US822955A - Furnace. - Google Patents

Description

PATENTED JUNE l2, 1906. J. A. KAVANAGH.-

FURNAGB.

APPLICATION PILBD'AUG. 9, 1905.

tial combustion to the boiler.

UNITED STATES PATENT OFFICE.

FURNACE.

Specification of Letters Patent,

Patented June 12, 1906.

Application led August 9, 1905. Serial No. 273,397.

To LZZ whom t may concern.-

Be it known that I, JAMES A. KAVANAGH, of New York, in the county of Kings and State of New York, have invented certain new and useful Improvements in Furnaces; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to that class of steam-boiler furnaces in which the products from the initial combustion pass through a bed of incandescent fuel for the purpose of thoroughly igniting their combustible constituents to obviate the creation of smoke and increase the efficiency of the consumed gases for the creation of steam.

The primary object of the invention is to provide improved means for introducing fresh heated air at such points relative to the secondary combustion on the bed of incandescent fuel as to insure the thorough con-l sumption and heating of the products and gases.

In the accompanying drawings, Figure 1 is a vertical longitudinal sectional view of a furnace equipped with my improvement, the furnace being applied to an ordinary land or stationary tubular boiler. Fig. 2 is a transverse sectional view showing the bridge-wall in front elevation.

Referring to the drawings, 1 designates the steam-boiler suitably mounted in a setting of masonry.

2 is the bridge-wall extending from the bottom of the furnace to and partly surrounding the boiler-shell to form a baffle and prevent the direct passage of the gases from the ini- Near its base the bridge-wall is provided with a plurality of transverse orifices 3, extending entirely through the same. Forward of the bridgewall the furnac'e is divided by a partition 4 to provide an ash-pit 5 and combustion-chamber 6, the latter also serving as a subsidencereceptacle for incombustible ashes.

7 is a grate over the ash-pit supported by the partition 4 and the front wall of the furnace. 8 is a second grate over the combustion-chamber spanning the space between the partition 4 and the bridge-wall. This grate 8 is a water-tube grate, shown connected at one end with the water-space and at the other end with the steam-space of the boiler.

The partition 4 is provided at its base with an opening affording access from the front of the furnace to the combustion-chamber 6 for the purpose of cleaning the latter. A door 9 normally closes this opening and is oon'- trolled by a handle 10, extending through the ash-pit to the front of the furnace within reach of the attendant.

In each side wall of the furnace I provide an air-inlet passage 12, having its outer extremity open to the atmosphere, preferably at the rear end of the furnace and extending inwardly to a point over` the partition 4. The portion of each of these air-passages in advance of the bridge-wall and above the grate S is provided with a plurality of outlet-ports 13 and a channel 14, extending vertically downward to a point within the combustionchamber and beneath the grate 8. Near their lower extremities and below the grate the channels 14 are formed with outlet-ports 15, opening into the combustion-chamber.

At 16 is shown an air-duct in the bridgewall extending throughout the width thereof in alinement at either end with conduits 17, leading from the passages 12. The duct is formed with outlet-ports 18, opening in the front face of the bridge-wall and has branches 19 extending downwardly and constituting fiues with outlet-ports 20 at a point in the bridge-wall below the grate 8, so that the latter is arranged intermediate these ports and ports 18.

In practice'the fire is made on grate 7 in the usual manner, and after attaining a certain degree of combustion a portion of the fuel is pushed back upon the water-grate S. Air passes by the natural draft up through the grate 7 from the ash-pit, after which the ases and consumed products are drawn ownwardly through the water-grate and bed of incandescent fuel thereon. Between their leaving the first grate and entering the second, however, highly-heated fresh air entrained from passages 12 in the furnacewalls and from duct 16 in the bridge-wall is mixed with the gases and effects a more thorough combustion than may have resulted upon the first grate. After passing through the second grate and into the combustion-chamber the gases are caught in a third draft of heated fresh air issuing from the channels 14 and likewise encounter the air from flues 19. Ample opportunity is here aorded for thoroughly mixing the gases IOO with the supply of heated air, effecting complete combustion of the carbon and unconsumed gases, after which the line of direction is through the orifices 3 of the bridge-wall and thence by way of the uptake to the boiler-tubes and smoke-stack.

