Year: 1885

page_text: I, JAMES HOWDEN, of 8 Scotland Street, Glasgow, in the County of Lanark,
North Britain, Engineer, do hereby declare the nature of this Invention to bo as
follows; that is to say :-
My said Invention has for its objects to improve the construction of certain parts
of steam boilers of or similar to the marine type, with the view of making them
better adapted for the high pressures which have recently come into use; to apply
improved apparatus for burning liquid fuel in such boilers; and to improve
apparatus for applying and using in such boilers air heated by otherwise waste
heat and supplied under a greater than atmospheric pressure. My improvements
combine to secure increased durability of the boiler with economy in the fuel
employed.
My improvements in construction apply more particularly to boilers having
internal furnace tubes combined with combustion chambers at the inner ends of
the furnace tubes, and with small return tubes. Each furnace tube is made to
consist of three or more short tubes made with outward flanges at their ends and
riveted together with a ring between the flanges at each joint. In addition to, or
in some cases instead of the rings at the joints, and where the length of each tube
section, or the greatness of the pressure renders it desirable, flat rings are placed
outside of the furnace tube and are fixed to them by pins screwed into them from
the inside of the tube. These rings and the furnace tubes are made as truly
circular and cylindrical as possible, and the rings by keeping the tubes cylindrical
greatly increase their resistance to collapsing pressure. The rings may be put on in
halves which are bolted together when in place.
The combustion chamber consists of the tube plate which at its lower part is
continued in the form of a ring round the end of the furnaco tube where it is
riveted to the flange of such tube, the circumferential part which is by preference
welded or otherwise formed so as to be in a single piece, and the back plate, or in
the case of a boiler with furnaces at both ends, the opposite tube plate. The
circumferential plate is formed with an outward flange for riveting to the tube
plate, and may have a similar flange for riveting to the back plate or the latter
may be made with a flange entering inside of the circumferential plate.

page_text: The apparatus for liquid fuel consists of one nozzle or a set of several
comparatively small nozzles for each furnace the oil or liquid fuel being injected
in the form of spray by means of such nozzle or nozzles and by air forced through
them, the air being heated and being made to act on the liquid fuel through inner
nozzles. The air is heated by apparatus of the kind described in my patent
specification No. 2789 of 1882; and the necessary pressure is imparted to it by a
pump or other suitable apparatus.
A portion of the air required for combustion is introduced separately from that
entering through the nozzles, and whilst not under so great a pressure, is by
preference still made of a pressure somewhat greater than that of the atmosphere.
With air thus under pressure and heated, less will be required for the combustion
of the fuel whether solid or liquid and the fire gases will consequently be less
diluted and their heat more intense and efficient. The small tubes if made of
ordinary sizes will be larger than is desirable with the compressed and heated air,
and they should be made smaller, or if kept of the usual size helical or zigzag
pieces of metal may be placed inside of them to cause the fire gases instead of
passing through them in the ordinary direct manner to take a tortuous or
lengthened course.
Dated this twenty cocond dex of Donamban 100%

page_text: Improvements in and Connected with Steam Boilers.
I, JAMES HOWDEN, of 8 Scotland Street, Glasgow, in the County of Lanark,
North Britian, Engineer 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, that is to say:-
My said Invention has for its object to improve the construction of certain parts
of steam boilers of or similar to the marine type, with the view of making them
better adapted for the high pressures which have recently come into use; to apply
improved apparatus for burning liquid fuel in such boilers; and to improve the
apparatus for applying and using in such boilers air heated by otherwise waste heat
and supplied under a greater than atmospheric pressure. My improvements
combine to secure increased durability of the boiler with increased efficiency and
with economy in the fuel employed.
And in order that my said Invention and the manner of performing the same
may be properly understood I hereunto append three sheets of explanatory
drawings to be hereinafter referred to in describing my improvements.
Figures, 1, to 4, on sheet, 1, of the accompanying drawings are longitudinal
vertical sections showing various modifications of my improved internal furnaces
or furnace shells, and figure, 5, is a transverse vertical section of a furnace or
furnace shell. Figures, 6 to 11 on sheet, 2, are enlarged views of parts all being
in section excepting figure, 10. Figure, 12, on sheet, 3, is an enlarged section of
one of the boiler tubes; and figures 13 and 14, are a sectional end elevation and a
longitudinal vertical section of a boiler provided with apparatus for using liquid
fuel. In these drawings the same reference letters and numerals are used to mark
the same or like parts wherever they are repeated.
My improvements in construction apply more particularly to boilers having
internal furnace tubes or shells, F, combined with combustion chambers, C, at the
inner ends of the furnace tubes or shells, and with small return tubes, T. Each
furnace tube, F, is made to consist of three or more short tubes made with outward
flanges, a, at their ends and riveted together with a ring, b, between the flanges at
each joint. In figure, 1, the left-hand furnace tube, F, is shown as consisting of
three lengths, and the right-hand furnace tube as consisting of four lengths; but
five or more lengths may also be used, the flanged joints riveted on the rings, b,
giving great strength to resist collapsing pressure.
In addition to or instead of the rings, b, at the joints, and where the length of
each tube section, or the greatness of the pressure renders it desirable, flat rings, R,
are placed outside of the furnace tube, F, as shown in figures, 2, 3, and 4, and these
flat rings are by preference fixed to the furnace tubes by pins, p, screwed into them
from the insides of the tubes as shown in the enlarged sections, figures, 6 to 9.
These rings, R, and the furnace tubes, F, are made as truly circular and cylindrical
as possible, and the rings by keeping the tubes cylindrical greatly increase their
resistance to collapsing pressure. The rings R, may be put on in halves which are
bolted together when in place, the joints being, by preference, made as shown in

