IMPROVE- MENTS IN COLLECTING OR DRAWING-OFF THE GASES FROM BLAST FURNACES
Year: 1865

page_text: LETTERS PATENT to John Addenbrooke and George Addenbrooke, both of
Darlaston, in the County of Stafford, Iron Masters, and Philip Anthony
Millward, of the same Place, Engineer, for the Invention of "IMPROVE-
MENTS IN COLLECTING OR DRAWING-OFF THE GASES FROM BLAST FURNACES."
Sealed the 27th March 1866, and dated the 29th September 1865.
PROVISIONAL SPECIFICATION left by the said John Addenbrooke, George
Addenbrooke, and Philip Anthony Millward at the Office of the
Commissioners of Patents, with their Petition, on the 29th September
1865.
We, JOHN ADDENBROOKE and GEORGE ADDENBROOKE, of Darlaston, in the
County of Stafford, Iron Masters, and PHILIP ANTHONY MILLWARD, of the
same Place, Engineer, do hereby declare the nature of our said Invention for
"IMPROVEMENTS IN COLLECTING OR DRAWING-OFF THE GASES FROM BLAST FURNACES,"
to be as follows, that is to say :-
Our Invention consists in forming around the throat of the furnace a
chamber, which chamber communicates with the interior of the furnace by
means of a series of openings, by preference sloping downwards towards the

page_text: centre of the furnace.
These openings may be formed by employing a series
of iron boxes around the throat of the furnace occupying the place of
several courses of the brickwork, or they may be protected from the great
heat by merely lining them with boxes formed of fire-clay, metal, or other
suitable material. The gases being thus drawn through the openings into
the surrounding chamber, may be thence conveyed to any suitable position
Thus from the very largely increased area of openings for the
escape of the gas, and from the openings being situate on the outside of a
circle,-instead.of.all the gases being drawn to one centre their velocity is very
largely diminished, and consequently--their-power-to- carry. dust into the
chamber, whilst from the increased size of this chamber round the throat of
the furnace the gases do not travel through it nearly so fast as they emerge
from the furnace, so that any dust carried thus far has a tendency to settle at
the bottom of the chamber, thus reducing the necessity for frequent
cleansing.
1
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Addenbrooke, George Addenbrooke, and Philip Anthony
Millward in the Great Seal Patent Office on the 29th March 1866.
I":
TO ALL TO WHOM THESE PRESENTS SHALL COME, we,. JOHN
ADDENBROOKE and GEORGE ADDENBROOKE, both of Darlaston, in the County of
Stafford, Iron Masters, and PHILIP ANTHONEY MILLWARD, of the sanie Place,
Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-ninth day of September, in the year of our
Lord One thousand eight hundred and sixty-five; in the twenty-eighth year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto us,
the said John Addenbrooke, George Addenbrooke, and Philip Anthony Mill-
ward, Her special licence that we, the said John Addenbrooke, George Adden-
brooke, and Philip, Anthony Millward, our executors, administrators, and
assigns, or such 'others as we, the said. John Addenbrooke, George Adden;
brooke, and Philip Anthony Millward, our 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 COLLECTING OR DRAWING-OFF THE GASES, PROM, BLAST

page_text: FURNACES," upon the condition (amongst others) that we, the said John
Addenbrooke, George Addenbrooke, and Philip Anthony Millward, our
executors or administrators, by an instrument in writing under our, 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 we, the said John Addenbrooke, George Adden-
brook, and Philip Anthony Millward, do bereby declare the nature of our
said Invention, and in what manner the same is to be performed, to be par-
ticularly described and ascertained in and by the following statement (that is
to say):-
Our Invention relates to blast furnaces, and consists of improvements in
collecting and drawing-off the gases therefrom, which improvements we
propose; to effect by the following form and mode of constructing the upper
portion of such furnaces, the operation of which will be herein-after more
particularly explained.
:
The object of our said Invention is to interfere as little as possible with the
perfect dissemination of the gases at the throat of the furnace, to offer a con-
siderably increased area for their escape; and so to diminish the velocity of the
said gases through the "draw off," as well as to keep the top or throat of the
furnace open, clear, and unobstructed for charging.
:
In order to more thoroughly disseminate the gases at the top of the furnace
than by other modes in which they are generally concentrated we form a
number of, openings round the throat, on the outside by preference, at about
four or five feet from the top; we also form an enclosed channel or gas flue,
between which channel or flue and the interior of the furnace itself these
openings form separate and collective communications. At any convenient
point at the side of the aperture flue or circular confluence chamber last
mentioned a main opening is made; through this main opening the collected
gases are conducted first into a receiver and thence through suitable pipes or
tubes to any places at which they are intended to be utilized. The apertures
above mentioned through the neck of the furnace are made to incline down-
wards from the exterior to the interior surface at a considerable angle, in
order to prevent any of the materials when charged falling, or escaping from
the interior of the furnace through the said. apertures into the confluence
chamber or flue surrounding the same. These apertures we prefer to form of
cast iron in segments and to place them level with each other in the neck of
7.

