US1184817A - Furnace. - Google Patents

Description

Patented May 30,1916.

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FURNACE.

PPLICATION FILED DEC. 1. 1911.

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J. W. BROWN.

FURNACE.

APPLICATION FILED DEC. I, 1911- Patented May 30,1916.

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UNITED STATES PATENT OFFICE.

JOHN W.

BROWN, 0! LAKEWOOD, OHIO, ASSIGNOB TO THE NATIONAL CARBON COI- PANY, OI CLEVELAND, OHIO, A CORPORATION OF NEW JERSEY.

FURNACE.

Specification of Letter! Patent. 1

To all whom it may concern:

Be it known that I, JOHN W. BRowN, a citizen of the United States, residing at Lakewood, in the county of Cuyahoga and State of Ohio, have invented a certain new and useful Improvement in Furnaces, of which the following is a full, clear, and exact description.

This invention relates to a furnace for the heating of finely divided material which is a conductor of electricity. 1

The object of the invention is to construct a furnace in which the electrical energy is transformed into heat energy within the body of material being heated, and brings that portion of the charge under treatment to its maximum temperature, in a short space of time, and further secures a uniform treatment of the material.

Generally speaking, the invention includes the elements and combinations thereof set forth in the accompanying claims.

Reference should be had to the accompanying drawings forming a part of this specification in which- Figure 1 is a central vertical section of one form of furnace; Fig. 2 is a vertical section of another form of furnace; Fig. 3 is a vertical sectionof another form of furnace; Fig. 4 is a figure of still another form of furnace; and Fig. 5 is a central vertical section of another form of furnace.

While the furnace disclosed is capable of treating any material which may form a conductor for the electric current, it is more especially intended for the treatment of granular or finely divided carbon. In heating this substance, in the forms of furnaces which have heretofore been proposed, it is difiicult to heat the charge with uniformity, and where such is not done, the resultant material after treatment must be subsequently dealt with to separate the carbon which has not been sufficiently treated for the purpose.

In the form of furnace here proposed, the material is fed into the heating zone of the furnace in such manner that the top may assume a slanting or conical form and the electric current is caused to pass between the top of the cone and the base thereof. This insures a complete heating of the material, and inasmuch as the quantity of material within the heating'zone at a given time is not great, this material will be brought to the desired temperature in a short space of time, and also, because of the small quantity under treatment at a given time, the entire quantity of material thus Patented May 30, 1916.

sage of the current may be subjected to this heat during any period of time which may be1 necessary to accomplish the desired resu 1:.

Referring to the forms of furnace shown in Fig. 1, the same comprises outer walls 1,

which are preferably made of refractory material that is a non-conductor of electricity, these walls-being joined to or built upon a base 2. At the upper portion of the wall there is a cover 3, which incloses the.

space within the walls. Within the walls 1 are other walls 4, preferably made of car-' bon, which extend from the base of the furnace up to a point below the cover. Supported by the walls 4 and 1 is an inside cover or floor 5, which incloses the'space between the walls 1 and 4. This space is filled with granular carbon forming'a layer of heat insulating material. In the case of the furnace there is formed a trough in which is placed a conveyer 6 of any desired type. This conveyer in operation removes material from the heating chamber and'conveys it to the outside of the furnace. Extending through the chamber above the conveyer are pipes 7 through which passes a cooling medium, the same acting to coolthe charge of material before the same is removed fromthe heating chamber. Extending through the cover 3 is a hollow electrode 8 which projects well into the chamber inclosed by thewalls'. The material to be treated is fed through the electrode 8, and for this purpose there is provided a funnel shaped member 9 upon the top of the electrode 8.

The bus bar 10 is electrically connected with the electrode 8, and serves as a means for the introduction of the electric'current. Above the cover 3 there is a cooling jacket 11, which is hollow and has pipes 12 and 13, communicating therewith, for the circulation of water through the jacket. Extending through the walls 1 and l are electrodes l-l and 15, the same intersecting the chamber within the walls 2 at a point just below the termination of the electrode 8. When the material is fed through the hollow electrode 8, and passes out at the lower end thereof, it' immediately spreads out to fill the heating chamber formed within the walls I. and the surface of the material as it is thus fed. assumes a slanting or conical form, as indicated at 17 in Fig. 1. The electrodes ll and 15 are so placed that they are substantially at the base of the conical portion assumed by the material in passing from the electrode 8. It will therefore be clear that the path of the electric current lies between the top and bottom of the conical portion of the charge, and therefore every particle of the material as it issues from the electrode is subjected to the heat produced by the resistance of the material, as the current passes through the same. As before stated. the material being treated is removed from the heating chamber at the lower portion thereof by the conveyer 6. This conveyer may be operated at any desired speed. and therefore it is possible to subject the material under treatment by the electric current to any desired extent or duration of treatment. It should be noted that the material in passing through the hollow electrode 8 is preliminarily heated by the heat radiating upwardly through the material from the heating chamber. The space. inclosed by the walls 4: and the covers 3 and 5 above the top of the material within the heating chamber forms a condensing chamber for the gases and vapors arising from the charge as the same is treated. These vapors when condensed may be removed from the chamber by means of the outlet 16. An opening 16 is also provided through which the uncondensed vapors and gases may be removed. thereby preventing an undue pressure on the condensing chamber arising from the accumulated gases. In the form of furnace shown, the electrodes may be so electrically connected that a single phase current, or a polyphase current may be used.

