USRE383E - Improvement in bagasse-furnaces - Google Patents

Description

UNITED STATES PATENT Urraca,

HA MUIGL lf. (HUMAN, 0F NICSV ORLEANS, LOUISIANA.

IMPROVEMENT IN BAGASSE-FURNACES.

Hin-einmal ion forming part ol Leiters laicnt No. llhhl, dated lh #einher 4|, tif, Reissue No. l, dalrd August 5, llf.

L "o rt/Z whom it mrty/ concern,.-

Be it known that I, SAMUEL H. GILMAN, nf the city of New Orleans, in the State of Louisiana, have invented a new and useful Improvement in Furnaces for Drying and Iurning Bagassc as a. Fuel for Practical Purposes; and I do hereby declare the following to be a full, clear, and exact description of the same, reference being had to the annexed drawing, which makes a part of this specification, and lettered to correspond therewith.

The object of my invention is the conversion of this said bagasse as it comes from the mill into such available fuel, in a new and more perfect and certain manner than has hercto- I'ore been done, by means of my improvement in the lmgasse-furnace aforesaid.

I will now proceed to describe the nature of myinvention and the general principles upon which it is based, and which entirely distinguishes it from all other furnaces heretofore made. My object being first to dry the bagasse, I form it into a conoid pile in the furnace, and preserve the size of the pile by continual accessions at its top while burning away at and consequently settling down to its hase, and as the green bagasse thus settles down from the top of the pile its temperature and the pressure upon it are gradually increasing until it arrives in the form of a dry dense mass at the burning base, having been dried hy its own fire and compressed by its own weight into a comparatively dense mass before arriving at the point of ignition. |I'he bagasse being received, dried, compressed, and ignited, my object is to carry the products of its combustion to another part of the same furnace,where the mixture and combustion of the gases are perfected and the ashes and silicious matter deposited. My object, also, is to prevent the formation of slag in the process of the combustion of bagasse by causing the draft through the furnace to pass over the burning surface of the pile with such strength and direction as will carry off to the second part the slag-generating products of combustion and prevent their accumulation at or near the fire in a sufficient quantity to form slag or cinders. rIlhe outlines of the interior surface of the receiving part of my furnace are all curvilinear, and adaptedto the corioid form of the pile of bagasse; consequently the channel around the pile for the passage of the draft of air is also curvilinear', and the next best to a straight liuc for the most rapid transmission of tiuids. The outlines ofthe interior surface ofthe second part of my furnace are all rectilinear, which is the best form lo facilitate the confusion of the currents and reducing and causing mechanically the mixture of the gasecus matters, and the deposit of the solid matters as they arrive from the first or receiving part of the furnace, in which first part the curvilinear channels offer so little obstruction to the passage of air that a natural draft is adequate to all the purposes ol' combustion and carrying off the slag-generating producls without the aid of any blast.

Having thus stated the object of my invention and the general principles upon which it is based and by which it is distinguished from all others, I will new proceed to describe the plan which has proved entirely successful in taking olf seven entire crops with furnaces of various sizes thc present season of 1855 and 1.856, and this experience is the basis upon which this specification is written. The time required to dry the bagasse and the quantity to be dried and burned in a given time deterH mine the size of the furnace. I found the time required to dry the bagasse while in a self-compressed conoid pile burning at its base to be eighty minutes, aud that the quantityof bagasse formed in eighty minutes,when making sugar at the rate of six hundred pounds per hour, would make a conoid pile fourteen feet high and ten feet in diameter at its base. rIhercfore I construct my furnace as follows: That part of my furnace in which the bagasse is received, dried, compressed, and ignited is in the form of a vertical hollow cylinder twelve feet in diameter, closed at the top by a hemisphericaf dome the interior of which is seventeen feet high from the bottom of the cylinder. The part of my furnace in which the products of combustion are received, mixed, and their solid parts deposited is of a square and arch-covered form eight feet wide and eleven feet high to the interior top of the arch, and opens out its full size from the aforesaid cylindrical part, making the entire length of the furnace through the round and square parts twenty feet. In the center, near the base of the rear wall of the square part, I make a i.' Il S 3 throat orllue,through which thenvailable heat ol" the furnace passes oi'fto the boiler orevaphating-pans. lhe arca ol' the vertical crossseetion ol' this throat is onethiril the area ol' the vertical cross-section when the cylindrical and square parts ofthe furnace unite.

