Improvements in the Application of Gaseous Fuel for Smelting Ores, and in Furnace, Crucible, and other Plant therefor.
Year: 1885

page_text: Improvements in the Application of Gaseous Fuel for Smelting
Ores, and in Furnace, Crucible, and other Plant therefor.
BRIERLEY DENHAM HEALEY, and BENJAMIN HOWARTH. THWAITE both of
37, Victoria St Liverpool, in the County of Lancaster Civil Engineers, do hereby
declare the nature of our invention for IMPROVEMENTS IN THE APPLICATION OF
GASEOUS FUEL FOR-SMELTING ORES AND IN FURNACE CRUCIBLE AND OTHER PLANT
THEREFOR to be as follows:-
Our invention consists in improvements in the plant for effecting the reduction
of iron ores by means of gaseous fuel and has especial reference to the manner of
effecting the combustion of the gas in the Blast Furnace, instead of having the air
supplying tuyeres and the gas tuyeres on opposite sides of the Blast Furnace
crucible so that the air and gas cannot commingle or become mixed before entering
into the zone of fusion we place the gas and air tuyeres side by side or one over
the other in such a way that the direction of the centre line of the bore of the
tuyeres shall point to one common centre or focus outside the inner circumference
of the crucible so that the volumes of air and gas shall be completely intermixed
before they enter the zone of fusion and thus prevent the oxygen of the air from
oxidising the metallic iron which in using the water or gaseous fuel reducing
process will contain only mere traces of carbon.
Our new arrangement will also permit us to obtain a perfect control over the
character of the action of combustion which can be made a partial or carbonising
and deoxidising one or a complete one with an excess of air and therefore oxidising
as desired, indeed both the operation of reduction and oxidation can be effected
with scientific exactness to any desired degree previous arrangements do not allow
this but the blast furnace air tuyers debouching air directly into the bath of molten
iron on one side, oxidises it and on the opposite side the gas tuyere, in the same
manner debouches gas into the molten metal, or metal in a more or less complete
state of fusion saturating it with carbon so that neither the action of reduction, or
oxidation can be effected with regularity or completeness and the action of
combustion is both irregular and incomplete.
In order to form a perfectly refractory or highly infusible lining for the tuyere
jet flues, in which the gas and air meet and become thoroughly mixed before
they enter into the interior of the crucible or zone of fusion, we use a mixture of

page_text: hydrate of alumina (Bauxite) and magnesite calcined and ground and mixed with
boiled liquid hydro-carbon.
We form the bore of the tuyere flue at the focus or common centre of the line of
direction of the gas and air tuyeres-of a sectional area at least equal to the
combined areas of the bores of the two gas and air tuyeres, we then from this point
until the flue opens out into the inside of the crucible gradually increase its
sectional area, so that the combustion is at its point of maximum heat production
in and completely fills the centre of the crucible We place a pair of tuyeres (1 gas
and 1 air) directly opposite each other, so that the whole action of combustion can
be made as intense and regular as practicable.
We also line the part of the crucible exposed to the most intense action of
combustion, and to the fusion of the metal with the mixture already described for
the tuyere flues,-for the upper part of the crucible we use dolomitic lime or
calcined magnesian limestone (dolomitic) or we may use the mixture of magnesite
and hydrate of alumina already referred to.
In order to permit the refractory lining to be renewed we mount the crucible on
the trunnions of a carriage mounted on wheels, running on rails, the columns
supporting the superstructure of the furnace being arranged to permit the with-
drawal of the carriage the trunnions are so mechanically arranged as to permit of
their being elevated, when the crucible is in situ, so as to make a connection with
the upper part or bosh of the furnace, or we may place an hydraulic lift in a pit
immediately under the crucible and into which it can be lowered for the renewal of
the dolomite or other lining.