In Fig. 2 the outer inclosing walls are indicated at 1 which walls rest upon the base 2", and a cover 3 rests upon the top of the walls 1. The walls, base and cover are usually made of refractory material. Within the walls 1 are other walls 4 preferably of carbon which extend from the base 2* to a point below the cover 3. or cover 5 resting upon the walls 4 and also supported by the walls 1. A partition o divides the heating chamber inclosed by the walls 4., this partition being substantially coextensive with the walls 4. \Vithin the base 2 at the lower portion, troughs are formed, each of which forms the lower portion of one of the heating chambers inclosed within the walls 4". \Vithin each of the troughs are conveyers (3" which may assume any desired form, and in each of the heating chambers above the conveyers are cooling pipes 7, through which may pass any suitable cooling medium. Extending through the cover 3 are electrodes 8" and 8. These electrodes extend into the heating chambers formed by the walls 4 and. partitions 5 and are hollow. Extending through the walls 1 and 4 are electrodes 14 and 15, these electrodes intersecting the wall l at a point which is just below the termination of the electrodes 8 and 8*. The electrodes 8 and 8 are cooled by water jackets, one of which is shown at 11*, in the same manner as has heretofore been explained. The materialto be treated is fed through the electrodes 8 and 8 in any suitable manner, and in passing from the lower end of the electrodes, fills the heating cham her; the top of the charge of the material as it passes from the hollow electrodes, assuming a slanting or conical form, as indicated at 17. The space above the charge of material inclosed by the walls I and by the cover 3 forms a condensing chamber for the gases and vapors as the material is heated, and the openings 16 are provided for the removal of the condensed gases and vapors, while, through openings 16" the uncondensed gases and vapors may be removed. The space between the walls .l and 1 and below the floor or cover 5 is filled with granular carbon to form a heat insulating body. The electrodes 8, S ll and 15 may be suitably connected with sources of electricity and the electric current employed may be either a single phase, a polyphase or a direct current. The manipulation of the material charged within the furnace is substantially the same as that which has heretofore been described.

In the form of the furnace shown in Fig. 3 the outer walls are represented at 1 and the inner walls at 4'. The middle partition is designated at 5" and extends to a height less than the height of the walls 4". The electrodes are represented at 8 and 8 .the current being introduced and led out from the heating chambers through these two electrodes. As stated with regard to the fur-. naces heretofore described, the inner wall members 4* and partition member 5" are of carbon. The space between the inner wall There is a floor 4" and the outer wall 1 maybe packed with anular carbon as shown in connection with *ig. 2, and with the exceptions above noted the furnace is the same as that shown and described in connection with Fig. 2.

In Fig. 4 the outer walls of the furnace are represented at 1,these being supported upon the base 2, and the furnace is provided with a cover 3 which rests upon the top of the walls 1. Within the outer walls 1 are inner carbon walls 4 which are spaced from the outer walls,-this space being filled with granular carbon to provide a heat insulating layer. The space between the walls 4 and 1 is inclosed at the top thereof by the floor or cover 5. In the lower part of the heating chamber a conveyer 6 is provided by which material is removed from the lower part of the heating chamber, and in consequence of which removal the material may flow or move through the chamber, thus making the furnace a continuously operating one. Above the conveyer 6 are pipes 7 through which a cooling medium maybe circulated for the purpose of cool-,

ing the material being treated, before it is removed to the outside air. The electrode 8 is preferably circular and forms, in effect, a floor with a central opening 9, through which material enters the heating chamber. The opening 9 upon the underside of the electrode is provided with a flange, this being for the purpose of guiding the material charged into the furnace, that it may assume the desired form, upon entering the heating chamber. The electrode 8 may be a circular electrode, or two oppositely disposed electrodes joined by a bus bar may be employed. The material to be treated is fed into the top of the furnace, and for this purpose there is provided the hopper shaped member indicated in the drawing. The space below the electrodes 8 and above the floor or cover 5 provides a condensing chamber in which the gases and vapors arising from the charge being treated may be condensed and these condensed vapors are withdrawn from the furnace by means of the outlets 16. It will be observed that the material to be heated must enter the heatingchamber through the opening 9 in the electrodes 8, thus entering through an opening of less diameter than that of the heatlng chamber, and as the material enters the heating chamber the top surface thereof will assume the slanting orconical form, the surface of which is represented at 16. It will be noted that the lower portions of this slanting surface meets with the electrodes 8 and therefore the electric current passing between the electrodes 8 and 8 will pass through the material comprehended within the slanting surface 16.

