IMPROVEMENTS IN STEAM GENERATORS AND OTHER ROLLERS GENERATORS BOILERS
Year: 1868

page_text: LETTERS PATENT to William Hawthorn, of the Town and County of
Newcastle-upon-Tyne, Engineer, for the Invention of "IMPROVEMENTS
IN STEAM GENERATORS AND OTHER ROLLERS"
Sealed the 28th August 1868, and dated the 11th March 1868..
PROVISIONAL SPECIFICATION left by the said William Hawthorn
at the Office of the Commissioners of Patents; with his Petition,
on the 11th March 1868..
I, WILLIAM HAWTHORN, of the Town and County of Newcastle-upon-
Tyne, Engineer, do hereby declare the nature of my said Invention for
"IMPROVEMENTS IN STEAM GENERATORS AND OTHER BOILERS," to be as follows,
that is to say:-
This Invention relates to a peculiar construction and arrangement of
the furnaces and flues of internal fluid boilers, and has for its object
the securing a long and unbroken run of flame, thereby transmitting
a greater amount of heat to the water or other liquid in the boiler
than when such flame is broken up or divided; as in the ordinary
multitubular boiler:
According to one mode of carrying out my Invention I construct an
outer shell of any desired. form and place two circular furnaces therein,

page_text: one at the right side of the shell and the other at the left. The centres
of these furnaces are situate on the same horizontal line, or nearly so,
as the centre of the shell; the inflamed gases pass along them into a
chamber at the back, and return towards the front in a circular flue
between the two furnaces; they then pass downward into another
circular flue, in which they again travel backwards until the reach
another chamber, where they divide and return to the front through
two flucs, placed one on the right, another on the left of the last-
mentioned flue. The heat may then pass up a dry up-take in front
of the boiler to the chimney, or the first flue may be shortened at
the front end, and a branch up-take may be brought from the fore
end of the small flue through the roof or side of the shell, or may
return back through the steam space and escape at the top. end or
side of the shell; but I prefer the first-named plan as not impairing.
the strength of the boiler. I do not confine myself to this particular
arrangement as to the number or disposition of the furnaces or flues,
and the centre flue or flues may be converted into a furnace or furnaces.
if desired, the flame returning through the outside flues (which in the
first arrangement formed the furnaces), then passing downwards and
back through either the large or small flues, and again returning.
towards the front, or the flame may if preferred be brought back
through one of the small flues and return through the other, the fore.
end of the bottom middle flue being shortened to allow the bend round
the front. The upper flues may all be used as furnaces, the gases
returning to the front through the lower middle flue, dividing and
extending backwards through the lower side flues to the up-take at
back end. In order to get a large space in the furnaces for com-
bustion the bars may be placed below the centres of the furnaces,.
ash-pits being formed at the sides of boilers with pipes communicating
with the bottom of furnaces. The shell and flues may be of any desired
shape, but for high-pressure boilers are preferred circular, and may if
required be fitted with water circulating tubes, either straight, tripoid,.
or of a cruciform shape, or with any tubes specially adapted to improve.
circulation and increase the effective heating surface. I also propose
to fix air pipes, so as to open through the shell and furnace bottoms
and under the fire-bars, in order to get a direct supply of hot or cold
air under the bars, and to place such pipes in any other part of the
furnaces or flues where they may be required. Perfect combustion
may be secured by the aid of a perforated fire-door and admission of

