Improvements in or appertaining to Steam Boiler or other Furnaces.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in or appertaining to Steam Boiler or other
Furnaces.
I, WILHELM OTTO AXEL LOWE, of 72, Aldersgate Street, London, Merchant, do
hereby declare the nature of this invention to be as follows:---
This invention relates to the furnaces of boilers for generating steam, and other
furnaces or heating apparatus. The object is to obtain more perfect combustion,
economy of fuel and the prevention of smoke. Hitherto air for combustion has been
admitted through the fire bars and fuel or at the bridge, and in many cases a large
portion of the gases has passed off unconsumed, owing to there being an insufficient
supply of air or from other cause, and hence the production of smoke."
By the present invention I admit a sufficient supply of air from the front of the
boiler direct into the fire where wanted, through openings or channels in the furnace
front, and at the only time it is required, namely, when coaling or raking the
fires, and this air is sufficiently heated before entering the furnace to cause the gases
to burst into flame the instant it is admitted, thus securing perfect combustion and
prevention of smoke with saving of fuel.
In carrying the invention into effect, I remove the ordinary boiler front, and fix
in its place a box front formed with a horizontal doorway through which the furnace
Above
can be charged with fuel, and which is provided with a door at the entrance.
or around or below this doorway is an air channel leading to a series of gills adapted
to inject air into the fire. These gills are arranged preferably in a semi-circle around
the fire doorway, and may be placed obliquely so as to direct the air current down-
wards on to the fuel. They also project slightly into the furnace to such a distance
that they become highly heated by the fire, and heat the incoming air as it passes
through the gills to a temperature that will secure a perfect mingling with the hot
gases, and aid in securing perfect combustion and prevention of s. and saving of
fuel. Furthermore the air channel surrounding or partly surrounding as it does the
fire doorway, forming a jacket as it were for the latter, has the effect of also heating
the air before delivery through the gills into the fire. The air channel aforesaid
that leads to the gills is controlled by means of a shutter or valve which is worked
by means of a regulating mechanism. This shutter remains normally closed, but it
is coupled to the fire door in such a manner that the door on being opened to charge
the fire with fresh fuel or for raking it, opens the shutter, thus admitting air
through the gills into the fire.
The closing of the air lid or shutter is controlled by a small cylinder containing
oil or other fluid, which passes through a number of valves in piston block, allowing
a free passage one way, but when the piston reverses, these valves close, with the
exception of one which (controlled by a set screw passing through hollow piston
rod) allows the oil or other fluid to pass only as required, thus regulating the speed
or descent of piston when force, or weight is used to draw the piston to one end of
cylinder. A spiral spring is also placed in the cylinder which, when no force is
used, keeps the piston block to one end of the cylinder. This cylinder is fixed above
the air box lid, and connected to the lid by a short chain or lever attached to piston

page_text: rod. The air box lid is raised by means of a chain or lever (passing over a pulley
fixed on a bracket bolted to air box) fastened to the furnace door so that when the
furnace door is opened, the chain or lever raises the lid, thus taking the weight of
lid from piston, allowing spiral spring to push piston to the other end of cylinder.
When the furnace door is shut, the weight of the lid falls on the piston causing the
oil or other fluid to be forced through the regulating valve as well as compressing
the spring which gradually descends. until the lid is closed.
In place of the ordinary dashpot arrangement for returning the door to place, I
may find it convenient for the purposes of avoiding friction to employ a series of
flexible corrugated pistons working hydrostatically or pneumatically.
In charging the fire with fresh fuel the opening of the door automatically and
simultaneously opens the shutter in the furnace front admitting a full supply of air
just when it is wanted, the shutters being. afterwards gradually closed as the fire
burns up and less smoke is given off. Furthermore the air admission can be
increased or decreased according to the kind of coal used and a greater or less supply
of air admitted as desired by regulating the shutter aforesaid which controls the
gills.
