IMPROVEMENTS IN UTILISING THE WASTE HEAT OF SMITHS' FIRES AND IN GENERATING STEAM
Year: 1873

page_text: LETTERS PATENT to William Mitchell, of Manchester, in the County
of Lancaster, Engineer, for the Invention of "IMPROVEMENTS IN
UTILISING THE WASTE HEAT OF SMITHS' FIRES AND IN GENERATING STEAM."
Sealed the 29th August 1873, and dated the 1st April 1873.
PROVISIONAL SPECIFICATION left by the said William Mitchell at the
Office of the Commissioners of Patents, with his Petition, on the
1st April 1873.
I, WILLIAM MITCHELL, of Manchester, in the County of Lancaster,
3 Engineer, do hereby declare the nature of the said Invention for "Im-
PROVEMENTS IN UTILIZING THE WASTE HEAT OF SMITHS' FIRES AND IN GENERATING
STEAM," to be as follows:-
My Invention consists in surrounding the hearths of smiths' fires
with a chamber containing water, and in utilizing the heat of the smith's
fire to evaporate the water in the said chambers, and to produce steam

page_text: which may be used for driving a steam engine or for other purposes,
thereby economising the fuel that would be required to raise an equal
amount of steam.
I also propose to suspend a vessel or tubes containing water in the
cover of the hearth, and connecting this vessel or tubes to the chamber
surrounding the hearth. When two or more smiths' fires are placed
near each other, the water chambers may be connected and the steam
from all the chambers may be collected in a boiler. The tuyere iron
passes through the water chamber, and the passage to the chimney is
also taken through a tube running through the boiler.
My Invention may be modified by forcing compressed air through
tuyeres into the fire-place under steam boilers.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Mitchell in the Great Seal Patent Office
on the 30th September 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
MITCHELL, of Manchester, in the County of Lancaster, Engineer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the First day of April, in the year of
our Lord One thousand eight hundred and seventy-three, in the thirty-
sixth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said William Mitchell, Her special licence
that I, the said William Mitchell, my executors, administrators, and
assigns, or such others as I, the said William Mitchell, 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
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
UTILISING THE WASTE HEAT OF SMITHS' FIRES, AND IN GENERATING STEAM,'
upon the condition (amongst others) that I, the said William Mitchell,

page_text: 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
Scal 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 Mitchell, 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 (that is to say) :-
My Invention consists in surrounding the hearths of smiths' fires with
a chamber containing water, and in utilising the heat of the smith's
fire to evaporate the water in the said chambers, and to produce steam
which may be used for driving a steam engine or for other purposes,
thereby economising the fuel that would be required to raise an equal
amount of steam. When two or more smiths' fires are placed near
each other the water chambers may be connected, and the steam from
all the chambers may be collected in a boiler. The tuyere iron passes
through the water chamber and the passage to the chimney is also taken
through a tube or tubes running through the boiler.
My Invention may be modified by forcing compressed air through
tuyeres into the fire-place under steam boilers.
And in order that my Invention may be fully understood and readily
carried into operation, I will proceed to describe the accompanying Sheet
of Drawings, reference being had to the figures and letters marked
thereon.
Fig. 1 is a front view, and Fig. 2 a longitudinal section of a smith's
hearth constructed according to my improvements, whereby the waste
heat is used for generating steam; a is a small cylindrical or other
shaped chamber containing the coal or other fuel for the smith's fire,
and b is the outer casing containing the water surrounding the chamber a,
the front end of the chamber a is open to admit the article to be heated,
and the back end of the chamber is connected to the back plate of the
casing 6 by the small tubes c. The tuyeres for supplying compressed
air to the smith's fire pass through the pipes d, d, and the products of

page_text: combustion from the smith's fire after passing through the tube c are
carried through the flues in the brickwork and thence to the chimney;
by this means the waste heat from the smith's fire is employed to pro-
duce steam, which may be used for driving a steam engine or for other
purposes, thereby economising the fuel that would be required to raise
an equal amount of steam.
When two or more smiths' fires of the above construction are placed
near each other the steam from the casings b may be connected by pipes
and conveyed to a boiler or reservoir, or it may be taken direct to drive
a steam engine or for other purpose.
Fig. 3 is a vertical section, and Fig. 4 a longitudinal section of my
improvements in generating steam. e is a small cylindrical chamber
containing the fire-grate f, the front end of the chamber e is closed and
it is provided with a firing door to supply fuel to the grate, the back end
of the chamber e is connected by small tubes to the back plate of the
outer casing 9, above the fire-grate fis or may be placed the tube h,
which is connected by pipes to the inside of the chamber e, these pipes
are placed above and at the sides to promote free circulation of water
in the tube h. The compressed air for promoting combustion in the
fire-grate fis supplied by tuyeres passing through the holes i in the door
which covers the end of the chamber e under the fire-grate, the external
air being thus excluded from the fire, the intense heat required for
rapidly generating steam is obtained by the compressed air passing
through the tuyeres. The whole apparatus is connected to an ordinary
cylindrical boiler by the elbow pipej and the passage k, the water cir-
culating from the large boiler to the supplemental heating apparatus as
shewn by the arrows. The end of the casing 9 is placed at a little
distance from the end of the ordinary boiler to which it is applied, the
space being partly filled up with brickwork in which is a passage or
passages to convey the products of combustion to the flue or flues of the
boiler.
I wish to remark that the apparatus shewn in Figs. 1 and 2 for
utilising the waste heat from smiths' fires may also be connected to an
ordinary steam boiler, as shewn in Figs. 3 and 4.
Having thus described the nature of my Invention, and a convenient
manner of performing the same, I wish it to be understood that I do not

page_text: intend to limit myself to the details given as the same may be con-
siderably varied or modified, and I declare that I claim,-
First. Utilising the waste heat of smiths' fires by placing the said
fire in a water chamber, as shewn and described in reference to Figs.
1 and 2.
And, secondly. The mode of generating steam by forcing compressed
air under the fire-grate, as shewn and described in reference to Figs.
3 and 4.
In witness whereof, I, the said William Mitchell, have hereto
set my hand and seal, this Twenty-sixth day of September One
thousand eight hundred and seventy-three.