IMPROVEMENTS IN BLAST FURNACES
Year: 1864

page_text: LETTERS PATENT to Charles Attwood, of Tow Law Iron Works, in the
County of Durham, Iron Master, for the Invention of "IMPROVEMENTS IN
BLAST FURNACES."
:
PROVISIONAL SPECIFICATION left by the said Charles Attwood at
the Office of the Commissioners of Patents, with his Petition; on the
16th September 1864:
I, CHARLES ATTWOOD, of Tow Law Iron Works, in the County of Durham,
Iron Master, do hereby declare the nature of the said Invention for "IMPROVE
MENTS IN BLAST FURNACES," to be as follows:
This Invention consists in the application and addition to the upper part of
such blast furnaces as are usually employed in the reduction or smelting of
iron ores of a condensing or collecting apparatus, consisting of chambers,
vessels, or receivers, or of a series of such, by means of which it is proposed
to preserve or recover the zinc contained in the iron ore, and which would
otherwise be blown from the tunnel head or other escape vents of such.
furnaces, and lost in the surrounding atmosphere.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed,
by the said Charles Attwood in the Great Seal Patent Office on the
16th March 1865.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
ATTWOOD, of Tow Law Iron Works, in the County of Durham, Iron Master,
send greeting.
WHEREAS Her most Excellent Majesty. Queen Victoria, by Her Letters
Patent, bearing date the Sixteenth day of September, in the year of our Lord
One thousand eight hundred and sixty-four, in the twenty-eighth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto
me, the said Charles Attwood, Her special license that I, the said Charles
Attwood, my executors, administrators, and assigns, or. such others as I,
the said Charles Attwood, my executors, administrators, or 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 "IM-
PROVEMENTS IN BLAST FURNACES," upon the condition (amongst others) that I,
the said Charles Attwood, my executors or administrators, by an instrument
in writing under my hand and seal, 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 Charles Attwood, 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 andbythefollowingstatement:
My said Invention consists of the application and addition to the upper part
of such blast furnaces as are usually employed in the reduction or smelting of
iron ores of a condensing or collecting apparatus, consisting of chambers,
vessels, or receivers, or of a series of such, by means of which it is proposed
to preserve and recover the-zinc contained in the iron ore, and which would
otherwise be blown from the tunnel head or other escape vents of such
furnaces, and lost in the surrounding atmosphere.
Before fully describing and explaining my said Invention of "Improve-
ments in Blast Furnaces" for smelting ores of iron, and the manner of
practising aud carrying out the same, I may observe that the object thereof is
twofold. For although it is only applicable to cases in which the ore or ores

page_text: 123
which may be smelted contain or are used in mixture with ores. containing.
zinc in quantities sufficient to either make the saving or collecting of that
metal, or its compounds from the gases which are evolved from such furnaces,
an object of pecuniary value for the sake of that metal, which is the first of
my proposed objects upon the one hand, yet on the other there are cases in
which, though it may not be disrable or profitable to collect such metal or
compounds thereof with that object, yet it may still be desirable or necessary
to effect their separation from such gases when they are intended to be
employed as combustibles for generating steam, or for the heating of the
blast, or for any other purposes for which it may be employed, which is.my
second object; both or either of which objects being obtainable by the use of
the same apparatus or improvement. For even when the latter object alone
may be contemplated, its use will still be necessary in such blast furnaces as
throw off the zinc or its oxide in any considerable quantities, as thereby.the
gases are rendered either partially or entirely unsuitable for raising steam or
heating blast, inasmuch as the metallic matter together with the earthy and
other matters mingled with each other in the gas become precipitated or
deposited upon the boilers and the pipes of the blast stoves, and being
emiently non-conducting substances with regard to heat, impede or prevent
its effective transmission to the water in the one case, and to the air required
to be heated in the other. Moreover, as respects the boilers, it is still more
hurtful, as it from time to time detaches itself, and falling off from them in
different places in crusts, scales, or flakes, exposes the plates to very sudden
and partial accessions and vicissitudes of heat to the great danger of causing
explosion, whilst it may be also perhaps in some degree chemically hurtful
to them.
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Now having pointed out the objects of my said Invention, I shall now
proceed to show by means of what apparatus I attain them. For this purpose
it is only necessary to attach to any tube or flue, or other conduit, such as
commonly is or conveniently may be used for the bringing of the gases from
the upper parts of the blast furnace (for their utilization for the purposes of
heating), chambers, flues, tubes, or vessels, or a series of them, containing
enough space and presenting sufficient internal surface or surfaces to cause
or admit of the precipitation or deposit of the zinc or of its oxide (both of
which are usually present) upon, their sides or on their bottoms.
Th: length, the form, the capacity, material, and construction of such
chambers, flues, or vessels so to be attached to the tubes or flues by which the
gases are drawn off from the blast furnaces, and, through which they are
intended to be transmitted, may be varied very much,according to convenience

