IMPROVEMENTS IN THE CONSTRUCTION AND WORKING OF GAS BLAST FURNACES AND IN THE METHOD OF PRODUCING GAS FOR THE SAME AND OTHER PURPOSES
Year: 1878

page_text: LETTERS PATENT to William Lloyd Wise, of Chandos Chambers, Adelphi,
in the County of Middlesex, for the Invention of " IMPROVEMENTS IN THE
CONSTRUCTION AND WORKING OF GAS BLAST FURNACES AND IN THE METHOD
OF PRODUCING GAS FOR THE SAME AND OTHER PURPOSES." A communication
from abroad by Mr. Aristide Balthazard Bérard, of Paris, France.
•
Sealed the 25th February 1879, and dated the 17th September 1878.
PROVISIONAL. SPECIFICATION left by the said William Lloyd Wise at the
Office of the Commissioners of Patents on the 17th September 1878.
WILLIAM LLOYD WISE, of Chandos Chambers, Adelphi, in the County of
Middlesex. "[MPROVEMENTS IN THE CONSTRUCTION AND WORKING OF GAS BLAST
FURNACES AND IN THE METHOD OF PRODUCING GAS FOR THE SAME AND OTHER
PURPOSES." (A communication from abroad by Mr. Aristide Balthazard Bérard;
of Paris, France.)
This Invention relates to the construction and working of a system of gas blast
furnace in. which the oxides to be reduced are subjected to very high temperature
(à la plus haute-température possible ") under the action of continually reducing
or of neutral gases, with the addition of a minimum of solid carbon ("charbon
solide") for saturating the oxygen of the oxide. The apparatus embodies two
principal portions, namely, a reducing furnace heated by gas with accessories for
utilizing the waste gases, and a gas-producing apparatus with regenerator.
The reducing furnace is a combination with a shaft or upright chamber of two
reverberatory gas furnaces, connected together so as to form a hearth. furnace
serving as an elaborating chamber for the re-actions which the ores have to undergo;
this portion corresponds to the blast furnaces now in use.
The sole or bed forms a double crucible, and is made moveable for facility of
maintenance and repairs. On a middle projecting portion rest the added fuel and
the other reducing substances contained in the shaft or upright chamber.. The
bottom, and sides of the sole or bed are lined with. fire-brick.covered with tightly

page_text: rammed "brasque," consisting of a mixture of carbonaceous substances held
together with a small proportion of fire-clay. A channel running all round the
circumference and lined with clay enables a perfectly tight joint to be made. The
sole or bed is raised or lowered by mechanical means. The metal produced by the
reduction of the ores under the action of the mixture of fuel and the gases falls into
the hollow parts of the sole or bed (there are two communicating with each other)
where it accumulates until the time arrives for tapping, which is effected by
unstopping one or both of two suitable apertures.
The slag flows through suitable apertures in the upper part of the moveable sole
or bed.
To facilitate the replacing of the sole or bed a temporary grating is formed under
across the shaft or upright chamber by introducing bars into suitable apertures.
The charge may thus be supported during the operation of substituting a fresh for
a worn out sole or bed.
The gases for heating the furnace are conducted from the gas generators (which
will be presently described) by suitable passages and are distributed by tuyeres.
The hot air for the combustion of the gases is fed to the central portion of each
tuyere.
By their combustion the gases heat the two crucibles of the sole or bed, after-
wards they converge towards the shaft or upright chamber of the furnace which
constitutes the ore-reducing chamber.
The flame may be rendered reducing, oxidizing, or neutral at will by the aid of
valves or cocks for regulating the admission of the air or the gases.
Provision is made to prevent the escape of gas or entrance of atmospheric air,
the irregular pressure of which would interfere with the proper working. The
arches are formed of cast iron lined with fire-bricks and kept cool outside by a
constant stream of water. The lining may consist of the fire-bricks of commerce,
those of magnesia, of bauxite, or of plumbago.
A special arrangement permits of repairs being effected and of easily changing
the flat arch pieces forming the bottom of the structure, and also their compression
endwise so as to counteract the shrinkage due to heat.
