IMPROVEMENTS IN STEAM BOILERS
Year: 1874

page_text: LETTERS PATENT to Alexander Melville Clark, of 53, Chancery Lane,
in the County of Middlesex, Patent Agent, for the Invention of
"IMPROVEMENTS IN STEAM BOILERS."-A communication from abroad
by Charles Haynes Haswell, of the City, County, and State of New
York United States of America
PROVISIONAL SPECIFICATION left by the said Alexander Melville
Clark at the Office of the Commissioners of Patents, with his
Petition, on the 17th April 1874.
•
I, ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the
County of Middlesex, Patent Agent, do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN STEAM BOLLERS," to be as
follows: :-
The design of this boiler and the nature of this Invention consists in
the first part of a construction of round shell. furnaces, lower flues, and
arched uptake, or vertical smoke connection, also arched horizontal
smoke connections, so far as the same may be practicable of attainment,

page_text: in order to offer the greatest resistance to rupture with the least material
and with the least practicable resort to braces, combined with economy
of weight, cost, and increased endurance, all of which elements are more
essential than heretofore.
In steam boilers of ordinary design, having either overhead return
tubes or tubes directly in lino with their furnace, and all set in the
longitudinal plane of the boiler, it is very difficult to so proportion their
diameter as to meet the several requirements of transverse area, heating|
surface, and diameter proportionate to their length, and to accommodate
the necessary steam space. The cause of this difficulty arising from the
circumstance that the area of the grate bars being given, and being a
positive and unalterable element for an assigned or required capacity of
boiler, the diameter of the shell, the transverse area of the tubes, the
height of the furnace and steam chamber, and the proportionate length
of the tubes to their diameter, are all imperative in their requirements
and cannot be restricted without impairing the operation of the boiler.
The second part of this Invention relates to steam boilers having a
"stcam chimney," notably marine boilers, but others also, and it consists
in retaining the boiler shell between the outer shell or cylinder and the
inner shell of the steam chimney and jointing it to the latter instead of
cutting it out as heretofore done, the said retained portion being per-
forated to allow a free circulation of the steam between the boiler proper
and the steam chimney.
The object is to strengthen the boiler in this its weakest part, which is
thus effected both in its capacity to resist the internal pressure and also
to resist the injurious wear at the base of the steam chamber, due to the
changes of pressure and temperature.
One arrangement of the improved boiler as described in the first part
of this Invention is represented by way of illustration in horizontal
section in Figure 1 and transverse section in Figure 2 of the accom- 3
panying Drawings.
Figure 3 is a sectional elevation of so much of a boiler as is required
to illustrate the second part of the Invention.
A is the shell of the boiler; B, furnace; C, lower flues; D, up-takes;
E, outside, upper, or overhead return smoke connections; F, middle 3
overhead connections; G, tubes connecting return connections or flues

page_text: E, F; J, lining to steam chimney H.; and 1, diaphragm in the outsido
flues.
The steam chimney may be placed at a point between the ends of the
boiler and a diaphragm I is employed in the outside flues E to cause
some of the heat, which would otherwise escape directly to the smoke
pipe to first traverse the length of the flue E.
The tubes G may be horizontal and the middle flue have vertical sides,
while the side flues E have one vertical side, but the more preferable
arrangement will be that shown in Figure 2, in which the tubes descend
from the middle flue, whose sides converge to a point below its bottom
and connecting with corresponding inclined sides of tube E. The
flues F will be wider than the length of tubes G to allow of putting in
the tubes from the flue.
By this arrangement of fire tubes the transverse area required by the
area of grate surface, the area of their heating surface, and the volume
of the steam chamber above can all be obtained without prejudice to
the height of the furnace below, and without involving an impracticable
length of boiler.
In an ordinary tubular boiler, when the tubes are set in its longi.
tudinal plane, it is impracticable to remove them and substitute others
without affording sufficient length for their withdrawal in the fire room.
By this arrangement of flues and fire tubes the tubes can be removed
and replaced at pleasure, and all the necessary work prosecuted within
the boiler.
By setting the tubes at an inclination, not only is the passage of the
heated air and smoke facilitated, but the tubes are rendered less liable to
become choked by the aggregation of soot and ashes cemented by the
moistur cfrom leaks, added to which greater space is afforded in the
central flue for the manual operation of withdrawing and replacing any
tubes that may require such operation.
In the ordinary overhead single return tubular or flue boiler the smoke
pipe must be placed at the extreme of the furnace end of the boiler,
and even in the drop flue or tubular boiler, returned on a level with the
crown of the furnace. The smoke pipe must be either at the extreme
back end of the boiler or immediately behind the furnace. No deviation
from these fixed points is practicable,
=

