IMPROVEMENTS IN STEAM BOILERS
Year: 1874

page_text: LETTERS PATENT to David Davies, of Crumlin, in the County of
Monmouth, Civil & Mechanical Engineer, for the Invention of
"IMPROVEMENTS IN STEAM BOILERS."
Sealed the 30th June 1874, and dated the 7th January 1874.
PROVISIONAL SPECIFICATION left by the said David Davies at the.
Office of the Commissioners of Patents, with his Petition, on the
7th January 1874.
I, DAVID DAVIES, of Crumlin, in the County of Monmouth, Civil &
5 Mechanical Engineer, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN STEAM BOILERS," to be as follows:-
The object of this Invention is to construct steam boilers, both angular
and cylindrical, in separate or independent sections or divisions, each
section in each group being worked singly if desired as a high-pressure
steam generator, but is so arranged that a series of such sections may be
grouped together and worked jointly, and thus form what I term a
"sectional steam boiler" of any given or required power, which arrange-
ment presents a much more extensive heating surface, and thereby

page_text: "
economises fuel, considerably reduces the time occupied by and the
labour required for cleaning, repairs, and the substitution of new for
worn out parts, and also reduces the risk or violence of those explosions
which are so frequent with ordinary steam boilers.
The first part of my present Invention consists in the construction of
sectional steam boilers, that is boilers formed by a series of independent
divisions, units, shells, or sections somewhat resembling a hollow
parallelopiped, or they may be formed to any other suitable shape or
outline, or they may be made with an enlargement at either end or at
both ends thereof if desired, and are herein-after called “sections."
These sections are constructed either of plain plate, angle, channel,
Z shaped, or flat bar iron, or of combinations of some or all of them, or
they may be made by flanging the plates and rivetting them together at
their edges or otherwise. For resisting the internal pressure of the steam
the front and back plates of these sections are strengthened by internal
stays similarly to the method generally adopted for strengthening the
flat surfaces of fire-boxes for locomotive engines. These stays may be
either solid bars or hollow tubes; in the latter case they may be so
arranged that the hot gases shall pass through them, and thus economise
heat. The lateral plates of these sections may also be stiffened to resist
the pressure of the steam by buckling or curving them to any desired
form. The ends of each of these sections are by preference made with
a moveable cover fastened by bolts and nuts, which covers can be
removed for the purpose of examining, cleaning, and repairing the
sections, and at the same time serve as suitable connections for pipes for
the inlet of water and the outlet of steam. I make these sections by
preference of one special size, according to requirements, say of a certain
unit of horse power, the several parts of such sections being cut,
punched, or drilled, and otherwise prepared by proper and suitable
machinery, so that when put together the said sections are duplicates of
each other.
To form my improved sectional steam boiler I take the requisite
number of the said independent sections and group them together in
any convenient or desired shape or position, either vertical, inclined,
horizontal, or otherwise, as each particular case may require. If desired
they can be arranged as a hollow square, and thus form their own fire-
box and render brickwork unnecessary. This arrangement admits of
the construction of a special class of vertical boiler by erecting on the