page_text: 3
under different local circumstances, and in proportion to the volume of the
gases intended to be transmitted, and to the very variable quantities of the
metal or metallic oxide which in each different instance has to be collected,
deposited,or separated by means of them But the objects being to collect or
separate only as much thereof as it may be profitable in respect of its own
value to collect, or as may be adequate to render the gases sufficiently free
therefrom to be fit and proper for their intended use for heating, experience
only in every separate instance will best determine the choice and the extent
of them, as well as of the many means which may suggest themselves for
increasing their efficiency, or which have been or may be used in cases of an
analagous description for securing a complete or adequate déposit. For in
some cases it may be found most convenient to depend upon the volume or
extent and capacity of such chambers or flues, or of a series of such, upon
the principle employed in cases in which the fume of lead as volatilized from
lead smelting furnaces is commonly collected, and where stone or brick flues
which are sometimes miles in length have been successfully made use of;
although no constructions approaching to any such väst dimensions may ever
need to be employed for the present purpose; or plates or sheets of metal
or other fit material may be suspended or erécted in or across the chambers
or flues, or vessels employed, in order to present a greater surface for impact
and deposit.; or water may be passed into or along or through them, or may
be injected into them in a kind of shower through plates or a system of plates
pierced with minute, and very numerous perforations; or steam, or both steam
and water may be passed into thein, although where steam is so employed,
and especially both steam and water, it will be necessary to use the steam so
sparingly and with such precautions as to prevent any sudden and extensive
condensation of it, such as would cause a vacuum and a consequent suction
of the inflamed gases from any of the connected furnaces, so as to cause
explosion in such chambers, flues, or vessels.
Having thus generally indicated the principles and modes by which the
objects of my Invention are to be effected, I further state that I prefer to any
other special apparatus for the collection and separation of the metallic
matters from the gases, a series of large tubes of about the geueral size of
the larger sized steam boilers (for which purpose old boilers may be con-
veniently employed),placing them, according to the space and the other cir-
cumstances of the locality, either in a line with each other, or side by side
or upon or over each other, or either vertically or horizontally, so as to be
traversed by the gases for such a distance as to allow of no important or
objectionable portion of the metallic matter to escape at their extremity intö

page_text: the furnaces in which such gases may have to be consumed, or into the open
air when they are not to be consumed. But this effect will be produced in a
less number of such vessels of any given size by such use of steam or water,
or of both, or of such plates as I have indicated. And speaking generally, it
will be found that five or six such boilers of good size, or a proportionally
larger number of lesser ones, will be practically sufficient to so far separate
and collect the metallic matter so as to effect the ends in view; although
undoubtedly the more there are or may be of them, and the greater. their
capacity, the more complete and perfect the effect will be.
There will indeed be cases in which it may be more necessary than in
general to employ such flues, chambers, or vessels in greater number, and of
greater aggregate capacity according to the greater quantity of metallic
matter thrown off by different blast furnaces, and to the value of the object
of very perfectly collecting it, for which varying cases no definite extent and
volume of apparatus can be laid down beforehand. But for such a case as
I myself shali generally have to employ it in, about such a number and size
of vessels as I have specified will very well produce as much effect as may
be adequate for the ends proposed. It may be easily seen that where the
gases are not wanted for combustion large flues or chambers built of brick or
stone, and carried to a considerable extent or distance, may in many cases
be found a very cheap and effective means to be employed.
Before the workman have occasion to enter the vessel, flues, or chambers,
the connection with the blast furnace will have to be effectually cut off
and a free influx of fresh air admitted, as the inhalation of the gases of
blast furnaces would be dangerous and fatal.
Having now described and particularly ascertained the nature of my said
Invention, and the manner in which the same is or may be used or carried
into effect, I wish it to be understood that what I claim as the Invention
intended to be secured to me by the said Letters Patent is, the application
for the purposes herein-before described of any apparatus of the kind
indicated to blast furnaces employed in smelting such ores as contain not
only iron, but also zinc or its oxide.
In witness whereof, I, the said Charles Attwood, have to this my
Specification hereunto set my hand and seal, the Thirteenth day of
March, One thousand eight hundred and sixty-five.
CHAS. ATTWOOD. (L.S.)