US647552A - Furnace, stove, or fireplace. - Google Patents

Description

No. 647,552. Patented Apr. a7., |900.

c. H. BENNETT.

FUBNAGE, STOVE7 0R FIIEPLAGE.

(Application led Feb. 25, 1899,) (N0 Model.)

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, the heat communicated to the grate bar or UNITED STATES i PATENT OFFICE.

CHARLES H. BENNETT, OF LOS ANGELES, CALIFORNIA.

yi-SLJRNACE, sTovE, 0R FiRPLACi-z.

sP'E'oIFmA'rio forming part of Letters Patent No. 647,552, dated Api-i1 17, 190e.

Application filed February 2 5, 1 89 9.

To @ZZ whom t may cortcerm.

Be it known that I, CHARLES H. BENNETT, a citizen of the United States, and a resident of the city of Los Angeles, in the county of Los Angeles and State of California, have invented certain new and useful Improvements in Furnaces, Stoves, or Fireplaces, of which the following is a specification.

One of the principal objects of my invention is to obtain a downdraft through the burning fuel, and thus to more perfectly consume the fuel. The tendency in combustion where the fuel is fed or thrown onto the fire from above is'tocause the lower portion of the fuel to be incandescent. That portion of the fuel which is above is caused to throw 0E its volatile products of combustion. Where the draft of air fed to the fuel enters below the fuel and passes up through the latter, the incandescent volatile products of combustion from the superincumbent freshlyadded fuel pass up and away from the fire and much of lthem (especially in bituminous coal) are not consumed, but pass out of the chimney in the form of smoke. In such escaping products there also passes a quantity of unconsumed carbon. The waste therefore is apparent.

By my invention the products of combustion--gases, carbon, and the like-escaping from the coal at the top of the lire are carried down into contact with the incandescent fuel by the downdraft of air and are there thoroughly consumed.

Another object of my invention is such a construction of one or more grate-bars for su pporting this fuel as shall enable the gratebars to be kept cool, and therefore prevent these bars from being melted or burned out by the heat of the fire being carried down against them and past them by the downdraft aforementioned.

Another object of my invention is to utilize bars by heating air, which may be carried to any place where the hot air is needed.

The several features of my invention and the various advantages resulting from its use, conjointly or otherwise, will be fully apparent from the following description and claim.

In the accompanying drawings, making a part of this application, similar letters of ref# erence indicate corresponding parts.

My invention is applicable to various kinds of furnaces, stoves, and grates..

Inasmuch as the invention is thoroughly illustrated by showing it as applied to a warme air furnace, I have in the drawings shown one kind of warmeair furnace and the application of my invention thereto.

In the drawings, Figure l is a front 'perL spective view of a warm-air furnace to which my invention has been applied. Fig. 2 represents a vertical central section ofthe fur nace, taken in the plane of the dotted line 2 2 of Fig. l. In this View a part of therear portion of the furnace unnecessary to the comprehension of my invention and containing merely a hot-air space is broken out and removed and the rear end of the furnace brought forward, as shown. The object of this condensation is to economize space on` the sheet of drawings. Fig. 3 represents a portion of a vertical central section of a porL tion of the side eXit-flues. This section is taken in the plane of the dotted line 3 3 of Fig. 4. .Fig t is a vertical central transverse section of the furnace, taken in the plane of the dotted line 4t i of Fig. 2. Fig. 5 is a plan view of the grate-bars and of those portions of the furnace-wall and of its projections which are in the immediate vicinity of these bars.

The outer enveloping shell or casing A is to be of any desired shape. At or near the bottom thereof is a suitable cold-air inlet to admit cold air to be heated for useful and well-known purposes. `Within this casing, but separated therefrom at a sufficient distance to allow hot air heated by the furnace to freely rise is the furnace B itself. In this furnace C is the fire-pot, composed of the lower division C3 and the upper division O2. The upper division has the inlet feed-passage C4, closed by the usual door C5.A Air to feed the `fire and to create a draft regulated by a suitable door is admitted through a suitable opening in the feed-door. This opening is located above the point where the charge of fuel comes when the furnace is properly filled. In the present illustrative instance the air-inlet'IB is in and through an opening in the door C5, and this inlet-passage is con` IOO trolled by a door IB2. At the upper portion of the furnace is the exit smoke-nue O6. Inasmuch as the usual course of the waste products of combustion-smoke, &c.-is downward through the furnace, this exit-flue C6 is usually closed by a draft-damper C7. This door may be operated by a rod C8 or otherwise.

