IMPROVEMENTS IN FURNACES CHIEFLY DESIGNED FOR HEATING METALS AND ORES
Year: 1870

page_text: LETTERS PATENT to William Robert Lake, of the Firm of Haseltine,
Lake, & Co., Southampton Buildings, London, Patent Agents, for
the Invention of "IMPROVEMENTS IN FURNACES CHIEFLY DESIGNED FOR
HEATING METALS AND ORES." -A communication from abroad by
William A. Sweet, of Syracuse, New York, United States of
America.
PROVISIONAL SPECIFICATION left by the said William Robert Lake
at the Office of the Commissioners of Patents, with his Petition,
on the 6th July 1870.
I, WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co.,
5 Southampton Buildings, London, Patent Agents, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN FURNACES CHIEFLY
DESIGNED FOR HEATING METALS AND ORES," a communication, to be as
follows:-
This Invention relates to that class of furnaces used chiefly in the
O heating of ores, metals, and similar refractory substances, or that

page_text: require a regular and uniform or high degree of temperature, and the
objects of the said Invention are,―
First. The introduction or injection of the fuel into the combustion
chamber after the fire is first started at such a point or points below the
surface of the ignited mass that the fresh material introduced cannot
set free its elements of combustion without coming in close contact
with a temperature sufficiently great to produce ignition of said elements.
The second object of the said Invention is the combination of certain
devices for the injection of the fuel into the combustion chamber by
which the dust and screenings that are ordinarily considered worthless
at mines and in yards may be most readily utilized with the greatest
possible facility, and thereby furnish a temperature of the highest degreo
of excellence both in quality and quantity.
Another object is accomplished in the construction and arrangement
of the grates and devices for supporting and controlling them, namely,
that the cinders and clinkers may be very quickly and easily removed
from the combustion chamber, and any repairs required in the interior
of the said chamber may be done without disturbing the grate bars or
requiring their removal from their supports.
The form and size of the combustion chamber should be carefully
proportioned to the nature of the work to be performed and the quality
of the fuel to be used in order to accomplish the best result or to give
the maximum of efficiency with the greatest economy. The theoretical
duty or extreme heating capacity of a pound of coal may be taken as
the unit or standard upon which to estimate the shape and size of the
combustion chamber, as the shape or form must be adapted to the
materials to be treated and the size to the amount of heat required in
the operation. As an example, where a crucible containing some very
refractory substance is to be intensely heated, or where a number of
crucibles, as in the making of glass, are used, a cylindrical form of com-
bustion chamber may be best adapted for the operation, and in such a
case the single crucible may be placed in the centre of the upper arch,
or if more than one are used as in the manufacture of glass the crucibles
can be arranged around the combustion chamber and above the grates,
also in the generation of heat, as under boilers or in puddling or smelting
and heating chambers, the shape must conform in a great degree to the
work required, and it must necessarily be of sufficient size to contain
the requisite quantity of coal or fuel to give at least the degree of
"

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temperature required. The combustion chamber is made about twice
as wide as the grate bars are long for the purpose of spreading the heat
as it is used under horizontal boilers, and the height of the said chambers
should always be from one-third to one-half greater than the length
of the grate bars, so that the mass of fuel when the chamber. is fully
charged reaches to a point as high or higher than the smallest dimension
of the base. The said chamber is formed of, fire-brick, soapstone;
plumbago, or other material which will resist the action of the intense
heat; near the top an opening is formed to serve as a flue to convey
the heat to the point of utilization, as under a boiler, or into a secondary
chamber where the substances are to be heated. When connected with
a secondary chamber or furnace, the point over which the heat passes
is termed the bridge wall of the furnace, and it is usually built as a
supplemental wall, so that it can be easily removed and replaced without
disturbing the other portions of the masonry. The grates are placed
at the bottom of the combustion chamber, one grate being pivoted in
such a manner as to drop to a vertical position and capable of being
controlled by a lever upon one end of the shaft that carries the grate;
this grate may consist simply of a series of arms, or tines, like those of
a fork mounted upon the shaft and fastened byya taper pin passed
through them and the shaft. The other grate is best formed of a frame
and bars the back edge (or end as the case may be), of which is pivoted
at a point below the shaft of the first grate and sufficiently far from
said shaft to permit the arms or tines of the said grate to reach it, 'con-
sequently, when the front edge of the second grate is raised as high as
the rear of the first grate, the grate bars will reach across the entire
space and will also have an inclination towards cach other. The front
edge of the second grate is supported upon a shaft provided with crank
levers to which are attached links for connecting the said shaft to the
grate. Upon one end of this shaft is a lever for partially rotating it;
and by turning the crank levers up and down the front edge of the
grate will be raised and lowered. Underneath the grates is a space or
chamber to receive the 'ashes, and to serve as a reservoir for-the blast;
when-a-fan or blowing engine is used: At the front of the combustion
chamber is a hopper or receiver for the coal, mounted in any convenient
manner upon the furnace. The bottom of the said hopper communicates
with the interior of the combustion chamber, by a slot through the wall
of the chamber made at such a point above the grates that when a fire
is once made in the furnace any coal forced through the said slot will
c

