Improvements in апа Connected WITH Furnaces, also Applicable to Ventilating and similar Purposes.
Year: 1886

page_text: Date of Application, 23rd Oct., 1886.
Complete Left, 5th May, 1887.
Complete Accepted, 7th June, 1887.
Improvements in
апа
Connected
WITH
Furnaces, also Applicable to Ventilating and similar Purposes.
We, JAMES BONTHRONE, Brewer, and ROBERT BARCLAY BONTHRONE, Engineer,
both of the Newton Brewery, Falkland, Fifeshire, do hereby declare the nature of our
invention to be as follows :-
This invention has reference to improvements in the mode of, and means or
appliances for, admitting and regulating the admission of air to the furnaces of steam
boilers, and other furnaces generally; and comprise certain improvements in the con-
struction of the front charging doors of furnaces, or it might be other special doors,
and their fittings for the said admission and regulation of the air thereto; which im-
provements are more simple, efficient and easily controlled and regulated by seeing
within the furnace without opening the doors than heretofore, so as to effect complete
combustion of the fuel and gases within the furnace, thus preventing the formation
and escape of all black smoke therefrom, besides effecting a great saving in the fuel
used. These improvements although specially designed and applicable for the air
admission doors of furnaces, are also applicable for the better regulation of the
admission and emission of the ventilating air of buildings.
The nature and novelty of the invention consist all as follows:-In admitting the
ai. (either from the outer atmosphere or heated, as is sometimes done), to each
furnace by numerous long fine or very narrow slits formed through and across the
door, preferably horizontally; or it may be formed, either horizontally or vertically.
through a special plate or plates fitted within the said door or in any other orifice in
the side or end wall for admitting the air to the furnace, and preferably as close to, or
in front of, the incandescent fuel where the hydrocarbon gases are evolved, as possible;
these narrow air admission slits would be formed preferably as close as convenient
over the whole door or plate in it or in the air orifice. The width of slits which has
been found to answer best in the door plates of the furnace of a steam boiler and of
that of a brewing copper, to which it has been experimentally applied, is rather less
than one sixteenth of an inch, and when the width of these slits was enlarged to one-

page_text: tenth of an inch, they were not found to be so efficient or effective in producing
complete combustion of the gases in the furnace.
Besides making these slits, according to this invention, narrow as stated, to be
regulated as from a nd., to th., of an inch, they are, by a further improvement,
formed with the sides of the slits widening or tapering outwards through the door
or plate from the narrow part, which is made very thin by being brought to a fine
edge preferably at the inner surface of the plate to the outside, but it might be
tapered either wide towards the inside, or to both sides, according as the narrow part
is formed at one side or in the middle of the plate, or plates when there are two, as
hereinafter described. The angle of the sides may vary considerably, as from 15
to 30 degrees, or even more than 30° for thin plates. This improved construction of
the slits has the advantage of heating the air with the least possible friction in passing
through them, and allows the light to radiate out through them from all parts of the
interior of the furnace, to meet the eyes of the fireman or attendant at nearly any
distance in front of the door; which advantages would not be obtained if the slits
were made parallel through the full thickness of plate. The slits would preferably be
made as close together over the plate as the thickness of the metal between them would
allow of the said tapering of the holes, and give sufficient strength of plate and door
for general use.
