IMPROVEMENTS IN FURNACES
Year: 1870

page_text: LETTERS PATENT to Walter Watson Hughes, of 48, Porchester Terrace,
Bayswater, in the County of Middlesex, for the Invention of
'IMPROVEMENTS IN FURNACES."
Sealed the 24th June 1870, and dated the 10th January 1870.
PROVISIONAL SPECIFICATION left by the said Walter Watson Hughes
at the Office of the Commissioners of 'Patents, with his Petition,
on the 10th January 1870.
I, WALTER WATSON HUGHES, of 48, Porchester Terrace, Bayswater,
in the County of Middlesex, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN FURNACES," to be as follows:-
This Invention consists chiefly in the more effectual combustion and
utilization of the fuel consumed in furnaces, and especially of the smoke
and gases evolved therefrom, in the facility for regulating the
temperature in furnaces, and for-producing an oxidizing, a reducing, or
neutral flame at will.

page_text: or
bojler.
In
working metals, or to any other description of furnace
many operations or industries I utilize the escaping as well as the
initial or primary heat.
My Invention consists, moreover, in the creation of a hot gaseous
blast by the direct combination of air with the products of combustion.
The constructive part of my Invention consists mainly in what I term
a "smoke and gas burner." This burner is constructed of any suitable
refractory or fire-resisting material and may consist of a single piece or
of various parts, its form and size are optional and should be suited to
local requirements. It is composed of air passages and cells, the former
traversing the entire apparatus, the latter being open at one end to
admit the radiated heat to their sides, and through them communicated
to the air passing through the adjoining passages. I invariably employ
a valvular apparatus in connection with the "smoke and gas burner"
for regulating the admission of air. Sometimes I add an air chamber.
The "smoke and gas burner" is placed between a draft or blast fire and
the apparatus to be heated. Several gas and smoke burners may, if
necessary, be arranged about the apparatus to be heated in order to
create, diffuse, or equalize any degree of heat that may be deemed
necessary.
The "smoke and gas burner may, furthermore, be associated with
or form part of the bridge of a furnace, boiler, or fire-place; but in
any case the "smoke and gas burner" or burners must occupy such a
position as to deliver heated air divided by the various cells to the
products of combustion, the volume of air being regulated by suitable
valves or dampers.
Another part of my Invention consists of a combined furnace, in
which, for the sake of distinction, one part or section is designated the
"fire chamber," a second part the "tapping furnace," a third part the
"reducer," and a fourth part the "calciners" or oxidizer. The fire
chamber is closed and its form may vary to suit any special purpose
or position. Fuel is introduced by means of a closed hopper or other
suitable apparatus when blast is used. "The bottom of the fire chamber
is composed of a mixture of clay and coke or of any other suitable
material. At the side and near the bottom of the chamber there is a
taphole or door for the flow or withdrawal of coal, slag, or clinkers.
Between the fire chamber and tapping furnace is placed a smoke and
gas consumer in connection, it may be, with an air chamber; and

page_text: between the tapping furnace and reducer, on each side of the flue con-
necting the two divisions, there should be placed a smoke and gas
burner, the three burners being in communication with air flues fitted
with regulating valves. When a blast is used air is forced into the fire
chamber, and is also admitted through the passages of the gas and smoke
burners. The tapping furnace and reducers are provided with rabble
The form as well as the size of
and raking doors and discharging holes.
this part of the apparatus may vary, as in the former part, according to
circumstances.
The fourth part or section of the apparatus, which I call the
"calciuers" or oxidizer, is made with one or more soles or bottoms,
which are so arranged that the heat escaping from the reducing furnace
is led by a separate flue to each of the calciners, one flue to a chamber.
underneath the sole or bottom of the lowest calcining chamber, and
thence into the lowest calcining chamber, and by the other flue to the:
upper calcining chamber, whence it escapes from both calcining
chambers into a flue or chimney. By means of dampers the waste or
escaping heat can be regulated within the calcining chambers, or shut
off from either of them at pleasure. The arches that carry the soles of
the calcining chambers are constructed with angle or hollow fire-bricks;
which are covered with fire tiles from two to three inches in thickness.
The radiated heat from the heat chamber rising through the openings
in the arch keeps the floor or sole of the lowest calciuing chamber at a
high temperature, and the heat of the under calcining chamber operates
in a similar manner upon the arch or sole of the one above it, and thus
facilitates the calcining, roasting, or oxidizing process. The upper
calcining chamber is provided with hoppers for the admission of ore or
other material, and both chambers with rabble doors for spreading such
The bottom calcining chamber is connected with the reducer by
one or more channels through which the calcined or roasted material is
passed; and there is an opening in the bottom of the upper chamber
through which the ore or other material is dropped into the lower one.
ore.
In the third part of my Invention 1 propose to obtain a hot gaseous
blast by passing the products of combustion over one or more smoke
and gas burners and thence nto a flue which is in connection with one
or more air flues subject to valvular or damper regulation.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Walter Watson Hughes in the Great Seal Patent
Office on the 25th June 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WALTER
WATSON HUGHES, of 48, Porchester Terrace, Bayswater, in the County
of Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Tenth day of January, in the year of
our Lord One thousand eight hundred and seventy, in the thirty-third
year of Her reign, did, for Herself, Her heirs and successors, give and grant
unto me, the said Walter Watson Hughes, Her special licence that I, the
said Walter Watson Hughes, my executors, administrators, and assigns,
or such others as I, the said Walter Watson Hughes, 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,"
upon the condition (amongst others) that I, the said Walter Watson
Hughes, my executors or administrators, 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 Fatent Office within six calendar months next and
immediately after the date of the said Letters Patent.
"
NOW KNOW YE, that I, the said Walter Watson Hughes, do hereby
declare the nature of my 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 accompanying
Drawings, and to the letters and figures marked thereon, that is
to say
:-
My. improvements in furnaces consist chiefly in the more effectual
combustion and utilization of the fuel consumed in furnaces, and
especially of the smoke and gases evolved therefrom, in the creation of
a hot
gaseous blast by the direct combination of air with the products
of combustion, and in the facility -for- regulating the temperature in
furnaces, and for producing an oxidizing, a reducing, or neutral flame