page_text: come in contact with the ignited mass upon the grates. Through the
said slot the fuel is injected in various ways preferably by a sliding
plunger operated by a lever so arranged that a considerable degree of
force can be applied to the plunger or injector. Instead of a reciprocating
plunger rollers may be used, so that a continuous injection of the fuel
may be produced. Through the arch above the slot air holes are made
so that in using highly bituminous fuel an additional supply of oxygen
can be furnished just above the point where the fresh fuel is introduced.
At the opposite side of the furnace openings are made and furnished
with hoppers to supply fuel in starting the fires, as in ordinary furnaces.
Holes are also formed in close proximity to the bridge wall and grates,
so that bars may be introduced for removing the cinders and ashes
when desired.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Robert Lake in the Great Seal Patent
Office on the 5th January 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Southampton
Buildings, London, Patent Agents, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Sixth day of July, in the year of our
Lord One thousand eight hundred and seventy, in the thirty-fourth
year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said William Robert Lake, Her special licence.
that I, the said William Robert Lake, my executors, administrators,
and assigns, or such others as I, the said William Robert Lake, my
executors, administrators, and assigns, should at any time agree with,
and no others, from time to time and at all times thereafter during the
term therein expressed, should and lawfully might make, use, exercise,
and vend, within the United Kingdom of Great Britain and Ireland,
the Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS
IN FURNACES, CHIEFLY DESIGNED FOR HEATING METALS AND ORES," a com-
munication to me from abroad by William A. Sweet, of Syracuse, New
York, United States of America, upon the condition (amongst others)
that I, the said William Robert Lake, my executors or administrators,

page_text: by an instrument in writing under my, or their, or one of their hands
and seals, should particularly describe and ascertain the nature of the
said Invention, and in what manner the same was to be performed, and
cause the same to be filed in the Great Seal Patent Office within six
calendar months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said William Robert Lake, do hereby
declare the nature of the said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained in
and by the following statement, reference being had to the accom-
panying Drawing forming a part of this Specification.
This Invention relates to that class of furnaces used chiefly in the
heating of ores, metals, and similar refractory substances, or substances
that require a regular and uniform or high degree of temperature, and
the objects of the said Invention are,-
First. The introduction or injection of the fuel into the combustion
chamber after the fire is first started at such a point or points below the
surface of the ignited mass that the fresh material introduced cannot set
free its elements of combustion without coming in close contact with a
temperature sufficiently great to produce ignition of such elements.
The second object of the said Invention is the combination of certain
devices for the injection of the fuel into the combustion chamber, by
which the dust and screenings that are ordinarily considered worthless
at mines, and in yards may be utilized with the greatest possible
facility and thereby furnish a temperature of the highest degree of
excellence.
Furthermore tlie construction and arrangement of the grates and
devices for supporting and controlling them permit the quick and easy
removal of the cinders and clinkers from the combustion chamber and
the execution of any repairs required in the interior of the said
chamber without disturbing the grate bars or requiring their removal
from their supports.
Figure 1 is a perspective view of my Invention a portion of the side
being removed to show the interior of the same; Figure 2 is a sectional
view of the said furnace from the front to the rear; Figure 3 is a