page_text: By the introduction of a vertical diaphragm I in the return flue or
flues of a steam boiler (of this or like design) as here shown, the products
of combustion can be so directed as to admit of the base of the smoke
pipe being located at any portion of the length of the boiler, thus
enabling the constructor of a steam vessel to locate the smoke pipe as
may suit his convenience as to its position with reference to the masts,
sails, or passage ways of a steam vessel.
By the use of arched connections and uptakes the required strength
is afforded without braces, and the under and inner surfaces of the con-
nections will serve the very useful and desirable purpose of being a 1
receptacle for ashes instead of their choking up the lower tubes as in all
other designs of tubular boilers.
In Figure 3 A¹ is the boiler shell; B¹, the outer shell of the steam
chimney; C', the inner shell; D', the portion of the boiler shell extending
from the outer shell of the steam chimney B¹ to the inner shell C¹; and 1
E', the perforations to allow the steam to circulate freely between the
boiler and the steam chimney.
Hitherto it has been customary to remove the entire portion D' of the
boiler shell, and it has been a great and entirely unnecessary cause of
weakness to the boiler, for by extending it to the inner shell C¹, its
strength to resist rupture is preserved directly in proportion to the width
of the metal retained, and the steam circulates just as well through the
holes as if the whole space was open.
Besides preserving much of the strength against the internal strain
heretofore lost, the weight of the steam chimney and smoke pipe on the
boiler is not so injurious because the shell is supported vertically by the
steam chimney with which it is connected, so that the injuries to the
joint between the chimney and the boiler shell, by the rising and falling
of the shell, due to the varying conditions of internal pressure and tem-
perature when steam is on, and external pressure and temperature when
it is off are avoided.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Alexander Melville Clark in the Great Seal Patent
Office on the 17th October 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALEXANDER
MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
Patent Agent, send grecting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Seventeenth day of April, 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 Alexander Melville Clark, Her special
licence that I, the said Alexander Melville Clark, my exccutors, adminis-
trators, and assigns, or such others as I, the said Alexander Melville
Clark, my exccutors, 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 Kingdom of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN STEAM BOILERS," a communication to mc from abroad
by Charles Haynes Haswell, of the City, County, and State of New
York, United States of America, upon the condition (amongst others).
that I, the said Alexander Melville Clark, my executors or admini-
strators, by an instrument in writing under my, or their, or one
of their hands and scals, 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 Alexander Melville Clark, 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, reference being had to the accompanying Sheet
of Drawings, and to the letters and figures marked thereon (that is to
say):-
The design of this boiler and the nature of this Invention consists in

