IMPROVEMENTS IN STEAM BOILERS OR GENERATORS
Year: 1882

page_text: LETTERS PATENT to Andrew Duncan Barclay of Kilmarnock in the County
of Ayr North Britain for an invention of "IMPROVEMENTS IN STEAM BOILERS
OR GENERATORS”
PROVISIONAL SPECIFICATION left by the said Andrew Duncan Barclay at
the Office of the Commissioners of Patents on the 16th June 1882.
ANDREW DUNCAN BARCLAY, of Kilmarnock, in the County of Ayr, North
Britain, "IMPROVEMENTS IN STEAM BOILERS OR GENERATORS."
This Invention has reference to a new or improved construction or general
arrangement of the parts, of a vertical steam boiler or generator for motive-power
engines or other purposes; which will give greater heating surface, and more perfect
circulation of the water, with less liability to derangement from the expansion and
contraction of its parts, than has been the case in the vertical steam boilers
heretofore in use.
The nature and novelty of this new or improved construction of steam boiler or
generator consist as follows:-In making the outer shell, and the internal fire-box
cylindrical, with an annular water space of a few inches between them, and both
formed with flat or slightly domed upper flanged close ends, to form a water and
steam space between them, and having a circular furnace or grate bars carried on
an edge ring secured near the bottom of the fire-box, with the furnace mouth
formed through the two shells and annular water space on one side, some little
distance above the furnace bars. The shell and fire-box would however be
preferably jointed together by solid or angle-iron flanges, and secured by screw
bolts near the lower part of the annular water space above the fire-grate, or to an
annular basement frame or box below the fire-grate, for the convenience of separating
the outer shell from the fire-box for repairs, or inserting the new water circulating
and heating tubes to be hereinafter described. The top end of the fire-box would
have a central circular hole cut out of it, preferably rather more than one third of
the diameter of the shell of the fire-box, but the size might be varied less or more,
and a cylinder or tube of the same size would be rivetted to this plate by a flange
concentric to the hole and shell of the fire-box projecting down into it to a little above

page_text: the fire, where it would be formed with a strong or domed end, and thus form a
centre cylindrical water space, also making the upper part of the fire-box annular.
An important feature of the improvements of this Invention and boiler, consists in
fitting the upper part of this annular space of the fire-box, with circular rows of
radial water circulating tubes above each other, preferably fitted over the spaces
between the tubes of the set or teir below, and expanded and secured at the ends,
through the shell of the fire-box and the central water cylinder or uptake trunk.
A set of heating tubes are fitted vertically, or at a slight angle, through the upper
water and steam space from the annular top plate of the fire-box over the horizontal
tubes, and through the top plate of the boiler. To both of which plates, the ends
of these tubes are preferably secured by screws and screw nuts on both sides, so as
to form stays to the top of the boiler and fire-box, as well as flue heating tubes, for
conducting the heated products of combustion from the top of the fire-box to the
smoke-box fitted above the boiler, after they have acted on the great outer heating
surface of all the radial tubes filling the upper part of the fire-box. In this improved
construction of boiler and fire-box, great heat is imparted to the water through the
sets of radial tubes, and through the central uptake water vessel immediately over
the fire, giving a free escape of the steam as it is raised, to the upper steam space,
and a perfect circulation of the water in the boiler, returning over the top of the
fire-box, and down the colder outer annular water space between the shell of the
boiler and the fire-box, through the whole of the horizontal sets of radial water
heating tubes, and up the hot central water space.
When it is not desired to carry the vertical flue heating tubes through the steam
space, they could be made short, or have the fire-box and radial water heating
tubes carried up to near the top of the boiler, and have this part filled with water
to the top, and have a steam receiver or dome fitted above the boiler for collecting
the steam, and drawing it off from, as in many other forms of steam boilers.
When desired, doors might be formed and jointed on the outer shell of the
boiler at intervals for removal, opposite to the ends of the radial tubes, to enable
these to be removed and replaced without separating the shell of the boiler from
the fire-box.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Andrew Duncan Barclay in the Great Seal Patent Office on the
16th December 1882.
