A NEW OR IMPROVED APPARATUS FOR UTILIZING THE WASTE HEAT FROM STEAM BOILER AND OTHER FURNACES, THEREBY ECONOMIZING FUEL
Year: 1871

page_text: LETTERS PATENT to John Mitchell, of Thurstonland, near Hudders-
field, in the County of York, and John Hirst Mitchell, of the same
Place, Millwrights and Machine Makers, for the Invention of "A
NEW OR IMPROVED APPARATUS FOR UTILIZING THE WASTE HEAT FROM STEAM
BOILER AND OTHER FURNACES, THEREBY ECONOMIZING FUEL."
Sealed the 30th April 1872, and dated the 14th November 1871.
PROVISIONAL SPECIFICATION left by the said John Mitchell and
John Hirst Mitchell at the Office of the Commissioners of Patents,
with their Petition, on the 14th November 1871.
We, JOHN MITCHELL, of Thurstonland, near Huddersfield, in the
County of York, and JOHN HIRST MITCHELL, of the same Place, Mill-
wrights and Machine Makers, do hereby declare the nature of the said
Invention for "A NEW OR IMPROVED APPARATUS FOR UTILIZING THE WASTE
HEAT FROM STEAM BOILER AND OTHER FURNACES, THEREBY ECONOMIZING FUEL," to
be as follows:-
The object of this Invention is chiefly to heat the feed water supplied
to steam boilers, but the apparatus may be employed for heating water

page_text: or other liquids or fluids to be applied to other purposes, and consists
of an arrangement of straight pipes fitted together in a cylindrical form,
connected at each end by means of a cast-iron disc bearers with suitable
thoroughfares forming a communication from one pipe to another or
connected by means of cast-iron elbow pipes of the same bore, the whole
mounted upon arms attached to and rotates or revolves on a hollow axis.
Each straight pipe is fitted with a scraper, which is a thin iron bar
extending from one end to the other with the edge resting on the outer
surface. These scrapers are each held to and maintained upon the top
or other sides of the pipes by means of weights attached thereto by loose
clasps encircling and hanging down underneath the said pipes as they
rotate or the cylindrical mass of pipes revolve, and which weights are
bars of iron, by preference of triangular shape in cross section with the
apex upward, to deflect the heat towards the pipes.
Each straight pipe is likewise provided with an inside scraper, which
consists simply of an iron bar of angular shape laid loose in the inside
of each pipe, which as the pipes rotate continually slides to the bottom
and thereby rubs or scrapes the interior of each pipe, which prevents
incrustation or substances adhering to the inner surface thereof.
Each joint is flanged and turned or planed accurately so as to be
(with the use of a little cement) made perfectly water-tight.
The whole is fitted together securely and mounted on suitable bearings
inside the flue betwixt the boiler furnace and chimney, with the axis in
a horizontal position.
The action of the heat current from the boiler furnace flue towards a
the chimney on the outer surface of the pipes heats the water inside.to
a high temperature, varying according to the quantity of water passed
through the pipes and the degree of heat in the flue.
The inlet and outlet pipes are connected to the revolving centres or
axes by means of conical joints accurately fitted, and the outlet pipe is a
also fitted with a safety valve and the connecting pipes with necessary
valves and taps.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Mitchell and John Hirst Mitchell in the
Great Seal Patent Office on the 14th May 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, JOHN
MITCHELL, of Thurstonland, near Huddersfield, in the County of York,
and JOHN HIRST MITCHELL, of the same Place, Millwrights and Machine
Makers, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fourteenth day of November, in the
year of our Lord One thousand eight hundred and seventy-one, in
the thirty-fifth year of Her reign, did, for Herself, Her heirs and
successors, give and grant unto us, the said John Mitchell and John
Hirst Mitchell, Her special licence that we, the said John Mitchell and
John Hirst Mitchell, our executors, administrators, and assigns, or
such others as we, the said John Mitchell and John Hirst Mitchell,
our 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
"A NEW OR IMPROVED APPARATUS FOR UTILIZING THE WASTE HEAT FROM STEAM
BOILER AND OTHER FURNACES, THEREBY ECONOMIZING FUEL," upon the condition
(amongst others) that we, the said John Mitchell and John Hirst
Mitchell, our executors or administrators, by an instrument in writing
under our, 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 we, the said John Mitchell and John Hirst
Mitchell, do hereby declare the nature of our said Invention, and in
what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement and accompanying
Sheets of Drawings (that is to say) :-
The object of this Invention is chiefly to heat the feed water supplied
to steam boilers, but the apparatus may be employed for heating water