page_text: arched uptake or vertical smoke connection, also arched horizontal
smoke connections as far as the same may be practicable of attaintment,
in order to offer the greatest resistance to rupture with the least material
and with the least practicable resort to braces, combined with economy
of weight, cost, and increased endurance, all of which clements are more
essential than heretofore.
In steam boilers of ordinary design, having either overhead return
tubes or tubes directly in line with their furnace, and all set in the
longitudinal plane of the boiler, it is very difficult to so proportion their
diameter as to meet the several requirements of transverse area, heating.
surface, and diameter proportionate to their length, and to accommodate
the necessary steam space, the cause of this difficulty arising from the
circumstance that the area of the grate bars being given, and being a
positive and unalterable element for an assigned or required capacity of
boiler, the diameter of the shell, the transverse area of of the tubes, the
height of the furnace and steam chamber, and the proportionate length.
of the tubes to their diameter, are all imperative in their requirements
and cannot be restricted without impairing the operation of the boiler.
The second part of this Invention relates to steam boilers having a
"steam chimney," notably marino boilers, but others also, and in consists
in retaining the boiler shell between the outer shell or cylinder and the
inner shell of the steam chimney, and jointing it to the latter instead of
cutting it out as heretofore done, the said retained portion being per-
forated to allow a free circulation of the steam between the boiler proper
and the steam chimney.
The object is to strengthen the boiler in this its weakest part, which is
thus effected both in its capacity to resist the internal pressure, and also
to resist the injurious wear at the base of the steam chamber, due to the
charges of pressure and temperaturo.
The improved boiler as described in the first part of this Invention is
represented in longitudinal sectional clevation in Figures 1 and 2; in
horizontal section in Figure 3; transverse section and end clevation in
Figure 4; and transverse section in Figure 5.
Figure 6 is a sectional elovation of so much of a boiler as is required
to illustrate the second part of the Invention; Figure 7 is a plan view
of Figure 6 inverted..

page_text: "
A is the shell of the boiler; B, furnace; C, lower flues; D, uptakes;`
E, outside, upper, or overhicad return smoke connections; F, middle
overhead connections; G, tubes connecting return connections or flues
E, F; J, lining to steam chimney H; and I, diaphragm in the outside
flues E.
In Figure 1 the steam chimney is arranged at a point between the
ends and the diaphragm I is employed in this arrangement to cause some
of the heat which would otherwise escape directly to the smoke pipe to
first traverse the length of the flue E..
The tubes G may be horizontal as in Figure 4, and the middle flue
may have vertical sides, while the side flucs E havo one vertical side as
in Figure 4, but the more preferable arrangement will be as in Figure 5,
the tubes descending from the middle flue, whose sides converge to a
point below its bottom and connecting with corresponding inclined sides
of tubes E. The flues F will be wider than the length of tubes G to
allow of putting in the tubes from the flue.
By this arrangement of fire tubes the transverse arca required by the
area of grate surface, the area of. their heating surface, and the volume
of the steam chamber above can all be obtained without prejudice to
the height of the furnace below, and without involving an impracticable
length of boiler.
In an ordinary tubular boiler when the tubes are sot in its longitudinal
plane, it is impracticable to remove them and substitute others without
affording sufficient length for their withdrawal in the fire room.
By this arrangement of flucs and fire tubes the tubes can be removed
and replaced at pleasure, and all the necessary work prosecuted within
the boiler.
By setting the tubes at an inclination, not only is the passage of the
heated air and smoke facilitated, but the tubes are rendered less liable
to become choked by the aggregation of soot and ashes cemented by the
moisture from leaks, added to which greater space is afforded in the
central flue for the manual operation of withdrawing and replacing any
tubes that may require such operation.
In the ordinary overhead single return tubular or flue boiler the smoke
pipe must be placed at the extreme of the furnace end of the boiler, and
even in the drop flue or tubular boiler, returned on a level with the crown

