IMPROVEMENTS IN STEAM BOILERS OR GENERATORS."
Year: 1865

page_text: LETTERS PATENT to Andrew Barclay, of Kilmarnock, in the County of Ayr,
North Britain, for the Invention of "IMPROVEMENTS IN STEAM BOILERS OR
GENERATORS." "
Sealed the 22nd June-1866, and dated the 29th December 1865.
ட்.
PROVISIONAL SPECIFICATION left by the said Andrew Barclay at the
Office of the Commissioners of Patents, with his Petition, on the
29th December, 1865. *
I, ANDREW BARCLAY, of Kilmarnock, in the County of Ayr, North Britain,
do hereby declare the nature of the said Invention of "IMPROVEMENTS IN
STEAM BOILEBS OR GENERATORS;" to be as follows, that is to say:-
This Invention, which has for its object the production in certain classes of
steam boilers or generators of a greater amount of steam for a given quantity
of fuel than has hitherto been obtained, consists essentially in opening a second
communication or communications between the water situated about the crown
of the fire-box and that around its sides. According to one modification under
which this Invention may be carried out, tubes are employed, the upper ends
DQ1

page_text: of which are fixed into the crown of the fire-box, their lower ends being bent
round and fixed into the sides; in this way a second communication or series
of communications is effected between the water situated in the upper and
lower parts of the fire-box; at the same time the surface of the tubes being
exposed to the action of the fire a much greater heating or absorbent surface
is obtained, from which immediately follows a proportionate increase of steam
generated. It is obvious that there are many other modifications under which
these present improvements may be employed, viz., the tubes may be carried
diagonally or in curved lines across from the crown plate to the opposite sides
of the fire-box, the sides and crown of the fire-box themselves being formed
suitably to receive their ends. The mode in which the herein-before mentioned
apparatus acts is as follows:-The water in the tubes becoming heated an
upward current is produced, which carries the hottest water to those parts of
the boiler which are at a lower temperature, the water at the lower tempera-
ture thus displaced passes down the sides of the fire-box into the hotter tubes,
and in time becomes heated and transmitted upwards to those parts of the
boiler at a lower temperature; in this manner a continuous circulation is
maintained.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Andrew Barclay in the Great Seal Patent Office on the 29th
June 1866.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ANDREW
BARCLAY, of Kilmarnock, in the County of Ayr, North Britain, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-ninth day of December, in the year of our Lord
One thousand eight hundred and sixty-five, in the twenty-ninth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Andrew Barclay, Her special license that I, the said Andrew Barclay,
my executors, administrators, and assigns, or such others as I, the said Andrew
Barclay, my executors, administrators, or 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 Kingdom of Great Britain and Ireland, the Channel

page_text: Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN STEAM BOILERS
OR GENERATOES," upon the condition (amongst others) that I, the said Andrew
Barclay, by an instrument in writing under my hand and seal, should par-
ticularly 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 Andrew Barclay, do hereby declare the
nature of my said Invention, and in what manner the same is to be performed,
to be particularly described and ascertained in and by the following statement,
reference being had to the accompanying Drawings, and to the letters and figures
marked thereon, that is to say:
My said Invention, which has for its object the production in certain classes
of steam boilers or generators of a greater amount of steam for a given amount
of fuel than has hitherto been obtained, consists essentially in opening a second
communication or communications between the water situated about the crown
of the fire-box and that around its sides. According to one modification under
which this Invention may be carried out tubes are employed, the upper ends
of which are fixed into the crown of the fire-box, their lower ends being bent
round and fixed into the sides; in this way a second communication or series
of communications is effected between the water situated in the upper and
lower parts of the fire-box; at the same time the surface of the tubes being
exposed to the action of the fire, a much greater heating or absorbing surface
is obtained, from which immediately follows a proportionate increase in the
amount of steam generated. It is obvious that there are many other modifi-
cations under which these present improvements may be employed, viz., the
tubes may be carried diagonally in curved lines across from the crown plate of
to the opposite sides of the fire-box, the sides and crown of the fire-box being
formed suitably to receive these. The mode in which the herein-before men-
tioned apparatus acts is as follows:-The water in the tubes becomes heated,
and an upward current is produced, which carries the hottest water to that part
of the boiler which is at a lower temperature; the water at the lower tempera-
ture thus displaced passes down the sides of the fire-box into the hotter water,
and it in turn becomes heated and transmitted upwards to those parts of the
boiler at a lower temperature; in this manner a continuous circulation is
maintained.
And in order that my said Invention may be properly understood I shall now
proceed to describe the system, mode, or manner in or under which the same is

page_text: or may be used, or practically carried into effect, reference being had for the sake
of more complete elucidation to the several Figures upon the explanatory Sheet
of Drawings which I have hereunto appended, that is to say, Figure 1 is a
longitudinal section of one form of boiler constructed under the first modifica-
tion of my improved arrangements; Figure 2 is a transverse sectional plan
on the line a, a, Figure 1. In both these Figures the same letters of reference
indicate corresponding parts, some only of such parts being visible in Figure 2.
The shell of the furnace A is of the truncated conical form usually employed
in boilers of the class now being specified into the sides B and crown C of which
are fixed the bent tubes D, by which a portion of the water is heated; the
lower ends of these tubes, as will be seen on referring to the Drawing, are
open to the water contained in the space between the furnace sides B and the
outer casing E, so that a free communication is thus obtained between the
portions of the water situated in these upper and lower portions of the boiler,
the value and utility of which are herein-after more especially set forth.
From the centre of the furnace crown the inverted truncated conical water
space F depends; and within this the conical tube G is situated, being held by
four brackets H, projected from the crown plate; the inner cone does not touch
the bottom of the outer one, neither is its lower end closed. The upper part
of the boiler proper is encased by a metallic covering I, which surrounds its
sides and top, and from which the chimney K is projected, a space L being
thus left between the casing and boiler shell. Openings or passages M are
made passing from the furnace to the space L, through which the heated
products of combustion pass from the furnace to the space, the outer casing I
confining the heat as much as possible against the boiler shell, until the very last
and comparatively non-generating products pass away through the chimney. By
this arrangement the whole of the surface of the boiler, with the exception of
that small portion not enclosed by the casing, is converted into a very effective
heating surface of a much larger area than is obtained in boilers of this class as
ordinarily constructed; consequently producing not only great economy in the
quantity of fuel burnt, but also by the large and long continuation of the sur-
face over which the heated products have to pass, all the heat which
would otherwise be wasted is utilized, and the gases ultimately pass off
having the more effective portions of their previously contained heat usefully
abstracted.
On referring to the Figures it will be observed that owing to the tubes pre-
senting a much larger area of heating surface to a given quantity of water
than what is obtained from the furnace sides the giving off of heat to the

