US275284A - Gas crucible-furnace - Google Patents

Description

(No Model.)

L. STILWELL.

GAS GRUOIBLE FURNACE.

No.,275,284. Patented Apr, 3,1883.

UNITED STATES PATENT QFFICE.

LYSANDER STILYVELL, OF NEWARK, NEW JERSEY.

GAS CRUCIBLE=-FURNACE.

SPECIFICATION forming part of Letters Patent No. 275,284, dated April 3, 1883.

Application filed May11,188-2. (No model.)

1'0 all whom it may concern Be it known that l, LYSANDER STILWELL, a citizen of the United States, residing in the city of Newark, Essex county, New Jersey, have invented certain new and useful Improvements in Gas Crucible-Furnaces, fully described and represented in the following specification and the accompanying drawings, forming a part of the same.

My invention consists in an improvement in the gas crucible-furnaces heretofore constructed with acrucible heating-chamber and pipes for combining air and gas together before combustion.

My improvements consist in the interposition between the crucible heating-chamber and the pipes in and by which the gas and air are combined of a mixing-chamber separate from both the heating-apartment and the said pipes, but having communication with both in the manner herein set forth, and arranged in relation to the heating or crucible chamber and the said pipes, as herein shown and described.

It also consists in the construction of such mixing-chamber and its connections with the pipes and heating-chamber, and in the combination, with the elements already known, of a gasoline-chamber connected with the air and gas combining pipes, and supplied with an airinlet for feeding air to said pipes charged with the vapor of gasoline.

My invention, will be understood by reference to the annexed drawings, in which Figure 1 is acentral vertical section of a machine embodying my improvements. Fig.2is a plan of the partition between the mixing and combustion chambers. Fig. 3 is a plan of the plate forming the bottom of themixing-chamber; and Fig. 4 is a section of the gas and air tubes just below said plate, on line 00 w in Fig. 1, showing the connections to the several gastubes.

A A is the base of the machine, formed in two parts, united by flanges at a, and constituting a receptacle for gasoline and air.

13 B are pipes inserted inthe top of A, and also into a plate, 0, forming the bottom of the mixing-chamber D.

E is the floor of the melting-chamber 1, formed of fire-clay or other refractory material,

resting upon an iron plate, F, which has the pocket G cast in its center, and a depression, of cone-shape, H, upon its lower side. The plate F forms the upper side of the mixing-chamber, and is perforated at b for the passage of the gases to the melting-chamber. The latter is formed of a cylinder, I, of fire-brick, and a cover, J, of the usual character.

A wire net, K, is shown secured between the flanges a, the space A beneath the same being filled with gasoline at pleasure by a fillingtube, L.

The upper part, A, of the chamber is shown provided with an air-inlet, M, which may be connected to any suitable blast apparatus. The inlet is shown provided at its inner end with an elbow, N, by which the air is directed toward the surface of the gasoline to aid in vaporizing it.

The pipes B are shown as six in number, arranged in a circle between the chambers A and D, and connected by nipples c to an annular pipe, 0, which receives a supply of gas from a branch, P. In the base of each pipe is secured an air-tight nozzle, d,which tapers upward to near the top of the pipe, but has an annular space, e, around it, as shown in Fig. 4, for the influx of the gas. The latter thus enters the pipe B around the nozzle, and rises with the air injected by the nozzle to the chamber D, where the gases are thoroughly mixed before entering the melting-chamber to be burned.

Apertures may be made through the firebrick floor for the passage of the gas without any burner-tube; but I have shown a more durable arrangement at I), which consists of metallic tubes fitted tightly to the openings 1) in the plate F, and are provided with platinum tips f, bent so as to direct the flame toward the crucible Q. With this construction the'floor of the chamber is formed by packing clay or other materials around the pipes 0, between the pocket G in the center and a flange, F, formed around the edge of plate F for the pur pose. The flange F and pocket G are shown in plan in Fig. 2, the space between the two represeutin g the fire-clay floor, from which the jets or tipsfproject, as shown in the drawings.

The operation of my invention is as follows: The gas, being supplied to branch P, feeds all forced upward through the nozzles d into the chamber D, where it is violently agitated and mixed with the inflowing'gas. From thence it emerges to the melting-chamber, where it is ignited at thejets f, and where the combustion produces great heat.

With the construction shown I have melted seventy-five ounces of silver in a crucible in twelve minutes from the time of lighting the gas, and ninety pennyweights of gold in another charge in fifteen minutes, while the devices previously known require thirty minutes to effect the same result.

It is obvious that certain parts of my invention may be used apart from others, and I do not'therefore consider the use of the gasolinechamber dependent upon the presence of the mixing-chamber, aseither may be used without the other in the combination claimed therefor.

I am aware that a gas cruciblefurnace has been made with burners or jets around a crucible, and with a removable cup for catching the overflow from the crucible, and I do not therefore claim such constructions as new; but in the said apparatus the air and gas were not mingled, except'in the tube by which the gas entered, as at B in my device, while my invention consists partly in interposing a mixingchamber between the tube and the point of combustion, as at D. The roof of such chamber I have shown formed of conical shape, projecting downward, as at H, to direct the gases to the burner-tubes b, and have utilized such depressed part in forming a pocket, Gr, beneath the crucible. The metal accidentally spilled into such pocket can only be removed as a button when cold, the plate I and the recess G being fixed in the machine, and not movable.