page_text: said hollow square boiler an independent circular section or series of
sections, forming a circular boiler, with an internal tube passing through
the same to form the up-take to the outlet flue or chimney, thus utilizing
the whole inside of the said tube as effective heating surface. Between
the outside of the circular section or sections and the inside faces of the
rectangular or flat sections there is a clear space for the flame and hot
gases to circulate freely, and so utilize the whole of the outside of the
circular boiler as effective heating surface, and consequently further
economising heat. When desired one or more of these cylindrical
sections or series of sections without tubes may be placed inside the
square fire-box in such manner as to allow the hot gases to circulate
freely around them on their passage to the chimney.
The second part of my present Invention consists in making a sec-
tional steam boiler of separate duplicate cylindrical sections, similarly
manufactured by machinery as those previously herein described, formed
with two-angle iron, Z shape in section, circular rings with two indented
or buckled circular plates rivetted (one to each) to the internal flanges
of the Z shaped circular rings, thus forming separate halves of the
cylindrical section, with concave or convex ends, which sections are to
be finally connected or united by bolts passing through the outer flanges
of the Z shaped circular rings. By removing the said bolts the end or
ends of each section may be opened for examining, cleaning, and
repairing the interior of such section.
When desirable the cylindrical sections may be made with one hoop
or ring, solid in section, with the two indented circular or buckled plates
rivetted one on each side; or they may be made by flanging the edges
of the two indented circular plates so as to connect them by bolts or
rivets, and if required these sections may also be strengthened with
internal stays. The ring or hoop may also be made of channel section
iron either solid or by rivetting two angle iron rings to one plate.
My improved sections, both the flat and circular ones, being made
duplicates of each other of the same kind afford great facilities for and
economy in effecting repairs and in substituting new for worn-out
sections; inasmuch as the inlet water pipe and the outlet steam pipe
being each fitted with a stop-cock or valve, it is only necessary to close
these pipes therewith and disengage them from the impaired section,
when the latter can be at once and easily removed, repaired, and returned

page_text: to its former position, or a new one be substituted therefor in a few
minutes without interrupting the generation of steam in the other
sections of the boiler.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said David Davies in the Great Seal Patent Office
on the 6th July 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, DAVID
DAVIES, of Crumlin, in the County of Monmouth, Civil and Mechanical
Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Seventh day of January, in the year of
our Lord One thousand eight hundred and seventy-four, in the thirty-
seventh year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said David Davies, Her special license that I, the
said David Davies, my executors, administrators, and assigns, or such
others as I, the said David Davies, my executors, administrators, and
assigns, should at any time agree with, and no others, from time to time
and at all times thereafter during the term therein expressed, should and
lawfully might make, use, exercise, and vend, within the United King-
dom of Great Britain and Ireland, the Channel Islands, and Isle of
Man, an Invention for "IMPROVEMENTS IN STEAM BOILERS," upon the
´ condition (amongst others) that I, the said David Davies, my executors
or administrators, by an instrument in writing under my, or their, or
one of their hands and seals, should particularly describe and ascertain
the nature of the said Invention, and in what manner the same was to
be performed, and cause the same to be filed in the Great Seal Patent
Office within six calendar months next and immediately after the date
of the said Letters Patent.
NOW KNOW YE, that I, the said David Davies, do hereby
declare the nature of the said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained
in and by the following statement thereof, that is to say :-
The object of this Invention is to construct steam boilers, both angular
and cylindrical, in groups of seperate or independent sections or divisions,
each section in each group being worked singly if desired as a high-

page_text: pressure steam generator, but is so arranged that a series of such sections
may be grouped together and worked jointly, and thus form what I term
a "sectional steam boiler" of any given or required power.
In order that my said Invention may be more clearly and more fully
understood and be more readily performed I now proceed to explain the
same with the aid of the three Sheets of Drawings annexed hereto, and
which form part of this Specification, reference being made to the said
Drawings by the numerals and letters marked thereon, and which
reference applies to each Figure on the same Sheet of the said Drawings
where the same index numerals and letters appear.
The sectional steam boiler which I now propose to explain consists of
a series of twenty angular sections or shells grouped together in pairs and
placed either in line or opposite each other. Ten of the said sections
forming the outer casing of the boiler and the other ten sections are
fixed within such casing so as to form ascending and descending flues or
channels for the products of combustion to pass through. The material
I prefer to use in the construction of these sections is that known as
hailon plate inan " of wood quality