Suitable provision is made to receive the waste products of combustion after they pass down through the grate and into the ash-pit. A practical and novel provision for this purpose is shown and consists as follows, viz: .This provision is in duplicate, there being one such on each side of the ash-pit and furnace. Adescription of one will suiice for both, viz: In the side of the ash-pit D is an opening E, and this connects with an exit-flue F, which is arranged so as to curve back and forth within the casing A. Thus it (this iiue) is enabled to come into contact with a large amount of air and to transmit its heat to the latter. The exit end of this flue F connects with `the exit passage or chamber G, in turn connecting with an exit-hue G2. It is to be noted that the upper end of the furnace through the exit C6 does, when the flue-door is open, connect with such passage or chamber. The several windings or branches of the iiue F are respectively represented by the characters F2, F3, F4, and F5.

I will now proceed to describe the means for sustaining the fuel in the furnace. I provide one or more grate-bars H. These are not common grate-bars, but ones that are tubular. Solid grate-bars would soon burn out for the reason that a downdraft carries the flame and heat into constant direct contact with the bars after the manner of the blowpipe, and the ordinary bars would soon warp and melt under the intense heat to which they are necessarily subjected. Through each of these tubular grate-bars H, I pass a rapidly-moving current of air, and the air thus passed takes the heat of the grate-bars, and thus highly heated passes into the space S between the casing A and the furnace B and is conducted thence ordinarily to be used along with the other heated air of the furnace. l

I am aware that water has been passed through ordinary tubes to keep the latter cool while used as grate-bars in steam-boilers. I employ air instead of water, inasmuch as water cannot be always obtained without expense and its use in such connection would entail the attendance of an operator to operate it and is, in fact, wholly impracticable in such a furnace.

I obtain in the use of air means for cooling the grate which are very economical and entirely practicable. In addition to providing a construction wherein tubular grate-bars and means for enabling air to pass through them are present, which construction and means constitute one feature of my invention, I-have invented the following novel construction of der to pass the air through at a proper speed, I must provide for the expansion of the air during the operation of heating it. This is done by flaring or tapering the hollow gratebar. I cause the amount of flare to be proportionate to the intensity of the heat to which the grate-bars will ordinarily be subjected, because the degree of expansion of the air as it passes through the grate-bars will depend upon the amount of heat which it receives. Thus the are of the tubular space within the grate-bar will rightly accommodate the moving air in the course of its expansion as it passes within' and through the grate-bars. While the roof and floor of the space within the grate-bar may each incline, the one upward and the other downward from the horizontal, or the roof maybe horizontal while the floorinclines downward, yet the preferred directions of the Hoor and roof are as shown. I have thus inventively located them (see Fig. 2) in order to the better enable them to carry into effect the purposes of my invention. Therefore I have located the floor H2 in a horizontal plane and the roof H3 of the gratebar in a plane inclined to the horizontal. Thus where the tubular space of the bar has a given iiare the angle of the inclination to the horizontal will be greater than where the iloor inclines down from the horizontal. This great inclination of the roof possesses a great advantage, to wit: It allows the heated air a good opportunity to easily pass off through and from the tubular passage PH of the gratebar in a natural rising current. Such an inclination of the roof of this tubular passage does not necessitate any further thickening of the grate-bar in the neighborhood of the inlet end I of the passage PH through it, because by locating the inlet ends of the bars- Viz. at that side of the furnace opposite where the feed-door is locatedas I have shown the inclination of the tops of the bars is downward from the doors, and this is an advantage, as it enables the fuel to be well handled lOO IIO

by the poker and causes the fuel to bank in a position where it can be readily reached by draw-bar or poker operated through the feeddoor.