page_text: water will take place much more rapidly in the case of the tubes than with
respect to the sides, so that the action of forming steam is much more intense
in the former case than in the latter; on this account then a continual circu-
lating current is established up through the tubes and down the sides of the
water space, and in the same manner the water heated by the central cone
rapidly ascends to the surface when it gives off the contained steam, and after
becoming cooler and less active the water descends through the inner conical
tube to be again heated, when the same action is produced as before. It will
thus be evident that by means of the peculiar method of disposing the tubes
and inner central cone relatively with the heating surfaces of the ordinary
furnace proper, a most complete circulation throughout all parts of the boiler
is produced, and owing to the great continual activity of this circulation the
deposit of materials held in suspension in the water is considerably reduced,
and the mechanical as well as chemical destruction thereby produced are also
much diminished, whilst, too, the passage of heat from the fuel to the water
is not obstructed by the formation of great thicknesses of scale.
Figures 3 and 4 are respectively a vertical and transverse section of another
mode of arranging a boiler of the class similar to that immediately preceding.
In this second case the tubes einployed in the first modification are dispensed
with, and the central cone is employed; otherwise the construction is similar,
and need not be herein re-specified.
In this second modification, however, a different arrangement is employed
for effecting or rather facilitating the circulation of the water in the space
between the furnace A and the shell B; this is carried out by placing several
tubes D in this space, one of which is shown dotted in Figure 3, whilst the
whole of these tubes D are shown in their fixed positions in Figure 4. The
reason for the introduction of these tubes is to render an easily accessible and
distinct or separate passage for the downward current in the boiler, thus pre-
venting the intermingling and consequent confusion of the upward and down-
ward currents which occurs in water spaces as ordinarily constructed, thereby
facilitating the disengagement of steam.
It is not considered absolutely necessary in all cases to employ these tubes D,
although in some cases it is preferred to do so. The tubes may be fixed to
the boiler shell by brackets in the manner shown, or in any other way,
according to the designs of the manufacturer. On again referring to Figures 1
and 2 it will be seen that these tubes D are shown applied thereto; it is
however to be understood that in this case, where the heating tubes are
employed, the use of the tubes D are not considered so essential.

page_text: Figures 5 and 6 of the Drawings represent respectively a vertical, longi-
tudinal, and transverse section of a rectangular boiler, construcied in every
way, except in form, in a manner corresponding to Figures 1 and 2, and the
same remarks used to render distinct the action and use of the several parts
employed in Figures 1 and 2 apply equally to this third arrangement, and
therefore need not be again specified; the bars marked c in all the Figures are
stays, and the fire or furnace hole is marked X. By substituting Figures 5
and 6 in the part of this Specification describing Figures 1 and 2, and sub-
stituting the latter form of the boiler shown in the last two Figures for that
shown in the former two, the description of the first will correspond to the
two last-mentioned Figures.
That modification mentioned in my Provisional Specification consisting of the
introduction of inclined, straight, or curved water tubes, I have not considered
necessary to more particularly illustrate by means of Drawings. It is, however,
to be particularly understood that with reference to the foregoing modifications,
excepting that illustrated by Figures 3 and 4, what I consider a very import-
ant feature is the introduction of those water tubes marked D in Figures 1,
2, 5, and 6, which tubes, as well as in the case of those inclined, are taken
from the crown to one of the sides, and not from side to side of the boiler.
I also consider very important the application of the outside casing marked I
in all the Figures.
Having now described the nature of my said Invention, and the manner in
which the same is or may be used or practically carried into effect, I would
observe in conclusion that what I consider to be novel and original and there-
fore claim as the Invention secured to me by the herein-before in part recited
Letters Patent is,-
First, the general arrangement and combination of parts resulting in the
construction, and several forms of steam generators for giving effect to the
several improvements herein-before specified with reference to steam generators
or boilers and the generation of steam.
Second, the introduction of tubes fixed into the crown and one side of the
furnace of steam generators for effecting a more perfect circulation of the
water, and a readier disengagement of steam, as herein-before described, or
any mere modification thereof.
Third, the use and introduction of a second inverted tubular passage within
the depending cone for facilitating the circulation of the liquid, as herein-before
described, or any mere modification thereof.
Fourth, the converting the whole or nearly the whole of the exterior surfaces

page_text: of boilers of the class herein-before specified into effective heating surface by
means of an outward casing.
In witness whereof, I, the said Andrew Barclay, have hereunto set my
hand and seal, this Twenty-seventh day of June, One thousand eight
hundred and sixty-six.
Witness,
ST. JOHN VINCENT DAY, C.E.,
Patent Office,
166, Buchanan Street,
Glasgow.
ANDREW BARCLAY. (L.S.)