IMPROVEMENTS IN FURNACES AND APPARATUS CON- NECTED THEREWITH FOR THE MANUFACTURE OF ALKALIES, THE PUDDLING OF IRON. THE ROASTING OF ORES. AND OTHER PURPOSES
Year: 1875

page_text: LETTERS PATENT to Christopher James Schofield, of Clayton, near
Manchester, in the County of Lancaster, Manufacturing Chemist,
for the Invention of "IMPROVEMENTS IN FURNACES AND APPARATUS CON-
NECTED THEREWITH FOR THE MANUFACTURE OF ALKALIES, THE PUDDLING OF
IRON. THE ROASTING OF ORES. AND OTHER PURPOSES.”
Sealed the 13th May 1875, and dated the 11th February 1875.
PROVISIONAL SPECIFICATION left by the said Christopher James
Schofield at the Office of the Commissioners of Patents, with
his Petition, on the 11th February 1875.
I, CHRISTOPHER JAMES SCHOFIELD, of Clayton, near Manchester, in
the County of Lancaster, Manufacturing Chemist, do hereby declare
the nature of the said Invention for "IMPROVEMENTS IN FURNACES AND
APPARATUS CONNECTED THEREWITH FOR THE MANUFACTURE OF ALKALIES, THE
PUDDLING OF IRON, THE ROASTING OF ORES, AND OTHER PURPOSES," to be as
follows:-

page_text: puddling of iron, the roasting of ores, and other purposes, and relates to
furnaces of that class in which materials are treated upon or in a rotating
angular bed or trough.
The first part of my Invention relates to furnaces intended for
operations in which the materials under treatment are required to be
stirred or agitated, and consists in the application and use in combination
with an annular rotating bed of an improved construction of stirring
apparatus arranged to facilitate the changing as required of the stirring
implements which are raised and lowered by means of pinions, and racks
carrying a frame in which are arranged the actuating wheels of the
spindles carrying the stirrers or agitators, the whole being so arranged
as that during the lowering operation the stirrers or agitators are set in
motion before coming in contact with the materials to be operated upon
in the annular bed, I prefer to place the stirring apparatus between the
exit openings or terminal flues of the annular flue where the heat is less
intense, and I form the roof with a dip or screen running as it were
across the annular flue at each side of the opening, through which the
stirring implements are inserted so as to protect the latter from the
direct action of the products of combustion. The screens do not dip
into the materials contained in the rotating annular bed. Portions of
the flanges of the standards are removed to enable the frame, geared
wheels, spindles, and agitators when raised by the racks to be withdrawn
and replaced.
In some cases I construct the standards with or I provide brackets
or supports, so that when one frame with its appurtenances is drawn out
of the grooves in the standards, another similar frame with wheels,
spindles, and stirring implements may be slid into position in gear with
the racks and lowered for immediate use, the apparatus previously
withdrawn being held so that its stirring implements may be changed,
and the apparatus again put in operation immediately on the withdrawal
of the apparatus last inserted and for the time being in use. In other
words the two sets of apparatus may be used alternately.
The second part of my Invention relates to furnaces intended for
puddling iron and for other processes requiring an intense heat, and
consists in the adaptation and use in combinatiom with a rotating
annular bed or trough of a chamber or vessel in which water is caused
to circulate in contact with the outer portions of the rotating annular

page_text: bed or trough in such manner as to prevent its being injured by
excessive heating. The chamber or vessel is provided with an inlet for
cold water (which may be introduced by a pump or other well known
means) and an outlet for water that has taken up heat from the annular
bed which heated water may be employed for feeding boilers or other
purposes, whereby the heat it contains may be utilized. The annular
chamber or vessel may be constructed of iron or of brickwork lined with
cement or other materials may be used. The water is caused to circulate
in contact with the outer sides of the lateral portions of the annular bed
as well as in contact with the outer side of the bottom of the bed. The
chamber or vessel containing the circulating water may be sealed by
means of a suitable joint or luting applied at both sides at or near the
upper parts of the water chamber or vessel and rotating annular
bed.
The third part of my Invention has reference to furnaces designed for
the roasting of ores and other analagous purposes, and consists in the
application and use in combination with a rotating annular bed of plates
or deflectors arranged in series parallel to each other, but in an annular
direction relatively to the course of the rotating annular bed in such
manner as at cach rotation of the annular bed to change the position of
the particles of ore or other material under treatment in the bed, and not
only to turn over such particles of ore or other material, but also to
move the entire contents of the annular bed nearer to the opposite side
to that at which such material under treatment was originally fed in;
and finally to cause the material after due treatment to pass out of the
furnace. By this arrangement ores or other materials to be operated
upon may be fed constantly on to the bed at one side, and as the bed
rotates will be gradually roasted and turned over and moved towards the
opposite side of the bed, whence after being under treatment for the
requisite time such ores or other materials will be ejected from the
furnace continuously or approximately so the length of time during
which the materials remain in the furnace may be regulated by adjusting
the speed of rotation of the bed, and the number and position of the
plates or deflectors employed.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Christopher James Schofield in the Great Seal
Patent Office on the 7th August 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHRISTOPHER
JAMES SCHOFIELD, of Clayton, near Manchester, in the County of
Lancaster, Manufacturing Chemist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eleventh day of February, in the year
of our Lord One thousand eight hundred and seventy-five, in the
thirty-eighth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Christopher James Schofield,
Her special licence that I, the said Christopher James Schofield,
my executors, administrators, and assigns, or such others as I, the
said Christopher James Schofield, my executors, administrators, and
assigns, should at any time agree with, and no others, from time]
to time and at all times thereafter during the term therein expressed,
should and lawfully might make, use, exercise, and vend, within the
United Kingdom of Great Britain and Ireland, the Channel Islands,
and Isle of Man, an Invention for "IMPROVEMENTS IN FURNACES AND
APPARATUS CONNECTED THEREWITH FOR THE MANUFACTURE OF ALKALIES, THE
PUDDLING OF IRON, THE ROASTING OF ORES, AND OTHER PURPOSES," upon the
condition (amongst others) that I, the said Christopher James Schofield,
my executors or administrators, by an instrument in writing under
my, or their, or one of their hands and seals, should particularly describe
and ascertain the nature of the said Invention, and in what manner ?
the same was to be performed, and cause the same to be filed in the
Great Seal Patent Office within six calendar months next and imme-
diately after the date of the said Letters Patent.
NOW KNOW YE; that I, the said Christopher James Schofield, do
.hereby declare the nature of my said Invention, and in what manner the 3
same is to be performed, to be particularly described and ascertained in
and by the following statement thereof, and the two Sheets of Drawings
therein referred to (that is to say):
My Invention has for its object improvements in furnaces and
apparatus connected therewith for the manufacture of alkalies, the 3