page_text: or other liquids or fluids to be applied to other purposes, and consists
of an arrangement of straight pipes fitted together in a cylindrical form,
connected at each end by means of two cast-iron disc bearers with
suitable thoroughfares forming a communication from one pipe to
another or connected by means of cast-iron elbow pipes of the same
bore, the whole mounted upon arms attached to and rotates or revolves
on a hollow axis.
Each straight pipe is fitted with a scraper, which is a thin iron bar
extending from one end to the other with the edge resting on the outer
surface. These scrapers are each held to and maintained upon the top
or upper sides of the pipes by means of weights attached thereto by loose
clasps encircling and hanging down underneath the said pipes as they
rotate or the cylindrical mass of pipes revolve, and which weights are
bars of iron, by preference of triangular shape in cross section with the
apex upward, to deflect the heat toward the pipes.
Each straight pipe is likewise provided with an inside scraper, which
consists simply of an iron bar of angular shape laid loose in the inside
of each pipe, which as the pipes rotate continually slides to the bottom,
and thereby rubs or scrapes the interior of each pipe, which prevents
incrustation or substances adhering to the inner surface thereof.
Each joint is flanged and turned or planed accurately so as to be
(with the use of a little cement) made perfectly water-tight.
The whole are fitted together securely and mounted on suitable
bearings inside the flue betwixt the boiler furnace and chimney, with
the axes in a horizontal position.
The action of the heat current from the boiler furnace flue toward
the chimney on the outer surface of the pipes heats the water inside to
a high temperature, varying according to the quantity of water passed
through the pipes and the degree of heat in the flue.
The inlet and outlet pipes are connected to the revolving centres or
axes by means of stuffing box conical joints accurately fitted, and the
outlet pipe is also fitted with a safety valve and the connecting pipes
with necessary valves and taps.
Such being the nature and object of our said Invention, we will now
proceed to explain more fully the construction and arrangement by the

page_text: aid of Drawings annexed hereto, of which Fig. 1 is an end elevation
and Fig. 2 is a plan view.
A is a hollow shaft composed of a series of flanged pipes with two
discs B and 'B¹ fixed in between two of the joints to form bosses, to which
are bolted a series of arms C, and to these arms are bolted a series of
elbow pipes D, and a blank flange is also placed between another
joint A¹ forming a division in the hollow shaft. These elbow pipes,
which are attached to the arms fixed on the disc B, are connected by
a series of straight pipes E to the elbow pipes attached to the arms fixed
on the disc B¹, and the arrangement is such that a continuous passage
is formed throughout the whole series or entire length of pipes, so that
water (or other liquid or fluid) on being introduced at one end of the
shaft or centre pipe A will pass into and through the elbow D¹ into and
through the straight pipe E¹, thence through the elbow D' into and
through the pipe E³, thence through the elbow D³ into the pipe E³, and so
on, alternately passing across from one end of the apparatus to the other
according to the letters and figures marked on the Drawings, until
finally arriving at the centre pipe or shaft A, but on the other side of the
division flange A³, when it passes out at the other end thereof A³.
Each of the straight pipes is provided with a scraper F, see Fig. 3,
which is a cross section of one of the pipes E connected by a strap G
to a weight H, which being heavier than the scraper always keeps it
(the scraper) on the upper side of the pipe, although each pipe rotates
or turns over by reason of revolution of the series of pipes when in
operation. Also each pipe E is provided in its interior with another
scraper or bar I, which by its gravity is caused to slide over the inner
surface as the pipe turns over. This apparatus is placed within the flue
leading from the furnace of a steam boiler or other furnace to the
chimney mounted on pedestals or bearings its shaft horizontal, and a
slow rotary motion is given to it by worm and wheel or any other
suitable means.
Fig. 4 is a modified form of scrapers and weight.
•

page_text: rotary motion of the machine alternately presents to the heat current the
whole of the outer surface of each pipe, thereby rendering the wear and
tear (which is very small) uniform throughout.
Having thus described the nature of our said Invention, and shewn
by Drawings in what manner the same is to be performed or put into
practical operation, we would have it understood that we do not confine
ourselves to the precise details in the construction or arrangement herein
described and shewn, but we claim an arrangement of pipes and scrapers
for the purpose set forth, capable of motion in manner substantially as
shewn and described.
In witness whereof, I, the said John Hirst Mitchell, for and on
behalf of myself and the said John Mitchell, have hereunto set
my hand and seal, this Ninth day of May, in the year of our Lord
One thousand eight hundred and seventy-two.
· JOHN HIRST MITCHELL. (L.S.)
Witness,
JOSEPH STEAD,
Clerk to Tasker & Brierley,
Halifax & Bradford.