A further improvement consists in the mode of constructing the said fine slotted
plate or plates and the door, and in the fitting of these, so as to regulate the size of
slits over the whole plate, and give a corresponding uniform opening and amount of
air to suit the size of fire and kind of firing, as also the closing of the openings and
shutting off of the air as the hydrocarbon gases cease to be given off after every
fresh charge of coal. By this improvement the plate pattern is made of the same
shape on both sides to the right and left of a vertical centre line and with the slits so
equally divided and parallel with the fine narrow edges of the slits all on one side, so
that when two castings are made from the one pattern they can be turned back to back,
which enables a very slight motion of the one plate over the other to give either the
full opening of all the slits through both plates or close them exactly and uniformly,
or give any intermediate exact opening of the slits over the whole plates. To give
this slight shifting motion of the two plates upon one another, they are mounted close
together within a rectangular recess formed within the frame of the hinged door of
the furnace; and are supported on lateral fulcrum edges projecting out and down
from their lower outside edges within the groove in the furnace door, and leave
sufficient play at the top within the said groove to oscillate to and fro half an inch or
so to one side or other off the perpendicular of their recesses at top, on their said
lower fulcrum edges. This tilting has the effect of moving the one plate upon the
other, that is, raising the one and lowering the other on their adjacent rubbing faces,
so as to open and close the whole of the slits gradually, equally, and simultaneously,
according to the extent of tilt or oscillation given to the two plates at top within their
recess. The weight of the plates themselves retain them in the position they are
tilted (open or close) to either side of the perpendicular, until shifted by hand or by
an automatic arrangement of mechanism. The recesses in the frame of the door are so
constructed that the plates may be put in and removed from the inside of the door,
by having a part of the inside projections of their recesses or flanges cut away at the
sides, and still allow the plates to oscillate freely without passing much air through
between the joints. A screw is fitted into one of the plates with a collar or other
equivalent, which regulates the extent to which the two plates may be tilted inwards
in their recess by the man, after each firing of the furnace and closing of the door,
the collar or other equivalent projection on the screw preventing the tilting of the
plates further than is sufficient to open all the slits to the extent desired, or close them
in the other direction. That is, although the slits in the plates might be an eighth or
a tenth of an inch in width and give this opening when fully tilted inwards, this screw
can be set so that they could not be tilted in to open more than a thirty-second or a
sixteenth of an inch when that was found to be the best amount of opening, and when
tilted outwards they would always close each other. These plates would preferably be

page_text: arched on the top the same as the door for the symmetry of the whole. When the
slits were formed vertically in the plates to give the same effect, the two plates would
require to be oscillated at the one end inwards or outwards.
Although this oscillating method of regulating the openings through the two plates
is preferred, from its simplicity and small liability to derangement, yet still the one
plate might be moved upon the other by a screw, a cam, or a lever, or other mechanical
equivalent to give the same effect; and whichever of these means is taken to shift
the one plate upon the other to open or close the slits, this motion may be given by
hand for the opening of the slits after firing the furnace, and an automatic arrange-
ment made to move the plates forward again to close the openings in as many
minutes as it was considered necessary to allow the hydrocarbon gases evolved from
the fuel to be all consumed with the air. This automatic arrangement may consist of
a regulating air, oil, glycerine, water or other fluid cylinder or cataract of any ordinary
well-known construction, the piston, (or it may be a float or rotating fan wheel,) of
which would be actuated by a spring or weight, put in action by the opening and
closing of the furnace door, or by the firemah, each time the plates were tilted to
admit the air, when the spring, or weight would actuate the oscillating lever or other
equivalent, which would re-tilt or oscillate the plates and close their slits each time the
cataract piston came back to its normal position. The speed of the piston and the
time it took to effect this purpose would be regulated by the displacement of air, water
or other fluid from the cylinder or cataract, through a small tap or plug set or
regulated by the fireman. A tilting vessel might also be used on the principle of a
sand glass to regulate this time, and which might free a catch to allow the spring to
actuate the lever or other arrangement made to tilt the plates at the proper time.
This new method of passing the air in narrow or thin streams has the effect of
dividing and softening the speed of the air, and heating it while passing through the
slits, as also by the direct radiation of the fire in passing within the furnace to meet
the combustible gases rising off the fuel, thus causing a more perfect combustion,
leaving little or no smoke or combustible gases to pass up the chimney.
Dated this 23rd day of October 1886.

page_text: Furnaces, also Applicable to Ventilating and similar Purposes.
JAMES BONTHRONE, Brewer ROBERT BARCLAY BONTHRONE, Engineer both of
Newton Brewery Falkland N.B. we do hereby declare the nature of our invention
for IMPROVEMENTS IN AND CONNECTED WITH THE ADMISSION OF AIR TO FURNACES,
ALSO APPLICABLE TO VENTILATING AND SIMILAR PURPOSES and in what manner the
same is to be performed, to be particularly described and ascertained in and by the
following statement :-
This invention has reference to improvements in the mode of, and means or
appliances for, admitting and regulating the admission of air to the furnaces of steam
boilers, and other furnaces generally; and comprise certain improvements in the con-
struction of the front charging doors of furnaces, or it might be other special doors
and their fittings for the said admission and regulation of the air thereto; which im-
provements are more simple, efficient and easily controlled and regulated by seeing
within the furnace without opening the doors than heretofore, so as to effect complete
combustion of the fuel and gases within the furnace thus preventing the formation
and escape of all black smoke therefrom, besides effecting a great saving in the fuel
used. These improvements although specially designed and applicable for the air
admission doors of furnaces, are also applicable for the better regulation of the
admission and emission of the ventilating air of buildings.