To give the furnace sufficient strength and lo prevent the radiation of heat, the walls should he about three feet thick, and to give a level bearing for the bed-plate of the hopper the dome brick-work is concd up on the outside to a thickness of four feet, rIhrough the apcxol" the domefromi he outsidetoinside is an open throat, through which the hagassc falls from a hopper into thc furnace. This throat is made fire and smoke tight hy swinging doors in the bottoni of the hopper. The hearth of the furnace is solid, and at or near the ground level. In the wall ofthe circular part, and directly opposite the flue through which the heat finally passes oii from the square part, and on a level with the hearth,

`l make the draftdoor about fifteen inches wide and two feet high, the opening of the door widening as it reaches the inside ol' the furnace-wall to thirty inches in width and falling to twenty inches in height. The top of the door and opening is of an arched form, and is made of and lined with metal. ll here give the size and proportions of this door which I consider best. They may be somewhat varied, perhaps, in the furnaces of different capacity; but the locality of this door I regard as essential, and it should always be situated so that a vertical plane passing through the middle of the square part oi' the furnace and extended through the center of the circular part would divide it vertically into equal parts. About three feet six inches above the floor, and directly in line above the draftdoor, I make a doubly-conical opening in the wall in the form of sections of two cones meeting each other midway the chamber-wall. The middle portion of this opening is lined with sections of two hollow cones to fit it, and fitted with a metal door. I call this the iiredoon77 because, in order to kindle the fires and keep the bagasse supplied therewith, and other required purposes, wood, from time to time, is thrown in at this door. On the radial line, which is a right angle to the radial line on which the above doors are constructed, I make openings, one on each side of the chamber. These openings are'of the same size and same construction as that of the draft-door, and are on the horizontal plane with the draft-door aforesaid, and are for the purpose of cleaning the furnace when afinal stoppage is made. Directly at the base ofzthe rear wall of the square arched chamber, and through which the throat leading to the boilers or evaporatingpans is made, I make across the furnace a pit in the ,earth about four feet Wide and thirtyinches deep. Adoor at each end of the pit closes the openings in the side Walls of this chamber. The openw ings are two feet square on the outside and enlarged to the width of the pit on the inside. 'llhese opei'iings are lined and closed with metal, and are arched at top. I call these the clear-out doors ol' this chamber. 'lhcboilers or evaporatingvpans are set in masonry or brick-work, and are ofthe usual or improved styles.

llavi ngthus briefly, clearly, and fully stated the object, nature, principles, size, structure, and forni of my furnace for drying and burn ing bagasse, l will now proceed to its operation.

Operation: rlhe bagasse is taken from the rollers of the mill by the usual endless belt or carrier, which drops it into a hopper immcdiatcly over the throat in the dome of the fun nace. In Vthe bottoni of this hopper are two swinging doors which open by thc weight of the bagassc, which passes through into the furnace and forms a conoid pile on its hearth. A fire of wood or coal having been previously lighted ou the hearth in front of the draftdoor and the furnace well heated, the bagasse ignites around the base of the pile to the height et' about three feet, and burns away and settles down as fast as it is received on the top, and thus preserves its size and shape uniform. The time required to form this pile heilig eighty minutes, it follows that the bagasse is exposed eighty minutes to dry by the heat of the furnace while settling down to the burning belt. The draft is admitted at the draft-door and passes around both sides ofthe pile through a narrow channel, with a burning-surface on one side and a brick wall on the other side a distance of fourteen feet, tothe square part of the furnace, when the different currents meet from the opposite directions, bringing along in their velocity nearly all the ashes or solid products of combustion into the square part of the furnace, when the meeting and mixing of the contents cause the solid matter to deposit in the pit and perfect the combustion of the gaseous matter before it passes through the throat to the boilers or evaporatingpans.

In the drawing', which is a central and vertical section lengthwise the furnace and across the boiler-dues, (the whole section being in the same plane,) A is the cylindrical domecovered chamber. B is the arched-covered chamber. C are the boilers, (or evaporatingpans, which can be set instead of the boilers.) Four boilers are shown, so as to represent a flue and return-flue under the boilers, which are all set two and two in a line. D is the pit athwart the arched-covered chamber. E is the draft-door. Fis one of the clean-out doors of chamber A. Gis thefire-door for wooding np. II is the throat leading to the hopper. I is the metalliciining of the top of the throat. K is the issue or throat leading to the fines under the boilers.

No. 383.-Improvemcnt in Bagasse Fumaces.

What I claim is, combining with the receiving chamber a squar mixing or second chamber, whose hearth is substantially levelv wi that of the receiving; chamber B, separate and distinct from the heat conduit or flue which conducts the heat to the boilers, and located combustion of` the gases thereof, after they pass out of the rst or burning chamber, and before they enter the heat conduit, or Hue, and thereby promoting the de osit of the solids, substantially as described, whether the said second c amber B is provided with a pit D or not.

I also claim the use and adaptation of' the it D, located in and combined with the second or mixing chamber fas an auxili bo increase the agitation and perfect the mixture and combustion oi the gases, and also to promote the deposit of the solids, substantially as ascribed. i SAMUEL H. Gamm.

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