page_text: at will.
In many operations or industries I utilize the escaping, as well
as the initial or primary heat.
My Invention is applicable as well to marine as to stationary or
locomotive land boilers, to furnaces for reducing ores, for melting and
working metals, or to any other description of furnace.
Before entering upon a special and detailed description of appa-
ratus illustrating the said "Improvements in Furnaces," I shall point
out in a general and comprehensive manner the chief and distinctive
features of my Invention. I propose then to effect a more complete and
thorough combustion of all the constituents, whether solid or gaseous,
of the fuel employed in furnaces by the use of what I term a
"smoke
and gas burner.". This burner, which may either be a single whole or
constructed of parts, is made of any suitable refractory or fire resisting
material, its form and size mainly depending upon local requirements.
It is composed of cells and air passages, the former being closed at that
end of the apparatus at which the air enters, the latter passing through
the entire apparatus. The position for the smoke and gas burner or
burners (for there may be more than one) is between a draught or
blast fire and the apparatus to be heated.
The operation of this part of my Invention will be more fully
explained hereafter.
This part of my Invention is applicable to every description of furnace
or boiler. I intend to place the fire chamber and the smoke and gas
burner generally at the entrance of an ordinary steam boiler, but when
this is not convenient they may be placed within the boiler; in both
cases the air is admitted to the smoke and gas burner or burners by
valves or dampers. There are certain furnaces whose construction and
arrangement I purpose to alter, and I think materially amend diminishing
at the same time their cost, principally by a compact association of
various special processes.
My improved furnace may be termed a composite furnace, in which
three different operations are carried on simultaneously. The compart-
ment next to the fire chamber I call the tapping furnace, next to that
is the reducing furnace, and finally come the calcining or oxidizing
furnaces. Between the fire chamber and the tapping furnace and on either
side or bottom of the flue connecting the latter with the former, I place
a smoke and gas burner or burners. I also place a smoke and gas, burner
in each side of the flue or opening connecting the tapping and reducing

page_text: furnaces. The air is regulated to all the smoke and gas burners by
valves in the blast pipes leading to them. That part of my proposed
furnace which I call the calciners is made with one or more soles or
bottoms, so arranged that the heat escaping from the reducing furnace
passes underneath and then above the soles or bottoms upon which the
ore is lying in the calcining chamber or chambers, and from thence to
the chimney. The arches L which carry the soles of the calcining
chambers are constructed of angular fire-bricks, or of fire-bricks having
any
form best suited to certain places or special objects, and these bricks
are covered with fire tiles from two to three inches in thickness. I
prefer in general the use of angle fire-bricks (represented on the
annexed Drawing in Figures 6 and 7) for the arches L seeing that they
allow the heat to circulate freely under the tiles that form the soles
or bottoms of the calciuing chambers, and thus keep them at a red
heat. The sole of the lower calcining chamber may be laid upon rows
of bricks placed upon a flat bottom, the heat passing in the first instance
between the rows of bricks which support the tiles forming the sole.
These composite furnaces with smoke and gas burners can only be
worked for smelting the ores of copper, iron, or other metals by the
use of a blast either hot or cold. They effect a saving of from 50 to 70
per cent. of fuel.
Every part of these furnaces which is exposed to
the action of heat is lined with fire-bricks or other refractory material.
In order that my improvements in furnaces may be more fully under-
stood I shall now refer to and explain them by means of various
illustrations shewn on the Sheet of Drawings hereunto annexed, the
same letters of reference indicating identical parts throughout all the
Figures.
Fig. 1 is a sectional plan at the line Z, Y; Fig. 2 is a longitudinal
section; and Fig. 3 is a cross section at the line X, W, of my proposed
composite smelting furnace. The heat necessary for the purposes of the
furnace is generated from fuel, which is passed by means of hoppers or
otherwise into a closed fire chamber shewn at Ạ. Then follow con-
secutively the three great divisions into which the composite furnace is
divided, the tapping furnace or division B, the reducer C, and the
calciner or series of calciuers shewn at D. The great degree, amount,
and capacity of heat which may be produced in my compound furnace
are the chief means by which I am enabled to carry on simultaneously
certain smelting processes that have hitherto been performed separately.

