Improvements in or connected with Furnaces, more especially intended for Use in Steam Boiler Furnaces.
Year: 1894

page_text: Date of Application, 23rd June, 1894
Complete Specification Left, 23rd M.r., 1895-Accepted, 27th Apr., 1895
PROVISIONAL SPECIFICATION.
Improvements in or connected with Furnaces, more especially
intended for Use in Steam Boiler Furnaces.
I JAMES YATE JOHNSON of 47 Lincoln's Inn Fields in the County of London
Gentleman do hereby declare the nature of this invention (which has been
communicated to me from abroad by Jean Pierre Serve of 17 Quai de Cuire
Lyons, (Rhone) in the Republic of France Engineer) to be as follows:-
This invention relates to improvements in or connected with furnaces and more
especially intended for use with steam boiler furnaces fed by air under pressure in
order to obtain intense combustion, and consequently a more liberal steam supply
than that resulting from the ordinary draught through the chimney and I will in
the following description presume it to be so applied.
This invention consists of means as hereinafter described for preventing the door
and the mouth front or entrance of the furnace from becoming so highly heated as
to inconvenience the firemen and to elevate objectionably the temperature of the
stokehold. Further objects of the said invention are to avoid the danger which
arises from flame issuing from the furnace by its mouth or entrance when the door
is opened, and also to prevent any leakage or escape of deleterious gases around
the door.
For the purpose of preventing the mouth and door of the furnace from becoming
100 highly heated, owing to their contact with the flames, these parts are, according
to this invention made with hollows, and a current or stream of water is caused to
circulate through them so as to exercise a cooling effect thereon.
To this end the mouth and door are provided with short tubes or nozzles
communicating through suitable tubes or passages with a water supply and with
discharge or circulating pipes. These pipes or passages in connection with the
door are so made of supple or flexible material or otherwise arranged as to allow of
the necessary movements of the door.
The furnace mouth may also be lined internally with fire-proof material which
protects it whenever the circulation of the water may happen to be momentarily
interrupted.
In order to prevent, when opening the door, any of the flames from rushing to
the outside, as a result of the pressure existing in the furnace at the time, there is
arranged within the mouth a pipe or passage adapted practically to fit the outline
of the furnace door, and provided with a slot or, preferably, a number of tuyere,
or ports, leading into the interior of the furnace, and inclined so as to converge
towards a point at the rear of the door.
This pipe or passage communicates with an external pipe or conduit leading to
an air-conduit which supplies the furnace with air under pressure and is provide!
with a valve arrangement operated by the movements of the door, so that the air
forced in is only allowed to enter when the said door is open.
In apparatus constructed in this manner it will be understood that when the door
is opened, the air under pressure which is forced in in convergent jets, towards the
back of the furnace, forms a species of wind curtain, which owing to its direction
opposes the escape of the flames and hot gases through the door-opening and the
tendency of the air thus forced in to carry external air along with it into the
furnace assists the air jets in preventing the outrush of flame.

page_text: It will be understood that the pipe or passage having the blast tuyeres or the
like formed in it, as stated may be situated within the furnace mouth, or be cast in
one piece therewith; or it may be arranged externally, if preferred, but it should
be protected in all cases from the heat of the furnace and with the same object the
Luyeres should he so constructed as not to project into the furnace and any
arrangement which provides for these conditions may be employed.
To prevent leakage or escape of gas through the door joints, in consequence of
the pressure existing in the furnace a pipe or passage is arranged within the portion
of the furnace mouth surrounding the door, the said pipe or passage having perfora-
tions leading to a groove provided in the part facing the door, while in, or around,
the door itself, and in coincidence with the said groove, there is provided another
similar groove, so that when the two grooves are joined together by the closing of
the door, they jointly form a passage.
The last mentioned pipe or passage communicates with the air pipe or passage
by which the furnace is fed with air, and is provided with a conduit or pipe
provided with a valve operated by the door so that the air blast is not forced in
unless the door be closed.
The said air thus admitted under pressure tends to escape through the joint of
the door, so that part of such air enters the furnace and part escapes to the
outside.
I do not limit myself to this precise arrangement as any other equivalent means
may be employed for preventing in the manner hereinbefore stated leakages and
escape of deleterious gases around the furnace door by supplying air under pressure
at the outlets as described.
Dated this 23rd day of June 1894.
Improvements in or connected with Furnaces, more especially
intended for Use in Steam Boiler Furnaces.
1 JAMES YATE Joussos of 47 Lincoln's Inn Fields, in the County of London,
Gentleman, do hereby declare the nature of this invention (which has been
communicated to me from abroad by Jean Pierre Serve of 17 Quai de Cuire
Lyons (Rhone) in the Republic of France, Engineer) 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 improvements in or connected with furnaces and more
especially intended for use with steam boiler furnaces fed by air under pressure in
order to obtain intense combustion, and consequently a more liberal steam supply
than that resulting from the ordinary draught through the chimney and I will in
the following description presume it to be so applied.
This invention consists of means as hereinafter described for preventing the door
and the mouth, front or entrance of the furnace from becoming so highly heated as
to inconvenience the firemen and to elevate objectionably the temperature of the
stoke hole. Further objects of the said invention are to avoid the danger which
arises from flame issuing from the furnace by its mouth or entrance when the door
is opened, and also to prevent any leakage or escape of deleterious gases around
the door.
I will describe the invention with reference to the accompanying drawings which
illustrate a turnace front constructed according to this invention.
Fig. 1 shows the furnace front in front elevation. Fig. 2 is a vertical section of

