IMPROVEMENTS IN FURNACES FOR SMELTING IRON
Year: 1870

page_text: LETTERS PATENT to Richard Brown, of Glasgow, in the County of
Lanark, North Britain, for the Invention of "IMPROVEMENTS IN
FURNACES FOR SMELTING IRON."
Sealed the 3rd February 1871, and dated the 22nd November 1870.
PROVISIONAL SPECIFICATION left by the said Richard Brown at the
Office of the Commissioners of Patents, with his Petition, on the
22nd November 1870.
I, RICHARD BROWN, of Glasgow, in the County of Lanark, North
Britain, do hereby declare the nature of the said Invention for "Improve-
MENTS IN FURNACES FOR SMELTING IRON," to be as follows, that is to say :—
This Invention has principally for its object to economise the fuel
employed in the manufacture of iron from its ores, and it consists in
constructing over or above the ordinary furnace or over equivalent parts
a separate chamber, and in arranging for the utilisation of more or less
of the combustible gases given off from the lower chamber or furnace
by burning them so as to heat in such separate or upper chamber the
calcined or incalcined, ores and limestone which are to be put into it

page_text: and when heated transferred to the chamber or furnace below therein to
have added to them the fuel necessary for completing the smelting
operation. The lower chamber or furnace is closed in at its top, but is
fitted with doors or valves for the introduction of fuel and of the materials
from the upper furnace. One or more pipes or ducts are provided at
or near the top of the lower chamber or furnace to lead away thence the
combustible gases produced in it, and whilst ducts convey part of such
gases to the blast heating stoves, steam boilers, and the like, other ducts
lead part of them to the upper chamber. Flues or spaces are by
preference formed round the. upper chamber for the combustible gases,
and from these flues a large number of jet orifices admit the gases into
the chamber. The gases are ignited in the flues, the air for their com-
bustion being admitted to them by inlet valves or flues. The upper
chamber may be open-topped unless it should be found necessary to
use a draught to induce the gases to enter it, in which case it may be
closed and a flue carried from it to a chimney. When the materials
are heated they are transferred to the chamber or furnace below through
suitable valves arranged so that the quantities may be measured and
the proper quantities of fuel apportioned to them. It is preferred to
effect the transfer by means of one or more pipes or ducts each fitted
with two valves or doors, the bottom one being closed whilst the materials
are being transferred from the upper chamber into the pipe, and the
upper one being closed in its turn when each pipe full is being dropped
into the lower furnace by opening the bottom door. The desired economy
of fuel is expected to arise from less fuel being required in the lower
furnace in consequence of the materials being supplied to it in a prepared
and highly heated state.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Richard Brown in the Great Seal Patent Office on
the 11th May 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, RICHARD
BROWN, of Glasgow, in the County of Lanark, North Britain, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-second day of November, in the 3
23

page_text: 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 Richard Brown, Her special licence
that I, the said Richard Brown, my executors, administrators, and
assigns, or such others as I, the said Richard Brown, 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 FOR SMELTING IRON," upon the condition (amongst others) that I,
the said Richard Brown, 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 Invcution, and
in what manner the same was to be performed, and cause the samo 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 Richard Brown, 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 in writing, reference being had to the accompanying
Drawings, that is to say :-
My said Invention has principally for its object to economise the fuel
employed in the manufacture of iron from its ores, and it consists in
the constructing and working of the furnace in a peculiar manner with
a view to the utilisation of more or less of the combustible gases given
off or produced in the lower part of the furnace by burning them or
portions of them so as to heat or act on calcined or uncalcined ores in
the upper part prior to these having added to or mixed with them the fuel
or carbonaceous matter necessary for completing the smelting operation..
And in order that my said Invention and the manner of performing
the same may be properly understood, I hereunto append two Sheets of
explanatory Drawings to be herein-after referred to and showing by
way of example three modes of constructing furnaces for smelting iron
with modifications of my improvements.
Figures 1 and 2, on Sheet 1, and Figure 3, on Sheet 2 of the Draw-
ings are vertical' sections, and Figures 4, 5, and 6, on Sheet 2, are
sectional plans corresponding respectively to Figures 1, 2, and 3, but