page_text: boxes in plan.
Figure 6 is a plan view, looking upwards, under the several sections
and fire-boxes, shewing my arrangement of the feed water pipes.
DRAWING No. 2.
Figure 1 is a longitudinal vertical section of another method of
arranging my improved sectional boiler, on the line A, A, Figure 3*,
shewing the sections B, B', so arranged horizontally as to form clear
flues or channels for the hot gases to pass through and heat such sections 1
on their passage to the chimney.
Figure 2 is a transverse vertical section of the same on the line B, B,
Figure 3, shewing the arrangement of the shells A, A', to form two fire-
boxes, which are enclosed in brickwork.
Figure 3ª is a plan thereof, with the brick top or covering removed 1
from over the sections B, B¹, so as to shew a horizontal arrangement of
such sections when enclosed in brick side walls.
Figure 5ª is a transverse section on the line C, C, Figure 6ª, shewing a
group of T shaped sections arranged in a stove of brickwork, for utilizing
the waste heat from furnaces for generating steam.
Figure 6 is a horizontal plan of the same with the top of the said
stove removed, to shew the arrangement of the said sections placed
horizontally, so as to form clear flue spaces.
Figure 7 is a longitudinal section thereof on the line D, D, Figure 6ª,
shewing the T shaped sections as fixed and supported in a stove of 2
brickwork; also shewing the outside moveable covers for steam and
water pipe connections, and to facilitate cleaning and repairing the
section.
Figure 8 is a transverse section on the line E, E, Figure 9ª, of one of
my improved sections formed without flanged edge plates, and shewing 3
the mode of stiffening flat shells with stays and tubes so placed that the
hot gases may pass through the latter.
Figure 9ª is a side elevation of the same, shewing the stays and tubes
placed alternately.

page_text: together.
Figure 11ª is a transverse section of the same.
DRAWING No. 3.
Figure 1' is a horizontal section on the line C, D, Figure 4', of another
boiler or method of grouping differently formed sections, and shewing
the arrangement of feed water pipes, leading through the flat sections C
to the cylindrical section D¹.
Figure 2 is a plan of the top of the said boiler, shewing the
cylindrical section D' supported on the flat sections C, and also shewing
the moveable covers V of the latter with the steam pipe connections A 16-
attached thereto.
Figure 3 is a vertical section through the centre of the said boiler,
5 shewing the feed water pipes A 10, the steam pipes A 16 for conveying
steam from the flat sections C to the cylindrical section D', for the
purpose of superheating it.
+
Figure 4 is a front elevation of the said boiler, shewing the method
of supporting such boiler on cast-iron standards U, so that sufficient
space may be left for removing the covers V₁ from the bottom of the
sections C.
Figure 5 is a horizontal section thereof on the line A, B, Figure 4b,
shewing the internal square fire-box formed by the four sections C.
Figure 6 is a plan view, looking upwards, of the bottom of the said
5 boiler, shewing the moveable covers V¹ with the feed water pipes A 10
attached thereto.
.
I form the said angular sections A, A1, A2, A5, A5 ×, with two
side plates 1, 1, Figure 5, and top and bottom and two end flanged
plates 2, 2, herein-after called "edge plates," firmly rivetted together, as
shewn. The inside space between the side plates 1, 1, is about four inches
at the bottom end, and about five inches at the upper end, thus forming
an inverted tapering shell, so as to liberate the generated steam more
freely from the surfaces of the heated plates.
To enable these sections to resist a very high internal pressure of steam
the side plates 1,1, are stiffened by transverse stays or stay bolts, as

page_text: shewn in Figures 2, 3, 4, and 5, which I place about five inches apart.
These bolts are secured by tapping and rivetting in the same way as
those ordinarily fixed in the construction of the fire-boxes of locomotive.
engines. By the mode of construction herein-before described, the edge
plates are equal in stiffness or strength to the side plates. The ends of
the sections are provided with moveable covers, properly fitted and
secured by bolts and nuts, to facilitate examining, cleaning, and repairing
the sections.
Ten of the said sections A, A³, are precisely similar in dimensions
and construction, and consequently one can be substituted for another,
except two inside ones, one to each fire-box, which have formed in and
through them, near their upper ends, a hole or channel All x,
for
conveying the products of combustion from the fire-boxes to the flues,
as shewn by the arrows in Figure 3. For this purpose, the four
sections A 2 are made shorter than the other sections, or are provided
with holes or channels near their lower ends, see Figure 3. The four
sections A 5, tapered on one side to suit the incline of the external
sections A, are alike, as also are the two rectangular centre sections A 5 ×,
except that the front one has formed through it two holes A 12, for
cleaning and repairing purposes, and the rear one has also two holes
through it A 13 ×, to allow the escape of the products of combustion.
To form my improved sectional steam boiler I take the said twenty
independent sections and group them together, see Figure 3, placing the
8 sections A in lines of two each, with their upper ends inclining or
leaning inwards towards each other, so that each pair of opposite
sections A touches or leans against a cylindrical steam superheater A 3,
and thus is formed, with the end shells A 5, my improved inclined fire-
boxes d. In the centre, between the two fire-boxes d, I place vertically
the two sections A1 in line, and midway between the said sections A 1
and the interior sections A, I place the four sections A 2, as shewn in
Figure 3. The grouping of the sections is completed by placing the
sections A 5, A5 ×, as shewn in Figures 4 and 5.
The distance or space between the several lines of sections at their
upper ends is determined by the diameter of the horizontal steam super-
heaters A 3, of which there are 6, or one of them between every line or
double pairs of sections at top, and resting in recesses formed in the tops
of the sections A5, A5×, see Figure 1, thus forming the tops of the