page_text: plán as seen from the top or above the grates. Like letters indicate the
same parts in all of the Figureš.; 4
;
.**
The form and size of the. combustion chamber should be carefully
proportioned to the nature of the work to be performed, and the quality
of the fuel to be used in order to accomplish the best results or to give
the maximum of efficiency with the greatest, economy. The theoretical
duty or extreme heating capacity of a pound of coal may be taken as the
unit or standard upon which to estimate the shape and size of the com-
bustion chamber, as the shape or form must be adapted to the material to
be treated and the size to the amount of heat required in the operation.
For example, where a crucible containing some very refractory substance
is to be intensely heated or where a number of crucibles, as in the making
of glass, are used, a cylindrical form of combustion chamber may be best
adapted for the operation, and in such a case the single crucible may be
placed in the centre of the upper arch, or if more than one are used, as
in the manufacture of glass, the crucibles can be arranged around the
combustion chamber and above the grates, also in the generation of
heat, as under boilers, or in puddling or smelting and heating chambers,
the shape must conform in a great degree to the work required and the
size must necessarily be sufficient for the requisite quantity of coal or
fuel to give at least the degree of temperature required. In the furnace
represented in the Drawing the combustion chamber is about twice as
wide as the grate bars are long for the purpose of spreading the heat as
it is used under horizontal boilers, and the height of the said chambers
should always be from one-third to one-half greater than the length of
the grate bars so that the mass of fuel when the chamber is fully charged
reaches to a point as high or higher than the smallest dimension of the
base, or in other words. if the chamber is a cylinder its height should be
as great. or greater than its diameter. The said chamber is formed of
the ordinary materials used in the construction of these furnaces such
as fire-brick, soapstone, or plumbago, or other material capable of
resisting the action of the intense heat. At B or near the top an opening
is formed to serve as a flue to convey the heat to the point of utilization,
as under a boiler or into a secondary chamber where the substances are
to be heated. When connected with a secondary chamber or furnace
the point over which the heat pässes is termed the bridge wall of the
furnace, and as it is exposed to the greatest temperature produced in
the combustion chamber it is usually built as a supplemental wall, as
.

page_text: shown at C, so that it can be easily removed and replaced without
disturbing the other portions of the masonry... At D and E are mounted
the grates at the bottom of the combustion chamber the grate D being
pivoted at fin such a manner as to drop to a vertical position, as seen
in Figure 3, and capable of being controlled by a lever g, Figures 2 and 3,
upon one end of the bearing or shaft that carries the grate. This grate
may consist simply of a series of arms or tines like those of a fork which
may be in length about one-third or less than the entire distance
across the grate space, they are mounted upon the shaft F as shown in
Figure 2, and are fastened by a taper pin passed through them and the
shaft so that they may be held 'firmly in a working position and yet be
conveniently separated and removed for repairing the interior of the
combustion chamber A. The grate E is best formed of a frame and
bars the back edge (or end as 'the case may be) of which is pivoted at a
point below the shaft of grate D and sufficiently far from the said
shaft to permit the arms or tines of the grate D to reach it, consequently,
when the front edge of the grate E is raised as high as the rear of the
grate D the grate bars will reach across the entire space, and will also
have an inclination towards each other as shown in Figure 1. The front
edge of the said grate E is supported upon a shaft H provided with
crank levers and ', to which are attached links m for connecting the
said shaft to the grate. Upon one end of the shaft is a lever K. for
partially rotating it, and by turning the crank levers up and down the
front edge of the grate will be raised, and lowered. Underneath the
grates at O is a space or chamber for receiving the ashes and which
serves as a reservoir for the blast when a fan or blowing engine is used.
At P upon the front of the combustion chamber is. a hopper or receiver
for the coal mounted upon brackets attached to the furnace or in any
other convenient manner. The bottom of the said hopper communicates
with the interior of the combustion chamber A by a slot Sthrough the
wall of the chamber A made at such a point above the grates that when
a fire is once lighted in the furnace any coal forced through the
said slot will come in contact with the ignited mass upon the grates.
B
=
In practice I find the said slot S may be best located from a quarter to
a third of the distance from the grates to the top of the bridge wall or fluc
space (best seen at Figure 2), but this point may be anywhere between
the flue space and the grates, provided there is ignited fuel above and
below it, so that each charge of fresh fuel shall come in immediate.