page_text: with the upper parts of the furnaces supposed to be removed. The same
reference numerals are used to mark the same or like parts wherever
they are repeated.
In the modifications shown in Figures 1 and 4 the lower part 1, 2,
and the arrangements and working in connection with the hearth are to
be understood as like those of existing iron smelting furnaces, but the
lower chamber 1, 2, as it is herein-after termed is covered over or closed
in at the top, and is formed with a valved outlet 3 at the side near the
top for a portion of the combustible gases given off with a duct 4 for
leading them to blast-heating stoves, steam boilers, and the like. There
are also other passages, 5, 6, 7, in the covered-in part of the furnace
which will be herein-after referred to. Above or on the top of the
main body of the furnace I construct a separate or upper chamber 8,
into the top of which I charge the calcined or uncalcined ore and the
limestone by preference broken into small pieces, and around this upper
chamber I construct flues or spaces 9 into which a portion of the com-
bustible gases from the lower chamber 1, 2, are led by a passage or
passages 5 provided with a regulating valve 6. From the flues 9 a
number of jet orifices 10 admit the combustible gases into the chamber 8,
and these gases are ignited in the flues 9 or in the orifices 10, or in
some of them, air for their combustion or partial combustion being
admitted either by a single valve such as the one shown at 11, or by one
or more valves placed so much higher up as not to cause the ignition of
that portion of the gases which enters the chamber 8 by the lowermost
of the orifices 10. If the air admitted into admixture with the com-
bustible gases is sufficient for their complete combustion then their
action in the chamber 8 will be simply to dry and heat the materials
and drive the carbonic acid off from the limestone; but it may be found
advantageous in practice to prepare the materials still further. Thus a
sufficient heating effect may be obtained by a partial combustion of the
gases in the chamber 8, and the portions of them not acquiring oxygen
from the air may deoxydise the ores to a greater or less extent, and
so still further facilitate the final smelting and fusing in the lower
chamber 1, 2. It is not necessary to form the flues or spaces 9, as
shown in the walls of the upper chamber 8, but if preferred the com-
bustible gases may be led by passages formed, for example, by a series of
external metal pipes fitted with branches leading to the jet orifices 10,
also the air for burning the gases may be led by branch pipes to the

page_text: orifices, so that the combustion may take place almost entirely within
the chamber. Hanging valves 12 are placed at the tops of the flues 9
to give free egress in the event of any accidental explosive action. On
a grating just within each air inlet valve 11 a small fire of coal or coke
is maintained to keep the gases ignited or to re-ignite them immediately
after any accidental extinction, and before quantities accumulate suf-
ficient to form a dangerous explosion. The upper chamber 8 may bc
open-topped unless it should be found necessary to use a draught to
induce the gases to enter it, in which case it may be closed by suitable
valves and a flue carried from it to a chimney; or the gases may be
induced to enter by taking the air for their combustion from the blast
main and directing it in jets into the gas flues so as to exert the well-
known current inducing jet action. When the materials are heated they
are transferred to the lower chamber 1, 2, being drawn out of the upper
chamber 8 by a door 13 at the bottom thereof, and first filled into a
box 14 fitted above an inclined passage 6 leading down into the centre
of the lower chamber 1, 2. When the proper quantity has been put into
the box 14 its top is closed by a slide 15 and double doors 16 which
formed the bottom of it are opened to allow the contents to descend.
In this way the quantities of materials transferred from the upper
chamber 8 to the lower chamber 1, 2, are easily known, and the proper
quantities of coke, coal, or carbonaceous fuel can be accurately appor-
tioned to them. The fuel may be charged into the lower chamber 1, 2,
by the same passage 6. I however prefer to put it in by three or other.
number of equidistant passages 7 arranged at the sides but directed.
towards the centre with the view of thereby obtaining a better mixing
of the ores and fuel. The introduction of the fuel may be effected by
means of the simple four-compartment cylindrical feed box 17 which is
held by a catch whilst the then uppermost compartment is being filled,
and which is then turned or allowed to turn down so as to empty the
compartment just filled into the passage 7, and at the same time put
another compartment into position for being filled. Slightly modified
forms of fuel feeding boxes 17 are shown in Figure 2, and a revolving
or oscillating feed box similar to any of these may be used for trans-
ferring the ores and lime from the upper chamber 8 into the lower
one 1, 2. I may here remark that this transference of the heated ores
and lime should be effected in such a way as to avoid contact of air as
much as possible, the door 13 being opened as little as may be and the
sides of the doorway being made close.