page_text: the furnace about four feet nine inches from the top; they may, however, be
fixed at different levels; and be formed partly or entirely of fire-brick or any
other suitable matérial:
When formed as segments or frames of cast iron and placed side by side
the required aggregate area of gas passage is obtainable with less depth of
opening than by any other mode in use, the apertures being very shallow and
all level with each other they occupy less depth of furnace; in practice we
have found this to be of considerable importance. By this arrangement and
construction not only a much larger area of opening is obtained for the free
exit of the gases, but the less depth of furnace taken-up-enables-the. "draw-
off" to be worked nearer to the surface of the "charge" or materials fed than
by any other plan; videlicit, at a depth of not more than four feet six inches
or four feet nine inches. This shallowness of the gas openings also allows the
more thorough preparation of the materials charged, as the gas continues
amongst them-to' very nearly the full height of the furnace. For the intro
duction of these improvements narrow throated furnaces do not require to be
widened, as is the case when a cylinder, bell-dome, or brick arching is
adopted, on the contrary, furnaces which are now too narrow will have their
capacities increased be the addition of the said apertures herein described, as
the gases then pass off freely below the narrow part of the throat. This
increase in the area of the "draw-off" also reduces the velocity of the gases
and consequently diminishes their tendency to carry dust into the flues and
conduits.
For cleaning out the confluence chamber small damper closed-apertures
are formed through the outside casing of flue and furnace. For regulating
the suction through the draw-off conduit pipes or tubes, or for closing
the same when required, a balanced dise valve or damper is fitted therein.
Having thus stated the nature and object of our said Invention, and
explained the means we propose to adopt for effecting the several improvements
generally, we now proceed to illustrate and describe the same more particularly;
reference, being made to the accompanying Drawing, which is intended to
farm sinnt of this Swecification
Fig. 1 represents a furnace constructed according to our said Invention in
front elevation; Fig. 2 is a section through the centre of the same vertically; 3
Fig. 3 is a plan at the line A, B, Figs. 1 and 2 respectively; Fig. 4 shews an
inner face view of an iron segmental aperture frame; Fig. 5. is a section'
through the same at C; D; and Fig. 6, a sectional plan at E, E. Similar

page_text: reference letters are used in each Fig., so that the following. index applies.to
the whole
a, the throat of the furnace; 'b, b, the sides; c, c, the charging doors;
d, the furnace head.
:
On reference to Fig. 2 it will be seen that the throat and head of the
furnace are open throughout. e, e, the draw-off apertures in the sides of the
throat; f, the chamber or flue surrounding the apertures, and into which
chamber the gases are drawn, as herein-after explained; h, the branch main
connecting the chamber or flue with the receiver; i, the receiver; j, the
suction main; k, the balanced disc, by which the connection between the
receiver and suction main and conduit is opened, closed, and regulated, as
required; 1, 1, small openings pierced in. the outer wall of the aperture chamber
for cleaning out the bottom of the flue when necessary.
The mode of working the furnace is as follows:-The materials .are
charged at top in the usual way and the blast applied at the tuyieres. The
highly heated gaseous products of combustion then rise from the zone of fusion,
and in their upward course roast off various volatile gases from the descending.
materials, with these they mingle, and together they are usually allowed to
escape to waste freely at the tunnel head. In our plan openings are placed for
the escape of the gases some four feet below the filling level or usual point of
their escape. The four feet of materials charged above the openings acts to
a certain extent as a damper, and as there is a slight suction or draught into
the openings, caused by the pull of chimney, the gases are induced to pass into
and through the apertures in preference to forcing their way upwards through
the materials charged.
The inclined surfaces of the apertures (see also Figs. 4 and 5) prevent the
materials charged from passing out of furnace into induction chamber. The
damper as it is opened or closed more or less regulates the power of the
suction. The side apertures materially increase the area for the escape
of the gases, and greatly relieve a narrow throated furnace, inasmuch as they
are drawn out of furnace before reaching the narrowest point.
Having thus fully described, illustrated, and explained our said Invention,
without restricting ourselves to the precise forms and dimensions or propor-
tions and arrangement of the parts shewn upon the Drawing, we hereby
further declare that what we more particularly claim and desire to include
under the before in part recited Letters Patent is,-
First, the shape and arrangement of openings, which is such that whilst
they are very lasting they prevent the escape of anything but the gases and a
very slight amount of dust, at the same time they draw off the gases from the

page_text: exterior of the circle of neck of furnace, instead of collecting them from the
larger outer area into the centre.
Secondly, that by the use of such openings a very much greater area is
afforded for the escape of gases, and that nearer to the surface of the materials
charged than can be obtained by any other mode in use.
Thirdly, we also claim the general combined arrangement of furnace top..
In witness whereof, we, the said John Addenbrooke; George Addenbrookė,
and Philip Anthony Millward, have hereunto set our hands and seals,
this Twenty-fourth day of March, in the year of our Lord One thousand
eight hundred-and-sixty-six.-