CERTAIN IMPROVEMENTS IN FURNACES FOR STEAM BOILERS AND OTHER PURPOSES
Year: 1869

page_text: LETTERS PATENT to William Walker, of Manchester, in the County of
Lancaster, Engineer, and David Davies, of the same Place, Engineer,
for the Invention of "CERTAIN IMPROVEMENTS IN FURNACES FOR STEAM
BOILERS AND OTHER PURPOSES,"
Sealed the 22nd March 1870, and dated the 29th September 1869.
PROVISIONAL SPECIFICATION left by the said William Walker and
David Davies at the Office of the Commissioners of Patents, with
their Petition, on the 29th September 1869.
We, WILLIAM WALKER, of Manchester, in the County of Lancaster,
Engineer, and DAVID DAVIES, of the same Place, Engineer, do hereby
declare the nature of the said Invention for "CERTAIN IMPROVEMENTS IN
FURNACES FOR STEAM BOILERS AND OTHER PURPOSES," to be as follows:-
The object of this Invention is to improve the combustion of fuel and
to reduce or prevent the escape of smoke from the furnaces of steam
boilers and other furnaces.
Our Invention consists in applying a jet of steam against the blades
or arms of a fan or wheel, supported in bearings in the fire-door or in

page_text: the front plate of the furnace. The steam causes the fan or wheel to
rotate rapidly on its axis, and this rapid rotation of the fan or wheel
induces a current of air into the furnace, which air mixed with the
steam passes over the fire on the grate. In some cases the steam may
be dispensed with, and the fan or wheel driven by power of any other
description, or the current of air caused by the fire may be sufficient to
drive the fan or wheel. When fresh fuel has been supplied to the
grate the fan or wheel is caused to revolve by the admission of steam
or otherwise, thereby drawing a current of air through perforations in
the furnace door or in the front plate; this current of air passing
through the fan or wheel is heated by coming in contact with the casing,
which causes it to mix with the smoke issuing from the green fuel, and
so consumes the smoke. The fan or wheel only requires to be kept in
motion for a few minutes after the fresh fuel is supplied to the furnace.
A similar fan or wheel may be placed near the bridge to introduce air
into the flue. We regulate the admission of air to the fire-place or flue
by a valve with openings, which can be increased or reduced in area by
a register plate moved slowly over a similar plate by a train of wheels
actuated by the fan or wheel or otherwise.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Walker and David Davies in the Great
Seal Patent Office on the 29th March 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, WILLIAM
WALKER, of Manchester, in the County of Lancaster, Engineer, and
DAVID DAVIES, of the same Place, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-ninth day of September, in the
year of our Lord One thousand eight hundred and sixty-nine, in the
thirty-third year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto us, the said William Walker and David Davies,
Her special licence that we, the said William Walker and David Davies,
our executors, administrators, and assigns, or such others as we, the
said William Walker and David Davies, our executors, administrators,
and assigns, should at any time agree with, and no others, from time

page_text: 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 "CERTAIN IMPROVEMENTS IN FURNACES FOR
STEAM BOILERS AND OTHER PURPOSES," upon the condition (amongst others)
that we, the said William Walker and David Davies, our executors or
administrators, by an instrument in writing under our, or their, or one
of our or 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 William Walker and David
Davies, 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 (that is to say) :-
The object of this Invention is to improve the combustion of fuel by
reducing or preventing the escape of smoke from the furnaces of steam
boilers and other furnaces.
Our Invention consists in applying a jet of steam against a fan or
wheel supported in bearings or revolving on a stud in the fire-door or
in the front plate of the furnace. The steam causes the fan or wheel
to rotate rapidly on its axis, and the draught in the chimney induces a
current of air into the furnace, while the rotation of the fan or wheel
causes the air mixed with the steam to pass over the fire on the grate.
In some cases the steam may be dispensed with, and the fan or wheel
driven in any other manner. When fresh fuel has been supplied to the
grate the fan or wheel is caused to revolve by the steam or otherwise,
and the current of air drawn through the perforations in the furnace
door or in the front plate passing through the fan or wheel becomes
agitated and mixed with the smoke issuing from the green fuel, and so
ignites or consumes the smoke. The fan or wheel only requires to be
kept in motion for a few minutes after the fresh fuel has been supplied
to the furnace. We regulate the admission of air to the fire-place or
flue by a valve with openings, which can be increased or reduced in
area by a register plate moved slowly over a similar plate by a train of
wheels actuated by the fan or wheel or otherwise.