page_text: 'flues, and reversing the direction of the current of the products of
combustion on their way to the outlet A 13 ×, which leads to the flue Y,
which flue Y is connected with the chimney by the opening or hole Y 1,
Figure 2. These superheaters A3 are separately connected with each
of the sections A, A1, A2, by the curved pipes A 6, and with the
· sections A 5, A 5 ×, by the pipes A 7, see Figures 1 and 4. When thus
placed in position the several sections are joined or united together by
plates of iron, as partly shewn in Figures 4 and 5, the whole are then
'securely bolted or rivetted to the cast-iron standards U, which standards
are made of sufficient height to allow the removal of the bottom
covers V 1, sce Figures 2, 3, 4, and 6. Each section is supplied with
water by a seperate and independent inlet or feed pipe A 10 leading from
the main water supply pipe A 11, which pipe A 11 receives its supply of
water from a feed pump or injector or other suitable and efficient source.
These inlet water pipes and the outlet steam pipes A 6, A7, are each
fitted with a stop-cock or valve conveniently situated, so that when any
section needs repairs or requires a new one in its place it is only
necessary to close its said pipes by its stop-cock or valve or by a "blind
flange" and to disengage such pipes from the impaired section when the
latter can be at once and easily removed, repaired, and returned to its
former position, or a new one be substituted therefor in a short space of
time without interrupting the generation of steam in the other sections
of the boiler.
On steam being generated in the several sections of my improved
sectional boiler such steam is conveyed from each section through
seperate and independent pipes A 6, A7, to the superheaters A 3; thence
the superheated steam passes through the two pipes A 8 to the cylindrical
steam receiver or reservoir A 15, which steam receiver is so fixed and
arranged in the chimney shaft that the escaping heated products of
combustion freely circulate around the said receiver and further super-
heat and dry the steam therein. The steam thus thoroughly and
economically superheated and dried passes from the said reservoir A.15
to the engine by the pipe A 9.
As the sections of my improved boiler admit of being constructed in
many different forms or shapes, and of being grouped together to form a
boiler in a great variety of ways, I have shewn other methods thereof on
Sheet 2 of Drawings, where Figures 1ª, 2, and 3ª represent a boiler
formed of long flat sections, somewhat similar to those herein-before