page_text: contact with so much heat that its carbon may not be carried off without
being ignited. Through the said slot S the fuel is injected in various
ways preferably (as shown in the Drawing) by a sliding plunger operated
by a lever Z so arranged that a considerable degree of force can be applied
to the plunger or injector.
- For small or portable fires I. adopt the construction shown in the
Drawing as the plungers are small and the mass is easily penetrated but
in my heating furnaces for rolling mills a multiplication of power is
necessary as I prefer to keep the mass of fuel upon the grates as high or
higher than the smallest dimension of its base. Instead of a recipro-
cating plunger, as shown, rollers may be used so that a continuous
injection of fuel may be produced. Through the arch above the slot S
air holes are made so that in using highly bituminous fuel an additional
supply of oxygen can be furnished just above the point where the fresh
fuel is introduced. A similar series of jets may also be found beneficial
in the arch as indicated at Y, Figure 2. At x upon opposite sides of
the furnace there are openings furnished with hoppers to supply fuel in
starting the fires as in ordinary furnaces. Holes 1 and 2, Figure 2, are
also formed in close proximity to the bridge wall and grates, so that
bars may be introduced for removing the cinders and ashes when
desired.
In using my Invention a fire is first started in the combustion
chamber the grates being placed as in Figure 1, and fuel is introduced
through the openings at x, until a burning or ignited mass is raised above
the opening at S which communicates with the bottom of the hopper P.
The fuel is afterwards supplied exclusively by the plunger or injector
carrying it from the bottom of the hopper through the opening S into
the already burning or ignited mass. This action tends to move the ashes
and cinders back towards the bridge wall or about to the point where the
two grates meet. Each fresh charge of fuel soon becomes coked or
charred and unites to form a mass of lumps even when the dust or
screenings or "slack" of mines and yards is used for fuel. The mass
so formed rests chiefly upon the front grate E, and against the bridge
wall C, consequently when it is desirable to clean the grates, the grate D
is dropped to the position shown in Figure 2, and by introducing a poker
through the hole 2 the operator can very thoroughly remove the ashes
and cinders without disturbing the mass of burning fuel. This operation.
being completed the blast may be shut off and the doors in the front of

page_text: the ash-pit opened so that on lowering the front edge of the grate E by
turning the crank levers 1, 1, down as in Figure 2, the front grate may
be cleaned without essentially disturbing an efficient fire. After the
grates are thus cleaned a poker may be introduced through the holes 1
which are formed on each side of the furnace and just in front of the
bridge wall and the cinders may be easily removed without stopping the
operation of the furnaces or waiting for fresh charges of fuel to become
ignited. Under some circumstances I prefer to use a number of
injectors feeding into the mass from opposite points or sides, but the
principle remains the same, viz., that of injecting the fuel into the
burning mass of the first fire.
Having thus fully described the said Invention as communicated to
me by my foreign correspondent, I claim,—
First. In combination with a combustion chamber, one or more
injectors for forcing the fuel into the side of a previously ignited mass
of fuel in the said chamber as described.
Second. In combination with a combustion chamber having one
or more injectors an adjustable grate for the purposes herein set
forth.
Third. In combination with the said chamber A and fuel injector an
arch with air holes for forcing additional supplies of oxygen into the
chamber just above the opening S substantially as described and for the
purposes set forth.
Fourth. In combination with the combustion chamber A the fuel
injector and grates D, E, and holes 1, 2, as described and for the purposes
set forth.
In witness whereof, I, the said William Robert Lake, have here-
unto set my hand and seal, this Fifth day of January, in the
year of our Lord One thousand eight hundred and seventy-one.
Witness,
E. C. JACKSON.
WILLIAM ROBERT LAKE. (L.S.)