page_text: figures, 5, 10, and 11. Protuberances, m, are formed on the rings, R, to receive
the screw pins, p, by which the rings are fixed to the furnace tubes, F; and the
rings, R, may be made with their inner edges fitting closely to the outside of the
furnace tube, F, as shown in figure, 6, or they may be made so as not to be in close
contact excepting at the parts where the screw pins, p, are fixed in as shown in
figures, 8, and 9.
In figure, +, the furnace tube, F, has the flanges, a, at its ends not formed on it
but on rings riveted upon it, which is a convenient construction when renewing
the furnace tubes of a boiler; and when the tube is made in this way the
strengthening rings, R, may be made entire and can be put on before the flange
rings, a, are riveted on.
The combustion chamber, C, consists of the tube plate, D, which at its lower
part is continued in the form of a ring round the end of the furnace tube, F, where
it is riveted to the end flange, a, of such tube; the circumferential part, E, which
is by preference welded or otherwise formed so as to be in a single piece, and the
back plate, G, or in the case of a boiler with furnaces at both ends, the opposite
tube plate, D. The circumferential plate, E, is formed with an outward flange, h,
for riveting to the tube plate or tube plates, D, and may have a similar flange for
riveting to the back plate, G, or the latter may be made with a flange entering
inside of the circumferential plate, E.
The
The apparatus for applying liquid fuel and of which a modification is shown in
figures, 13, and 14, of the drawings, consists of one nozzle or a set of comparatively
small nozzles for each furnace the oil or liquid fuel being injected in the form of
spray by means of such nozzle or nozzles and by air forced through them, the air
being heated and being made to act on the liquid fuel through inner nozzles.
air is heated by apparatus of the kind described in ny patent specification No. 2789
of 1882; and the necessary pressure is imparted to it by a pump or other suitable
apparatus. A portion of the air required for combustion is introduced separately
from that entering through the nozzles, and whilst not under so great a pressure
is by preference still made of a pressure somewhat greater than that of the
atmosphere.
In the arrangement shown in figures, 13, and 14, a single nozzle, N, is used for
injecting the liquid fuel into each furnace, F, the oil being supplied to each nozzle
by a branch, k, from a pipe, L, whilst the compressed air is supplied to an inner
nozzle in each nozzle, N, by a branch, n, from a pipe, q, to which there is also
connected a pipe, 8, for admitting steam to pass along with or instead of the air
when considered desirable. The forward part of the furnace, F, is lined with fire-
brick, U, a part being raised for the jet of oil spray to strike against, and this
firebrick lining becoming intensely heated on its inner surface insures the ignition
and complete combustion of the oil. The air which enters otherwise than through
the nozzle, N, is heated by passing by an inlet, V, into a casing, W, in the smoke
box this casing having fitted to it vertical tubes, X, through which the fire gases
pass on their way from the boiler tubes to the uptake. The air after passing
amongst the tubes, X, descends through enclosed spaces, Y, at the sides and is
admitted through valves, Z, into casings, 15, covering the front ends of the
furnaces, F. Each outer furnace door, 16, has connected to it an inner door or
plate, 17, and this plate and the plate, 1S, forming the inner side of the casing, 15,
are perforated with holes proportioned and arranged to distribute the entering air
in an advantageous manner.
With air under pressure and heated as described, less will be required for the
combustion of the fuel whether solid or liquid, and the fire gases will consequently
be less diluted and their heat more intense and efficient. The small tubes, T, if
made of ordinary sizes will be larger than is desirable with the compressed and
heated air; and the tubes should be made smaller, or, if kept of the usual size,
helical or zigzag pieces of metal may be placed inside of them to cause the fire
gases, instead of passing through them in the ordinary direct manner, to take a
tortuous course. Figure, 12, is an enlarged section of a tube, T, provided internally

page_text: with a helical strip of metal, 19, for the purpose indicated, such strip when not the
entire length of the tube being by preference placed at the smoke-box end.
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. The combination of internal combustion chambers constructed substantially
as hereinbefore described with internal furnace tubes or shells constructed of three
or more short lengths fixed together by means of outward end flanges with
interposed rings substantially as herein before described.
2. Placing Hat rings upon furnace tubes or shells of internally-furnaced steam
boilers substantially in the manner and for the purposes hereinbefore described.
3. Combining apparatus substantially as herein before described with reference
to figures, 13, and 14, of the accompanying drawings; that is, the apparatus for
applying liquid fuel combined with the apparatus for heating the air supply or a
portion of it by the otherwise waste fire gases.
4. Providing helical or zigzag or equivalent pieces of metal in the tubes of steam
boilers which are supplied with air under pressure substantially as and for the
purposes hereinbefore described.
EDMUND HUNT,
Applicant's Agent.