Improvements in Steam-boiler and other Furnaces.
Year: 1898

page_text: Improvements in Steam-boiler and other Furnaces.
I, HORACE CRAIGHEAD, of 855, West End Avenue, Borough of Manhattan, City,
County and State of New York, United States of America, Manufacturer, do
hereby declare the nature of this invention and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:-
This invention has relation to boiler and other furnaces, and has for its object to
provide improved means for assisting the combustion of the ordinary fuel on the grate,
and increasing heating effect from the combustion of fuel without increasing the
quantity of fuel consumed. In carrying my invention into effect, I propose to
provide the walls of the furnace with a suitable conduit or retort, and supply
thereto from a suitable source, a mixture of oil and steam. The oil and steam
carried through the conduit becomes heated by reason of its proximity to the fire,
and issues as a combustible vapor, through a series of nozzles or apertures above
the grate. The vapor combines with the gases rising from the coal or other
ordinary fuel, where, igniting at once, they ignite the escaping gases and the two
continue to burn together with a very hot flame. My invention will be more
readily understood from the succeeding description and claims, taken in connection
with the accompanying drawings, in which-
Figure 1 represents a longitudinal sectional view of a furnace provided with
my improved burner.
Figure 2 represents a transverse sectional view of said furnace.
Figure 3 represents a horizontal sectional view.
Figure 4 represents an enlarged vertical sectional view of the bridge-wall.
Figure 5 represents an enlarged horizontal sectional view of one corner of the
furnace.
Figure 6 represents a view corresponding to Figure 1, showing a modification.
Figure 7 represents an enlarged detail sectional view of a part of said
modification.
The same reference characters indicate the same parts in all the figures.
In the drawings, a portion of a water-tube boiler of well known type is repre-
sented, in connection with the furnace, but it will be well understood that the
form of the boiler is not material to my invention. Referring for the present to
Figures 1 to 5, inclusive, a a¹ a represent the bridge-wall and side walls of the
furnace, enclosing the fire-chamber, 6 represents the grate, and c represents a
portion of a boiler located above the fire-chamber. Said walls are provided with
an internal chamber or cavity a², in which a coil of pipe e is located, the said pipe
extending in continuous convolutions on the three sides of the furnace, from an
inlet-pipe at its lowest point on one side of the furnace, to a blind termination et
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page_text: at its highest point on the other side of the furnace. Supports for this pipe are
provided, comprising upright plates ff upon the inner sides of the pipes, and
bolt-rods ff attached to these plates and extending through to the outside of
the furnace walls, where they are anchored by means of blocks f2f2 on the sloping
rear side of the bridge-wall a, and plates ff on the side walls a¹. Opposite the
uppermost length of pipe in the coil e, the walls are formed with a series of trans-
verse apertures a3 a³ connecting the cavity a containing the pipe with the fire-
chamber, each aperture being fitted with a metallic sleeve or bush e, which
terminates a little short of the inner face of the wall. A series of small pipes or
nozzles el are fitted into the top pipe in the coil e, and project part-way through
the sleeves . This construction prevents the ends of the nozzles from being
destroyed by the action of the fire. These outlets or jets from the coil or retort e
are so located on the three sides of the furnace as to cause the contents of the
retort to intermix freely with the gases arising from the bed of fuel on the grate b,
said gases being as yet in an incomplete state of combustion. A continuous supply
of the mingled gas and oil is kept up through the inlet-pipe e³ by means of suitable
apparatus connected therewith; but as such apparatus forms no part of my
present invention, I have not illustrated the same. The mingling of the oil and
steam vapor with the gases from the grate fuel effects a much more complete
combustion, and secures a hotter flame than is secured when the ordinary fuel
is used alone.
In Figures 6 and 7, I have shown another embodiment of my invention, in
which the pipe-coil is dispensed with, and in its place is employed a retort 9 com-
posed of fire-brick. The retort is shown in sections of brick gg, incorporated in
the furnace walls on three sides of the fire-chamber, on the inside of said walls,
said bricks having interlocking projections or sutures ²² at their ends. The
several bricks are composed of crucible clay, to resist the fire, and each is longi-
tudinally apertured or provided with ducts on the inside, the walls of which ducts
are preferably glazed to retain the liquid or vapor. The ducts collectively form a
conduit having continuous convolutions, as in the case of the pipe-coil. The
mingled oil and steam is introduced to an inner pipe g, into the lowest part of the
retorts g, and in its progress from the said lowest point to the upper portion of
the retort, becomes vaporized by the action of the fire and issues into the fire
chamber, through a series of jets or apertures leading from the top length or
convolution of the duct. At the junction of the inlet-pipe and the retort of
fire clay, and surrounding the said inlet-pipe g³, is a suitable packing g³.
The invention may be varied by introducing the oil and steam into the upper-
most pipe or conduit, and discharging the vapor from nozzles in the lower pipe or
conduit, thus preventing the oil from settling unvaporized in the lower pipes.
This variation is desirable in furnaces where the heat is lacking in intensity."
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is
1. In combination, a furnace having a grate, and a retort located in the walls of
the furnace above the grate, and adapted to be heated by the fire on the grate,
said retort having jets or outlets opening into the fire chamber above the grate,
substantially as and for the purpose set forth.
2. In combination, a furnace having a grate, and a retort adapted to be heated
by the fire on the grate, said retort having outlets so constructed and arranged as
to discharge into the fire chamber above or beyond the grate.
3. In combination, a furnace having a grate and a retort adapted to be heated
by the fire on the grate, said retort being located in the wall of the furnace, and
having outlets in the form of nozzles extending partly through the wall, and
having sleeves surrounding them.
4. In combination, a furnace having a grate, and a retort arranged to discharge

page_text: into the fire chamber and adapted to be heated by the fire on the grate, said retort
comprising a number of sections fitted together at their ends.
5. In combination, a furnace having a grate and a retort adapted to be heated
by the fire on the grate, and to discharge into the fire chamber above the grate,
said retort comprising a number of sections that are fitted together at their ends
and apertured so as to have a conduit having continuous convolutions.
Dated this 22nd day of December 1898.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.