In Fig. 5 the side walls are represented at 1', the base at 2 and the cover at 3,

these being substantially the sameas shown in Fig. 4. Within the walls 1 are the inner walls 4 which extend from the base to a point below the cover 3. through these walls and the outer walls as well are the electrodes 8. Above the walls 4 is a partition or floor 9, which, in shape, is the same as that of the cross section of the furnace. This floor 9? is formed with a central opening having a surrounding flange upon the underside. The material enters the heating chamber through this opening and upon entering the chamber, assumes the desired form heretofore explained. An eh ctrode 8 extends through an opening in the cover 3 to a point just within the walls of the heating chamber, so that the material entering the heating chamber flows around -the electrode 8, and the path of the electric current .between the electrodes 8 and 8 is such as to heat the material comprehended within the slanting surface16 It will be Extending understood that the material, as it is fed a into the furnace through the hopper shown above the cover 3 will completely surround the electrode and thus form a closure for the space between the opening in the cover 3 and the electrode 8. moved from the bottom of the heating chamber by a conveyer 6 in a manner similar to that previously disclosed, and, in fact, with the exception of the differences noted, this furnace is substantially the same as those which have heretofore been disclosed.

In all the furnaces which have been described, the heating efi'ect is applied to the material as it enters the heating chamber, and at this time is caused to assume a form which permits the electric current to come into intimate contact with thevarious particles, and thus, by the transformation of the electric current into heat energy, all the portions of that part of the charge being treated are subjected to the heat which is developed by the current. The quantity of material which is treated in a given period of time is small, and by using a suitable quantity of electrical energy, it is possible to heat the material which is subjected to the electric current in a very short time, and to give it the required amount of treatment in a very short time. It is true that the charge is continually descending The material is re I in substantially uniform time, for if they do not, and some particles are delayed, those particles or portions of the charge which are delayed will become heated to a higher temperature than the remaining parts of the charge, and hence the electric current will, to a greater extent, flow through those portions which are heated, than through those portions of the charge which are not so highly heated. This, then, will result in an unequal heating or treatment of the material, as it passes through the heating zone, and results in a non-uniform product.

The material passing through the upper part ofthe heating chamber or through the zone wherein the material is heated passes therethrough with substantially uniform movement, and therefore, from the fact that the electric current flows between the top and the base of that portion of the charge of material having the slanting sides, it has been found that all the material comprehended, in a given period of time, between the slanting sides will be thoroughly subjected to the heating action of the current.

Having described my invention, I claim:

1. In a furnace, a heating chamber therein, means for introducing material into said chamber in substantially conical form, and means for introducing an electric current to flow substantially between the top and bottom of the conical portion of the charge.

2. In a furnace, a heating chamber therein, means for introducing material into said chamber through an opening which is of less cross sectional area than the cross sectional area of the heating chamber whereby the material assumes a slanting top surface, and means for introducing an electric current to flow substantially between the top and bottom of the material comprehended by the slanting surface.

3. In a furnace provided with outer walls, inner walls within said outer walls, said inner walls inclosing a heating chamber, means for feeding material into said heating chamber through an opening of less cross sectional area than the cross sectional area of the heating chamber whereby the material introduced into the furnace has slanting top sides, means for introducing an electric current to flow substantially between the top and bottom of the material included within the slanting sides, a conveyer situated at the lower part of the heating chamber whereby the material may be removed therefrom.

4. In a furnace having an exterior wall{ interior walls within the exterior walls an spaced therefrom, granular carbon filling the space between the interior and exterior terior walls inclosing a heating chamber wherein material introduced therein may be heated, and means for heating the mateiial within the heating chamber.

6. In a furnace having exterior walls, i11

.terior walls within the exterior walls and spaced therefrom, said interior walls being formed of carbon, granular carbon materia filling the space between the interior walls and the exterior walls, and means for heating the material within the interior walls.

7. In a furnace, a heating chamber therein, a tubular feeding member extending from the outside of the furnace into the heating chamber, the said tubular member being of less cross sectional area than the cross sectional area of the heating chamber whereby the material assumes a cone-shape after passing through the tubular member, means for heating the material in the apex of said cone. 7

8. In a furnace, a plurality of heating chambers, a plurality of hollow electrodes extending into said heating chambers whereby the material to be treated may be introduced therethrough and a conducting partition between said chambers whereby the electric current is caused to pass through the hollow electrodes and the said )artition.

9. In a furnace, a plurality o heating chambers therein, said chambers being separated by a conducting partition, hollow electrodes extending into said chambers whereby the material may be introduced into the chambers through the said electrodes, means for causing the material to move through the said chambers.

In testimony whereof, I hereunto afiix my signature in the presence of two witnesses.

JOHN W. BROWN. Witnesses:

F. D. LAURENCE, RICHARD A. HANEY.

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