IMPROVEMENTS IN THE FURNACES OF STEAM BOILERS
Year: 1868

page_text: LETTERS PATENT to John Fieldhouse, of Birmingham, in the County
of Warwick, Engineer, for the Invention of "IMPROVEMENTS IN THE
FURNACES OF STEAM BOILERS."
Sealed the 12th February 1869, and dated the 31st August 1868.
PROVISIONAL SPECIFICATION left by the said John Fieldhouse at
the Office of the Commissioners of Patents, with his Petition, on
the 31st August 1868.
I, JOHN FIELDHOUSE, of Birmingham, in the County of Warwick,
Engineer, do hereby declare the nature of the said Invention for "IM-
PROVEMENTS IN THE FURNACES OF STEAM BOILERS," to be as follows:-
My Invention consists of the improvements herein-after described in
the furnaces of such steam boilers as are provided with internal flues, the
said boilers being commonly called Cornish boilers.
My Invention has for its objects principally to effect a more perfect
heating of the water in the boilers, and to consume or partly consume
the smoke given off by the fuel employed to heat the said boilers.

page_text: In constructing and arranging the parts of the furnaces of the said
boilers according to my Invention, I use, in addition to the ordinary fire-
grate in the front end of the internal flue of the boiler, a second fire-grate
situated underneath the front end of the boiler, the said second fire-grate
being placed in a chamber or fire-place made for its reception. On the
said second fire-grate a small fire only is maintained. The smoke and
products of combustion from the fuel on the ordinary grate pass along
the internal flue to the rear end of the boiler. They then pass back
along external side flues to the front end of the boiler, and enter by
nearly vertical flues the chamber or fire-place in which the second fire-
grate is placed. In passing over the fire on the grate in this chamber or
fire-place the smoke is consumed or partly consumed. The heated air
and products of combustion finally pass along a flue underneath the
boiler to the chimney or stack. The small fire on the second fire-grate,
in addition to consuming or partly consuming the smoke from the com-
bustion of the fuel on the upper or ordinary grate, also heats the bottom
of the boiler, and thereby effects such a circulation of the water as
prevents the unequal heating of different parts of the boiler. The fire-
place or chamber in which the second fire-grate is placed is provided.
with an ash-pit and fire-doors.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Fieldhouse in the Great Seal Patent Office
on the 22nd February 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
FIELDHOUSE, of Birmingham, in the County of Warwick, Engineer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirty-first day of August, in the year.
of our Lord One thousand eight hundred and sixty-eight, in the thirty-
second year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said John Fieldhouse, Her special licence
that I, the said John Fieldhouse, my executors, administrators, and
assigns, or such others as I, the said John Fieldhouse, my executors,
administrators, and assigns, should at any time agree with, and no
others, from time to time and at all times thereafter during the term

page_text: prevents the unequal heating of different parts of the boiler. The fire-
place or chamber in which the second fire-grate is placed is provided
with an ash-pit and fire-doors to admit the necessary amount of
atmospheric air. Instead of one additional fire-grate or chamber, in
some cases two or more may be employed for the purposes described.
Having explained the nature of my Invention, I will proceed to
describe, with reference to the accompanying Drawings, the manner in
which the same is to be performed.
Figure 1 represents in end elevation, Figure 2 in transverse vertical
section, Figure 3 in longitudinal vertical section, and Figure 4 in
horizontal section a Cornish steam boiler provided with a single internal
flue containing my improvements. The same letters of reference are
employed to indicate the same parts in Figures 1, 2, 3, and 4.
a is the ordinary fire-grate of the boiler situated in the front end
of the internal flue c of the said boiler. Below the said ordinary fire-
grate a and underneath the front end of the boiler is the second or
additional fire-grate d, upon which a small fire only is maintained. The
said additional fire-grate d is situated in a fire-place or chamber into
which the ordinary external side flues f, f, of the boiler open, the said
fire-place or chamber being also in communication with the flue under-
neath the bottom of the boiler. a is the door of the ordinary fire-
grate a, and d², d³, are the doors of the second fire-grate d and its
ash-pit. The course which the heated air and products of combustion
take through the boiler and flues thereof is indicated by the arrows
in Figures 3 and 4, that is to say, the heated air and products of com-
bustion from the fuel in the principal and ordinary fire-place a pass
along the internal flue c to the flues e at the back end of the boiler,
and return along the external side flues f. f, to the front end of the
boiler. At the said front end of the boiler they descend by the
flues f, f. (see Figures 1 and 3) over the fire on the second grate d,
and thence pass by the central bottom flue g underneath the boiler b
to the main flue h leading to the chimney or stack. The unconsumed
gases from the fire on the fire-grate a on passing over or through the
fire on the second fire-grate d are ignited thereby, and the smoke and
the combustible products are also consumed or partly consumed. By
the heat from the small fire at the bottom of the front end of the
boiler, and the flame and heat resulting from the combustion of the
gases and combustible matters from the ordinary fire at the said small