Practice has demonstrated that the gases passing to the boiler-tubes from a furnace constructed in accordance with my invention are essentiaily volatile and free from solid matter carried in suspension. The air introduced at the point of initial combustion, as well as that subsequently mixed with the gases, is fresh and not vitiated by prior passage over or in contact with a bed of fuel and is, furthermore, highly heated in its travel through the passages in the furnace-walls and the duct and flues in the bridge-wall, thus reducing the possibility of condensation to a minimum.

I claim as my inventionl. In a furnace having an initial fire-bed and a grate designed to support a bed of incandescent fuel, the draft being upward through said fire-bed and downward through said grate, passages within the side walls of said furnace extending longitudinally thereof and having outlets for the introduction of air to the gases at points in the travel of the latter intermediate the fire-bed and said grate, and channels supplying additional air to the gases after the passage thereof through said grate.

2. In a furnace having an initial fire-bed and a grate designed to support a bed of incandescent fuel, the draft being upward through said fire-bed and downward through said grate, air-passages in the side walls of said furnace having outlets designed to introduce air to the gases at points in the travel of the latter intermediate the initial fire-bed and said grate, and channels leading from said passages and having outlets below said grate.

3. In a boiler-furnace having an initial fire-bed and a grate designed to support a bed of incandescent fuel, a bridge-wall at the rear of said grate extending from the bottom of the furnace to the boiler-shell, air-passages in the side walls of said furnace extending longitudinally thereof and open at the rear end of said furnace, and an air-duct in said bridge-wall, each having outlets designed to introduce air to the gases at points in the travel of the latter intermediate the initial fire-bed and said grate.

4. In a boiler-furnace having an initial fire-bed and a grate designed to support a bed of incandescent fuel, a bridge-wall at the rear of said grate extending from the bottom ofthe furnace to the boiler-shell, air-passages in the side walls of said furnace and an airduct in said bridge-wall, each having outlets designed to introduce air to the gases at points in the travel of the latter intermediate the initial fire-bed and said grate, and channels leading from said passages and having outlets below said grate.

5. In a boiler-furnace having an initial fire-bed and a grate designed to support a bed of' incandescent fuel, a bridge-wa l at the rear of said grate extending from the bottom of the furnace to the boiler-shell,A air-passages in the side walls of said furnace and an air- .duct in said bridge-wall, each having outlets designed to introduce air to the gases at points in the travel of the latter intermediate the initial fire-bed and said grate, and ues leading from said duct having outlets below said grate.

6. In a boiler-furnace having an initial fire-bed and a grate designed to support a bed of incandescent fuel, a bridge-wall at the rear of said grate extending from the bottom ofthe furnace to the boiler-shell, air-passages in the side walls of said furnace, an air-duct in said bridge -wall conduits establishing communication between said passages and said duct, said passages and duct having outlets designed to introduce air to the gases at points in the travel of the latter intermediate said fire-bed and said grate, channels leading from said passages having outlets below said grate and flues in said bridge-wall leading from said duct and also having outlets below said grate.

7. In a boiler-furnace having an initial fire-bed and a grate designed to support a bed of incandescent fuel, a bridge-wall at the rear of said grate extending from the bottom of the furnace to the boiler-shell, said bridgewall having transverse orifices near its base, the draft being upward through said fire-bed, downward through said grate and through said orifices in the bridge-wall7 air-passages in the side walls of said furnace having outlets designed to introduce air to the gases at points in the travel of the latter intermediate the initial fire-bed and said grate, and channels leading from said passages and having outlet-ports below said grate and intermediateuthe latter and said orifices of the bridgewa 8. In a boiler-furnace, a bridge-wall extending from the bottom thereof to the boilershell and having transverse orifices near its base, a partition in advance of said bridgewall forming an ash-pit and a combustionchamber, a grate between said partition and the front wall of the furnace, a second grate between said partition and said bridge-wall, an air-passage within a side wall of said furnace extending longitudinally thereof and having outlets opening above said second grate, and channels extending into said combustion-chamber and below said second grate.

9. In a boiler-furnace, a bridge-wall extending from the bottom thereof to the boilershell and having Atransverse orifices near its IOO IIO

base, a partition in advance of said bridgewall forming'an ash-pit and a combustioncharnber, an opening near the base o1 said partition7 a door for controlling the same, a grate between said partition and the front wail of the furnace, a second grate between said partition and said bridge-wall, air-passages in the walls of said furnace having outlets above said second grate, and channels extending into said combustion-chamber and( 1o below said second grate.

In testimony whereof I have signed this specification in the presence of two subscrib-

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