IMPROVEMENTS IN SMOKELESS FURNACES FOR VARIOUS PURPOSES
Year: 1876

page_text: LETTERS PATENT to James William Bonta, of New Brighton, Pennsylvania,
United States of America, Chain Manufacturer, for the Invention of
"IMPROVEMENTS IN SMOKELESS FURNACES FOR VARIOUS PURPOSES."
Scaled the 23rd September 1876, and dated tho 3rd August 1876.
COMPLETE SPECIFICATION filed by the said James William Bonta at the
Office of the Commissioners of Patents on the 3rd August 1876.
JAMES WILLIAM BONTA, of New Brighton, l'ennsylvania, United States of
America, Chain Manufacturer. "IMPROVEMENTS IN SMOKELESS FURNACES FOR
VARIOUS PURPOSES."
My improvements relate generally to furnaces which are heated by base burning
coal magazines.
My coal magazine is closed at the top by a tight fitting movable door, and is
separated by grate bars at the bottom from a closed ash-pit, which is provided
with a pipe for injecting a blast of air to supply the necessary quantity of oxygen
required for the combustion of the coal, and maintain a certain degree of pressure
in the furnace. In these magazines the coal is partially coked before it falls to
the grate Eurface, and the inflammable gases generated in the process of coking
collect until they fill the upper portion of the magazine, and are then forced
outward by their own pressure from the lower portion of the magazine where they
ignite and contribute by their combustion to the heating power of the furnace.
The chamber for containing the material to be heated is situated at the side of
the coal magazine, and is provided at or near its lower portion with outlets or
flues extending downward, and affording means of exit for the carbonic oxides or
other uninflammable gaseous products of combustion.
My Invention is applicable to the purpose of heating blanks which are to be
forged or formed in dies, and for melting refractory substances.
As applied to the purpose of melting copper my Invention is especially valuable,
because it prevents to a great extent the escape of metallic vapors which would
otherwise be lost.
The principal advantages of my Invention arise from its saving in fuel, the
complete combustion of the fuel used, the absence of smoke, and the greatly -
increased heating power of the furnace.
In the accompanying Drawings I have illustrated my Invention as applied to
various purposes.

page_text: The Drawings represent, first, a furnace for rapidly imparting uniform heat to
long iron rods or bars, which is shown in Figures 1, 2, 3, and 4; secondly, a
modified form of my furnace for rapidly heating small blanks, shown in Figures 5,
6, and 7; thirdly, a furnace for melting copper and other metals and refractory
materials, shown in Figures 8, 9, 10, and 11.
Referring to the Drawings representing the first modifications of my Invention.
Figure 1 is a top view of the furnace.
Figure 2 is a longitudinal vertical section through the line x, x, on Figure 1.
Figure 3 is a longitudinal vertical section through the line y, , on Figure 1.
Figure 4 is a transverse vertical section through the lines, s, on Figure 1.
In the Drawings A is a coal magazine extending longitudinally along one side
of a furnace and separated at the bottom by the grate bars B from a series of two
or more closed ash-pits C, having tight fitting sliding bottoms D for facilitating
the removal of ashes and cinders. A series of openings in the top of the coal
magazine allow access to its interior, and are provided with tight fitting movable
covers. Ench ash-pit is provided with an injection pipe E for the supply of air
to promote combustion and to maintain the proper pressure in the furnace. The
air blast pipes are each provided with a valve for the purpose of regulating the
quantity of air admitted.
The inner side wall of the coal magazine has a series of apertures F a short
distance above the grate bars opening into the heating chamber G, which also
extends from one end of the furnace to the other and immediately adjoins the
apertures F. The bed of the heating chamber G may if desired be inclined toward
the magazine, as shown in Figure 4. The heating chamber is provided with a
downward outlet H, containing a valve or damper for regulating the pressuro in
the furnace and the exit of the uninflammable products of combustion. Access
is obtained to the heating chamber G at either end through suitable openings
closed by the vertically sliding doors I. In addition to the sliding doors I, movable
leflecting shields K are arranged on the outside of the furnace for the purpose of
deflecting the flame which puffs out of the heating chamber when the door is first
opened.
The operation of this furnace is as follows:-
By the use of separate ash-pits, each provided with an independent air blast pipe,
the combustion of the coal in the magazine may be regulated at pleasure by
supplying more or less oxygen at particular points, as the case may require, thereby
effecting a uniform combustion of the coal at the base of the magazine from one
end to the other, and a uniform supply of heat to the heating chamber from one end
to the other.
