Improvements in or in connection with Steam Boiler and other Furnaces.
Year: 1898

page_text: Date of Application,
28th Anr 1898
Complete Sponification Left 30th Jan.. 1899-Accepted, 28th Apr.,
1899
Date of App
Complete Specification Left, 30th Jan.. 1899—Accepted, 28th Apr.,
1899
PROVISIONAL SPECIFICATION.
Improvements in or in connection with Steam Boiler and other
Furnaces.
We, JOHN ROBERTS, of 3, Back Ennerdale Road, Cleator Moor, in the County
of Cumberland, Tinsmith, and THOMAS PATTINSON, of 2, Aldby Street, Cleator
Moor aforesaid, Accountant, do hereby declare the nature of this invention
to be as follows:-
The invention has for its object to obtain more perfect combustion, economy
of fuel and prevention of smoke in the furnaces of boilers for generating steam,
and other furnaces or heating apparatus.
The present system of supplying the fire with cold air direct thereto from
the atmosphere, results in considerable waste of fuel, as the air admitted must
be quickly heated, otherwise the gases will pass out unburnt causing smoke. In
order to overcome this we propose to heat the air, before being admitted into
the furnace fire, to as high a degree as can be got without burning or destroying
it. This air has in itself a heating effect upon the boiler and fire, and not the
cooling effect which the present system has, resulting in an extravagant use of
fuel and having an injurious effect upon the boiler.
It is well known that considerable heat passes through the flues after leaving
the boiler flues into the chimney and is consequently lost. This heat we pro-
pose to return to the furnace without interfering with the unburnt gases which
pass out by the chimney as usual. To effect this we provide a stove or apparatus
for heating the auxiliary air supply which is located between the boiler and the
chimney, and in the path of the furnace gases, this apparatus being formed
with tubes and the hot gases passing between the tubes on the outside, the
current of air passing through the inside on its way to the furnace. The air
heated by this stove is conveyed to the furnace to supply the deficient oxygen
to secure combustion. Accordingly we bring a pipe or pipes from the stove to
the ashpit and introduce the air heated by the stove through this pipe which
may be from three inches in diameter upwards into the ashpit under the firebars,
thus bringing it through the fire. This pipe extends the whole length of the
furnace and terminates in the ashpit immediately under the grate. In some
boilers the pipe may pass through the centre of the boiler flue or under the same.
In every case however it must be protected from the cold air on its outer side.
To withstand the greater heat developed under this system the firebars may be
specially prepared of fireclay, or water tube bars may be used. The furnace end
of the boiler must be closed in by a half door hinged airtight to prevent cold air
passing in or diverting the current from the stove. The door is also made to
open to admit the ashes being withdrawn from under the grate.
When the fire is being replenished, the fire door being open during this opera-
tion, the current of hot air will stop, consequently it will become much hotter
in the stove and when the fire door is closed again the auxiliary air supply will
again commence, thus supplying the necessary oxygen to consume the smoke.
A sliding damper is placed between the stove and the chimney which, when open,

page_text: admits hot air into the chimney preventing the tubes burning when not in use.
A valve may also be provided in the pipes which convey air from the stove to
the ashpit so that the flow of auxiliary air thereto can be regulated to a nicety.
A steam jet may be inserted in the pipe if desired to form an induced air current
or in some cases it may be requisite to force the air current through by a pro-
peller or fan, or the natural draught of the furnace may be sufficient to induce a
current of heated air into the fire through this pipe.
In thus describing our invention it will be understood that the invention may
be modified to suit special circumstances. It may however in some cases be
necessary to erect a separate stove to be heated by exhaust steam from the
engines, or exhaust steam may be turned into the first mentioned stove, also if
required a scraper may be made to scrape off soot from the outside of the stove
tubes.
Improvements in or in connection with Steam Boiler and other
Furnaces.
We, JOHN ROBERTS, of 3, Back Ennerdale Road, Cleator Moor, in the County
of Cumberland, Tinsmith, and THOMAS PATTINSON, of 2, Aldby Street, Cleator
Moor, aforesaid, Accountant, do hereby declare the nature of this invention
and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement:.
The invention has for its object to obtain more perfect combustion, economy
of fuel and prevention of smoke in the furnaces of boilers for generating steam,
and other furnaces or heating apparatus.
The present system. of supplying the fire with cold air direct thereto from
the atmosphere, results in considerable waste of fuel, as the air admitted must
be quickly heated otherwise the gases will pass out unburnt causing smoke. In
order to overcome this we propose to heat the air before being admitted into
the furnace fire, to as high a degree as can be got without burning or destroying
it. This air has in itself a heating effect upon the boiler and fire, and not the
cooling effect which the present system has, resulting in an extravagant use of
fuel and having an injurious effect upon the boiler.
The invention will be understood from the following description, reference
being had to the accompanying drawings, in which :-
Figure 1 is a longitudinal section of our invention applied to a Cornish boiler;
Figure 2 an end view.
Referring to these figures, A is the boiler, B the furnace flue and C the grate.
It is well known that in many cases hitherto considerable heat passes through
the flues after leaving the boiler flues into the chimney and is consequently lost.
This heat we propose to return to the furnace D without interfering with the
unburnt gases which pass out by the chimney as usual. To effect this we
provide a stove E or apparatus for heating the auxiliary air supply, which is
located between the boiler A and the chimney, and in the direct path of the
furnace gases which pass from the furnace flue B to the chimney,
this apparatus being formed with tubes, and the hot gases passing between the
tubes on the outside, the current of air passing through the inside on its way to

