US551476A - Furnace - Google Patents

Description

no. FURNACES,

,l "fa-mace structuren 2 Sheets-Sheet 2.

. POWELL.

PURNAGE.

U. wir? f Patented Deo. 17, 1.895.

*v UNITED STATES PATENT EEICE.

EDVIN POIVELL, OF PITTSBURG, PENNSYLVANIA.

FuRNAoE.

SPECIFICATION forming part of Letters Patent No. 551,476, dated December 17, 1895.

Application filed August 28, 1895. Serial Nm 560,747. (No model.)

To aZZ whom it may concern:

Be it known that I, EDWIN POWELL, a citizen of the United States, residing at Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented or discovered a certain new and useful Improvement in Furnaces, of which improvement the following is a specification.

My invention relates to furnaces for the evolution of heat from fuel in the various descriptions of heating apparatus employed in manufacturing and mechanical operations and the generation of steam for the numerous purposes required in the arts and trades; and its object is to provide means whereby the thorough, economical, and smokeless consumption of fuel may be effected in a structure of simple and inexpensive construction and ready applicability to existing conditions of location, service, and relation to other structures in connection with which it may be required to be used.

To this end my invention, generally stated, consists in the combination of a furnace or fuel-chamber, a fire-bed therein which is closed to access of air below it, an air-supply passage above said fire-bed, a combustionchamber, an exit throat or passage connecting the fuel-chamber, at or near the fire-bed thereof, with the combustion-chamber, and a gas-conduit leading from the fuel-chamber, above the normal plane of ineandescence therein, to a point of discharge adjacent to the discharge-outlet of the exit throat or passage.

The improvement claimed is hereinafter fully set forth. 1

In the accompanying drawings, Figure 1 is a vertical longitudinal central section through a metallurgical furnace, illustrating an application of my invention; Fig. 2, a vertical transverse section through the same at the line w of Fig. 1;A Fig. 3, a vertical longitudinal central section through a glass-furnace, illustrating a modification of detail;` and Fig. 4, a vertical' transverse section through the same at the line y y of Fig.v 3.

In the practice of my invention I provide a downward-draft furnace or fuel-chamber 1, having at or near its top a fuel-supply passagepr openjmg 2, closed by a door 3, and having its bottom formed by a grated or perforated iire-bed 4, the openings in which are provided to permit the passage of ashes into a lower closed ash-pit 5, having a tight door 6 for the removal of ashes, and provided preferably with a water-pan G on its bottom. The walls of the fuel-chamber 1 are closed on all sides, except as to the openings of the fuelsupply passage 2 and fire-bed 4, above specified, one or more air-supply passages 7 formed in the front wall of the fuel-chamber at a point above the normal level of the fuel therein and controlled by a door or register 8, a cleaning-passage S) in the front wall at or near the level of the fire-bed, controlled bya door 10, and gas-discharge passages 11 and 12, to be presently described. The ash-pit being also tightly closed, the draft of the fuel-chamber is downward from the air-supply passages 7 through thenbody of fuel.

A combustion-chamber 13, in which the heat evolved from the fuel in the fuel-chamber 1 is utilized for the particular purpose for which it maybe required-as, for example, the melting or reheating of metal, glass, rizo., the burning of brick, lime, or pottery, the generation=of steam, or other calorific action-is located adjacent to the fuel-chamber l, and is separated therefrom by the rear wall 111 thereof. An exit throat or passage 11, through which the major portion of the gaseous products of combustion evolved from the fuel in the fuel-chamber 1 are discharged into the combustion-chamber 13, leads from the fuelchamber l, at or about the level of the highest incandescence therein-that is to say, at or closely adjacent to the top of the fire-bed 4--into the combustion-chamber 13. A gasconduit 12, of which either one or more may be employed, a plurality being indicated in dotted lines in Fig. "2, leads from the fuelchamber 1 at a point above the normal plane of incandescence therein, and, preferably, as shown, slightly above the top of the normal charge of fuel in the chamber, to a point of discharge to the combustion-chamber adjacent to the discharge-outlet of the exit throat or passage 11 thereto, the object of said conduit 12 being to provide an avenue for the passage of the smoke and partially-consumed gases which may rise through the unconsumed and cooler portions of the fuel, at and below the top of the charge, from the upper poortion ICO - 1o tion of portions of the-charge above that which is in a state of incandescence is found to be completely consumed.

As shown in Fig. 1, the point of discharge of the gas-conduit 12 is on one of the b0unda ries of the exit throat or passage 11, between the fire-bed 4 and the outlet ofthe passage 11, to the combustion-chamber 13, so that the products of combustion which pass through the conduit 12 meet the heated gases passing zo through the exit-throat 1l before the latter are discharged into the combustion-chamber,

, and the conduit 12 and passage 11 thus have a common outlet to said chamber, which outlet is adjacent to the point of dischargeof the conduit 12. The same result willfhowever, be attained if the conduit 12 and passage 11 deliver the gaseous products from the fuelchamber to the combustion chamber through separate and contiguous outlets, the

3o only requisites as to the location of the point of discharge of the conduit 12 being that it shall be such that the gaseous products pass- 4ing out of the conduit 12 must immediately mingle with the hot gases which pass through 3 5 ,the exit throat orfpassagel, and that it shall be sufhciently far remove from the fire-bed to insure that the gaseous products passing through the conduit 12 shall escape therefrom entirely beyond and clear of all portions 4o of solid fuel, and shall meet the gases which are evolved from the incandescent portion of the fuel at a point where their traverse is unimpeded by solid fuel or ashes.