Gates closed hermetically during operations are provided in the sides of the
furnace to serve in case of need for working, and also during repairs to the sole or
crucibles.
Sight holes are provided to permit of seeing what passes inside and of estimating
the temperature of the furnace.
After having acted on the ore in the shaft or upright chamber of the furnace the
gases are still further utilized in generating steam and in heating the air intended
for combustion, as herein-after described.
The ore fluxes and solid fuel in the proper proportions are fed in through an
aperture provided with a water joint and a closing arrangement with double flaps.
These substances fill the chamber forming the charging hopper, which can be raised
or lowered at will.
The gas after having passed through the column of substances contained in the
reducing shaft or upright chamber are conducted to a tubular boiler as well as to
an appliance for heating the blast. This appliance consists of a mass of brick work
in which flues are arranged longitudinally.
In the space between the various courses of the flues are erected in a transverse
direction wrought or cast iron tubes in which the air circulates, they are thus
bedded in the masonry and protected from the action of the flames. They
terminate at their ends two by two, or three by three, in a chamber closed her-
metically by a cover. An asbestos joint made at the end of each' tube in the
chamber prevents loss of blast and allows each tube to be replaced separately with
the greatest ease. Plate iron doors cover the space occupied by the chambers on
each side of the appliance, and the space is filled in with fine sand to avoid loss
of heat.
The generator for producing the steam for driving the general blowing apparatus

page_text: of the whole system is placed on the masonry of the appliance for heating the blast,
and receives heat from this masonry which serves to some extent as a reservoir of
caloric. This generator may be of any suitable construction, preferring a multi-
tubular boiler arranged horizontally.
Dampers serve to regulate the distribution of gas to the boiler and to the stove
for heating the blast, according to the requirements of working.
Doors placed at the ends of the above-named appliances facilitate the cleaning of
the boiler and flue tubes of the stove.
On 'leaving the boiler and 'the stove the burnt gases pass on to a chimney by a
suitable flue; underneath the chimney is arranged a helical exhauster for exhausting
the gas, and reducing or suppressing the pressure in the reducing shaft or upright
chamber as well as on the sole or bed of the reverberatory furnaces. Any other
method of ventilation or exhaustion may be employed for this purpose.
Arrangements may be made for placing a similar gas extractor in the vertical
passage at the outlet of the shaft or upright chamber; the motion would then be
transmitted from the top.
To facilitate the putting into operation of 'the whole system, and increase the
means for generating steam and for heating the blast, a supplementary grating may
be erected. This may be an ordinary grating or an arrangement for continuous
self-acting feed, smoke consuming, and supplied with a hot blast either with an
impelled current or at atmospheric pressure.
The apparatus for the production of gas consists of two distinct portions, nan:ely,
the gas producer proper and the purifying regenerator.
The gas producer comprises a hopper for charging the coal having a double
closing arrangement, one with water seal and the other with flaps; an elaborating
chamber wherein the gas is produced; a moveable hearth provided with apertures
for cleaning out; a suitable number of inclined blast tuyeres; apertures for stirring
the coal and passages or tubes for the erection of the temporary grating during
the replacing of the hearth.
The regenerator .comprises a charging hopper provided with close fitting doors;
a receiver for coke mixed with lime serving for the regeneration and the purification
of the gas; a moveable sole with apertures for cleaning out; passages for the
introduction of the bars ("de ringards"), serving to form the temporary grating
when the sole is charged; an aperture for stirring a blast tuyere; a superheated
steam tuyere an apparatus for superheating the steam; an exhauster, a flap, or
door capable of intercepting the communication between the gas producer and the
regenerator, and a damper.
The gases on leaving the gas producer pass into the regenerator, which they
reach by a suitable passage. By their own heat they superheat the steam in the
superheating apparatus for supplying the tuyere. They are then drawn along 'by
the exhauster, which forces them through the layer of incandescent coke with
which the receiver is charged.
In the journey which the gas has to make in order to pass through this column
of coke raised to a high temperature by the blast tuyere it will acquire a con-
siderable increment of heat.
