Improvements in and connected with Steam Boilers.
Year: 1895

page_text: Date of Application, 17th Oct., 1895
Complete Specification Left, 7th July, 1896-Accepted, 8th Aug., 1896
PROVISIONAL SPECIFICATION.
Improvements in and connected with Steam Boilers.
We, STEPHEN ALLEY, and JOHN ALEXANDER MACLELLAN, of Sentinel
Works, Polmadie, in the County of Glasgow, North Britain, Engineers, do hereby
declare the nature of this invention to be as follows, that is to say :-
Our said invention has for its object to construct a steam boiler suitable for high
or other pressures, in an improved manner, and se as to secure efficiency,
with compactness, accessibility of all parts, and other practical advantages.
A boiler made according to our invention comprises a number of sections of a
vertical flat form, each section consisting of a rectangular arrangement having two
header or end pipes connected by numerous tubes, and being placed with one
diagonal vertical. The header pipes and tubes of one section are placed at right
angles to those of the adjacent sections on each side of it; and the fire gases from
an external furnace hereinafter described are made to pass horizontally or nearly
eo through and amongst the tubes. The header pipe to which the lower ends of
the tubes of a section are connected is closed at its upper end and its lower end is
connected to a horizontal cylinder serving as a water reservoir and extending
helow and at right angles to the series of sections. Similarly, the header pipe to
which the upper ends of the tubes of a section are connected is closed at its lower
end and its upper end is connected to an upper horizontal cylinder. In one
modification there are two lower cylinders and two upper cylinders, and the upper
cylinders may be connected to a single higher cylinder, the three upper cylinders
forming, in part, a steam space or reservoir. External down-flow pipes connect
the two upper cylinders with the lower cylinders, and a vigorous circulation takes
place the water descending through the down-flow pipes into the lower cylinders,
thence passing into the lower ends of the lower header pipes, through the tubes into
the upper header pipes, and into the upper cylinders. The header pipes may be
connected by screw couplings to nipples screwed into the upper and lower cylinders
or other joint connections may be used and each section can be easily detached and
removed without disturbing other sections. The spaces between the header pipes
are closed by curved plates lined with asbestos or other suitable material, and
these plates can be detached separately to give access for cleaning the outsides
of the tubes, external plates of sheet iron or steel being applied to cover the header
pipes and plates. The header pipes may be round but are by preference of square
or rectangular section, a row or rows of tubes connected to cach being arranged
zig-zag rather than in a straight line or lines.
The furnace, which is external, is formed of firebrick or is a metal structure
enclosing a firebrick structure having spaces or passages through which the air
(which may be forced) for combustion passes taking up heat passing through the
firebrick. The fire gases pass from the furnace to the boiler tubes by preference
hrough a perforated screen of firebrick which distributes them over the space
ccupied by the tubes.
Dated this Sixteenth day of October 1895.
EDMUND HUNT,
Applicants' Agent.

page_text: Improvements in and connected with Steam Boilers.
We, STEPHEN ALLEY, and JOHN ALEXANDER MACLELLAN, of Sentinel
Works, Polmadie, in the County of Glasgow, North Britain, Engineers, 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 :-
Our said invention has for its object to construct a steam boiler suitable for
high or other pressures, in an improved manner, and so as to secure efficiency with
compactness, accessibility of all parts, and other practical advantages.
A boiler as made according to our invention is shown on an accompanying sheet
of explantory drawings,
Figures, 1, and 2, thereof being respectively a transverse vertical section and a
sectional side elevation.
Figures, 3, and 4, are elevations of separate tubular sections or elements of the
improved boiler.
Figure, 5, is an end elevation of the tubular sections or elements as combined
together, with other parts of the boiler in vertical section.
Figure, 6, is an end elevation of certain parts of the boiler.
Figures, 7, and 8, are enlarged views, at right angles to each other, of details.
In these drawings the same reference letters and numerals are used to mark the
same or like parts wherever they are repeated.
A boiler made according to our invention comprises a number of sections
or elements, A, of a vertical flnt form, each section consisting of a rectangular
arrangement having two header or end pipes, A 1, connected by numerous tubes, A 2,
and being placed with one diagonal vertical. The header pipes, A 1, and tubes, A 2,
of one section are placed at right angles to those of the adjacent sections on each
side of it; and the fire gases from an external furnace, M, hereinafter described
are made to pass horizontally or nearly so through and amongst the tubes. The
header pipe, A1, to which the lower ends of the tubes of a section. are connected,
is closed at its upper end and its lower end is connected to a horizontal cylinder, D,
serving as a water reservoir and extending below and nt right angles to the series
of sections. Similarly the header pipe, A1, to which the upper ends of the tubes
of a section are connected, is closed at its lower end and its upper end is connected
to an upper horizontal cylinder, C. There are two lower cylinders, D, and two
upper cylinders. C, and the upper cylinders may be connected to a single higher
cylinder (not shown) the three upper cylinders forming in part a steam space or
reservoir. External down-flow pipes, E, connect the two upper cylinders, C, with
the two lower cylinders, D, and a vigorous circulation takes place, the water
descending through the down-flow pipes into the lower cylinders, thence passing
into the lower ends of the lower header pipes, A 1, through the tubes, A 2, into
the upper header pipes, and into the upper cylinders.
The header pipes, A 1, may be connected by screw couplings to nipples screwed
into the upper cylinder, C, and lower cylindere, D, but they are, by preference, made
as shown in the drawings with Banges and bolted to stools or other con-
nections, C, D 1, fixed to the cylinders. Each section, A, can be easily detached
and removed without disturbing the other sections. The downflow pipes, E, are
connected by coupling pieces, G, H, to the upper cylinders, C, and the lower
cylinders, D, and are jointed together at their other ends by coupling pieces, J, K,
so as to form a frame similar in shape to the tubular sections, A. The tubular