The floor of the doorway in the box front may form an auxiliary dead plate for the
furnace. The ordinary dead plate in fact may be perforated for air to pass through,
or it may be dispensed with altogether in which case the fire bars are lengthened
to a point immediately adjacent to the floor of the doorway. The furnace door itself
may be provided with openings or grids for the admission of air, controlled by means
of shutters to regulate the amount of opening thereof.
I have described the above ways of carrying my invention into effect, but I wish it
to be understood that I do not limit my invention to any given form of openings or
gills, as nozzles, louvres or any other suitable form of openings can be employed.
Furthermore, the invention can be applied to all kinds of boilers or furnaces,
grates or stoves worked with either open ashpits or closed ashpits, under natural or
forced draught, with direct fan pressure or otherwise.
Dated this 29th day of March 1898
WM. P. THOMPSON & Co.,
of 6, Lord Street, Liverpool, Patent Agents for the Applicant.
Improvements in or appertaining to Steam Boiler or other
Furnaces.
I, WILHELM OTTO AXEL LOWE, of 72, Aldersgate Street, London, Merchant, 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 —
This invention relates to the furnaces of boilers for generating steam, and other
furnaces or heating apparatus. The object is to obtain more perfect combustion,
economy of fuel and the prevention of smoke. Hitherto air for combustion has been
admitted through the fire bars and fuel or at the bridge, and in many cases a large
portion of the gases has passed off unconsumed, owing to their being an insufficient
supply of air or from other cause, and hence the production of smoke.
By the present invention I admit a sufficient supply of air from the front of the
boiler direct into the fire through openings or channels in the furnace front, and this
air inay be sufficiently heated before entering the furnace to cause the gases to burst

page_text: into flame when it is admitted, thus securing perfect combustion and prevention of
smoke with saving of fuel.
The invention will be understood from the following description, reference being
had to the accompanying drawings, in which:
Figure 1 is a front view of a boiler with my invention applied thereto, part being
broken away to show the channels E;
Figure 2 a longitudinal section of the front part of the boiler;
Figure 3 a perspective view of the front of a boiler with my invention fitted
thereto;
Figure 4 a modification.
Figure 5 the invention when used without the box front F.
Referring to these figures, A is the boiler which in this case is a single tube or
Cornish boiler, B the furnace, the ashpit, and D the grate. I admit all the
air that can be got from the front of the boiler direct into the furnace B through
openings or channels E in the furnace front F, which openings or channels are
controlled by a shutter or valve El so that the admission of air can be regulated.
I remove the ordinary boiler front and fix in its place a box front F formed
with a doorway through which the furnace can be charged with fuel, and which is
provided with a door at the entrance. Above or round (or below) this doorway is
an air channel f leading to a series of openings or channels E adapted to let air into
the fire. These openings are arranged preferably in a semicircle round the fire
doorway and may be placed obliquely so as to direct the air current downwards on to
the fuel. They may also project slightly into the furnace to such a distance that
they become highly heated by the fire, and heat the incoming air as it passes through,
and aid in securing perfect combustion, prevention of smoke and saving of fuel.
Furthermore the air channel f surrounding or partly surrounding as it does the fire
doorway, forming a jacket as it were for the latter, has the effect of also heating the
air before delivery through the openings into the fire. The air channel aforesaid
that leads to the openings is controlled by means of a shutter or valve E¹ which is
worked by means of a regulating mechanism (not shown) or it can be worked
by hand.
K is a shaft being a prolongation of the spindle K¹ of the door hinge, which when
the door is opened or closed to charge the fire with fresh fuel or to rake it, will
operate the aforesaid mechanism. This opens the shutter E by means of the con-
necting rod M and arm 0, said mechanism holding open the shutter for a certain
interval of time, thus admitting air through the openings into the fire. When the
door is closed again after charging the furnace, the shutter still remains open but
will close slowly. The mechanism which I use is not shown on the drawings or
described in the specification, as it does not form the subject of the present
invention.
