IMPROVEMENTS IN THE PROCESS OF MANUFACTURING CAST IRON
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by William Spence at the Office of the
Commissioners of Patents on the 9th May 1883. Communicated to him from
abroad by Alfred Braconnier of Nancy in the Republic of France, Mining
Engineer
WILLIAM SPENCE of 8 Quality Court, Chancery Lane, in the County of
Middlesex Patent Agent "IMPROVEMENTS IN THE PROCESS OF MANUFACTURING
CAST IRON (a Cominunication to me from abroad by Alfred Braconnier of Nancy
in the Republic of France, Mining Engineer)
,,
This invention consists in the process of injecting through the twyers of a blast
furnace the gases issuing from any suitable coal gas generator by previously
heating such gases elsewhere or external to the furnace at as high a temperature
as required.
These gases will have been by such means freed in the first instance from
certain impurities injurious to the quality of the cast iron and especially of sulphur
which is so difficult to be got rid of in all the processes of manufacture of iron
and steel.
The economy of fuel in the blast furnace depends on obtaining as high a
temperature as possible in the zone of sinelting in the crucible inasmuch as the
more rapidly the materials are fused the fewer units of heat will be required to
smelt a given weight thereof.
The results obtained with the Schlesing gas blow pipe leave no doubt as to
the possibility of obtaining in the crucible of a blast furnace extremely high
temperatures by the simultaneous injection of hot air and heated coal gas issuing
from a special generator by a blast direct from the blowing apparatus.
Owing to the comparative moderate quantity of hot blast that would be required
the apparatus may be modified so as to dispense with the reversing and the
working of the valves.
By the use of continuous apparatus there will be given to the hot blast a
constant temperature which can be regulated at will and the construction of
the apparatus is facilitated by the equilibrium of pressure externally and internally
of the passages through which the blast to be heated will circulate.

page_text: The coal to be employed ought to be fed into the apparatus by the best known
means adapted to free it from the iron pyrites which is essential for the purification
of the gases.
The generator is or may be a small blast furnace (with cold blast supplied)
partly in the form of a cupola furnace and terminating at top in a dome in the
centre of which will be adapted an inlet with two valves for the charging of the
coal. A cock will be sufficient to maintain the equilibrium required for working
the upper valve.
In order to convey the gas to the heating apparatus there is used by preference
a narrow conduit with fire brick lining
The different qualities of smelting will be obtained by varying the proportions
of the different elements of coal, coke and hot air.
By the process described the following results are obtained: Economy of weight
of coal used, greatly diminished consumption of coke, the means of using on a large
scale for the manufacture of cast iron fuel hitherto unsuited for the production of
coke and generally all kinds of fuel improvement in the quality of the cast iron
produced, treatment of minerals so highly sulphurous as to have been hitherto
rejected diminished cost in the manufacture of cast iron reduction in the
dimensions of blast furnaces, and diminished danger of accidents in blast furnaces
owing to the cooling in the crucible and difficulties of observation of the working
of the process.