The upper part of the interior of the blast furnace we construct in the form of a
series of inclined retorts each one inclined in the contrary direction to the one
above or below it, so that the minerals can continually gravitate from one incline
to another and in order to save space two retorts are placed opposite each other
inclined in reverse directions or four retorts may be placed at right angles to each
other the lowest retorts terminating in the same crucible. The minerals from the
said retorts are subjected to the same fusing, deoxidising decarbonising, or
carbonising action as desired, by this inclined retort arrangement the weight of the
mineral is not thrown upon the charge in the crucible and the mineral is therefore
more easily permeated by the gaseous combustion, and as the spongy mass of
deoxidised mineral gravitates down the face of the tuyeres or through the intense
zone of fusion it is instantly liquified.
The retorts should be kept entirely filled so as to compell the ascending gases to
permeate through the charge and in order to keep the retorts free from obstruction
we provide air tight and refractory brick encased doors at the mouth of the retorts
to enable the workmen to draw out or push down any fused mineral producing an
obstruction or irregularity in the working of the furnace.
To allow the action of the furnace to be more closely watched we provide air
tight sight holes through the brickwork forming the retorts, and also in the doors
provided with a transparent infusible material such as tale or mica, when we desire
to transfer the fused metal tapped from the Blast Furnace directly into a Siemens
Steel Melting Furnace we construct the latter at such a lower level as will ensure
the flow of the metal by gravity from the tap hole to the open hearth of the
Siemen's Furnace or we may arrange the level of the Siemens Furnace in relation
to that of the Blast Furnace as to permit the metal at the Blast furnace to be
tapped into a ladle mounted on a carriage with which it is weighed and
afterwards tapped into a runner leading to the hearth of the Siemen's furnace.
In the apparatus for producing water gas when we employ the same we use an
arrangement of two valves within one casing one valve is used for directing the
flow of air from the hot blast stoves into the gas producers for revivifying the
carbonaceous fuel and the other for directing the water or other gaseous fuel into
the Blast Furnace gas conduits leading to the Gas tuyeres, we arrange said valves
in such a way that one is closed automatically as the other is opened.

page_text: The gas flues from producers and air flues from hot blast stoves we place as
much as practicable below the surface of the ground and form them of fireclay
tubes bedded in brickwork. The flues above the ground we form of wrought
iron casings internally lined with fireclay tubular linings.
The gas producers we place just sufficiently high above the ground to permit
clinkers to be withdrawn.
We connect the producer vessel and its recuperator vessel together by a square
flanged joint bolted between each top connection.
We form independent platforms over the producers, recuperators, and stoves clear
of the sheet ifon casings, so that the latter may be renewed without the necessity
of taking the platform down overhead.
In order to utilise all the heat radiated from the sides of the Crucible of the
furnace we use a water lined sheet iron casing-open at the upper end for the
escape of the vapour of evaporation, a continual flow of water is produced by
means of an arrangement of supply and escape pipes.
Between the upper end of the dolomitic lining of the crucible and the siliceous
superstructure of the furnace we provide a neutral layer formed of bauxite which
will prevent the silica of the firebrick from coming into contact with the dolomitic
material.
The upper part of the crucible casing we make movable so as to allow the
dolomitic lining to be renewed or repaired.
It will be seen by our arrangement of twin tuyeres for controlling combustion
and regulating its character. we can produce as the sole products of combustion,
carbonic acid gas. This gas is neutral having neither an oxidising, deoxidising
or carbonising action on iron. This is especially valuable in the fusion of pure
metallic iron.

page_text: Improvements in the Application of Gaseous Fuel for Smelting
Ores, and in Furnace, Crucible, and other Plant therefor.
BRIERLEY DENHAM HEALEY and BENJAMIN HOWARTH THWAITE both of
37 Victoria Street Liverpool in the County of Lancaster, Civil Engineers, do
hereby declare the nature of our invention for IMPROVEMENTS IN THE APPLICATION
OF GASEOUS FUEL FOR SMELTING ORES AND IN FURNACE CRUCIBLE AND OTHER
.
PLANT THEREFOR, and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement:—
Our invention consists in improvements in the plant for effecting the reduction
of iron ores, by means of gaseous fuel and has especial reference to the manner of
effecting the combustion of the gas in the Blast Furnace. Instead of having the
air supplying tuyeres and the gas tuyeres on opposite sides of the Blast Furnace
crucible so that the air and gas cannot commingle or become mixed before entering
into the zone of fusion, we place the gas and air tuyeres side by side or one over
the other in such a way that the direction of the centre line of the bore of the
tuyeres shall point. to one common centre or focus, so that the volumes of air and
gas shall be completely intermixed on entering the zone of fusion and thus prevent
the oxygen of the air from oxidising the metallic iron which in using water gas or
other gaseous fuel for the reducing process will contain only mere traces of carbon.