page_text: puddling of iron, the roasting of ores, and other purposes, and relates
to furnaces of that class in which materials are treated upon or in a
rotating annular bed or trough.
The first part of my Invention relates to furnaces intended for
operations in which the materials under treatment are required to be
stirred or agitated, and consists in the application and use in combina-
tion with an annular rotating bed of an improved construction of stirring
apparatus arranged to facilitate the changing as required of the stirring
implements, which are raised and lowered by means of pinions and racks
carrying a frame in which are arranged the actuating wheels of the
spindles carrying the stirrers or agitators, the whole being so arranged
as that during the lowering operation the stirrers or agitators are set in
motion before coming in contact with the materials to be operated upon
in the annular bed. I prefer to place the stirring apparatus between the
exit openings or terminal flues of the annular flue, where the heat is less
intense, and I form the roof with a dip or screen running as it were
across the annular flue at each side of the opening through which the
stirring implements are inserted, so as to protect the latter from the
direct action of the products of combustion. The screens do not dip
into the materials contained in the rotating annular bed. Portions of
the flanges of the standards are removed to enable the frame, geared
wheels, spindles, and agitators when raised by the racks to be withdrawn
and replaced.
In some cases I construct the standards with or I provide brackets or
supports, so that when one frame with its appurtenances is drawn out of
the grooves in the standards another similar frame with wheels, spindles,
and stirring implements may be slid into position in gear with the racks,
and lowered for immediate use, the apparatus previously withdrawn
being held so that its stirring implements may be changed, and the
apparatus again put in operation immediately on the withdrawal of the
In other words
apparatus last inserted and for the time being in use.
the two sets of apparatus may be used alternately.
The second part of my Invention relates to furnaces intended for
puddling iron, and for other processes requiring an intense heat, and
consists in the adaptation and use in combination with a rotating annular
bed or trough of a chamber or vessel in which water is caused to cir-
culate in contact with the outer portions of the rotating annular bed or

page_text: trough in such manner as to prevent its being injured by excessive
heating. The chamber or vessel is provided with an inlet for cold water
(which may be introduced by a pump or other well known means), and
an outlet for water that has taken up heat from the annular bed which
heated water may be employed for feeding boilers or other purposes,
whereby the heat it contains may be utilized. The annular chamber or
vessel may be constructed of iron or of brickwork lined with cement, or
other materials may be used. The water is caused to circulate in contact
with the outer sides of the lateral portions of the annular bed, as well as
in contact with the outer side of the bottom of the bed. The chamber
or vessel containing the circulating water may be sealed by means of a
suitable joint or luting applied at both sides at or near the upper parts
of the water chamber or vessel and rotating annular bed.
The third part of my Invention has reference to furnaces designed for
the roasting of ores and other analogous purposes, and consists in the
application and use in combination with a rotating annular bed of plates
or deflectors arranged in series parallel to each other, but in an angular
direction relatively to the course of the rotating annular bed in such
manner as at each rotation of the annular bed to change the position of
the particles of ore or other material under treatment in the bed, and
not only to turn over such particles of ore or other material, but also to
move the entire contents of the annular bed nearer to the opposite side
to that at which such material under treatment was originally fed in,
and finally to cause the material after due treatment to pass out of the
furnace. By this arrangement ores or other materials to be operated
upon may be fed constantly on to the bed at one side, and as the bed.
rotates will be gradually roasted and turned over and moved towards the
opposite side of the bed, whence after being under treatment for the
requisite time such ores or other materials will be ejected from the
furnace continuously or approximately so; the length of time during
which the materials remain in the furnace may be regulated by adjusting
the speed of rotation of the bed and the number and position of the
plates or deflectors employed.