ANDREW DUNCAN BARCLAY, of Kilmarnock, in the County of Ayr, North
Britain. "IMPROVEMENTS IN STEAM BOILERS OR GENERATORS"
My said Invention has reference to a new or improved construction or general
arrangement of the parts of a vertical steam boiler or generator for motive-power
engines, or other purposes, the object of which is to give greater heating surface,
and more perfect circulation of the water, with less liability to derangement from
the expansion and contraction of its parts than has been the case in the vertical
steam boilers heretofore in use.
In order that my said Invention, and the manner of performing the same, may
be properly understood, I have hereunto appended two sheets of explanatory
Drawings to be hereinafter referred to, and representing modifications of my improved
steam boilers.
In these Drawings, the same reference letters are used to mark the same or like
parts where repeated.
Figure 1 on Sheet 1 of these Drawings is a vertical section of one modifi-
cation, or combination of the parts, of the improved boiler, and Figure 2 is a
horizontal section of the same as at the line 1--1 in figure 1. Figure 3 is a
vertical section of a modified arrangement of the boiler, and figure 4 is a horizontal
section taken as at the line 2 - -2 in figure 3. Figure 5 is a detailed section
showing one mode of connecting the outer shell of the boiler to the shell of the flue,
so that it may be readily disconnected. Figures 6 and 7 represent portions of
plates of the inner and outer shells of the annular flue showing the arrangement
of the water tubes. Figure 8 on sheet 2 of the Drawings is a longitudinal vertical
section of a boiler of the locomotive type, as constructed in accordance with my
improvements, and figure 9 is a transverse vertical section of the same, as at the
lines 3 3 in figure 8. Figure 10 is a longitudinal vertical section of portion
of a single flue or cornish boiler, constructed in accordance with my improvements.
Figure 11 is a vertical section through the plates forming the outer and inner shell
of the annular flue space of the boiler, and showing the mode which I adopt for
tapping the holes and showing the water tube inserted.
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Referring to figures 1 and 2 on the first sheet of these Drawings the improved
boiler is formed with an outer annular water space A and a central cylindrical
water space B between which is an annular flue space or upper fire-box C, conveying
the products of combustion upwards from the furnace F towards the smoke-box
and chimney E. E. The boiler thus consists of an outer shell A¹ with an inner
shell B and an intermediate shell C₁ forming the annular flue space C within.
The shell Benclosing the central water space B is formed with a closed and
rounded or domed end B2 just over the furnace F. The upper end of the boiler
shell A is closed by a flanged plate or plates A² fitted with a steam dome A³,
and the upper end of the annular flue space C. is closed by a flanged annular
plate or plates C³, connecting the shells B and C. A steam space or combined
water and steam space A' is thus left between the upper end of the annular flue
space and the upper end of the boiler, and the products of combustion are
led through the steam space to the smoke-box E and uptake or chimney E¹
by an annular row or series of vertical flue tubes D connected to the upper
end plate C² of the annular flue C. and to the upper end plate A² of the boiler
shell,

page_text: Connecting the annular water space A of the boiler, and the inner water
space B. are arranged a large number of short water tubes G passing through and
screwed or expanded into the shells B¹ and C¹. These tubes are fitted radially and
horizontally, and as close together as possible within the annular flue space,
and their external surfaces are exposed to and intercept a large proportion of the
heat of the fire gases passing upwards through the annular flue space C to the
smoke-box and chimney E. E¹.
The furnace is formed by grate bars F¹, carried on an edge ring f fitted over
projecting and supporting bracket pieces f' bolted or otherwise secured to the
lower closed end ring a of the annular water space A near the bottom of the
fire-box F. The furnace mouth F is carried through the two shells A', C¹, forming
the annular water space A on one side some little distance above the furnace bars F¹.
The annular flue space C forms an upward continuation of the fire-box or
chamber F by which the fire gases pass to and through between the flue tubes D.