Our new arrangement will also permit us to obtain perfect control over the
character of the action of combustion which can be made neutral carbonising or
deoxidising, or we may obtain complete combustion with an excess of air and
therefore oxidising. Both the operation of reduction and oxidation can by our
invention be effected with scientific exactness to any desired degree. Previous
arrangements do not allow of this but the blast furnace air tuyeres debouch air
directly into the bath of molten iron on one side, oxidises it, and on the opposite
side the gas tuyeres in the same manner debouch gas into the molten metal in a
more or less complete state of fusion saturating it with carbon, so that neither the
action of reduction or oxidation can be effected with regularity or completeness,
and the action of combustion is also both irregular and incomplete.
In order to form a perfectly refractory or highly infusible lining for the tuyere
jet flues in which the gas and air meet and become thoroughly mixed before they
pass into the centre of the crucible or zone of fusion we use a mixture of hydrate
of alumina (Bauxite) and magnesite calcined and ground and mixed with boiled
liquid hydro-carbon, or we may use waterlined combustion flues and utilise the
greater part of the heat therefrom.
We form the bore of the tuyere flue at the focus or common centre of the line of
direction of the gas and air tuyeres of a sectional area at least equal to the
combined areas of the bores of a pair of gas and air tuyeres, then from this point
until the flues open out into the inside of the crucible they are gradually increased
in sectional area, so that the combustion is at its point of maximum heat intensity
in the centre of the crucible. We place a pair of tuyeres (1 gas and 1 air) directly
opposite each other so that the whole action of combustion can be made as intense
and regular as practicable in the centre of the crucible.

page_text: We also line the part of the crucible exposed to the most intense action of
combustion and to the fusion of the metal with the mixture already_described for
the tuyere flues, but we may use for this purpose magnesite bricks. For the upper
part of the crucible we use both ordinary fireclay blocks or dolomitic lime or
calcined magnesian limestone in the form of blocks (dolomitic) or we may use the
mixture of magnesite and hydrate of alumina already referred to.
In order to permit the refractory lining to be renewed we mount the crucible
on the trunnions of a carriage mounted on wheels running on rails the columns
supporting the superstructure of the furnace being arranged to permit of the
withdrawal of the carriage and the crucible. It is so mechanically arranged as.to
allow of its being elevated when the crucible is in situ so as to make a connection
with the upper part or bosh of the furnace, or we may place a hydraulic lift in a
pit immediately under the crucible and into which it can be lowered for the
renewal of the dolomitic or other lining.
The upper part of the interior of the blast furnace we construct in the form of a
series of inclined retorts each one inclined in the contrary direction to the one
above or below it, so that the minerals can continually gravitate from one incline
to another and in order to save space two retorts are placed opposite each other
inclined in reverse directions or four retorts may be placed at right angles to each
other the lowest retorts terminating in the same crucible.
The minerals from the said retorts are subjected to the same fusing, deoxidising
decarbonising or carbonising action as desired. This inclined retort arrangement
relieves to a greater or less degree the charge in the crucible from the weight of
the mineral above, and the mineral is therefore more easily permeated by the
gaseous combustion and as the spongy mass of deoxidised mineral gravitates down
the face of the tuyeres or through the intense zone of fusion it is instantly
liquified.
The retorts should be kept entirely filled so as to compel the ascending gases to
permeate through the charge. In order to keep the retorts free from obstruction
we provide air tight and refractory brick encased doors at the mouth of the retorts
in outer casing to enable the workmen to draw or push down any fused mineral
producing an obstruction or irregularity in the working of the furnace.