The steam which it contains will be decomposed on contact with the coke, and
the same will be the case with the tar vapour. The small quantity of carbonic
acid, which might still exist, will be transformed into carbonic oxide. Lastly, the
sulphurous gases are absorbed by the lime mixed with coke, the object of which 'is
to facilitate the fusion of the layers.
In this manner gas is obtained of high temperature, rich and pure.
The gas thus prepared is led to the reducing furnace and employed as previously
described.
'When the ore to be treated by the improved apparatus contains precious metals
such as gold, silver, or platinum, it is advisable to extract these metals while at the
same time producing the pig iron under economical conditions. For this purpose
it is sufficient to charge in with the iron ore lead substances, such as red or yellow
.

page_text: litharge, carbonates of lead, et cætera, in such proportion as is suitable for dissolving
and saturating the precious metals for which the lead has a great affinity, but these
substances should be free from sulphur. The oxides of lead quickly reduced at a
temperature lower than that of the oxides of iron yield metallic lead which falls in
small globules into the middle and lower region of the reducing shaft or chamber,
thus effecting an operation of washing on the oxides of iron in the course of
reduction, by means of which the lead absorbs the precious metals by solution.
The lead passes into the sole or bed where it occupies the lower position in the
bath of molten metal. There by contact with the iron in fusion it continues to
absorb the precious metals, for which it has a greater affinity than has the iron.
An addition will in this case be adapted to the moveable sole or bed of the
furnace for receiving the lead and forming a sort of reservoir, from which a portion
may be taken from time to time and dropped on the surface of the bath of molten
iron which it passes through, in order to absorb particles of precious metal that
may have escaped the first operation of washing effected in the shaft or upright
chamber.
The lead containing the gold, the silver, or the platinum will then be tested, and
the litharge obtained by the cupellation will serve for use over again.
The arrangements herein-before described with slight modifications of <letail
are applicable to the second fusion of the metal, thus superseding the ordinary
cupola.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Lloyd Wise in the Great Seal Patent Office on the 17th
March 1879.
WILLIAM LLOYD WISE, of Chandos Chambers, Adelphi, in the County of
Middlesex. "IMPROVEMENTS IN THE CONSTRUCTION AND WORKING OF GAS BLAST
FURNACES AND IN THE METHOD OF PRODUCING GAS FOR THE SAME AND OTHER
PURPOSES." A communication from abroad by Mr. Aristide Balthazard Bérard, of
'Paris, France.
This Invention relates to the construction and working of a system of gas blast
furnace in which the oxides to be reduced are subjected to the highest possible tem-
perature under the action of continually reducing or of neutral gases, with the addi-
tion of a minimum of solid carbon (charbon solide) for saturating the oxygen of the
oxide.
The apparatus embodies two principal portions, namely, a reducing furnace
heated by gas with accessories for utilising the waste gases, and a gas-producing
apparatus with regenerator.
The Drawings illustrate a mode of carrying out the Invention.
Figs. 1 and 2 shew the reducing furnace which consists of two reverberatory gas
furnaces, connected together so as to form a hearth furnace, serving as an elaborat-
ing chamber for the re-actions which the ores have to undergo; this portion corre

page_text: sponds to the blast furnaces now in use. The sole or bed forms a double crucible
and is made moveable for the facility of maintenance and repairs. On a middle
projecting portion rest the added fuel and the substances to be reduced contained in
the shaft or upright chamber Z. The bottom and sides of the plate iron sole or bed
are lined with fire-brick covered with a tightly ramined mixture of earth and coal
lust (brasque), or of other carbonaceous substances bound together with the smallest
possible proportion of fire-clay. A channel running all round the circumference
and lined with clay allows of a perfectly tight joint being made. The sole or bed
is raised or lowered by mechanical means.
The metal produced by the reduction of the ores under the action of the mixed
fuel and gases falls into the hollow parts of the sole or bed in two portions (which
communicate with each other), where it accumulates until the time arrives for
tapping or running it off, which is effected by unstopping one or both of the
apertures A, A'.