page_text: of the furnace. The smoke pipe must be either at the extreme back end
of the boiler or immediately behind the furnace. No deviation from
these fixed points is practicable.
By the introduction of a vertical diaphragm I in the return flue or
flues of a steam boiler (of this or like design) as hero shown, the pro-
ducts of combustion can be so directed as to admit of the base of the
smoke pipe being located at any portion of the length of the boiler, thus
enabling the constructor of a steam vessel to locate the smoke pipe as
may suit his convenience as to its position with reference to the masts or
sails, or passage ways of a steam vessel.
I do not submit a round shell or furnace as a novelty, but I do submit
that arched connections and uptakes are novel, that they afford the
required strength without braces, and that the under and inner surfaces of
the connections will serve the very useful and desirable purpose of being
a receptacle for ashes instead of their choking up the lower tubes as in
all other designs of tubular boilers.
I do not submit fire tubes set transversely to the longitudinal plane of
a boiler as a novelty, as they were so placed in the two instances of the
steamer Kamschatka and ferry boat Essex, in the United States of
America, and by Hepworth and Miller in this country, but they were
confined to the furnace alone, and led directly from it to only one rect-
angular connection in the first case, and to the furnace in the other,
and in neither of these cases were the tubes set at an inclination, but I
do submit that they have never been so placed at an inclination or even
horizontal in connection with an overhead return side and centre con-
nections or flues as shown, whereby any required amount of transverse
area of heating surface can be obtained by simply adding to the length
of the boiler.
Further, I submit that a design of boiler, when both inclined and
horizontal tubes set in the manner shown can be removed or replaced
within the boiler, is novel.
I further submit that although horizontal diaphragms and even
vertical diaphragms have been placed in a boiler, yet that they were for
the purpose of duplicating or diverting the passage of the products of
combustion, but that in this design it is introduced for the very different
purpose of dividing the products so as to enable the chimney to be placed
where required.

page_text: In Figures 6 and 7 A¹ is the boiler shell; B', the outer shell of the
steam chimney; C₁, the inner shell; D', the portion of the boiler shell
extending from the outer shell of the steam chimney B' to the inner
shell C¹; and E¹ the perforations to allow the steam to circulate freely
between the boiler and the steam chimney.
Hitherto it has been customary to remove the entire portion D¹ of the
boiler shell, and it has been a great and entirely unnecessary cause of
weakness to the boiler, for by extending it to the inner shell C', its
strength to resist rupture is preserved directly in proportion to the width
of the metal retained, and the steam circulates just as well through the
holes as if the whole space was open.
Besides preserving much of the strength against the internal strain
heretofore lost, the weight of the steam chimney and smoke pipe on the
boiler is not so injurious, because the shell is supported vertically by the
steam chimney with which it is connected, so that the injuries to the
joint between the chimney and the boiler shell by the rising and falling
of the shell due to the varying conditions of internal pressure and tem-
perature when the steam is on, and external pressure and temperature
when it is off are avoided.
Having described the nature of the Invention and the manner of
performing the same, I declare that what I claim as the Invention
to be protected by the herein-before in part recited Letters Patent is,―
1st. The vertical connection or uptake of a steam boiler constructed
with arched sides and ends.
2nd. An arched top and bottom to an overhead heat and smoke con-
nection of a steam boiler with vertical or inclined sides.
3rdly. The location of the tubes of a steam boiler inclined or horizontal
transversely to its longitudinal plane in combination with an overhead
return centre and side, horizontal, or inclined heat and smoke con-
nections (or two side connections in the case of a single series of tubes
being used) whereby they may be removed and replaced within the
confines of the boiler.
4thly. The application of a vertical diaphragm to the heat and smoke
connections or side flues, whereby the heat and smoke may be so divided
as to enable the smoke pipe of a steam boiler to be set in any portion of
its length

page_text: 5thly. A. horizontal or inclined flue or heat and smoke connection of
a steam boiler with its sides converging to a centre external thereto.
6thly. The continuation of the shell of a steam boiler within the
circular ring or space between the outer shell and the inner course or
lining of the steam chimney with perforations in said continuation, sub-
stantially as and for the purpose specified.
In witness whereof, I, the said Alexander Melville Clark, have
hereunto set my hand and and scal, this Sixteenth day of
October, in the year of our Lord One thousand eight hundred
- and seventy-four.
Witness,
HY. SWALES,
53, Chancery Lane,
London.
A. M. CLARK. (L.S.)