page_text: air through the ash-pit pipe nearest the back of the bridge, or through
one or more perforated air pipes placed at convenient distances in the
travel of the flame. The circulation will be very good, as the greatest
evaporation will take place over the furnaces and upper flues where
the escape of the steam to the surface is perfectly free, and the cold
water is gradually heated as it rises to replace the steam by the action
of the lower flues, and as the flame is almost unbroken in its travel
through the flues it gives out the greatest amount of heat on its way
to the chimney.
Some of the principal advantages to be derived from the arrangement
above mentioned are, cheapness of first course, fewer repairs, and greater
facility for effecting them, increased strength, and dispensing with the
necessity for many stays. The boiler will not prime, the circulation
being easy, and will keep the engines going with a considerable depth
of water in the hold or engine room, should the ship have sprung a
Berious leak.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Hawthorn in the Great Seal Patent Office
on the 7th September 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
HAWTHORN, of the Town and County of Newcastle-upon-Tyne, Engineer,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eleventh day of March, in the year
of our Lord One thousand eight hundred and sixty-eight, in the
thirty-first year of Her reign, did; for Herself, Her heirs and successors,
give and grant unto me, the said William Hawthorn, Her special
license that I, the said William Hawthorn, my executors, adminis-
trators, and assigns, or such others as I; the said William Hawthorn,
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 Islands, and Isle of Man, an Invention for "IM-

page_text: PROVEMENTS IN STEAM GENERATORS AND OTHER BOILERS," upon the condition
(amongst others) that I, the said William Hawthorn, my executors or
administrators, by an instrument in writing under my hand and seal,
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 William Hawthorn, 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 relates to a peculiar arrangement of the furnaces
and flues of internal fluid boilers, and has for its object the securing
a long and unbroken run of flame, thereby transmitting a greater
amount of heat to the water or other liquid in the boiler than when
such flame is broken up or divided, as in the ordinary multitubular
boiler.
According to one mode of carrying out my Invention I construct an
outer shell of any desired form and place two circular furnaces therein,
one at the right side of the shell and the other at the left. The centres
of these furnaces are situate on the same horizontal line, or nearly so
as the centre of the shell; the ignited gases pass along them into a
chamber at the back, and return towards the front in a circular flue
between the two furnaces, they then pass downwards into another
circular flue, in which they again travel backwards until they reach
another chamber, where they divide and return to the front through
two flues, placed one on the right and the other on the left of the last-
mentioned flue. The heat may then pass up a dry up-take in front of
the boiler to the chimney, or the first flue may be shortened at the
front end, and a branch up-take may be brought from the fore end of
the small flues through the roof or side of the shell, or may return
back through the steam space and escape at the top end or side of the
shell; but I prefer the first-named plan as not impairing the strength
of the boiler. I do not confine myself to this particular arrangement
as to the number, shape, or disposition of the furnaces or flues, and

page_text: the centre flue or flues may be converted into a furnace or furnaces
if desired, the flame returning through the outside flues (which in
the first arrangement formed the furnaces), then passing downwards
and back through either the large or small flues, and again returning
towards the front, or the flame may if preferred be brought back
through one of the small flues and return through the other, the fore
end of the bottom middle flue being shortened to allow the bend round
the front. The upper flues may all be used as furnaces, the gases
returning to the front through the lower middle flue, dividing and
extending backwards through the lower side flues to an up-take at
the back end. In order to get a large space in the furnaces for com-
bustion the bars may be placed below the centres of the furnaces,
ash-pits being formed at the sides of the boilers with pipes com-
municating with the bottom of the furnaces. The shell and flues may
be of any desired shape, but for high-pressure boilers are preferred
circular, and may if required be fitted with water circulating tubes,
either straight, tripoid, or of a cruciform shape, or with any tubes
specially adapted to improve circulation and increase the effective
heating surface. I also propose to fix air pipes so as to open through
the shell and furnace bottoms and under the fire-bars, in order to get
a direct supply of hot or cold air under the bars, and to place such
pipes in any other part of the furnaces or flues where they may be
required. Perfect combustion may be secured by the aid of a perforated
fire-door and admission of air through the ash-pit pipe nearest the back
of the bridge, or through one or more perforated air pipes placed at
convenient distances in the travel of the flame. The circulation will
be very good, as the greatest evaporation will take place over the
furnaces and upper flues where the escape of the steam to the surface
is perfectly free, and the cold water is gradually heated as it rises
to replace the steam by the action of the lower flues, and as the flame
is almost unbroken in its travel through the flues it gives out the
greatest amount of heat on its way to the chimney.
Some of the principal advantages to be derived from the arrangements
above mentioned are, cheapness of first cost, fewer repairs, and greater
facility for effecting them, increased strength, and dispensing with the
necessity for many stays. The boiler will not prime, the circulation
being easy, and will keep the engines going with a considerable depth
of water in the hold or engine room should the ship have sprung a
serious leak.