The slag or dross runs off through the apertures B and B placed in the upper
part of the sole or bed.
To facilitate the replacing of the sole or bed a temporary grating is formed under
the shaft by introducing paddles or bars into the apertures C, C, C.
The charge may thus be supported during the operation of substituting a new for
a worn out sole or bed.
The gas for heating the furnace, which is a mixture of carbonic oxide and
carbonated hydrogen, is conducted from the gas generators (herein-after described)
through the pipes D, D, and is distributed by various inclined tuyeres.
The hot air to be used for the combustion of the gas is conducted to the central
portion of each tuyere from the conduits E. The combustion of the gas first heats
the two crucibles of the sole or bed, then converges towards the shaft or upright
chamber of the furnace, which forms the ore-reducing chamber.
The flame may be rendered reproducing, oxidizing, or neutral at, will by the aid
of valves or cocks for regulating the admission of the air or the gases. A neutral
flame is most favourable for the. work as it gives out the greatest heat.
The ignited gases which traverse the charge of ore and fuel composing the bed
of fusion are necessarily subject in this passage to a certain resistance, which must
be overcome either by the initial pressure of the gases and air on their admission
into the furnace, or by means of a partial vacuum in the furnace effected by an
exhauster (herein-after described).
But in order to obtain pressure or effect a partial vacuum within the furnace it
is in both cases essential to prevent the escape or leakage of gas as well as the
introduction of the exterior air, the irregular pressure of which would interfere
with a proper regular working. In view of which the doors or apertures should be
hermetically closed. The apparatus should be lined with cast or wrought iron
plates and the joints carefully made.
The arches are formed of cast-iron blocks (voussoirs) provided with an inner
lining of fire-brick and kept cool on the outer side by means of a constant stream of
water. This system of arch is quite new, and has the double advantage of pre-
venting the infiltrations of gas, and a too rapid wear of this, the portion of the
apparatus most exposed to the heat, without sensibly affecting the development of
a very high temperature, it at the same time facilitates repairs.
The lining may consist of the fire-bricks of commerce, or those of magnesia, of
bauxite, or of plumbago.
A special arrangement which is shewn in the Drawings allows of repairs and the
replacing of the flat arch blocks forming the base of the construction, and of their
compression endwise to counteract the shrinkage by reason of the heat.
Doors F, F, which are hermetically closed during operations, are provided at the
sides of the furnace to serve in case of need for carrying on the operations and for
the purpose of repairs to the sole, or bed, or crucible.
Sight holes G, G, permit of watching the operations taking place inside, and
enable the temperature of the furnace to be estimated.

page_text: After having acted on the ore in the shaft Z of the furnace the gases are further
utilised for the generation of steam and for heating the air destined for their com-
bustion, as heréin-after described.
'The materials composing the charge, ore, fluxes, and solid 'fuel, coke, charcoal, or
peat, etc., in the proportion strictly necessary for the absorption of the oxygen of
the oxides are fed in 'through the opening H, which is provided with a water joint
and a closing arrangement with double flaps. These substances fill the plate-iron
chambers I, 'I, forming the charging hopper, which is made 'to be raised or lowered
at will.
By this arrangement the entrance of the exterior air as well as loss of
gas is
prevented. It has also the advantage of allowing time for 'the substances to get
hot and to arrive in a proper state in the shaft Z where the reduction commences..
The charging is effected under the most favourable conditions in regard to
regularity, distribution of the substances, and without the workman being incon-
venienced by the heat.
The gases impelled by their own natural pressure or drawn by the exhauster, or
by these two methods in conjunction, after 'having traversed the column of materials
contained in the reducing shaft Z pass through a passage J, J, J, 'to the tubular
boiler K, K, and also to the air-heating apparatus L, L.
This apparatus shewn in Figs. 1 and 3 consists of a brickwork construction in
which the passages M, M, M, are arranged longitudinally. In the intervals or spaces
between the various courses of passages M are erected 'the transverse wrought or
cast iron heating tubes in which the air circvlates; they are 'thus bedded in 'the
masonry and protected from the action of the 'flame. Their open ends terminate
two 'by 'two or three 'by three in a chamber N, N, closed hermetically 'by a cover.