page_text: described, but with circular edges, the whole being enclosed in brick-
work. The fire-boxes in this case are formed with the three sections A,
A 1, one of which, A 1, is placed vertically in the centre with one
section A. on each side thereof inclining inwards and leaning against the
steam superheaters A 3, as shewn in Figure 2°. The front and back
sections B, B¹, of the fire-boxes are similar to the six sections B, B1, at
the back thereof (Figures 1 and 2), all which latter sections are placed
horizontally in such a manner that their sides form, when parallel to
each other, clear flue spaces up one side and down the other of each
section, as indicated by the arrows in Figure 1ª. The said horizontal
sections are so fixed that the moveable covers thereof are outside the
brickwork, which forms the sides of the enclosure of the boiler, thus
securing the important desideratum of having every joint in sight and
easy of access.
The arrangement of the water supply is similar to that herein-before
described. The three sections B at the back of the fire-boxes are
connected to the sections B¹ by the curved steam pipes H, so that on
steam being generated in the sections B it passes through the sections B1,
which are placed at a higher level, and thence by the pipes A 13 and the
main steam pipe A 14 to the cylindrical steam receiver fixed in the
chimney, as herein-before described.
Figures 5º, 6º, and 7ª shew a sectional boiler formed by a group of flat
T shaped sections J, K, set in a stove of brickwork for the purpose of
utilising the waste heat from puddling, blast, or other furnaces, or the
said boiler may be heated by gas, or from a special fire-box or furnace,
as may be most convenient or economical. The ends of these sections,
which project through the brickwork (see Figure 7), are each provided
with a moveable cover. The part K on each section forms a steam chest
capable of supplying dry steam, and also admits a clear flue space L.
The steam is conveyed from the chest K by the pipes M and N to the
cylindrical steam receiver, as herein-before described.
Figures 8 and 9ª represent a long flat section, the plates O of which
are stiffened by stays P and tubes Q placed alternately, the tubes Q
being so arranged that the hot gases may pass freely through them.
Figures 10 and 11ª shew a cylindrical section constructed with two
metal rings G of Z shape in section, firmly rivetted to two indented or
buckled circular plates R, one to each ring, thus forming two halves of

page_text: the cylinder, and which are united together by bolts passing through the
outer flanges of the rings G,. as shewn in Figure 11ª. Sections thus
constructed can, by removing the said bolts, be opened to full view for
cleaning and repairing.
When desired cylindrical sections may be made with one solid or
channel hoop or ring with the two end plates rivetted thereto, the said
plates being stiffened to resist the internal pressure of the steam by
staying them as described for flat angular sections, or by tubes which
will allow the hot gases to pass through them.
The sectional boiler shewn on Sheet 3 of the Drawings is of a special
class of vertical boiler formed with four long flat sections C, similar in
form and construction to those herein-before described and shewn in
Sheet 1 of the Drawings, except at their edges, which are made at an
angle of 45°, as shewn in plan, so as to form an outside flange for
connecting them by bolts with a plain packing piece E placed between
them to form a space F for utilizing the edges as effective heating
surface also. These flat sections C are placed upright at right angles to
each other, thus forming an internal square space or fire-box. Within
this square space and a suitable height above the bottom of the fire-box
I fix an independent circular tubular section D or series of connected
sections with its internal tube E passing through it to form the up-take
leading to the chimney, thus utilizing the whole inside of the tube as
effective heating surface; and as the outside of the said tubular section
is surrounded by the inside faces of the flat sections C there is left a
clear space for the flame and hot gases to circulate freely around the
said tubular section, and so to utilize the whole outside thereof as
effective heating surface also.
Each shell is fitted with seperate feed water pipes A. 10, and also
steam outlet pipes A 16, similarly to those herein-before described for
Drawings 1 and 2.
Another important advantage of my improved sectional steam boiler
is that being constructed of sections independent of each other each
section has perfect freedom to expand in any direction without in any
way affecting any other section in its group.
Having thus fully explained the nature of my said Invention, and
the method of nerforming the same. I desire it to be understood that T

page_text: do not restrict myself to the precise dimensions, outline, shape, or form
of the separate sections of my improved sectional steam boiler, nor to
the precise method of constructing such sections, as the sections admit
of very numerous modifications in construction, and methods of grouping
or arranging to form a boiler, neither do I confine myself to the mode
of setting or fixing such boilers as now illustrated, but what I claim as
my Invention and desire to secure by the herein-before mentioned in
part recited Letters Patent is, the construction of flat shells or sections
and the formation of steam boilers with a number of such seperate and
independent sections or shells grouped and united together, substantially:
-as herein described and shewn in the Drawings.
In witness whereof, I, the said David Davies, have hereunto set
my hand and seal, this Fourth day of July, in the year of our
Lord One thousand eight hundred and seventy-four.
DAVID DAVIES. (L.S.)