IMPROVE- MENTS IN THE 'CONSTRUCTION OF FURNACES AND IN THE ARRANGEMENT OF FLUES OR PASSAGES FOR ECONOMIZING FUEL THEREIN.
Year: 1872

page_text: LETTERS PATENT to John Ashwell, of 95, Highgate Road, Kentish
Town, in the County of Middlesex, for the Invention of "IMPROVE-
MENTS IN THE 'CONSTRUCTION OF FURNACES AND IN THE ARRANGEMENT OF
FLUES OR PASSAGES FOR ECONOMIZING FUEL THEREIN.
PROVISIONAL SPECIFICATION left by the said John Ashwell at the
Office of the Commissioners of Patents, with his Petition, on the
16th July 1872.
I, JOHN ASHWELL of 95, Highgate Road, Kentish Town, in the
5 County of Middlesex, do hereby declare the nature of the said Inven-
"
A
"
tion for "IMPROVEMENTS IN THE CONSTRUCTION OF FURNACES AND IN THE
ARRANGEMENT OF FLUES OR PASSAGES FOR ECONOMIZING FUEL THEREIN," to be as
follows:

page_text: The furnace is composed of four walls and a roof in which openings
serving as flues or passages are formed at intervals for the introduction
of air from a fan or blower, and others for the reception of fuel which
is supplied as required for maintaining the necessary heat within the
chamber.
In the chamber a boiler is fitted supported upon divisional supports
or piers between which the heat and products of combustion are free to
play before the spent gases are allowed to pass off into a chimney or
uptake.
The openings are covered by flaps or other valves to regulate the
intensity of the heat in the chamber, and the boiler is so arranged and
supported that the direct action of the fire is prevented impinging upon
its exterior to injure it.
The boiler may be of any form with flat or rounded bottom, and
it may have a passage through it like an ordinary Cornish or saddle
boiler.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Ashwell in the Great Seal Patent Office on
the 16th January 1873...
TO ALL, TO WHOM THESE PRESENTS SHALL COME, I, JOHN; 2
ASHWELL, of 95, Highgate Road, Kentish Town, in the County of
Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent bearing date. the Sixteenth day of July, in the year:
of our Lord One thousand eight hundred and seventy-two, in, the thirty- 2
sixth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said John Ashwell, Her special licence, that
I, the said John Ashwell, my executors, administrators, and assigns,
or such others as I, the said John Ashwell, my executors, adminis-
trators, and assigns, should at any time agree with, and no others, from 3
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 CON-
STRUCTION OF FURNACES AND IN THE ARRANGEMENT OF FLUES OR PASSAGES FOR 3

page_text: .
ECONOMISING FUEL THEREIN," upon the condition (amongst others) that I,
the said John Ashwell, my executors, or administrators, by an instru-
ment in writing under my, or their, or one of their hands and seals,
should particularly describe and ascertain the nature of the said Inven-
tion, 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 Ashwell, 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 thereof, reference being had to the Drawings
hereunto annexed, that is to say:-
-
This Invention relates to the construction of furnaces, and to the
arrangement of flues and passages for economising fuel and obtaining
heat therefrom.
Furnaces according to this Invention are composed each of four walls
and a roof or crown in which openings are formed at intervals for the
introduction of air from a fan or blower and for the reception of fuel,
which is supplied as required for maintaining the necessary heat within
the chambers.
In the chambers a boiler is fitted supported upon divisional supports
or piers between which the heat and products of combustion are free to
play before, the spent gases are allowed to pass off into a chimney or
uptake.
The openings are covered by flaps or other valves to regulate the
intensity of the heat in the chambers, and the boiler is so arranged that
the direct action of the fire is prevented impinging upon its exterior to
injure it.
The boiler may be of any form with flat or rounded bottom, and
it may have a passage through it like an ordinary Cornish or saddle
.boiler.
The Invention will be more particularly understood by reference to
the accompanying Sheet of Drawings, in which Figure 1 represents a
longitudinal section of a furnace with a boiler A of the Cornish stamp in
position upon two intermediate piers or walls B, B, shown more clearly
in the transverse sections, Figures 2 and 3, one of these being through
the line a, b, and the other through the line c, d, of Figure 1. C is the