Figs. 3 and 4 illustrate a modification in which the discharge of the products of combustion from the exit throat or passage 1l and the gas-conduit 12, respectively, is effected through separate outlets, as above specified, the outlet of the passage 1l opening into the combustion-chamber 13, as in the instance first described, and that of the gas-conduit 12,

also opening into the combustion-chamber,

above and closely adjacent to that of the passage 11. The partially-consumed products of combustion escaping from the outlet of the gas-conduit 12 meet and mingle with the n' T-heated gases discharged from the outlet of the assage 11, as both enter the comv bustion-chamber, and the former are, as in the instance first described, thoroughly consumed, producing a iame of intense heat in the combustion-chamber. The combustionchamber 13 is shown as of the form employed in glass-furnaces, having glory-holes 15 in the upper portion ofl its walls, but it will be obvious that it may be of any other desired construction, without departure from my invention.

l have found in practice that an unusually high heat is generated, and a complete com- 7o bustion effected, by a construction embodying the essential features above described, and, while the precise action of the furnace in the evolution and combustion of gasesmay be difficult of ascertainment with absolute certainty, it is my present understanding that this advantageous result is due to the following facts: The smoke and partially-consumed gases which are vevolved from the portion of the body of fuel above that which is in a high 8o statel of incandescence are disengaged and pass ou slowly, -at a comparatively low tem.- perature, owing to the resistance of the unconsumed and cold solid fuel above the level at which they are generated. On the other hand, the gases evolved from the incandescent portion of the fuel escape freely, rapidly, and at a high-temperature through the exit-passage 11. The latter gases are, therefore, capable of carrying with them and con- 9o suming and utilizing the combustible products which meet and mingle with them at the ldischarge-outlet of the conduit l2, thereby generating a correspondingly higher degree -of heat than would be attainable if the unconsumed products from the upper portion l. of the charge of fuel were led into and through the incandescent portion thereof, and before the gases of combustion were released therefrom, as has been proposed, and set forth in roo Letters Patent, prior to my present invention.

The essential feature of difference between my improvement and the prior constructions referred to consists in the provision of the described means for eecting the union of the productsof combustion of a downwarddraft furnace from the unconsumed and the incandescent portions of the charge of fuel, respectively, at a point wholly exterior to the fuel-chamber, where the traverse of the hot 1 1o ter gases is unimpeded by solid fuel, and so that combustion shall s .1 i a t the outlet through which the gaseous products pass into the combustion-chamber, and produce a flame of exceptionally high heatat said outlet.

I claim as my invention and desire to secure by Letters Patent- 1. The combination, substantially as set forth, of a furnace or fuel chamber, a rebed 12o therein which is' closed to access of air from below it, an air supply passage above said rebed', a combustion chamber, an exit throat or passage connecting the fuel chamber, at or near its rebed, with the combustion cham- '125 ber, and a gas conduit leading from the fuel chamber, above the normal plane of incan' descence therein, to a point of discharge adjacent to the discharge outlet of the exit Y throat or passage and exterior to the bed 0f r 3o incandescent fuel.

2. The combination, substantially as set F-J-rnace structured forth, of a furnace or fuel chamber, a rebed therein which is closed to access of air from below it, an air supply passage above said irebed, a combustion chamber, and passages connecting the fuel chamber and combustion chamber, said passages leading out of the fuel chamber at or near the point or level of highest incandescence, and above the normal plane of incandescence, respectively, and discharging exterior to the bed of incandescent fuel.

3. The combination, substantially as set forth, of a furnace or fuel chamber, a rebed therein which is closed to access of air from below it, an air supply passage leading into the fuel chamber above the normal upper level of the charge of fuel, a door or register controlling said passage, a combustion chamber, an exit throat or passage leading from the fuel chamber, at or near the level of the rebed, to the combustion chamber, and a gas conduit leading from the fuel chamber, above the normal upper level of the charge of fuel, and discharging, exterior to the bed of fuel, to the combustion chamber.

4. The combination, substantially as set forth, of a furnace or fuel chamber, a irebed therein which is closed to access of air from below it, an air supply passage above said and having its discharge outlet Wholly exterior to the fuel chamber and open to the products of combustion delivered through the exit throat or passage.

5. The combination, substantially as set forth, ofa furnace or fuel chamber, a flrebed therein which is closed to access of air from below it, an air supply passage above said irebed, a combustion chamber, an exit throat or passage leading from the fuel chamber, at or near its iirebed, to the combustion chamber, and a gas conduit leading from the fuel chamber, above the normal plane of incandescence therein, to the combustion chamber, and having a discharge outlet therein, independent of, land adjacent to, that of the exit throat 0r passage.

In testimony whereof I have hereunto set my hand.

EDWIN POWELL.

Witnesses GEO. W. BLAIR,

.T. SNOWDEN BELL.

Images