page_text: readily carried into operation we will proceed to describe the accom-
panying Sheet of Drawings, which is drawn to a scale of about half the
real size.
Figure 1 is an elevation, and Figure 2 a plan, partly in section, of
part of the front plate of an ordinary flued boiler shewing the firing
door adapted to receive our improved apparatus.
a is the front plate, and 6 the firing door, which is provided with a
cylindrical casing 6', the front plate 6' forming part of which is made
with any convenient number of radial or other openings; these openings
are covered or uncovered as may be required by the register plate c, in
which is a corresponding number of openings. In the centre of the
plate 6 is fixed the hollow stud d on which the register plate c is
mounted, and the circumference of this register plate is provided with
the fine toothed rim c' which is connected to the plate c by the stud c³
fixed to the rim c³, and the segmental slot c³ in the plate c. The spindle
or shaft d¹ passes through the stud d, and to its inner end is fixed the
fan or wheel e, the circumference of which is provided with wings or
buckets, as shewn in Figure 3, and the blades or arms e¹ of which are
either straight, as shewn in Figure 3, or curved if preferred; these blades
or arms may project beyond the circumference of the fan or wheel, as
shewn in Figure 2. The space between the fan or wheel e and the plate 6ª
may be filled by a block of fire-clay or other non-conductor of heat, as
shewn at 6 in Figure 2; it is evident that this block must have per-
forations through it corresponding to those in the plate 6º. Above the
firing door, or in any other convenient position, is the pipe f, the upper
end of which opens into the steam space of the boiler, and the lower
end is brought near to the circumference of the fan or wheel e, as shewn
in Figure 3. The tap f' is placed in the pipe f to admit or shut off the
steam. The firing door is closed by the latch g, as usual, which may
be curved round the casing b¹, or arranged in any other suitable manner.
At the outer end of the shaft d¹ is a toothed pinion e³, around which
passes the endless chain or band h; this chain or band gives motion to
the toothed wheel i, which is mounted on a short shaft revolving in a
bush cast on the firing door; and to this short shaft is fixed the worm j
gearing into and driving the wheel k on the shaft l, on which is fixed or
cut the worm m gearing into the toothed rim c¹.

page_text: The mode of operation is as follows:-The radial openings in the
register plate' c are supposed to coincide with those in the plate 6³, so as
to admit the greatest quantity of air to the furnace when the grate has
just been supplied with fuel. The operator after having closed the firing
door turns the tap f¹ to allow the steam to flow through the pipe f on
the fan or wheel e; the action of the steam causes the fan or wheel to
rotate rapidly, thereby giving motion to the chain h, and through it and
the parts before referred to to the rim c'. At the commencement the
rim c' does not impart motion to the plate c because the stud c³ is at
liberty to move in the slot c³, but as soon as the stud comes against the
end of the slot the plate c partakes of the rotary motion of the rim c¹,
and gradually closes the radial openings in the plate b³. So long as they
are open or partially open a current of air is drawn into the furnace by
the draught in the chimney; and this air combined with the steam
employed to drive the fan or wheel mixes with the products of com-
bustion, and ignites the inflammable gases, thus preventing or reducing
the smoke. The number of teeth in the wheels and pinions and the
speed of the fan or wheel must be regulated to close the apertures in the
plate 6 within a certain time, and this time depends upon the nature
of the fuel, the size of the furnace, and other circumstances, which vary
in almost every instance.
The Drawing represents an apparatus suitable for the furnace of a
steam boiler. The apparatus for admitting the air to the furnace
may be attached to the front plate of the furnace instead of being
connected to the firing door, as shewn, and instead of the circular register
plate shewn any other form of sliding plate may be used.
Figure 4 represents a section of the firing door constructed according
to a modification of our improvements. Figure 5 is an elevation of part
of the same. In this case we connect to the inner end of the casing b¹
a series of cast-iron annular rings 64, through the spaces between which
the air passes after it has passed between the arms of the fan or wheel.
These rings b' become heated by the fire on the grate, and consequently
the current of air passing between them is also heated before it enters
the furnace. The centre may be filled up with a block of fire-clay or
otherwise.
Instead of making the arms e' rigid, as shewn in Figure 3, they may be
made capable of swivelling on their centres, so that they may be set at
an angle for the purpose of agitating or propelling the air; when this

page_text: is found desirable the said arms are provided with shanks fitting in the
boss of the fan or wheel; and we vary the angles of the arms by an
apparatus similar to that described in the Specification of Letters
Patent granted to Robert Griffith on the Thirteenth day of September
One thousand eight hundred and forty-nine, Number 12,769, or other.
suitable apparatus now in use for feathering or varying the angles of
the blades of screw propellers may be employed. We would also remark
that the said arms may be set at an angle without being moveable.
Our Invention may also be modified by driving the fan or wheel e by
the direct application of power transmitted by a band to a pulley on the
axle of the fan or wheel or otherwise; and instead of closing the air
apertures in the firing door by gearing driven from the fan or wheel, as
shewn in Figures 1 and 2, the self-closing motion may be imparted
through a train of wheels actuated by a weight or spring, or in any
other convenient manner.
Having thus stated the nature of our Invention, and described the
manner of performing the same, we wish it to be understood that what
we claim as our Invention of improvements in furnaces for steam boilers
and for other purposes is,―
First. The application of a fan or wheel in the fire-door or front plate
as described.
Secondly. The combination of a fan or wheel actuated by steam or
otherwise with an apparatus for shutting off the admission of air, as
shewn and described.
And, lastly. The application of feathering arms or blades to the fan
or wheel by which the air admitted to the furnace is agitated or propelled.
as described.
In witness whereof, we, the said William Walker and David Davies,
have hereto set our hands and seals, this Twenty-sixth day of
March One thousand eight hundred and seventy.