The outer shell A¹ and fire-box F are preferably jointed together by solid or angle-
iron faced flanges H rivetted to the plates of the shell A¹, secured by screw
bolts H¹ and nuts h. near the lower part of the annular water space A above the
fire-grate, or the outer shell may be jointed to an annular basement frame or box
below the fire-grate, for the convenience of separating the outer shell from the
fire-box F or lower supporting shell for repairs or for inserting the radial water
circulating and heating tubes G.
The smoke-box E and uptake to the chimney E¹ is conical and is flanged at e
and connected to the top of the outer shell A2, or it may be by an annular angle-
iron ring e¹ rivetted to it and to an angle-iron L on the upper end A³ of the outer
shell A¹ Within the smoke-box may be fitted a coil of water pipes I connected to
the water space of the boiler and leading through the smoke-box. In this coil which
is shown by the dotted lines the feed water supplied through the inlet ¹ to the
boiler, may be partially heated by the escaping products of combustion before
passing into the boiler through the upper end as is shown at i¹.
The radial water circulating tubes G in the annular flue space or upper
fire-box C, are fitted in horizontal rows above each other, the tubes in each row
being fitted over the spaces between the tubes of the set or row below. These
tubes G are by preference fitted into the shells B¹ and C¹. in the manner indicated
by figures 6 and 7, which represent portions of the cylindrical shells B¹. C¹. as if
flattened out to form plane surfaces. In this arrangement, which is devised to
distribute the tubes so as to leave as nearly as possible an equal surface of metal
between each, and to equalise the strain over the plates, the tube holes are drilled
in horizontal rows, so disposed that the centre lines of each alternate row are more
distant from each other than those of the intermediate rows. This disposition of
the tubes has the advantage of interposing part of the tubes of each row over the
spaces formed by rows below, so that at the outer ends even of the radial tubes
there is no point at. which the fire gases can pass directly upwards without
impinging on the surface of the tubes, while at the inner ends of the radial tubes,
the tubes can be arranged to enter the inner shell B¹ without reducing the space
between the tubes of two rows and weakening the plates. The tubes G, for
example in row numbered 1 are placed centrally between those in the row
numbered 2; but as this disposition if followed throughout would have a free
vertical space between the tubes at their outer end; the tubes of the row number 3
are so placed as to divide the free vertical space left between every alternate pair
of tubes of rows number 1 and 2; while row number 4 is so placed as to divide i
the spaces left between the remaining pairs of rows number 1 and 2. Row
number 5 is vertically over row number 2, and row number 6 over row number 1.
The tubes G are by preference fitted into the shells B', C', by being screwed at
both ends g, and having the holes in the shells tapped to correspond, as shown in
figure 11 For this purpose a long screw tap is passed through the hole in the
outer shell A' and entered into the corresponding hole in the shell C. Both holes
are tapped together and the tube G for that hole is screwed to correspond exactly.

page_text: The pitch of the screw is the same for both ends of the tube, but the outer hole is
tapped of a diameter slightly exceeding that of the inner hole. The tubes may
however be expanded into the holes in the plates.
The heating or flue tubes D which are fitted vertically, or at at slight angle
through the upper water and steam space A from the annular top plate of the flue
space or upper fire-box C and through the top plate of the boiler, are preferably
secured by screws and screw nuts d on both sides, so as to form stays to the top of
the boiler and annular flue space or upper fire-box C as well as flue heating tubes
for conducting the heated products of combustion from the fire-box to the smoke-
box E, after acting on the surface of the radial tubes G.
In this improved construction of boiler, great heat is imparted to the water
through the sets of radial tubes G, and through the central water space or vessel B,
immediately over the fire F, giving a free escape of the steam as it is raised to the
upper steam space A*. A perfect circulation is also ensured of the water in the
boiler which returns over the top of the annular flue or upper fire-box C, and down
to the colder outer annular water space A between the shell A¹ of the boiler, and
that C' of the annular flue space or upper fire-box C, as also through the whole of
the horizontal sets of radial water heating tubes G, and up the hot central water
space B.
When it is not desired to carry the vertical flue heating tubes D through the
steam space A they may be made short, or the arrangement, shown in figures 3 and
4 may be adopted in which the annular flue space or upper fire-box C, and water
heating tubes G are carried up to near the top of the boiler, and the flue tubes D
are dispensed with.