page_text: he furnace.
enu
F is an inlet pipe for the fresh air entering through the
roup of tubes, through which it passes into the hot box G. The air in this
ox, passing longitudinally in the direction of the arrow, returns through the
ext group of tubes nearest the furnace into the tube H, which conveys the hot
ir from the stove to the under side of the grate C, in order to supply the deficient
xygen to secure combustion. This pipe H extends the whole length of the
poiler, and terminates in the ashpit immediately under the grate C. In some
poilers the pipe may pass through the flue B or under the same.
To
If on outside
of boiler the pipe must be protected from the cold air on its outer side.
withstand the greater heat developed by this system, the firebars may be specially
prepared of fireclay, or water tube bars may be used. The ash pit is closed at
end by an ashpit door I hinged airtightly to prevent cold air passing in or
diverting the current from the stove. The door is also made to open to admit
the ashes being withdrawn from under the grate.
N is a partition between the grate and the bridge which forms an air space.
O is a pipe conveying some of the air from the pipe H to this space P, and thus
the hot air will not only pass into the burning fuel on the grate, but some of it.
will also mix with the products of combustion at the bridge. Instead however
of supplying this pipe 0, we may supply the pipe O¹ leading in an opposite
direction, as shown by dotted lines.
When the fire is being replenished, the fire door J being opened during this
operation the current of hot air through the pipe H will stop, consequently it
When the fire door is closed again
will become much hotter in the stove E.
the auxiliary air supply will again commence, thus supplying the necessary
oxygen to consume the smoke. A sliding damper is placed between the stove
and the chimney, which when opened admits hot air into the chimney, pre-
A valve K may also be provided
venting the tubes burning when not in use.
in the pipe which conveys air from the stove to the ashpit, so that the flow of
auxiliary air thereto can be regulated to a nicety. A steam jet L
inserted in the pipe if desired, to form an induced air current, or in some cases
it may be requisite to force the air current through by means of a propeller or
fan or the natural draught of the furnace may be sufficient to induce a current
of heated air into the fire through the pipe.
may be
Immediately underneath the grate we provide a baffle or deflecting plate M.
The hot air current passes under this plate and a portion of it passes up at the
far end of the plate to the back end of the grate, while the rest passes up at the
sides of this plate and so feeds the front end of the grate. The greater portion
of the air however goes direct to the furthest half of the grate, and the effect is
that it tends to make the fire brightest nearest the bridge.
In thus describing our invention it will be understood that it may be modified
to suit special circumstances. It may however be necessary in some cases to
erect a separate stove to be heated by exhaust steam from the engines, or the
exhaust steam may be turned into the first mentioned stove. Also if required
a scraper may be made to scrape the soot from the outside of the stove tubes.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is:
1. In steam boiler or other furnaces, arranging between the furnace and the
chimney in the path of the exhaust furnace gases, an air heating appliance
formed with tubes, the hot gases passing between the tubes on the outside and
the air current passing through the inside on its way to the furnace or vice
versa, in combination with a pipe or passage for conveying the air from the
heating appliance to the furnace, whereby the heat of the exhaust gases is used
to impart heat to the air for combustion before the latter is admitted to the
5 furnace fire.
2. In steam boiler or other furnaces, the combination therewith of an air

page_text: heating appliance located in the direct path of the exhaust furnace gases, said
appliance consisting of groups of tubes through which the air is passed alter-
nately and thereby heated to the required temperature by the hot waste gases
of the furnace fire, substantially as described.
3. In steam boiler or other furnaces, the combination with the air heating
appliance of a baffle or deflecting plate arranged immediately under the grate
in such a manner that the hot air current shall pass under this plate to the back
end of the grate, so as to give a greater draught at the back than at the front,
and tend to make the brightest fire nearest the bridge, substantially as described.
4. In steam boiler or other furnaces the combination with the air heating
appliance of a partition N, arranged between the bridge and the grate leaving
an air channel between, and an air supply pipe leading air to this channel, so as
to supply a current of air which will mix with the products of combustion at the
bridge, substantially as described.
5. The general combined arrangement and construction of parts forming our
improved air heating appliance for steam boiler and other furnaces, substan-
tially as set forth.
Dated this 28th day of January 1899.
WM. P. THOMPSON & Co.,
Patent Agents, of Liverpool, Manchester, Birmingham, and London.
WM. P. THOMPSON & Co.,
Patent Agents, of Liverpool, Manchester, Birmingham, and London.