The nature and novelty of the invention consist all as follows:-In admitting the
air (either from the outer atmosphere or heated, as is sometimes done), to each furnace
by numerous long fine or very narrow slits formed through and across the door, pre-
ferably horizontally; or it may be formed, either horizontally or vertically through a
special plate or plates fitted within the said door or in any other orifice in the side or
end wall for admitting the air to the furnace, and preferably as close to, or in front of,
the incandescent fuel where the dydrocarbon gases are evolved, as possible; these
narrow air admission slits would be formed preferably as close as convenient over the
whole door or plate in it or in the air orifice. The width of slits which has been found
to answer best in the door plates of the furnace of a steam boiler and of that of a
brewing copper, to which it has been experimentally applied, is rather less than one
sixteenth of an inch, and when the width of these slits was enlarged to one-tenth of
an inch, they were not found to be so efficient or effective in producing complete
combustion of the gases in the furnace.
Besides making these slits according to this invention, narrow as stated, they are
by a further improvement, formed with the sides of the slits, widening or tapering
outwards through the door or plate from the narrow part, which is made very thin by
being brought to a fine edge preferably at the inner surface of the plate, to the out-
side, but it might be tapered either wide towards the inside, or to both sides, according
as the narrow part is formed at one side or in the middle of the plate, or plates, when
there are two, as hereinafter described.
The angle of the sides may vary considerably, as from 15 to 30 degrees, or even
more than 30 degrees for thin plates.
This improved construction of the slits has the advantage of heating the air with
the least possible friction in passing through them, and allows the light to radiate out
through them, from all parts of the interior of the furnace, to meet the eyes of the
tireman or attendant at nearly any distance in front of the door; which advantages

page_text: would not be obtained if the slits were made parallel through the full thickness of
plate.
The slits would preferably be made as close together over the plate as the thickness
of the metal, between them would allow of the said tapering of the slits, and give
sufficient strength of plate and door for general use.
A further improvement consists in the mode of constructing the said fine slotted
plate or plates, and the door, and in the fitting of these so as to regulate the size of
slits over the whole plate, and give a corresponding uniform opening, and amount of
air to suit the size of fire and kind of firing, as also the closing of the openings and
shutting off of the air, as the hydrocarbon gases cease to be given off after every fresh
charge of fuel.
By this improvement the plate pattern is made of the same shape on both sides to
the right and left of a vertical centre line, and with the slits so equally divided and
parallel with the fine narrow edges of the slits all on one side, so that when two
castings are made from the one pattern they can be turned back to back, which enables
a very slight motion of the one plate over the other to give either the full opening of
all the slits through both plates or close them exactly and uniformly, or give any
intermediate exact opening of the slits over the whole plates.
To give this slight shifting motion of the two plates upon one another, they are
mounted close together within a rectangular recess formed within the frame of the
hinged door of the furnace; and are supported on lateral fulcrum edges projecting
out and down from their lower outside edges within the groove in the furnace door,
and leave sufficient play at the top within the said groove to oscillate to and fro half
an inch or so to one side or other of the perpendicular of their recesses at top, on their
said lower fulcrum edges.
This tilting has the effect of moving the one plate upon the other that is, raising
the one and lowering the other on their adjacent rubbing faces, so as to open or close
the whole of the slits gradually equally and simultaneously, according to the extent
of the tilt or oscillation given to the two plates at top within their recess.