page_text: sections, A, are enclosed by a casing, L, consisting preferably of two sheets of
thin steel or other metal with a sheet of asbestos or other suitable non-conducting
material placed between them. The casing, L, is made in sections which are fixed
to the tubes, A 1, in a manner hereinafter described so that any sheet of tubes can
be got at for the purposes of examination or repair without disturbing the others.
The spaces between the header pipes may however be closed by curved plates
lined with asbestos or other suitable material and these plates can be detached
separately to give access for cleaning the outsides of the tubes, external plates of
sheet iron or steel being applied to cover the header pipes and plates. The header
pipes, A1, may be round or of square or rectangular section, a row or rows of
tubes being connected to each and which may be arranged zig-zag rather than in a
straight line or lines.
The furnace which is external to the boiler may be constructed solely of fire-
brick, but is preferably a metal structure, P, enclosing a firebrick structure, M,
having spaces or passages through which the air (which may be forced) for
combustion passes, taking up heat passing through the firebrick. The furnace, M,
is made with an arched roof and with an internal arch, N, projecting out from the
bridge, N 1, towards the middle of the furnace in a manner to form a baffle for the
fire gases. An air-conduit, Q, with a flared top for natural draught is fixed to
the metal casing, P, and is provided with a butterfly valve or damper, Q1,
adjustable by means of a rod, Q2, a lever, Q3, and chains, Q4, for controlling
the supply of air. Between the walls of the furnace, M, and the metal casing, P,
an air space, M 1, is provided with which the air-conduit, Q. and the ashpit, PI,
cominunicate for the purpose of supplying air to the furnace through the tire
bars, P2. Fans, 13, or other suitable apparatus are provided in connection with
the air-conduit, Q, to supply forced draught by the passage, M 1, to the ash-
pit, P1, and thence through the firebars, P2, to the furnace, M. The air-
conduit, Q, also communicates with the interior of the furnace, M, by means of an
opening in the roof of the furnace closed by a disk valve, M 2, worked by a
chain, M 3, and a crank shaft, M 4, turned in bearings in the air-conduit shell.
With this construction the air passing between the outer shell, 1, and the furnace
walls takes up and utilises heat passing through those walls. The fire gases from
the furnace, M, have their complete ignition secured by passing through a
perforated screen or chequer work of firebrick, S, in the space, N 2, between the
arched piece, N, and the roof of the furnace, the chequer work becoming intensely
heated. The brick chequer work, S, also distributes the fire gases over the space
occupied by the tubes. The space, N 2, communicates by a short flue, T, with an
pening in the casing, P, enclosing the tubular sections, A, of the boiler. The
fire gases pass in contact with the component tubes of the tubular sections, A,
and finally escape to a funnel or chimney, T 1, at the further end of the boiler.
The furnace, M, instead of being placed at the end of the boiler may be placed
under or at either side of it.
The small tubes, A 2, of the tubular sections, A, connecting the header tubes, A1,
are expanded and properly beaded through openings in the outer sides of the
large tubes these openings being closed by screwed plugs, A 3, as shown in
Figures, 7, and 8. In cases however where very small tubes are employed they
may be brazed or otherwise fixed into the header tubes, A 1, and the openings
closed by the screwed plugs, A. 3, may be dispensed with. Some of the plugs, A 3,
are made with central projections which are screwed to form studs for fixing the
sections of the casing, L, to the tubular sections, A.
The tubes, A 1, may be made large enough to have fixed to each more than one
row of the tubes, A 2, the tubes of one row being in that case placed opposite the
spaces between the tubes of the other row.
In the improved boiler hereinbefore described each tubular section, A, may be
detached without moving the others, and each individual tube can be removed and
be replaced by another without disturbing the section it belongs to.

page_text: Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is:
1. In combination, an external boiler furnace of brickwork, an outer metal
shell between which and the furnace walls the air for combustion passes and is
heated, a boiler casing with which the furnace communicates and which encloses a
series of sets of water tubes fixed in large end tubes and forming rectangular
frames or sections. The tubes of each section being at right angles to those of
the adjacent sections, upper steam cylinders and lower water cylinders connected
respectively to the highest and lowest parts of the sections of tubes, and separate
pipe connections for the downward flow of the water substantially as herein before
described.
2. In combination, an external boiler furnace of brickwork, an outer metal
shell between which and the furnace walls the air for combustion passes and is
beated, a baffle arch extending over about half the lower part of the furnace and
above the arch chequer brickwork, for the passage and ignition of the fire gases,
on their way from the furnace to a series of vertical sections of water tubes
forming the boiler heating surface, the tubes of ench section being at right angles
to those of the adjacent sections; and an outlet flue or chimney for the discharge
of the spent fire gases after they have traversed the series of water-tube sections
or frames substantially as herein before described.
3. a steam boiler the combination of sections or elements ench made up of
two straight and parallel large tubes connected by smaller straight tubes at right
angles to the large tubes so as to form a flat rectangular sheet or frame, the
sections or clements being placed side by side with the tubes of one section at
right angles to those of the other and bolted to upper and lower cylinders, and
being in combination with an external furnace substantially as bereinbefore
described.
Dated this Sixth day of July 1896.
EDMUND HUNT,
Applicants' Agent.