An.asbestos joint made at the extremity of each tube in the chamber prevents any
loss of air and enables each tube to be replaced separately with the utmost facility.
Sheet-iron doors cover the space occupied 'by the chambers on each side of the
apparatus, and the intervening space is filled in with fine sand for the prevention
of loss of heat. For the small space occupied by this apparatus a large heating
surface and a considerable useful effect are obtained.
The steam generator which produces the steam for actuating the general blowing
apparatus of the whole system is placed on 'the masonry of the air-heating apparatus
and receives some of the heat acquired by this masonry, which in some 'measure is
a reservoir of caloric. This generator may be of any suitable kind, preferring a
tubular generator erected as shewn in the 'Drawings.
Dampers O and P regulate 'the distribution of the gases to 'the generator and the
air-heating apparatus as the nature of the operations may require. Doors placed
at the ends of the above-mentioned appliances facilitate the cleaning of the genera-
tor tubes and the passages of the air-heating apparatus.
On passing from the boiler and air-heating apparatus the burnt gases proceed to
the chimney 'Q through the flue q, q. Underneath the chimney is placed the helical
exhauster R which exhausts the gases and reduces or suppresses the pressure in the
reducing chamber as well as on the sole or bed of the reverberatory furnaces which
are first acted upon. Other methods of ventilation or exhaustion may be employed,
but the arrangement described is preferred, which is simple and economical.
velocity of rotation of the helical exhauster is varied as desired by mechanical means
so as to exactly counterbalance (equilibrer) 'the effect of diminution of pressure
(partial vacuum).
The
'The apparatus may be arranged for a similar gas exhauster, to be placed in the
vertical flue R' at the opening into the shaft, in which case it would be driven from
above (Fig. 1).
To 'facilitate the working of the whole system and increase the means for gene-
rating steam and heating the air a supplimentary fire-grate is provided at S. This
may be an ordinary grate, or better, the arrangement shewn in the Drawings, which
is constructed 'to feed the fuel automatically to consume its smoke, and is 'fed with
hot air either under pressure or not; it works under conditions of great economy..

page_text: I will now describe the gas-producing apparatus. These apparatus (shewn in
Figs. 4 and 5) consist of two distinct parts :-
1. The gas producer proper.
2. The purifying regenerator.
The gas producer employed comprises a hopper E for feeding the fuel which has
a double closing arrangement, the one hydraulic the other closing with flaps; an
elaborating chamber F wherein the gas is produced; a moveable sole or bed G pro-
vided with four openings for the purpose of cleaning; a suitable number of inclined
blast tuyeres H; several stoking apertures I and passages or tubes K for putting
in the temporary grate whilst the sole or bed is in course of being replaced.
height of the charge reduced to the most convenient limit.
The
With the important object of obtaining gases possessing of themselves a high
temperature free from steam and all mixture of carbonic acid without tar in
suspension untransformed into carbonated hydrogen, and as free as possible from the
sulphurous gases evolved from the coal, a regenerator is employed which comprises :-
A feeding hopper L, which is closed hermetically by means of flaps or close fitting
doors; a receiver or chamber M, M, for coke mixed with lime, which serves for re-
generating and purifying the gases (the coke must be dry); a moveable sole or
bed N; provided with apertures for the purpose of cleaning; orifices 0, 0, for the
insertion of the bars (ringards) which have to form the temporary grating whilst the
moveable sole or bed is being replaced; an opening P for stoking; a tuyere for
air Q; a tuyere for superheated steam R; an apparatus for superheating steam S;
an exhauster T; a door U, capable of intercepting the communication of the gas
producer with the regenerator; and a damper V.
The gases on leaving the gas producer pass into the regenerator through the con-
duit X, X. By their own heat they superheat the steam in the apparatus S, which
feeds the tuyere R. They are then drawn by the fan or helical exhauster T, which
forces them through the layer of incandescent coke with which the receiver or
chamber M is filled.