By means of the inclined bed of the heating chamber a series of bars are gradually
heatod, and as the bar next the fire is taken out the others roll downward by their
own gravity, and successively occupy the hottest part of the heating chamber.
The carbonic oxides or uninflammable gaseous products of combustion are carried
intothe back part of the heating chamber by the blast from the flame openings F,
and fall by their own gravity into tho downward outlet H through which they are
expelled by the pressure maintained in the furnace.
When, owing to the pressure in the furnace when in operation, the doors are
suddenly opened a puff of flame darts out of the heating chamber which might
injure the operator but for the deflecting shield which catches and turns the flaine
Intterally. When the stored up pressure within the heating chamber has been
relieved, the shield is removed and the heated bar taken out from the hotter side
of the chamber, while at the same time a cold bar is introduced into the opposito
side.
The Drawings illustrating the second modification of my Invention aro as
follows:-
Figure 5 is a front view of the furnace.
Figure 6 is a central longitudinal vertical section of the same.
Figure 7 is a central transverse vertinal section

page_text: In this furnace the heating chamber a occupies the central portion of the furnace
at a convenient height, and extends from front to rear. It has flaring sides and is
separated by grate bars b from a closed ash-pit c, having a tight fitting sliding
bottom d, and provided with an injection pipe e for the introduction of a blast of
air. In this instance the heating chamber, which is also a combustion chamber,
has a flat ceiling f, and derives its supply of fuel from two coal magazines on
opposite sides, extending up to the top of the furnace, and closed at that point by
tight fitting inovable covers.
The outlet g, for the uninflammable products of combustion, extends through the
rear wall of the furnace and communicates with a downward flue on the outside
of the furnace, which is to be connected with a sewer or carried to any other
convenient point. This outlet should be provided with a valve or damper / to
regulate its capacity.
Access is had to the heating chamber, for introducing objects to be heated,
through the opening i in the front wall. This opening is closed by the vertically
sliding door j, which falls by its own gravity but can be elevated by depressing the
foot lever, which is connected with the door by the chain l, rocker m, and
chain n.
The foot lever when depressed also acts upon the valve o, which is arranged in
the air blast pipe, and is held open by the spring 2 when the foot lever is elevated.
By this arrangement when the door is raised to allow access to the heating chamber
the valve is closed and the air blast shut off, while the closing of the door permits
the valve to open and renews the blast.
In this furnace also the coal is partially coked in the magazine before it reaches
the combustion chamber, and objects introduced into the combustion chamber to be
heated are thus preserved from contact with raw coal.
In operation the blast of air introduced into the ash-pit forces its way upward
through the grate bars, and the inflammable gases generated in the magazines force
their way out at the bottom of the magazines, and are burned with the coal in the
combustion chamber. The flat ceiling of the combustion chamber between the
coal magazines has a reverberatory effect upon the flames from the incandescent
coal and burning gases. A certain degree of pressure is maintained in the furnace
by means of the air blast, sufficient to expel the carbonic oxides through the outlet
from the combustion chamber.
By means of this furnace a very high heat can be maintained with but little loss
when the door is open, and objects introduced into the combustion chamber are
rapidly and conveniently heated without being allowed to come in contact with
any raw coal.
--
The Drawings illustrating the third modification of my Invention are as follows:-
Figure 8 is a longitudinal vertical section through the centre of the melting
chamber and charging chamber.
Figure 9 is a transverse vertical section through the dotted line x¹, x¹.
Figure 10 is a horizontal section through the dotted line y¹, y¹.
Figure 11 is a horizontal section through the dotted line 2, 2.
This modification of my Invention consists of a melting chamber having an
inclined bed established between two series of coal magazines, such as herein.
after described, and provided with openings for various purposes as follows respec-
tively-1, for admitting the flames from the coal magazines; 2, for admitting jets
of air; 3, for admitting the charge of metal to be melted; 4, for drawing of the
molten metal; 5, for allowing access to the interior for the purpose of cleaning the
bed; 6, for permitting the inspection of the interior; and 7, for the discharge of the
uninflammable gaseous products of combustion, the latter openings being provided
with valves by means of which the pressure in the furnace is regulated.
The coal magazines are situated over closed ash-pits, from which they are sepa-
rated by grate bars, and the opposite sides of the magazines have narrow openings a
short distance above the grato bars through which the flames from the burning fuel
are forced by the effects of blasts of air injected into the ash-pits.

page_text: The space between the magazines is covered, and constitutes a reverberatory
chamber, the bottom of which is inclined longitudinally, and at its highest end is
situated a short distance below the horizontal openings in the coal magazines.