We may utilise the hollow internal space formed by the inclined walls as a
chamber in which gas may be burnt for heating the inner walls of the furnace and
accellerating the reducing action in the furnace. To allow the action of the furnace
to be more closely watched we provide air tight sight holes through the brickwork
forming the retorts, and also in 'the doors provided with a transparent infusible
material such as tale or mica.
When we desire to transfer the fused metal tapped from the Blast Furnace
directly into a Siemens Steel Melting Furnace we construct the latter at such a
lower level as will ensure the flow of the metal by gravity from the tap hole into
a ladle mounted on a carriage with which it is weighed and afterwards tapped from
the ladle into a runner leading to the hearth of the Siemens Furnace.
In the apparatus for producing water gas when we employ the same we use an
arrangement of valves. One valve is used for directing the flow of air from the
hot blast stoves into the gas producers for revivifying the carbonaceous fuel and
the other for directing the water gas or other gaseous fuel into the Blast Furnace
gas conduits which lead to the gas tuyeres. The gas and hot air valve seatings are
water lined and provided with water lined mushroom valves, the spindles of which
are hollow and are provided with flexible water supply pipes.
The air blast enters into an annular casing fixed at the lower end of the gas
producers in such a way that the clinkers can fall into a cast iron or brick bend
provided with a barred door, so that on opening the door the clinkers can easily
be removed. The annular air supply casing is provided with holes through
which bars can be passed and each of the said holes is provided with an easily.
removable cap.

page_text: The gas producers we place just sufficiently high above the ground to allow of
the clinkers being withdrawn into suitable wagons. We connect the producer
vessel and its recuperator vessel together by a square joint with flanges bolted or
rivetted. We form independent platforms over the producers, recuperators, and
hot air stoves, clear of their iron casings, so that the latter may be renewed without
the necessity of taking the platforms down.
In order to utilise all the heat radiated from the sides of the crucibles of the
furnace we use a water lined sheet iron casing open at the upper end for the
escape of the vapours of evaporation and a continual flow of water is ensured by
means of an arrangement of supply and escape pipes.
Between the upper end of the dolomitic lining when such is used in the crucible
and the siliceous superstructure of the furnace we provide a neutral layer formed
of bauxite bricks which will prevent the silica of the firebrick from coming into
contact with the dolomitic material. The upper part of the crucible casing we
make movable so as to allow the dolomitic lining to be renewed or repared.
It will be seen by our arrangement of twin tuyeres for controlling combustion
and regulating its character that we can produce as the sole product of combustion
carbonic acid gas. This gas is neutral having neither an oxidising, deoxidising or
carbonising action on iron, and is especially valuable in the fusion of pure metallic
iron.
The accompanying sheet of drawings is intended to form part of and to be
explanatory of our specification but we wish it to be understood that we do not
confine ourselves to the exact arrangements shewn therein.
Referring to the Drawing figure 1 is a vertical section through crucible of Blast
Furnace taken through centre of tuyeres and figure 2 is a plan in section through
tuyeres.
The letters of reference refer to the same or corresponding parts where used on
the various figures.
The gas tuyeres are marked a and the air tuyeres b. The gas combustion flues c
may be of varying lengths and shapes to suit gas of different calorific qualities and
pressures. The lines of direction of the tuyeres may be arranged so as to focus
inside the crucible as shewn at d or to focus outside the crucible as shewn at e.
The refractory lining f of combustion flue is provided with movable casings to
facilitate repairs. The inner basic lining may terminate just above the com-
bustion flue opening, or it may be constructed up to the level of the main body of
the furnace but we preferably confine the use of the basic material to that part
of the crucible in which the initial action of deoxidation occurs and in which
the molten metal or slag collects. The tap hole and symphole are of ordinary
construction.
If we construct the entire crucible with dolomitic material we surround same
with a firebrick wall h and an outer casing of water i which is open at the top for
free evaporation..
Figure 3 represents another arrangement for the formation of the combustion
flues in which instead of refractory material we use water coils in which water is
constantly flowing. Figure 4 is a cross section of our arrangement for effecting
the renewal of the basic lining of the lower crucible of the furnace.
The crucible which is strongly encased with heavy cast iron flanged and bolted
plates is built internally with basic material and we mount on a carriage j,
provided with knee joints and lifting screws k which can be actuated by means
of shaft and bevel gearing and arranged so as to propel the carriage which is
supported on tyred wheels running on rails.