In this case the central water space or vessel B is enclosed by a domed upper end
or cover A³ rivetted to the shell B and forming a steam dome A³ from which the
steam is led away by a pipe J. The central upper space is connected to the outer
annular space by the radial tubes G, which also form means of supporting the central
vessel B.
When desired, doors might be formed and jointed on the outer shell of the boiler
at intervals for removal, opposite to the ends of the radial tubes, to enable these
to be removed and replaced without separating the shell of the boiler from the
fire-box.
It is however preferred to connect the outer shell A¹ of the boiler to the inter-
mediate or flue shell C in such wise that it can be removed to admit of inspection
or renewal of the tubes G. For this purpose the outer shell A' is connected to the
shell C by means of an annular angle iron or angled plate L rivetted to the outer
shell and bolted to a similar annular angle-iron L³ rivetted to the shell C¹. The
bearing faces l. 1 are truly faced up, and are bound together steam-tight by means
of studs M screwed into the angle iron L' and passing through square holes in the
angle-iron L to the outside where they are fitted with strong screw-nuts m. The
angle-iron flanges H at the lower end of the outer shell A¹ where it joins the lower
fire-box, being also connected by bolts E', it is only necessary when desired to
remove the shell A¹ of the boiler to unscrew these nuts h and m, and raise the
shell A¹. The radial tubes G may then be inspected or removed and repaired.
The improvements in the construction of steam boiler described with radial tubes
closely fitted in an annular flue space or fire-box though most advantageously
adapted for boilers of the vertical class, may also be applied to boilers of the
horizontal type. Modifications of horizontal boilers fitted with my improvements
are illustrated in figures 8, 9 and 10 on Sheet 2 of the Drawings. In the boiler of
the locomotive type shown in figures 8 and 9, the fire-box F is continued in the
form of an annular flue space C, as in the vertical arrangement, and is fitted with
radial tubes G to intercept the heat of the fire gases. The water space B is a little
lower than the centre of the boiler, and the flue space C is formed in a circle round
it, so that steam space may be left at the upper side of the boiler. A dome A¹¹ is
also provided as usual. The products of combustion pass from the flue space Cinto
the smoke-box E, and out by the chimney E¹.

page_text: The horizontal boiler shown in figure 10, represents my improvements applied to
the cornish type of boiler. The flue space C is made annular, and is fitted with
radial heating tubes G. This arrangement has the advantage that an extremely wide
furnace F can be had in front. The fire-bars F' are carried in the usual way, and
the hot flame and products of combustion pass from the furnace F over a bridge F³,
and play on the end B³ of the central water space B, by which the hot gases are
deflected radially. They then pass through the annular flue space C to a smoke-
box and chimney not shown in the Drawings.
Having thus described my said Invention, and the manner of performing the
same, I have to state that I do not restrict myself to the precise details herein
described or delineated, but what I believe to be novel and original, and therefore
claim as the Invention secured to me by the hereinbefore in part recited Letters
Patent is:
First. The arranging and combining of the parts of steam boilers, substantially
in the improved manner herein described and illustrated by the accompanying
Drawings, and as distinguished in the modifications shown in figures 1 and 2; 3 and
4; and 8, and 10.
Second. The construction or arrangement of the parts of steam boilers with an
annular flue space or fire-box formed between a central and an annular water
space, such annular flue being fitted with rows of radial water tubes, substantially
as herein described, and illustrated by the accompanying Drawings.
Third. Arranging and constructing steam boilers with an annular flue space or
fire-box fitted with radial water heating tubes extending from a central to an outer
annular water space and upwards from the firebox to the smoke box end of the
boiler substantially as herein described, and illustrated by Figures 3 and 4 or 8, 9
and 10 of the accompanying Drawings.
In Witness Whereof, I the said Andrew Duncan Barclay, have hereunto set
my hand and seal, this fourteenth day of December, in the year of our
Lord One thousand eight hundred and eighty two.
Witness,
W. R. M. THOMSON,
Patent Agent
Glasgow.
ANDREW DUNCAN BARCLAY (L.S.)