The chamber A, in which the gasoline is stored, is shown as filled with cotton waste, or other absorbent material, R, that the vapor may be carried off by the blast of air without the priming or blowing away of the liquid.-

The screen K servesto keep the waste in place, especially when the apparatus is moved about; but would not be needed were any heavier absorbent material used than the cotton.

It will be seen from the above that theprominent feature of the construction is the location of the injector-tubes B d between an air or gasoline vessel and a mixingchamber, and the arrangement of the latter between the tubes B d and the crucible-chamber I. The respect ive chambers may therefore, if preferred, be formed in one connected casting, and the air and gas tubes be led inside by other arrangements than those shown. The piping-connections shown herein are, however, very cheap and effective, being formed of ordinary gasfitt-ings united by right and left hand threads, and admit of ready examination and removal for repairs.

The tubes B are each provided with a branch at the middle to receive the gas-nipple c, a nipple below the branch having the air-nozzles soldered therein, and a nipple or pipe above the branch to guide the gas upward, with the air, into the mixing-chamber. Each tube B is screwed into the castings A and O, and the nipples c are then inserted to connect each tube with the annular supply-pipe O.

The machine may be constructed with a single pipe Bin the center of the chambers A and I), or with any number of pipes B, as preferred; but the chamber would be provided in any case with a number of outlets, as at b, and the combustion-chamber I used for heating any other object than a crucible, as may be desired.

I am aware that a hollow dome located beneath the crucible chamber has been patented in No. 227,852, of May 18, 1882, for collecting and igniting the air and gas previously mingled in the mixing-tubes, and I do not therefore claim such an intermediate chamber broad- 1y, but only when used as a mixing-chamber alone. In the said patent the flameis said to strike the-bottom of the crucible and pass up into the furnace, while in my construction no flame is produced below the crucible; but the gas and air, after mingling, as described, in the chamber beneath the same, are conducted through jet-tubes and ignited first in the crucible-chamber itself.

For certain purposes it may be desirable to use a portion of my construction without employing all the parts described in one combination, and I have therefore made separate claims, as is usual, to the combinations I regard as new. I do not, however, claim myinvention in combination with any other furnace than the one described, in which a chamber expressly adapted to receive a crucible is implied, as I am aware that many gas-furnaces for other purposes have been used, and that my invention is particularly adapted for the application of a gas-flame to a crucible in the manner herein described.

If desired, the burners may be arranged in other relations to the chamber I, and may enter the same upon one side, or otherwise, as preferred.

I am aware that many constructions have been devised for carburizin g air to be burned, and I do not therefore claim such an invention. I am aware that an apparatus for can burizing air for various kinds of furnaces is shown in English Patent No. 2,214 of 1873. I therefore disclaim said English patent, as well as the carburetor A, or any equivalent therefor, when used apart from the specific combination claimed herein; but I am not aware of any crucible-furnace in which air is passed over gasoline to absorb the vapor and then, mixed with a fixed gas supplied by jets in a nozzle, as herein shown and described.

I am aware that a mixing apparatnsis shown in English Patent No. 652 of 1867, for mingling and propelling a mixture of air and gas by means of a steam-jet, and I therefore disclaim such English patent, my invention consisting in the arrangement herein described and shown.

I hereby reserve the right to make subsequent application for the method and process herein shown and described; also for the construction and combination of my apparatus, not herein specifically claimed or disclaimed.

Having thus described the nature of my invention, I claim the same as follows:

1. The combination, with the combustionchamber I and mixing-chamber D, provided with a gas and air supply pipe, of the intermediate plate, F, provided with flange F, the pocket G, having the conical projection H, and tubes 1), connecting said mixing-chamber with the chamber I, substantially as shown and specified.

2. The combination, with air and gas pipes constructed substantially as described, of the mixin g-chamber D, formed of the plate 0, having the tubes B secured to it, and of the plate F, having the recess or stationary pocket G formed in its upper side, the pocket being surrounded with the refractory floor-packing E, and the plate being provided with the burner-tnbes I), penetrating the plate F, and refractory filling E, substantially as shown and described.

3. In a crucible-furnace, the combination of chamber I, chamber D, and communicating tubes b, tubes B, having nozzles (Z located therein, and the gasoline-chamber A, provided with airinlet M, substantially as herein set forth.

4. In a crucible heating-furnace, a combustion-chamber, I. supported upon a closed base having pocket G and gas-conveying tubes 1), in combination with the mixing-chamber D and gas-chamber A, connected by means of pipes B, having nozzles d, the parts being arranged and organized substantially as specified.

5. The combination of a crucible-furnace with the chamber A, provided with a wire screen, K, and air-inlet pipe M, as shown, in combination with the chamber D, the two chambers being connected by the pipes B, havingnozzles d, the same being provided with a gas-supply pipe, 0, and connecting means substantially as shown, and for the purpose set forth.

In testimony whereofI have hereunto set my hand in the presence ot' two subscribing witnesses.

LYSANDER STILWELL.

Witnesses:

WM. F. D. CRANE, WALTER M. OoNGER, Jr.

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