In order to permit the withdrawal of the crucible and carriage we support
the superstructure of upper crucible on water jacketted girders. We may also
surround the plates of the movable crucible with a water casing or we may
connect the chamber containing it with the air supply conduits of Hot Blast
Engines and thus keep the crucible casing plates at a low temperature by means
of a continuous circulation of air,

page_text: The Tuyere combustion flue m is readily disconnected from the tuyere combustion
flue n when the latter is built in crucible lining. But the ends of the tuyeres may
be simply placed just inside the plates of the crucible.
The plates of the crucible are arranged to suit the tymphole o and tap hole p
when the crucible lining requires renewing we lower it by means of the bevel
gearing and screws and then slide the water cased plates into the grooves of formed
on the underside of the girders. We generally prefer to use two sets of lower
crucibles and carriages one of which is always ready for use when the other
requires renewing. We may also mount the crucible on trunions which on being:
lowered allow the crucible to be turned over to permit of its being renewed or we
may lower the crucible by means of a hydraulic ram into a pit so as to facilitate
repairs in which latter case we also prefer to have a spare crucible and carriage
ready for repairs.
$
Figures 5 and 6 are vertical sections of our inclined Blast Furnace Retort
arrangement, on this system the Blast Furnace is divided into two portions by
means of a hollow inclined partition wall q. The hollow portion of wall is used
as a gas and air combustion chamber the gas and air entering at r. We divide the
chamber into vertical flues by partition walls in such a way that the heat passes
upwards and downwards so as to transmit the heat to the walls and finally
escaping into an escape chimney flue by this means the process of deoxidation
is considerably accelerated and in order to further accumulate the heat we may
partially chequer the partition walls.
The material may be assisted to gravitate discensionally for which purpose.we
provide doors 8.
The
Figures 7 and 8 shew sections of the air blast tuyeres of water gas producers
and of the air and gas valves. The annular air blast tuyere t is provided with
plug holes u. These on being removed allow of the entry of clinker bars which
are passed through both the hand holes and the air jet holes by which the air blast
enters. The air enters the annular air casing by means of the mushroom valve u.
We also provide air holes u¹ at different levels in the water gas producer. The gas
valve is provided with water spindle w and hollow mushroom valve x.
water supply and exit connections are effected by means of flexible pipes y so as
to allow the spindle to freely move for closing and opening the valve which closes
upon a water cased seat to which is attached the bend z. The actuating handle
may be put below the valve which moves upwards as drawn, or the elbow may be
superceded by a short pipe to which the seat may be attached and in which case
the gas main may be put over the valve.
Figures 9 and 10 shew sections of our method of constructing the tuyere gas
combustion flue formed of specially shaped basic seliceous or other refractory
material, around this is a water air vessel which may serve as a water or air
heater. Figure 11 shews a general plan of the furnace gas producers and air and
gas connections.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed. We declare that
what we now claim is :-
1. The method used for the combustion of gas in its application to Blast furnaces
for the reduction of iron ore in the manner substantially as herein shewn and
described.
2. The method of forming the water cased supports for crucible lining which
allow of withdrawing the well of crucible in the manner substantially as herein
shewn and described.
3. The movable systems for effecting the basic lining by mechanical or hydraulic
appliances, substantially as herein shewn and described.
4. The method of inclined retorts in Blast furnace by means of hollow partition
walls with or without gas combustion chamber, substantially as herein shewn and
described.

page_text: 5. The annular air tuyeres and gas and air valvular arrangements for water gas
producer, substantially as herein shewn and described.
6. The method of using magnesite and basic blocks and material for the crucible;
of a blast furnace, substantially as herein shewn and described.
7. The method of constructing the tuyere gas and air combustion flues to
withstand high temperatures for Blast furnace operations substantially as herein
shewn and described.
8. We also claim the provision of supplying air at different heights for water,
gas producers, substantially as herein shewn and described.
Dated this 2nd day of April 1886.
"
B. D. HEALEY.
B. H. THWAITE.