page_text: 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 FURNACES OF STEAM BOILERS," upon the condition (amongst others)
that I, the said John Fieldhouse, my executors or administrators, by an
instrument in writing under my, or their, or one of their hands and
seals, 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 Fieldhouse, 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 thereof, that is to say:-
My Invention consists of the improvements herein-after described in
the furnaces of such steam boilers as are provided with internal flues, the
said boilers being commonly called Cornish boilers.
My Invention has for its objects principally to effect a more perfect
heating of the water in the boilers, and to consume or partly consune
the smoke given off by the fuel employed to heat the said boilers.
In constructing and arranging the parts of the furnaces of the said
boilers according to my Invention, I use, in addition to the ordinary fire-
grate in the front end of the internal flue of the boiler, a second fire-grate
situated underneath the front end of the boiler, the said second fire-grate
being placed in a chamber or fire-place made for its reception. On the
said second fire-grate a small fire only is maintained. The smoke and
products of combustion from the fuel on the ordinary grate pass along
the internal flue to the rear end of the boiler. They then pass back
along external side flues to the front end of the boiler, and enter by
nearly vertical flues the chamber or fire-place in which the second fire-
grate is placed. In passing over the fire on the grate in this chamber or
fire-place the smoke is consumed or partly consumed. The heated air
and products of combustion finally pass along a flue underneath the
boiler to the chimney or stack. The small fire on the second fire-grate,
in addition to consuming or partly consuming the smoke from the com-
bustion of the fuel on the upper or ordinary grate also heats the bottom
of the boiler, and thereby effects such a circulation of the water as

page_text: fire, the front end and bottom of the boiler are effectually heated, and
such a circulation of the water set up as prevents the unequal heating
of different parts of the boiler. The parts of the boiler which I have
not described are of the ordinary kind and constitute no part of my
Invention.
Figure 5 represents in end elevation, Figure 6 in transverse vertical
section, Figure 7 in longitudinal vertical section, and Figure 8 in
horizontal section a Lancashire steam boiler provided with two internal
flues containing my improvements. In this arrangement I place an
additional fire-grate at the front end of each of the external side flues
of the boiler instead of an additional fire-grate at the front end of the
boiler as in the first-described arrangement. a, a, are the ordinary
fire-grates in the internal flues c, c, of the boiler b, the said flues c, c,
opening into the external side flues f, f, as usual; i, i, are the additional
fire-grates situated in fire-places or chambers made at the front ends
of the boiler, and on either side the ordinary fire-grates a, a, as best
seen in Figures 6 and 8. The chambers or fire-places in which the
additional fire-grates i, i, are situated open into the side external
flues ff, and communicate with the bottom flue g. The heated air and
products of combustion from the fires on the ordinary fire-grates a, a,
pass along the internal flues c, c, and enter the external side flues f,f, by
the back flues e, e. The unconsumed gases and products of combustion
from the said fires a, a, passing along the flues f, f, meet with the
fame and heated air from the fires on the additional fire-grates i, i,
where their combustion or partial combustion takes place. The flame
and heated air then descend by the flues f, f, into the bottom flue g
under the boiler, and from thence by the main flue to the stack or
chimney. Each of the additional fire-grates i is provided with a door
marked 2. Instead of employing solid fuel in the chambers or fire-
places d and i, i, of the boilers to form the additional fire or fires,
gaseous fuel may be used to obtain the same or nearly the same result,
that is to say, the grate or fire-bars represented in the said fire-places
or chambers d, i, i, may be dispensed with, and a series of gas jets
placed in the said chambers. The flame and heat resulting from the
combustion of the gas supplied to the said jets cause the ignition of
the gases from the ordinary fire or fires, and the consumption or partial
consumption of the smoke as described when solid fuel is used.
Although I have described and represented the best ways with which

page_text: I am acquainted of arranging the additional fire grate or grates or
fire chamber or chambers of the furnace, yet I do not limit myself
to any particular position in the furnace of the said fire grate or grates
or fire chamber or chambers, so long as they are in communication with
the gases and products of combustion from the ordinary fire or fires
and in communication with the outlet flues of the boiler, neither do I
limit myself to the particular arrangement of the flues.
My improvements are applicable to the furnaces of marine steam
boilers as well as to the furnaces of ordinary stationary steam boilers.
Having now described the nature of my Invention, and the manner
in which the same is to be performed, I wish it to be understood that
I do not limit myself to the precise details herein described and illus-
trated as the same may be varied without departing from the nature
of my Invention; but I claim as my Invention the improvements iu
the furnaces of steam boilers provided with one or more internal flues
herein-before described and illustrated in the accompanying Drawings,
that is to say, applying to the furnaces of the said boilers one or more
additional fire-grates or fire-places or chambers on or in which an
additional fire or fires either of solid fuel or gaseous fuel arc placed for
the purposes and substantially as described and illustrated.
In witness whereof, I, the said John Fieldhouse, have hereunto
set my hand and seal, this Eighteenth day of February, in the
year of our Lord One thousand eight hundred and sixty-nine.
Witness,
RICHARD SKERRETT,
Clerk to George Shaw,
Birmingham.
JOHN FIELDHOUSE. (L.S.)