Each coal magazine is closed at the top by a tight fitting door.
The reverberatory chamber is lined with fire-brick, and its roof is perforated in
the centre to communicate with a charging chamber arranged on the top of the
furnace. The opening in the roof of the reverberatory chamber is closed by a fire-
brick slide.
An air blast pipe having a series of perforations is built into the roof for the
purpose of supplying oxygen directly to the melting chamber.
The charging chamber is provided with a tight fitting movable cover at the top
and a movable bottom swinging upon a horizontal axis just above the fire-brick
slide.
"
Referring to the Drawings, A', a', represent the side walls of my furnace B', b¹,
the inner walls extending from end to end, by which the interior is divided into
three parts. The upper central portion of the furnace is occupied by the melting
chamber C and the lower central portion by the dead-air chamber c¹.
The upper
outer portions of the furnace, on either side of the melting chamber, are respectively
occupied by the coal magazines D¹, D², D³, d¹³, ď², d. The magazines on either side
are separated from each other by the transverse walls E¹, E, e, e, which extend
down to the base of the furnace, and also separate from each other the ash-pits on
either side, which are respectively indicated by the letters F, F, Fƒ ƒ ƒ
The magazines are provided respectively with movable grate bars G¹, G, C³,
ggg and their ash-pits are respectively closed at the bottom by the tight fitting
alides H, H, I, h, l, h³. Air is injected into the furnace through the several
blast pipes I, I, I³, 1, 3, 3. These blast pipes are each provided with a valve ¹
for regulating the blast. The coal magazines are each provided with a movable
cover L, The inner walls separating the coal magazines from the melting
chamber are perforated by the horizontal openings (1) M², m³, for the passage of
the flames from the incandescent coal into the melting chamber. The melting
chainber has an inclined bottom c* and an inclined ceiling c. The inclined bottom
or bed of the melting chamber is situated a short distance below the horizontal
openings from the coal magazines. The wall at the higher end of the melting
chamber has an opening (4) closed by the movable plug N¹ to allow access to the
chamber at that point for the purpose of cleaning the bed. The wall at the lower
end of the melting chamber is provided with an opening (3) closed by the movable
plug O¹ for drawing off the molten metal from the bed. One or more peek holes
are made at convenient points to allow inspection of the interior of the melting
chamber. One of these peek holes (5) closed by the movable plug P¹, is shown in
Figure 8 of the Drawings.
Afetal to be melted is fed into the melting chamber from the charging chamber Q¹
on the top of the furnace. The charging chamber is arranged immediately over a
vertical opening q³ in the roof of the melting chamber. This opening is closed by
the movable fire-brick slido g. The bottom of the charging chainber R¹ is affixed
to the horizontal shaft r², and swings downward when the fire-brick slide is with-
drawn, and thus discharges into the melting chamber the material theretoforo
deposited in the charging chamber. The horizontal shaft projects through the
end wall of the charging chamber, and is provided with a crank 3, by means of
which the bottom is swung upward into place after its load has been discharged,
thus permitting the replacing of the fire-brick slide. The charging chamber is
provided with a tight fitting cover 9³. This cover is removed for the purpose of
filling the charging chamber with the material to be melted, and is then replaced
prior to the withdrawal of the fire-brick slide, and the discharge of the contents of
the charging chamber into the melting chamber.
The uninflammable gaseous products of combustion are discharged from the
melting chamber through the downward flues S', st. In Figure 9 of the Drawings
a portion of the end wall of the melting chamber is represented as broken away

page_text: for the purpose of showing the downward flue s¹. The mouth of the other flue S¹
is seen upon the opposite side of the central portion of the Drawing (Figure 9).
The side walls of the melting chamber above and below the horizontal openings
M1, m, are beveled toward the openings, as shown at M³, m³, M³, m³. The opera-
tion of this furnace is as follows:-
The magazines are filled with coal, which being ignited at the bases of the maga-
zines is kept supplied with oxygen by means of the air-blast pipes which inject air
into the ash-pits, from which it is forced upward through the grate bars. The coal
contained in the magazines is partially coked before it is consumed, and the maga-
zines are filled with gas. The excess of gas generated in the magazines finds its
way out through the horizontal openings MI, m³, where it is inflamed, and con-
tributes by its combustion to the heating power of the furnace. The flames from
the incandescent coal and gas are forced by the air blasts into the melting cham-
ber through the horizontal openings upon the opposite sides thereof, and respectively
reverberate in opposite directions, concentrating their heat upon the bed of the
melting chamber.