page_text: The modification of my improved furnaces shown in Figures 2 and 5
differs from that shown in Figures 1 and 3 already described, simply in
having a direct downward communication between the upper chamber 8
and the lower chamber 1-2, my invention being that in working this
furnace the lower chamber 1-2 will always be so full of materials that
those materials will support the bottom of the column of materials in
the upper chamber, which last will then gradually descend in proportion
as the materials below become worked off. The fuel may be supplied by
measuring boxes 17, as indicated in Figure 2, the quantities so supplied
being in this modification regulated in accordance with the descent of
the top of the materials in the upper chamber 8. The measuring
boxes 17 shown in Figure 2, are cach made with a single compartment
which is turned up again after each downward discharge, cither by
means of a handle or in consequence of being weighted to do so auto-
matically. If necessary, the measuring box may be formed with spaces
as shown at the left-hand side of Figure 2, for the passage of a stream
of water to kept it cool. Passages 5 are shown in Figure 2 for leading
the gases to act in the upper chamber 8 up from the lateral parts of the
top of the lower chamber 1-2; if preferred, however, a conical enlarge-
ment or a series of indentations may be formed in the sides of the upper
chamber 8, as indicated by the dotted lines at 18, and the proportion of
gases may pass from such enlargement or series of indentations by one
or more passages into the flues 9, or the gases for the upper chamber 8
may be led from the main gas outlet 3 by a branch pipe indicated by
dotted lines at 19 in Figure 2.
If the column of materials in the upper chamber 8 is found to bear
down too heavily when the communication with the lower chamber 1-2
is directly downwards, as shown in Figure 2, the bottom of such upper
chamber may be formed as shown in Figure 3, with two, three, or more
passages 20, which instead of descending directly downwards may
diverge or be inclined slightly towards the sides of the lower chamber
1-2, and this arrangement will probably in any case conduce to a
better mixing together of the heated ores and lime with the fuel, the
last being introduced into the lower chamber 1-2 by measuring boxes
17 and passages 7, arranged alternately with the passages 20 from the
upper chamber.
Having thus particularly described my said Invention and the manner
in which the same is to be performed, I have to state that I do not

page_text: restrict myself to the precise details herein described or delineated; but
that what I believe to be novel and original and claim as the Invention
secured to me by the herein-before in part recited Letters Patent is,―
1. The constructing and working of furnaces for smelting iron, sub-
stantially in the improved manner herein described and delineated.
2. The constructing of the furnace with an upper chamber (8), with
arrangements in connection therewith for utilising a portion of the
combustible gases formed in the lower chamber (1-2), by causing them
to heat or act on the ores and limestone in such upper chamber, sub-
stantially as herein-before described.
3. The constructing of the upper chamber (8) with the orifices (10),
or their equivalent, for obtaining the direct action of the gases in the
chamber, as herein-before described.
4. The constructing of the furnace with passages and measuring
boxes or valves for introducing fuel into the lower chamber (1, 2), in
combination with the arrangements for heating or acting on the ores or
limestone before their admixture with the fuel, substantially as herein-
before described.
5. The fitting of furnaces for smelting iron with revolving or oscil-
lating feed boxes 17, substantially such as are herein described and
delineated.
In witness whereof, I, the said Richard Brown, have hereunto set
my hand and seal, this Tenth day of May, in the year of our
Lord One thousand eight hundred and seventy-one.
Witness,
EDMUND HUNT,
Patent Agent,
Glasgow.
RICHARD BROWN. (L.S.)