IMPROVEMENTS IN THE MANUFACTURE OF ZINC AND IN THE APPARATUS EMPLOYED THEREIN
Year: 1863

page_text: PROVISIONAL SPECIFICATION left by John Henry Johnson at the Office
of the Commissioners of Patents, with his Petition, on the 25th March
1863. A communication from abroad by Adrien Muller, of Paris, in
the Empire of France, Manufacturer.
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of
Middlesex, Gentleman, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN THE MANUFACTURE OF ZINC AND IN THE APPARATUS EMPLOYED
THEREIN," a communication from abroad by Adrien Muller, of Paris, in the
Empire of France, Manufacturer, to be as follows:-
This Invention relates to the manufacture of zinc in blast furnaces, and
consists of certain improvements in connection with the processes of smelting
and of condensation.
According to this Invention it is proposed that the fuel employed shall be
raised to a high temperature in special furnaces before being supplied to the
blast furnaces, which are to be closed at the top and provided with a suitable
cover or plug. This furnace is filled with fuel only, although, if desired, the
ore and flux may be charged at the top of the furnace with the fuel, but,
according to this Invention, it is proposed to supply the furnaces with the ores
and fluxes in a state of division by blowing the same into them through one
or more blast pipes or tuyeres, the temperature of the ores and fluxes having
been previously raised in suitable furnaces, kilns, or bearths. In order that
the supply may be regular and constant a special distributor or feeding appa-
ratus is adapted to the blast pipes, consisting of a closed hopper communicating

page_text: directly with the upper side of the blast pipe. Into the lower portion of this
hopper there is fitted a grooved or channelled plug, to which a rotatory motion
is imparted by suitable gearing. Immediately beneath each of these blast
pipes there is fitted a second blast pipe, through which air alone is injected,
their object being to maintain the temperature of the fuel at such portion of
the furnace where the ores and flux are injected. In order that the gases may
traverse the centre of the fuel a series of annular or other projections are
formed on the inner sides of the furnace towards the upper part thereof. On
arriving at the top of the furnace the gases are drawn off at a high velocity
through a pipe of small bore, the lower end of which opens into a metal
chamber or receptacle for the fluid zinc carried over with the gases and fume,
this receptacle being heated by a small furnace, which also heats a portion of
the pipe or passage sufficiently to prevent any deposit of solid zinc therein. The
lower end of this pipe is provided with a nozzle, which directs the gases and
other products against a metal plate, in order to agglomerate and collect a
portion of the rich fume and separate the fluid zinc from the same. The
gases then pass through a series of metal chambers divided by partitions, and
fitted with doors at the bottom for the deposit and collection of the heavier
fume; the gases carrying with them only the lighter fume are mixed with jets
of steam, one jet of which produces the draught requisite for the prevention
of the escape of the gases from the top of the furnace when opened to receive
the charge of fuel. The gases and solid particles being thus, mingled with
steam pass into a succession of vertical columns, where they are subjected to
the action of jets of water in a finely divided state, whereby the steam is con-
densed and the solid particles descend into a reservoir of water below.
From this reservoir the water flows off into large shallow depositing basins or
tanks where the solid matter precipitates, and is afterwards collected and dried
to be again blown into the furnace with the oro and flux. The gases are
finally caused to pass through a scrubber filled with coke, over which a stream
of water is allowed to flow constantly. The extremities of those pipes through
which the gases and fume pass are provided with doors which facilitate their
cleansing when required.