In the course which the gases have to take to traverse this column of coke which
has been brought to a high temperature by the blast tuyere Q, they receive a
considerable addition of heat.
The steam (from water) which is contained in the gases becomes decomposed on
contact with the coke; the same obtains in the case of the vapours evolved from
the tar. The small portions of carbonic acid which may be present become trans-
formed into carbonic oxide.
Lastly, the sulphurous gases are absorbed by the lime mixed with the coke, the
object of which is also to facilitate the fusion of the layers.
Gas is thus obtained of a very high temperature, very rich, and as pure as
possible.
The gas thus prepared is conducted through the passage Z to the reducing furnace
and employed as before stated.
When the ore to be treated in the improved apparatus contains precious metals,
such as gold, silver, or platinum, it is advisable to extract these metals, while at the
It
same time producing the cast or pig iron (fonte) under economical conditions.
then suffices to charge in with the iron ore, lead substances, such as red or yellow
litharge, carbonate of lead, and others of a like nature, in a proportion suitable for
dissolving or saturating the precious metals for which lead has a great affinity, but
these substances should not contain sulphur. The oxides of lead quickly reduced at
a temperature lower than that of the oxides of iron, yield metallic lead, which falls
in small globules into the middle and lower portion of the reducing shaft, effecting
a washing operation on the oxides of iron in course of reduction, by means of which
the lead absorbs the precious metals by solution.
The lead passes to the sole or bed, where it occupies the lower part of the bath
of molten metal. There by contact with the iron in fusion it continues to absorb
the precious metals, for which it has greater affinity than has iron.
An addition shewn in Fig. 1 of Sheet 1 is in this case made to the moveable sole

page_text: or bed of the furnace for the purpose of receiving the lead, and forms a species of
reservoir, from the contents of which a portion may from time to time be taken and
poured in the form of rain on the surface of the bath of molten iron, through which
it passes, absorbing the last portions of the precious metals, which may have
escaped the first washing operation effected in the shaft; thus there are two
methods of procedure.
The lead containing the gold, silver, or platinum is then tested (coupellé), and the
litharge thereby obtained is used over again.
I would here remark generally that the same arrangements as those herein-before
described are with slight modifycations of detail applicable to the second fusion of
the cast iron (fonte), thus advantageously superseding the ordinary cupolas.
Having thus described the nature of the said Invention, and the manner of per-
forming it, as communicated to me as aforesaid, I would have it understood. that
what I consider to be novel and original, and therefore claim as secured to me under
the Letters Patent herein-before in part recited' is,--
1. The combination of two reverberatory gas furnaces with a reducing or smelting
furnace, substantially as herein-before described.
2: The application in furnaces for reducing ores by gas of a double crucible-sole
or bed, made moveable, substantially as herein-before described.
3. The method, substantially as herein-before described; of keeping cool' the
arches of reverberatory furnaces, and the constructing them as herein-above set
forth, with reference to the accompanying Drawings.
4. The arrangement, substantially as described and shewn, for utilising. waste
heat from a reducing furnace to generate steam.
5. The combination with the reducing furnace of apparatus, substantially as
described and illustrated, for heating air under pressure by the waste heat.
6. The constructing and working gas regenerators, substantially as herein-before
described, and shewn in the accompanying Drawings, and particularly the use or
employment in combination Of lime for the purification of the gases; of super-
heated steam to facilitate the decomposition of the hydro-carburets, and to increase
the proportion of the combustible gases; and of a column of incandescent' coke to
increase the temperature of the gases before use, as herein-above set forth.
7. The application in a gas regenerator of a moveable sole or bed, substantially as
described and shewn.
8. The combination of parts constituting the improved compound apparatus, con-
structed, arranged, and operating substantially as shewn in and described with
reference to Figs. 1, 2, 3, 4, and 5 of the accompanying Drawings for the purposes
specified.
9. The method, substantially as described, of extracting precious metals.
'
In witness whereof, I, the said William Lloyd Wise, have hereunto set my
hand and seal, this Seventeenth day of March, in the year of our Lord
One thousand eight hundred and seventy-nine.
W. LLOYD WISE. (L.S.)