IMPROVEMENTS IN THE CONSTRUCTION OD STEAM ROLLERS BAR MUN NODE FERNCTUAL CONSUMPTION OF SMOKEILE FOR THE MORE EFFEC
Year: 1855

page_text: LETTERS PATENT to John Stewart, of Preston, in the County of Lancaster,
Boiler Maker, for the Invention of "IMPROVEMENTS IN THE CONSTRUCTION
OD STEAM ROLLERS BAR MUN NODE FERNCTUAL CONSUMPTION OF SMOKE
Sealed the 26th February 1856, and dated the 7th September 1855.
PROVISIONAL SPECIFICATION left by the said John Stewart at the Office
of the Commissioners of Patents, with his Petition, on the 7th September
1855.
I, JOHN STEWART, of Preston, in the County of Lancaster, Boiler Maker,
do hereby declare the nature of the said Invention for "IMPROVEMENTS IN THE
CONSTRUCTION OF STEAM BOILERS FOR THE MORE EFFECTUAL CONSUMPTION OF SMOKE"
to be as follows:-
This Invention relates to a peculiar construction and arrangement of the
flues and furnaces of steam boilers of all kinds when more than one furnace
is employed, whereby the smoke is more effectually consumed than can be
accomplished by the ordinary existing arrangements.
The improvements consist in forming a passage connecting the furnaces of
the boiler or boilers where more than one furnace is used, thus affording a
communication between one furnace or flue and another. A damper is placed
at the opposite end of each flue, and when any one furnace is supplied with
fresh or green fuel the damper at the opposite end of its flue is closed, and the
smoke from the newly-supplied fuel is compelled to traverse the passage con-
necting the furnace with the other or others, and to pass over the incandescent
fuel contained therein, thereby effectually consuming the smoke as it passes
to the chimney. If found desirable, the dampers may be placed immediately
behind the fire grates instead of at the further ends of the flues.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Stewart in the Great Seal Patent Office on the
6th March 1856.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
STEWART, of Preston, in the County of Lancaster, Boiler Maker, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Seventh day of September, in the year of our Lord
One thousand eight hundred and fifty-five, in the nineteenth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me.
the said John Stewart, Her special license that I, the said John Stewart. my
executors, administrators, and assigns, or such others as I, the said John
Stewart, 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 "IMPROVEMENTS IN THE CONSTRUC-
TION OF STEAM BOILERS FOR THE MORE EFFECTUAL CONSUMPTION OF SMOKE," upon
the condition (amongst others) that I, the said John Stewart, by an instru-
ment 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 John Stewart, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-
formed, 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:
This Invention relates to a peculiar construction and arrangement of the
flues and furnaces of steam boilers of all kinds where more than one furnace is
employed, whereby the smoke is more effectually consumed than can be accom-
plished by the ordinary existing arrangements.
The improvements consist in forming a passage connecting the furnaces of
the boiler or boilers where more than one furnace is used, and thus affording
a communication between one furnace or flue and another. A damper is
placed at the opposite end of each flue, and when any one furnace is supplied
with fresh or green fuel the damper at the opposite end of its flue is closed, and

page_text: the smoke from the newly-supplied fuel is compelled to traverse the passage
connecting the furnace with the other. or others, and to pass over the.incan-
descent fuel contained therein, thereby effectually consuming the smoke as it
passes to the chimney. If found desirable, the dampers may be placed immie-
diately behind the fire grates instead of at the further ends of the flues. The
dampers may also be placed in the brick flue on each side of the boiler, so as
to cut off the connection with the chimney. **
And in order that the said Invention may be fully understood, I shall now
proceed particularly to describe the same; and for that purpose I shall refer
to the several Figures on the Sheet of Drawings hereunto annexed, the same
letters of reference indicating corresponding parts throughout all the Figures.
Figure 1 of the Drawings represents a longitudinal vertical section of my
improved boiler, taken between the two flues; Figure 2 is a transverse section
of the same, taken along the transverse passage connecting the flues; Figure 3
is a longitudinal vertical section of the same, taken through the centre line
of one of the flues; and Figure 4 is a front or end elevation of the same.
A is the main shell or outside casing of the boiler; and B, B', are two
internal cylindrical flues, each fitted with a separate grate and door at one end,
whilst at the opposite end, or, if desired, immediately behind the furnace
bridge, is fitted a damper C, C¹; D is the transverse passage connecting one
flue or furnace with the other; and E is a valve or regulator in the body of
the dead plate for the purpose of regulating the supply of air to the furnace.
The fire door frame may be made to project a few inches from the end of the
boiler, so that a valve may be placed on the side of the framing to admit the
fresh air instead of having the valve E in the dead plate.
In using these boilers, the alternate system of firing is employed; and when
either of the two furnaces B or B¹ requires feeding with fresh or green fuel,
its damper C or C¹ is first closed, thus shutting off all direct communication
with the chimney, excepting through the lateral passage D and along the
adjoining flue.
Thus, supposing the furnace B requires firing, its damper C will be first closed
or partially closed if desired; and when the fresh fuel is thrown on the smoke,
unconsumed gases and other products of combustion must of necessity pass
through the lateral passage D and over the incandescent fuel in the adjoining fur-
nace B', where, by the heat evolved therefrom, and by the aid of a current of
fresh air entering through the valve E, such smoke and gases will be effectually
consumed before reaching the chimney. The damper C will remain closed so
long as any smoke or unconsumed gases are thrown off from the green fuel, after
which it may be opened, and the corresponding damper C' of the adjoining

page_text: furnace B¹ closed preparatory to a supply of fresh fuel being supplied thereto,
if requisite, whereupon the direction of the smoke and gases through the lateral
passage I will be reversed, the perfect combustion taking place in the furnace
B as it had previously done in the furnace B'. Although I have berein-before
described and illustrated only the arrangement of lateral opening and dampers
as applied to an internal flue boiler, yet I by no means confine or restrict
myself to such application, as it will be obvious to the practical man that by
suitable modifications the flues of external boiler furnaces may be built with
a lateral passage for connecting the two furnaces when required, and fitted
also with dampers and air valves or regulators, substantially in the manner
herein before described, whereby the same result, namely, a more perfect
combustion, will be attained.
Having now described and particularly ascertained the nature of my said
Invention, and the manner in which the same is or may be used or carried
into effect, I would observe, in conclusion, that I do not confine or restrict
myself to the precise details or arrangements which I have had occasion to
describe or refer to, as many variations may be made therefrom without
deviating from the principles or main features of my said Invention; but
what I consider to be novel and original, and therefore claim as the Inven-
tion secured to me by the herein-before in part recited Letters Patent, is,
the construction of the furnaces of steam boilers, with a lateral passage to
connect one furnace with another, and the application of dampers or doors to
the flues of furnaces so constructed, for the purpose of compelling the smoke
and products of combustion to pass from one furnace over the incandescent
fuel of the other, with a view to the prevention of smoke and the obtainment
of a more perfect combustion, as herein-before described.
In witness whereof, I, the said John Stewart, have hereunto set my hand
aud seal, the First day of March, One thousand eight hundred and
fifty-six.
JOHN STEWART. (L.S.)