace under pressure, producing` a rapid oxidation of the sulfur in the ores, and an intense heat is developed and maintained by releasing the sulfurous gases as the ores are melted, these gases combining with the oxygen of the heated airblast, and are driven into the ore body.

The usual blast furnace practice is to drive the air-blast into the ore body in the furnace through separate round openings or twyers, resulting in an unequal oxidation. The blast penetrating the ore mass in the fusing Zone at separate and individual locations tends to produce accretions at and around the twyer-openings, which interfere with the uniform distribution of the air blast through the ore mass, thus lessening the efficiency of the furnace. The ore body in the furnace also covers these twyer openings, obstructing the free passage of air into the ore mass, and causing uneven and variable results at different points because of the uneven delivery of the air, caused by such obstructions.

The object of my present invention is to provide an improved apparatus for carrying out the proce-ss claimed in my Patent 846,498, granted March 12, 1907, the said improved apparatus comprising a furnace which disn penses entirely with separate twyers, and preferably formed with a widened hearth.

To these ends, my invention consists in the construction and combination of parts substantially as hereinafter described and claimed.

Of the accompanying drawings :-Figure l is a vertical section of a furnace embodying` my improvements. Figs. 2, 3 and 4 are similar views, illustrating modifications hereinafter described.

Similar reference characters indicate the same or similar parts on all of the figures of the drawings.

Referring first to Fig. l, a suitably supported hearth is represented at 20, its wall 21 being formed with a discharge-hole 22, through which the molten product passes to the spout 23 for tapping it off. This heal-tlv section may be constructed in any wellknown or preferred manner. Its shape in plan may be round or elongated. The vertical portion 2l is shown in this figure as hollow to form a water jacket, or it may be solid as indicated in Fig. 4.

The upper portion or furnace wall proper is indicated at 24 said upper portion being supported in position so as to be entirely separated from the lower portion or hearth wall 2l by an annular space or passage way 25 for the air for the blast. A suitably constructed hot air box 26 surrounds the furnace and is in open communication with the annular space or passage way 25, the supply of hot air at the proper temperature being obtained by means of any suitable apparatus and supplied under pressure to the box 26 through the pipe 27.

Then the wall sections 21 and 24 are made hollow, a suitable supply of water for coo-ling purposes is furnished thereto through pipes 28 and 29. The upper portion or furnace wall proper 24 may be supported in its position relatively to the hearth wall section 2l by means of an inclined top 30 of the box 26, the upper edge of said top 30 being secured in any suitable way to the outside of the section 24. Supporting braces 31 may also be employed, or they may be omitted.

The hearth is greater or wider in diameter than the lower edge of the wall section 24. Therefore, when ore is repeatedly supplied in any suitable way through the upper portion of the furnace so as to form and maintain a low charge with inclined sides from the base upward, the natural incline of fall of the sides of the pile or heap of ore below the lower edge of the upper section 24 will be such that the loose ore or the molten mass cannot fall or How into the annular space or air passage way 25. Below said annular space or passageway, when the furnace is filled with ore, there is a confined circular air-space or annular chamber which circles the entire body of ore on the furnace hearth so that the hot air supplied under pressure through said annular passage way is distributed evenly and against the exposed surface of the ore body instead of being driven into the ore at separate locations as is the case when a series of twyers are employed. Therefore the air penetrates the ore uniformly at all points and under uniform pressure over the entire surface below the lower edge of the furnace section 2t. And the hot blast is confined in the space into which it is driven because it is not free to pass upward over the surface of the ore pile.

It is well known that with twyer openings through the walls of blast furnaces as usually constructed, the inner ends or openings of the twyers are covered by the ore and free passage of air through the twyers is more or less obstructed, thus lessening the efliciency and capacity of the furnace. It also involves much trouble and annoyance to keep the twyer openings free. By my construction the annular opening is kept free from any obstruction by the ore in the furnace, because the relation of the bottom of the upper section 24 of the furnace to the top of the widened hearth section 21 is such as to make impossible the obstruction of the continuous twyer opening between the two sections by ore falling into said opening.

In Fig. 2 the structure is substantially the same, but in said figure I have shown the upper portion of the furnace as closed by a masonry top 32, said top supporting a hopper 33 having a cover 34 which is adapted to be tightly closed. With this structure the ore may be supplied through the hopper 33, while the products of combustion escape through a suitable outlet or stack 35. In said Fig. 2 I also show the top of the air boX 26 as having a flange 36 on which rests the ring 37 which is secured around the furnace section 24. In said ligure I also show the top of the hearth section 2l as inwardly and downwardly inclined and the lower edge of the furnace section 24 as rounded, this being a form which may be preferred for some purposes in that the annular air blast is directed squarely against the inclined surface of the lower portion of the ore charge. Fig. 3 shows a structure similar to Fig. 1

but having the sides of the furnace section 24 tapering or converging downwardly instead of having parallel walls.

In Fig. 4lthe structure is substantially the same as in Fig. 2 but the sides of the hearth section or wall converge instead of bein@ parallel or vertical as indicated at 210, said section or wall being formed solid of any suitable material.

It will. be observed that in each form of furnace illustrated individual twyers are absolutely dispensed with, but an opening is formed which is so protected that it will not become clogged either by the loose ore covering or falling into or over said opening, or the molten mass rising above its normal height, the result being that the pressure of air is absolutely uniform over all portions of the base of the heap or pile of ore, because the passage of air through the continuous twyer is always free from obstruction.

It is to be understood, of course, that in cross section the furnace may be either circular or of other shape. l

It is to be understood that I do not limit in vself to the precise details of construction described and illust 1ated, since I may variously modify the same within the limits of mechanical skill.

Having now described my invention what I claim is 1. A smelting furnace comprising a hearth and having side walls in two entirely separated portions with an annular space between them, and means for forcing an air blast through said annular space in a downward direction upon surface portions of a heap of ore on said hearth.

2. A smelting furnace with a top or upper section and a hearth or lower section of greater diameter, the two sections sepa.- rated by a space, and an air box permanently attached to both top and bottom sections, and inclosing or covering the opening or space between said sections the plane of said space being above the plane of the base of a heap of ore on said hearth and adapted to direct the air in a downward direction on said base.

In testimony whereof I aiix my signature, in presence of two witnesses.

CORYDON W. MUNSN.

IVitnesses BLANCHE M. VAN ARSDALE, ALONZO G. DUER.

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