In order to increase the capacity of the gratebars for transmitting heat to the air passing through them, (whenever such increased capacity is needed,) I provide within this bar a ange or flanges or projections FH, which extend into the tubular space of the bar and transmit heat from the latter to the air contained within. In other Words, I increase the surface of the grate-bar which comes in contact with the air moving through it. Thus I transmit the heat more rapidly to the air and heat the latter more rapidly, increase the speed with which it (the air) passes through the grate-bars, and am thereby enabled to heat the air from this source more quickly and at the same time keep the grate-bars cooler and in a condition wherein they are but the lire-grate bars themselves, to wit: In orlittle liable to be injured from the heat in contact with their exterior surface. The shape of these bars and their (interior) spaces in cross-section may be varied as desired. A preferred shape thereof is shown in Fig. A, where the grate-bars and the tubular passage are alike heart-shaped, the narrower or pointed portion being below. Such a shape confers upon the grate bar great resistive strength in a vertical direction. This is the direction-viz., from above downward--in which the greatest pressure is exerted upon the grate-bars. The bottom of the bars being narrow affords the ashes falling between adjacent bars or between the bars and the adjacent sides of the fire-pot better opportunity to pass down and leave these spaces clear for the passage of the downdraft through them.

It is to be understood that the application of my invention is not to be limited to any special shape of fire-pot or those other accompanying portions of the furnace which are old, well known, and are to be found in many shapes and forms in common use.

The downdraft, irrespective of the particular shape of the grate-bars aforementioned, keeps the fire substantially clear of ashes, as the draft carries the latter down between the grate-bars into the ash-pit.

The mode in which my invention operates is as follows: The fuel is placed upon the grate-bars H and lighted. The upper exit or door C7 in the roof of the fire-pot is opened until the fire has become thoroughly kindled. This door C7 is then closed and the air entering through the inlet-port IB of the door C5..

passes down through the fuel and between the grate-bars, and thence down and through the passage E into the `Iiues F and rising passes through these flues F into the exit flue or chamber G, and thence out through the exit-flue G2. By these means the fiues F, dto., are heated and transmit their heat to the air within the casing A in the usual manner. This heated air is, as customary, conveyed to the place or places where it is needed. The grate-bars soon become heated and transmit their heat to the air within them. This air expands and moves through the tubular space PH of each grate-bar H and out of the enlarged end thereof and passes upward into the space between the furnace and casing and goes past the feed inlet-passage C4, as shown in Fig. 6, and adds to the hot air, (aforementioned,) which is to be conveyed to the point or points where needed. Meanwhile the cold air entering the inlet end of the tubular bars H, preferably by means of an introductory tube IH, passes into and through said gratebars and keeps the latter at a comparatively low temperature by withdrawing heat from the bars and conveying it onward, as aforementioned. On the drawings arrows duly indicate the respective directions of the various aforementioned currents of air.

From the foregoing description of the construction and mode of operation of my invention it is believed that the latter will be readily understood.

Where the fire-pot C3 is circular or oval in the planes of the grate-bars, a frill or other suitable projection or projections G9 may be present to partially fill the space between the inner side of the pot and the adjacent gratebar, substantially as shown.

To enable those not fully skilled in the art to understand the use of certain parts not heretofore described and forming no part of my invention, I here specify that the doors F6 (indicated in Figs. l and 4) give access to the branches F2, F3, F4, and F5 of the iiues F, so that the latter may be inspected, cleaned, and repaired.

D2 indicates the usual door of the ash-pit,

' through which access may be had to the ashpit and to the under side of the fire-grate bars.

My invention is especially applicable to furnaces; but, as heretofore indicated, my invention is applicable not only to furnaces but also to the fireplaces of stoves and other fireplaces.

What I claim as new and of my invention, and desire to secure by Letters Patent, isV

In a furnace or the like, a fire-pot, feeddoor, and inlet, and the grate-bars H, hav- 95 ing passages PH through them, inlet-ports to these passages, the latter Haring, as they approach their outlet, the bottom of the bars lying in a horizontal plane', and their tops inclined, substantially as and for the purposes rco specified.

CHARLES H. BENNETT.

Attest:

OHAs. M. LESLIE, K. SMITH.

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