page_text: The blast, either hot or cold, passes through the pipe E, whence it
enters the fire chamber through the orifices F and acts immediately upon
the burning fuel. It also passes through the tubes G, which convey it
to the gas burners H in the flue between the fire chamber and the
tapping furnace. The hot air from the passages of these gas burners
comes in contact with the products of combustion from the fire and
ignites the smoke and gases into a pure white heat as they are about
to enter the tapping furnace. When the greatest heat is required in the
reducing furnace I shut the valves in the pipes or flues G and open the
valves in the pipes or flues I leading to the smoke and gas burners H
placed in the connecting flue between the tapping furnace and the
reducing furnace. As before the hot air from the air passages in the
smoke and gas burners causes instant ignition of the unconsumed
products of combustion before they enter the reducing chamber. The
waste heat from the reducing furnace passes at a high temperature
through one of the flues J into the heat chamber K, and thence through
the flue T (Fig. 3) into the lower calcining chamber, and through the
other flue J to the upper calcining chamber, whence it escapes from
both chambers into the chimney S. But the whole of the waste heat
from the reducing furnace may be made to pass under and above the
soles or bottoms of both calcining furnaces, and thence to the chimney S.
The waste heat from the reducing furnace can by means of dampers be
turned off from either of the calcining furnaces for the purpose of
rabbling the ore or for charging the calcined ore into the reducing
furnace.
The general arrangement of the parts of the composite furnace here
represented I consider to be the most suitable and effective, though it
may occasionally be found convenient to vary the position of the different
The calciner or
compartments into which my furnace is divided.
calciners, for instance, might be placed above the reducing furnace; if,
however, an effective communication be kept up between the several
cbambers their position is in a great measure arbitrary.
Having pointed out the form of the composite furnace and the course
of the blast through it, I will now state how the smoke and gas burner
is so effective in causing a perfect combustion of the smoke and gases.
The divisions between the cells and air passages are made of thin fire-
clay tiles or other refractory material, and are kept at a red heat by the

page_text: radiated heat in the flue or flues, being pressed into the cells by the force
of the blast, the pressure in the tapping and reducing furnaces being
from 8 to 10 oz. to the square inch. Before leaving the cells the air
is brought to a high temperature, and when it mingles with the products
of combustion the whole is at once converted into pure white heat..
This part of my Invention, the smoke and gas burner, is applicable to
every description of furnace or boiler, and the effect it produces is in
all cases similar to that which has been described in the foregoing
example. An illustration of its applicability to an ordinary land boiler
is represented in Fig. 4, and also in Fig. 5. In the former example the
smoke and gas burner is shewn in its most effective, and, in the great
majority of cases, in its most convenient position; in the latter it is shewn
placed in the centre flue of a boiler. In marine and other boilers its
position will depend mainly upon the conformation of the furnace to
which it is to be applied and upon the necessities and peculiarities of the
situation.
A plan of the upper part of the smoke and gas burner occurs in
Fig. 1, immediately adjoining the fire chamber, and vertical sections.
of the apparatus may be seen between the tapping furnace and the
reducer in the same Figure..
Such then are the various parts and details of my Invention. Their
practical effect and utility may now be exemplified in the working and
operation of my composite copper and iron smelting furnace already
described. A pulverized compound of copper ore and flux is put into
the stopper M, and falls upon the sole or floor of the upper calcining
chamber D, over which it is spread, and where it becomes to a con-
siderable extent desulphurated. It is then made to descend through the
aperture N formed in the floor of the upper calcining chamber into
the lower calcining chamber, where it is exposed to a higher temperature
and nearly all the sulphur expelled from it. From this chamber the
calcined ore and flux are pushed through the openings P down the
pipes O (Fig. 2) into the reducing furnace C, where being rapidly
smelted the metal and slag run into the tapping furnace B.
The slag
is then drawn off in the usual way. The regulus or metal is not tapped
out until it rises in the furnace to the bottom of the rubble door or lower
part of the slag escape. As to raw or calcined iron ore it is placed with
the necessary flax (both finely pulverized) into the lower calcining

page_text: Secondly. The general construction of composite ore smelting furnaces
fitted with smoke and gas burners, substantially as herein-before
described.
In witness whereof, I, the said Walter Watson Hughes, have here-
unto set my hand and seal, this Twentieth day of June, iu tho
year of our Lord One thousand eight hundred and seventy.
(L.S.) WALTER WATSON HUGHES.