page_text: And in order that my said Invention may be more readily understood
I shall now proceed more particularly to describe the same, and for that
purpose shall refer to the several Figures on the Sheet of Drawings
hereunto annexed, the same letters of reference indicating corresponding
parts in all the Figures.
Figure 1 of the Drawings represents a front view of my improved
boiler having two furnaces on the centre line, with the first flue between
them, and the other flues placed below them with the smoke box or
up-take on the front of the boiler, as herein first described; Figure 2
is a longitudinal vertical section through A, B, on Figure 3 on the
centre line of the boiler, shewing the flame box, first and second flues,
and front and back chambers in section; Figure 3 is a cross section
of the boiler on the line C, D, of Figure 2 through the front chamber,
shewing the circulating tubes or water stays; Figure 4 is a cross
section on the line E, F, of Figure 2 through the flame box, and back
chamber with the water stays; Figure 5 is a sectional plan of the
boiler on the line G, H, of Figure 2 through the centres of furnaces
and first flue, one furnace having the bars, &c. shewn in; Figure 6 is
a vertical section on the line I, K, of Figure 2, shewing the furnaces
(with the air pipes communicating with ash-pits), the first flue, second
flue, and third flues all in section.
In these Figures A represents the shell of a cylindrical boiler, and
B, B, the two internal furnaces, one of which only is shewn fitted up
with furnace bars and fire-bridge. Both these furnaces communicate
at the rear end with a flame box C, subdivided by the fire-brick wall D
situate opposite the centre line of the middle flue E. This flue E,
which is on the same horizontal line as the centre of the boiler and
of the two furnaces B, B, returns towards the front of the boiler, where
it communicates with the front chamber F, such chamber opening into
the bottom or second flue G; the second flue again traverses the greater
portion of the length of the boiler, and opens at the rear end into a
back chamber H communicating with the two smaller return flues I, I,
situate one on each side of the said second flue G. The two flues I, I,
traverse a third time the length of the boiler, and open at their front
ends into the dry up-take K. The ash-pits are formed at the sides of
the boiler with pipes L, L, communicating with the bottom of the
furnaces; M, M, represent numerous water stays or circulating tubes,
which may be arranged as found most convenient or suitable for the

page_text: particular form of boilers required; N, N, are perforated fire-doors for
facilitating combustion and preventing the formation of smoke. Access
is afforded to the interior of the boiler through the closed man-holes
at O, O, and the lower part of the up-take is provided with a hinged
door P for enabling the same to be cleaned when requisite.
Having now described and particularly ascertained the nature of
my said Invention, and the manner in which the same is or may
he used or carried into effect, I would observe in conclusion that
what I consider to be novel and original, and therefore claim as the
Invention secured to me by the herein-before in part recited Letters
Patent is, the construction of steam generators and other boilers having
the furnaces, flame boxes, and first flues so placed as to be on or nearly
on the horizontal centre line of the boiler, so that their upper portions
are as close to the surface of the water or other fluid as is practicable,
and in which the flame and products of combustion are made to traverse
through a series of flues placed underneath the furnaces and first flues
in such a way that the heat is gradually absorbed by the water or other
fluid from the surface downwards.
In witness whereof, I, the said William Hawthorn, have hereunto
set my hand and seal, this 4th day of September, One thousand
eight hundred and sixty-eight.
WILLIAM HAWTHORN. (L.S.)