Improvements in Blast Furnaces.
Year: 1896

page_text: PROVISIONAL SPECIFICATION.
Improvements in Blast Furnaces.
I, ADOLPHUS WOLSKI of Konskic, Russian Poland, Mining Engineer, do
hereby declare the nature of this invention to be as follows:-
This invention relates to a blast furnace in which furnace gases are withdrawn
from the upper part of the furnace and returned through a conduit and nozzles
into the furnace at the height of the reducing zone where said furnace gases are
regenerated by the evolved carbonic acid. Very hot air is blown into the melting
place or hearth and cold air into the upper or preparatory zone above the reducing
zone. A portion of the furnace gases is at the same time led to the air heater for
the hot air blast.
Dated this 2nd day of Jul 1806
CAPITAINE & VON HERTLING,
89 Chancery Lane, London, W.C., Agents for the Applicant.
I, ADOLPHUS WOLSKI of Konskic, Russian Poland, Mining Engineer, do
hereby declare the nature of this invention and in what manner the same is to
be performed, to be particularly described and ascertained in and by the following
statement:-
Blast furnaces of the kind hitherto in use require from 30 to 55 per cent. more
fuel than is theoretically sufficient even when the ordinary losses in heat are taken
into consideration. This is occasioned through having to burn fuel in excess of
heat requirements in order to obtain an excess of carbonic oxide for the reducing
process as well as through the different operations in the blast furnace process-
smelting slag and crude iron, reduction of iron ores, and preliminary treatment of
the materials to be melted-being dependent upon one another.
Blast furnaces have for object firstly to reduce iron ores by means of a gaseous
mixture of carbonic oxide and carbonic acid and secondly to separate, by smelting,
the reduced iron from the slag producing parts of the iron ores.
This object, together with the suppression of the loss in fuel, is attained by
means of the blast furnace of this invention in which the gases used in the reducing
process remain nearly constant in the same, as they move in a circle and are
continually regenerated, permitting also the different operations in the three zones
of the furnace to be dependent upon each other, namely, smelting slag and crude
iron in the lower part, reducing iron ores in the middle part and preliminarily
preparing the material to be treated, in the upper part.
The construction of the blast furnace of the invention does not greatly differ
from that of the ordinary blast furnaces any of which may be furnished with the

page_text: means for the self regeneration of the gases. Air heated to a very high temperature.
the limits of which are soon determined by practice, is introduced into the lower
part of the furnace for the purpose of producing the highest heating effect under
the minimum expenditure of fuel. Carbonic oxide (CO) is thereby evolved from
the carbon of the coke, charcoal, or like fuel as the product of the imperfect
combustion. This carbonic oxide which will be present in considerable excess,
passes over into the reducing zone of the furnace and there reduces at low
temperatures the iron ores according to the formula :-Fe 0, +3 CO = Fe + CO,.
It is necessary to render this carbonic acid useful for the reducing process and thus
prevent unnecessary consumption of, and save, carbon. It is most advantageous
to keep constant the quantity of the gas for the reducing process and this is
effected by the self regeneration of the blast furnace gases. To this end the
furnace gases are taken from the top or from a lower part of the blast furnace by
a special aperture and conducted into the reducing zone. Here the carbonic acid
is regenerated to carbonic oxide. By this means in addition to the saving in fuel
the employment for the blast furnace process, of ordinary coal, anthracite, brown
coal, turf and naphta, or the residues of petroleum which hitherto have only been
used with great difficulty, is rendered practicable.
A mixture of carbonic acid and carbonic oxide carrying with it its heating
properties passes into the upper or preparatory zone of the furnace. For the
purpose of utilising this heat the necessary quantity of cold air is blown in through
the nozzles at the bottom of this zone in order to keep up the preliminary
preparation of the materials to be smelted and of the crude fuel previous to the
passage of the same into the reducing zone, the moisture being thus driven out of
the materials. During the introduction of the cold air at this place there is
brought to combustion partly the excess gases escaping from the furnace and
partly the sulphur evolved from the ores. The introduction of the gases to the
interior of the furnace is effected by a jet of compressed air which is supplied
from ordinary hot air pipes or from special devices giving a high pressure.
In the accompanying drawing is shewn in sectional elevation a blast furnace
with the improvements of this invention applied thereto.
A are nozzles for heated air. B hot air pipes. C pipes for conducting the blast
furnace gases from the upper part to the lower part of the reducing zone. D air
jet nozzles for introducing blast furnace gases which serve to form the reducing
atmosphere in the interior of the middle part of the furnace. E apertures for the
withdrawal of furnace gases in the upper part of the reducing zone. F cold
air nozzles.
:
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
A blast furnace which by self regeneration of the furnace gases in the reducing
zone of the same through blowing in such gases at the height of said zone and by
a circular movement given to the reducing atmosphere in the middle part of the
furnace affords a saving of fuel, and by introduction of air into the upper part of the
furnace permits of a partial and convenient application of the crude fuel,
substantially as described and shewn.
Dated this 2nd day of Auril 1807
CAPITAINE & VON HERTLING,
89 Chancery Lane, London, W.C., Agents for the Applicant.