page_text: the same, and Fig. 3 shews in vertical section a part of the apparatus drawn to a
larger scale.
For the purpose of preventing the mouth A and door B of the furnace from
becoming too highly heated, owing to their contact with the flames, these parts are,
according to this invention, made with hollows as shewn in the drawings, and a
current or stream of water is caused to pass or circulate through them so as to
exercise a cooling effect thereon.
To this end the mouth A and door B are provided with short tubes or
nozzles a a respectively communicating through suitable tubes or passages
with a water supply and with discharge or circulating pipes; these pipes or
passages b in connection with the door are so made of supple or flexible material or
otherwise arranged as to allow of the necessary movements of the door.
The furnace mouth A may also be lined internally with fire proof material C
which protects it whenever the circulation of the water may happen to be
momentarily interrupted.
In order to prevent, when opening the door B, any of the flames from rushing to
the outside, as a result of the pressure existing in the furnace at the time, there is
arranged within the mouth A a pipe or passage D adapted practically to fit the
outline of the furnace door, and provided with a slot or preferably a number of
tuyeres or ports d leading into the interior of the furnace F and inclined so as to
converge towards a point at the rear of the door B as indicated by the dotted lines
in Figure 2.
This pipe or passage D communicates with an external pipe or conduit D
(Fig. 1) leading to an air conduit which supplies under pressure (it may be from
the same source which supplies the furnace) and is provided with a valve arrange-
ment operated by the movements of the door B, so that the air is forced in only
when the said door is open.
In apparatus constructed in this manner it will be understood that when the
door is opened, the air under pressure which is forced in in convergent jets, towards
the back of the furnace, as shewn in the dotted lines in Fig. 2, forins a species of
wind curtain, which owing to its direction, opposes the escape of the flames and
hot gases through the door openings and the tendency of the air thus forced in to
carry external air along with it into the furnace assists the air jets in preventing
the outrush of flame.
It will be understood that the pipe or passage D having the blast tuyeres d or
the like formed in it as stated may be situated within the furnace mouth, or be
cast in one piece therewith, or it may be arranged externally if preferred with the
tuyeres passing through the double wall of the mouth A but it should be
protected in all cases from the heat of the furnace; and with the same object the
tuyeres d should be so constructed as not to project into the furnace and any
arrangement which provides for these conditions may be employed.
To prevent leakage or escape of gas through the door joints in consequence of
the pressure existing in the furnace, a pipe or passage E is arranged within the
portion of the furnace month surrounding the door, the said pipe or passage E
having perforations leading to a groove provided in the part facing the door,
while in, or around, the door itself, and in coincidence with the said groove, there
is provided another similar groove so that when the two grooves are joined
together by the closing of the door, they jointly form a passage as shewn more
clearly in Fig. 3.
The pipe or passage E communicates by the pipe E' with a source of supply of
air under pressure which may be the same as that by which the furnace is fed with
air and the pipe or conduit E' is provided with a valve operated by the door B so
that the air blast is not forced in unless the door be closed.
The said air thus admitted under pressure by the perforated pipe E tends to
escape through the joint of the docr so that part of such air enters the furnace and
part escapes to the outside.
I do not limit myself to this precise arrangement as illustrated in the drawings

page_text: as any other equivalent means may be employed for preventing in the manner
hereinbefore stated leakages and escape of deleterious gases around the furnace
door by supplying air under pressure at the outlets as described.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. In combination with furnaces, a furnace front kept cool by a current of water
passed or circulating therethrough and provided with a pipe or passage connected
with a supply of air under pressure and passing around or partly around the
furnace mouth, the said pipe or passage being provided with slots or tuyeres
inclined so that the discharge therefrom converges towards a point at the rear of
the door and arranged so that when the said door is opened the air is forced
inwardly in convergent jets substantially as hereinbefore described.
קיין
or
2. In combination with furnaces, a furnace front kept cool by a current of water
circulating or passed therethrough and provided with a passage surrounding the
mouth thereof and connected with a supply of air under pressure the said
passage having perforations leading to a groove provided in the part facing the
door so as to secure the injection of nir under pressure in the joint of the door when
closed substantially as described.
3. A furnace front for steam boilers having its upper part and door kept
cool by a current of water circulating or passing therethrough in combination with
a blast pipe or passage passing around or partly around the furnace mouth and
provided with converging tuyeres and with a second blast pipe or passage arranged
within the furnace front surrounding the door and provided with perforations
opening into a groove formed in the part facing the door substantially as and
for the purposes hereinbefore described and illustrated in the accompanying
drawings.
Dated this 3rd day of March 1805
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.