page_text: roof or crown of the furnace supported by the two outside walls D, E;
and between which is a bridge or short wall F for breaking up the
direct action of the flame from the bars G, and to prevent it impinging
upon the end of the boiler the lower part of the wall at e, e, is provided
with apertures through which air can be forced or otherwise supplied to
the chambers H, H, for supporting the combustion of the fuel used
within them, the fuel, preferably small coal, being supplied thereto.
through the apertures or feed holes f,f, formed in the roof or crown.
Any number of these feed holes can be employed, so that the chambers
can be fed and heated to any extent for obtaining and maintaining the
required degree of heat, the fuel being spread or allowed to fall upon
the floors g, g, of the chambers in thin layers for the perfect consump-
tion. The heat from the larger quality of fuel upon the bars G is
sufficient to heat the chambers for first firing the small coal as it falls
from the ledges or spreaders h, h, after which the heat is retained for
the continuous firing, the front opening being used only for supplying
air to the chambers.
There are other openings in the front wall at i, i, which can be used
in conjunction with the central firing opening or alone.
:
I form passages j, j, in the piers or walls B, B, to permit of the
heated gases and vapour from the fuel passing into the central chamber
for impinging against the central portion of the bottom of the boiler in
order to utilize all the products of combustion before they can pass away
to the chimney or uptake K, the passages L, L, leading to which are
furnished with dampers to regulate the draft to any extent.
It will be seen that nearly the whole of the barrel of the boiler below
the water line is exposed to the action of the heat within the chambers,
and as the fresh air enters through the apertures e, e, or over the bridge
it becomes warmed, and its tendency is to rise, and in doing so it takes
up more heat which circulates around and about the boiler before it can
descend to the outlet apertures L, L, to be led to the chimney. By
this means the boiler is acted upon over a much larger portion of its
barrel and more uniformly than is usual, the intensity of the heat being
also retained in the chambers to give the best possible effect in lieu of
being allowed to escape in the ordinary manner before the gases have
been fairly developed for throwing off their calorific qualities.
The small coal falls upon the floors of the chambers and becomes
entirely consumed, 'there, being only ashes left, which can be removed

page_text: from time to time through openings arranged in the side walls D, E, or
they may be drawn to the front through the air passages e, e, by a rabble
or tool for the purpose.
The boiler is so placed within the chambers that the direct action of
any flame from the fuel is prevented from striking against it, conse-
quently it does not become burned or deteriorated thereby. The heat at
the upper parts of the chambers consumes all smoke, and a clean shell
of the boiler is the result. The supply of small coal can go on con-
tinuously or intermittently from hoppers fitted above the feed holes, and
by fitting the ledges h, h, upon movable supports the fuel may be spread
over the floor in thin layers at intervals.
The walls are preferably lined with refractory clay, and the transverse
bridge or stop wall M may be loosely fitted to permit of its removal
when required for a workman to enter should any repairs be required or
the central chamber cleaning.
I do not limit my Invention to the exact construction of furnace
shewn in the Drawings, nor to its use for Cornish boilers only, as
changes in the construction for different kinds or shapes of boilers can
be made without departing from the essential feature of my Invention.
And having now described the nature of my said Invention, and in
what manner the same is to be performed, I declare that I claim,―
Firstly. The construction of furnaces and arrangement of flues or
passages therein, substantially in the manner and for the purposes set
forth.
Secondly. I claim the heating of boilers or vessels by gases arising
from fuel within chambers in which they are placed in the manner
described.
Thirdly. I claim the method of retaining heat within furnace chambers
in which small coal is used for the perfect combustion of smoke, as
described.
In witness whereof, I, the said John Ashwell, have hereunto set
my hand and seal, this Fourteenth day of January One thousand
eight hundred and seventy-three.
JOHN ASHWELL. (L.S.)