In the use of my improvement for the purpose of melting copper and other
metals there are two advantages-
First. The great heating power of the furnace, which results from the double
reverberation of the flames which I have described, and the mode of charging the
furnace, by which I guard against the escape of heat from the melting chamber
during the process of charging it with metal to be melted.
Secondly. The prevention of the escape of metallic vapors from the furnace,
which is a consequence of the use of the downward flues for the outlet of the unin-
flammable products of combustion. Metallic vapors collect upon the roof of the
melting chamber, and finally condense and fall back upon the bed. Only a com-
paratively small portion of them. escape from the downward outlets S¹, 8².
It will, of course, be understood that the area of the outlets for the escape from
the melting chamber of the uninflammable products of combustion will be varied
according to circumstances, in proportion to the area of the grate surface and the
quantity of fuel consumed. As the object of the outlets S', 8¹, is simply to provide
for the escape of the carbonic oxides from the furnace, their inner mouths are
arranged as low as possible. It will be seen that the lower edge of the mouths of
the outlets is in the same plane with the lower boundary of the horizontal openings
M', m³, or, in other words, in the same plane as the upper edge of the side walls
of the inelting chamber bed. The outlets for the discharge of the carbonic oxides
are provided with the valves or dampers T', for the purpose of regulating, in con-
junction with the air blast valves, the pressure maintained in the furnace.
In addition to the air blast pipes in the ash-pits I provide a pipe U¹, which is
embedded longitudinally in the ceiling or roof of the melting chamber. This pipe
is provided with a series of perforations u¹, u², u', through which jets of air are
forced into the melting chamber in a downward direction. These downward jets
of air, in addition to providing sufficient oxygen to insure the complete combustion
of the inflammable gases discharged into the melting chamber from the side
magazines, have the mechanical effect of blowing the flames from the magazines
downward toward the melting chamber bed, and of increasing the heat of the
melting chamber at the bottom.
I claim as my Invention in a self-feeding smoke consuming furnace for heating
blanks
First. A base burning coal magazine arranged over a closed ash-pit provided with
a blast pipe for injecting air in combination with a lateral heating chamber
having ontlets from its bottom for the discharge of the uninflammable products of
combustion in a downward direction, substantially as described.
Secondly. In combination with the heating chamber of a furnace, substantially
such as described, a door or doors for closing the opening or openings of
the heating chamber in combination with a movable deflecting shield or shields
for the purpose of laterally deflecting the hot air puffed out from the heating
chamber upon the opening of the door or doors.

page_text: Thirdly. A heating chamber provided with an outlet for the escape of uninflam-
mable products of combustion, and an opening or mouth for allowing access to its
interior provided with a movable door and a closed ash-pit provided with a pipe for
the injection of air in combination with two vertical chambers or magazines closed
at the top by movable covers for containing coal and discharging the same after
partial coking into the opposite sides of the heating chamber, substantially as shown
and described.
Fourthly. A sliding door for closing the mouth of the heating chamber of a
furnace, and mechanism for raising such door in combination with a valve arranged
in the air blast pipe of the furnace in suitable position to be acted upon by the
mechanism, which raises the door whereby when the door is raised the valve is
closed substantially as described.
Fifthly. Two series of base burning coal magazines arranged over two correspond-
ing series of closed ash-pits provided with pipes for injecting blasts of air in
combination with a melting chamber, substantially such as described, situated
between the coal magazines, and having narrow openings in its opposite side walls
a short distance above its bed for admitting the flames from the lower parts of the
coal magazines, substantially as set forth.
Sixthly. A series of base burning coal magazines, substantially such as described,
and a melting chamber having an inclined bed, in combination with downward
flues leading from the melting chamber when the inner mouths of the said flues
are at or nearly at the same level as the lower boundary of the openings in the
side walls of the melting chamber bed, substantially as described.
Seventhly. A melting chamber, substantially such as described, in combination
with a charging chamber situated above the melting chamber and provided with
a movable cover and a swinging bottom for facilitating the charging of the melting
chamber without permitting the escape of the heat therefrom, substantially as set
forth.
Eighthly. A melting chamber and a charging chamber, substantially such as
described, in combination with a fire-brick slide for closing the opening in the
melting chamber which communicates with the charging chamber.
Ninthly. A perforated pipe for injecting downward jets of air into the melting
chamber in combination with a sido magazine or magazines having a lateral open-
ing or openings through which the gases and flames from the magazine or magazines
are discharged into the melting chamber, substantially as shown and described and
for the purposes set forth.
Witnesses,
EDW. PAYSON,
GEO. W. MIATT.
JAMES WILLIAM BONTA. (L.S.)