The weight of the plates themselves retain them in the posisition they are tilted
(open or close) to either side of the perpendicular, until shifted by hand or by an
automatic arrangement of mechanism. The recesses in the door are so constructed
that the plates may be put in and removed from the inside of the door, by having a
part of the inside projection of their recess at top cut away and still allow the plates
to oscillate freely without passing much air through between the joints; or the plates
may be put in anti removed, by having the bottom of the frame of the hinged door
constructed with a space of sufficient width to admit of the two plates being passed
through the space, and then inserting a bolt through each end of the frame, on
which bolt the. fulcrum edges of the plates may rest. A screw is fitted into one
of the plates with a collar or other equivalent, which regulates the extent to which
the two plates may be tilted inwards in their recess by the man after each firing of
the furnace and closing of the door, the collar or other equivalent projection on the
screw preventing the tilting of the plates further than is sufficient to open all the slits
to the extent desired or close them in the other direction. That is although the slits
in the plates might be an eighth or a tenth of an inch in width and give this opening
when fully tilted inwards, this screw can be set, so that they could not be tilted in to
open more than a thirty-second or a sixteenth of an inch when that was found to be
the best amount of opening, and when tilted outwards they would always close each other.
These plates would preferably be arched on the top, the same as the door for the
symmetry of the whole.
When the slits were formed vertically in the plates, to give the same effect, the two
plates would require to be oscillated at the same end inwards or outwards.
Although this oscillating method of regulating the openings through the two plates
is preferred, from its simplicity and small liability to derangement, yet still the one
plate might be moved upon the other by a screw, a cam, or a lever, or other mechanical
equivalent to give the same effect; and whichever of these means is taken to shift
the one plate upon the other to open or close the slits, this motion may be given by an

page_text: automatic arrangement, though preferably the regulation would be controlled by
hand.
This new method of passing the air in narrow or thin streams has the effect of
dividing and softening the current of air, and heating it while passing through the
slits, as also by the direct radiation of the fire in passing within the furnace to meet
the combustible gases rising off the fuel, thus causing a more perfect combustion,
leaving little or no smoke or combustible gases to pass up the chimney.
In order that our invention may be properly understood, and readily carried into
effect, we will now proceed to describe the drawings hereunto annexed.
Fig. 1. is a front elevation of one form of door, applicable to furnaces generally,
constructed according to our present invention.
Fig. 2 is a vertical section of Fig. 1 taken on the line A. B, showing the door
with the slits in the posisition
"full open."
"
Fig. 3 is also a vertical section of Fig. 1. taken on the line A. B. showing the door
with the slits in the posisition "full closed."
Fig. 4 is a vertical part section of Fig. 1 taken on the line C. D., drawn to an
enlarged scale, showing the tilting handle and regulating screw, the plates being in
posisition nearly "full open."
Fig. 5 is also a vertical part section of Fig. 1 taken on the line C. D. drawn to an
enlarged scale, showing the tilting handle and regulating screw, the plates being in the
posisition "full closed."
In each of these figures the same letters of reference indicate the same parts; p. 1.
and p. 2. are the two slotted plates mounted within r. the rectangular recess formed
within the hinged frame of the door, and supported on e lateral fulcrum edges
projecting out and down from their lower outside edges. As will be seen from
Figs. 2, 3, 4 and 5, sufficient play is left at the top within the recess, to allow of the
plates being oscillated on their lower fulcrum edges to and fro to one side or other of
the perpendicular. The effect of this tilting the plates from say posisition in Figs. 2
and 4 to that in Figs. 3 and 5, is to raise p. 1. and lower p. 2. on their adjacent
rubbing faces, so as to close the whole of the slits equally and simultaneously until
they reach posisition shown in Figs. 3 and 5 when the sum of the two opposite
motions has been sufficient to close the whole of the slits. The necessary travel varies
of course with the width of the slits, and for a door with plates twelve inches deep at
their centre, and having slits one-sixteenth of an inch in width, this amount of travel
at the highest points of the plates is equal to three-eighths of an inch.
s. s. are the slits
constructed as hereinbefore described, t. h. is the tilting handle, e the collar, and r. s.
the regulating screw, h. the hinge pieces, and oh is the opening handle.
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. The general arrangement and combination of parts, constituting the door or
orifice for admitting air to furnaces generally; the same operating in the manner
hereinbefore described and as shown upon the annexed drawings.
2. The subdividing and softening of the air current by passing it through slits
varying from one thirty second to one tenth of an inch in width.
3. The particular manner in which the sides of the air passages are formed, that is
of a tapering form.
4. The particular arrangement adopted for the purpose of opening and closing
the slits, that is mounting two exactly similar plates and tilting them on fulcrum
edges.