In charging the fire with fresh fuel, the opening of the door C automatically and
simultaneously opens the shutter E' in the furnace front, admitting a full supply of
air the shutters being afterwards closed as the fire burns up and less smoke is given
off. Furthermore the air admission can be increased or decreased according to the
kind of coal, and a greater or less supply of air adınitted as desired by regulating the
shutter aforesaid which controls the openings. The floor G of the doorway in
the fixed front may form an auxiliary dead plate for the furnace, the ordinary dead
plate H in fact may be perforated for air to pass through, or it may be dispensed
with altogether, in which case the firebars D are lengthened to a point immediately
adjacent to the floor G of the doorway. The furnace door C' itself may be provided
with openings or grids for the admission of air controlled by means of shutters to
regulate the amount of opening thereof.
I have described the above way of carrying the invention into effect, but I wish
it to be understood that I do not limit myself to any special form of openings E, as
nozzles, louvres or any other suitable form of openings can be employed. Further-
nore, the invention can be applied to all kinds of boilers or furnaces, grates or stoves
worked with open ashpits or closed ashpits, under natural or forced draught or with
"

page_text: direct fan pressure or otherwise; also the shutter E' may be operated simply by hand.
The mechanism for opening the shutter by hand is shown in Figure 4, in which S
is an angular lever or arm on the boiler front which normally keeps the shutter E¹
closed. T is a hand lever which when pulled strikes the lever or arın S and opens
the shutter E¹.
In Figure 5 I remove the box front and provide a front F with openings or
channels E which openings or channels are controlled by the shutters or valves U so
that the admission of air can be regulated. The openings or channels are placed in
the furnace front F itself and in the furnace door so that the incoming air will mingle
with the gases in the furnace and supply the deficient oxygen which is necessary to
complete the combustion. These channels or openings are by preference arranged
in a semi-circle in the boiler front as shown having a movable semi-circular
shutter E adapted to close the opening or regulate the amount of opening thereto
so as to admit the amount of air that is required. The air supply is thereby
admitted direct to the furnace purely by the influence of the natural draught induced
by the chimney and fire. The shutters for regulating the openings may be dispensed
with if desired.
I may even use a double front arrangement in which the front plate of such
double front is slotted or perforated to admit air, while the plate behind is perforated
with a number of holes, as shown in Figure 6. The door is also made double with
each plate perforated. The front and back plates of such double front are arranged
at suitable distance apart, so as to form a chamber between, into which the cold air
is admitted through the front plate and heated and then passed through the back
plate into the fire. The perforations are used with or without shutters or valves.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is :-
1. In a boiler or other furnace providing the furnace front with openings or
channels so arranged as to admit air uniformly into or over the fire, so that the
incoming air may mingle with the gases in the furnace and supply the deficient
oxygen that is necessary to complete the combustion substantially as described.
2. In a boiler or other furnace, providing the furnace with a double front, and
double door, each composed of perforated plates arranged at suitable distances apart
so as to form an air chamber between, substantially as and for the purpose
described.
3. In boiler or other furnaces the combination of openings or channels E so
arranged as to admit air uniformly into and (or) over the fire, and shutters or valves
adapted to control the admission of air through said openings and admit the requisite
amount for combustion, substantially as described.
4. In boiler or other furnaces, fixing to the furnace front a box front formed with
a horizontal doorway through which the furnace can be charged with fuel, and an
air channel arranged above or around this doorway having a series of openings
adapted to let air into the fire in combination with a shutter or valve so arranged as
to control the admission of air through said openings, substantially as described.
5. In a boiler or other furnace, the provision in the furnace front of the series of
orifices for the admission of air, projecting slightly into the furnace such a distance that
they become highly heated by the fire, and heat the incoming air as it passes
through substantially as described.
6. The general combined arrangement and construction of parts substantially as
set forth in reference to Figures 1, 2 and 3, Figure 4, Figure 5, and Figure 6.
WM. P. THOMPSON & Co.,
Patent Agents, of Liverpool, Manchester, Birmingham and London.