page_text: Fig. 1 represents in side elevation a furnace embodying the first part
of my Invention; Fig. 2 is a plan; Fig. 3 is a vertical section to an
enlarged scale taken in the line A, B, of Fig. 2.
Fig. 4 is a cross section through one of the standards for supporting
the stirring apparatus.
a is the rotating annular bed or receptacle which is covered by a
roof 6 supported by side walls, as shewn. The annular bed contains the
materials to be operated upon by the products of combustion from the
reverberatory fire-place c. The exits for the products of combustion
from the annular flue are at d. They lead into another flue e, so that
the flame and heated products of combustion on entering the annular
flue are split up or divided into two streams, travelling in opposite
directions along the annular flue, as indicated by the arrows in Fig. 2,
and meeting and leaving together by the exit e, as shewn. g is an
opening formed in the annular roof for the insertion of the instruments
for mixing, turning over, and otherwise manipulating the substances
under treatment. At each side of the rotating annular bed I fix two
stationary standards ¼ of the cross section shewn in Fig. 4. Between
the flanges of each standard works a rack in gear with a pinion m
carried by a cross shaft n, to which rotatory motion may be communi- .
cated when required by any well known arrangement for the purpose.
The racks carry a cross frame composed of two bars 1, 12, between
which work in gear with each other a number of spur wheels o whose
spindles o¹ have their bearings in the bars 1, 1, as shewn. One of these
wheels gears with a spur wheel o³ formed with a short hollow spindle or
elongated hollow boss o³. Through this hollow spindle or boss passes
the upper part of an actuating spindle or shaft driven by suitable
gearing. The upper part of the spindle or shaft and the hole in the
hollow spindle or boss o³ are of angular section, or feathered or other-
wise arranged so that the hollow spindle or boss and its spur wheel are
left free to move up and down independently of the actuating spindlo or
shaft o, but cannot rotate without turning it when in position for
work.
os is a bevel wheel fixed on the actuating spindle or shaft in gear
with a similar wheel o' on a horizontal shaft o³, driven in this case
through mitre wheels o³, oº, by another shaft o" provided with fast and
loose pulleys o", o¹, so as to be driven by a strap or band. This driving
arrangement may obviously be modified to suit circumstances.

page_text: The spur wheel o³ driven by the actuating spindle or shaft o³, as above
described, communicates motion to the train of spur wheels o in gear
with it. The stirring implements p are carried by the lower ends of the
spindles o¹ of the wheels o so as to dip into and agitate the materials
contained in the annular bed of the furnace when the said spindles
are rotated by their wheels o. I place the stirring apparatus between
the exit openings d of the annular flue, as shewn, the temperature there
being comparatively low in consequence of the heat being mainly drawn
away by the exits d, and I form the roof 6 with a dip or screen running
as it were across the annular flue at each side of the opening g so as to
protect the stirring implements from the direct action of the products of
combustion. The screens do not dip into the materials contained in the
rotating annular bed. Portions of the flanges k¹ of the standards near
their upper parts are removed to enable the frame P, P, with the
wheels o, o, spindles o¹, and the agitators when raised by the racks / to
be withdrawn and replaced, or a duplicate set of apparatus to be
substituted.
Instead of the hollow boss o³ I may use a clutch box, the segments of
the box being made sufficiently deep to ensure that the stirrers shall be
brought into action before touching the material requiring to be stirred.
Figs. 5, 6, and 7 shew a modification. In this arrangement the
standards k are formed with projecting parts or brackets k³, k³, forming
tables or supports, so that when one frame 1, 1, with its wheels, spindles,
and stirrers has been raised it may be drawn out from the racks along
the one pair of tables or supports (say k²), and another similar set of
apparatus kept in readiness on the other pair of tables or supports
(say ³) may be thereupon slid along the said tables or supports into
gear with the racks and lowered into position for operating upon the
materials under treatment in the annular bed. The apparatus with-
drawn will be supported by the tables or supports k³, and if necessary its
stirring implements p may be moved and others substituted. In this way
two sets of apparatus may be used alternately in such manner as to
cause practically speaking no interruption in the stirring of the materials
under treatment. In the arrangement now under notice the whole of
the spur wheels o are provided with hollow spindles or elongated hollow
bosses, the upper ends of which extend somewhat above the upper bar 1¹
of the cross frame and are slotted. The solid spindles o' are also slotted
and are held at their upper ends in the hollow bosses by keys or cotters o*,

page_text: as shewn. The stirring implements p are fixed to the lower ends of the
spindles o¹ by cotters to facilitate their ready removal and replacement.
Fig. 8 shews in cross section part of a furnace embodying the second
part of my Invention.
With the rotating annular bed a is combined a chamber or vessel t in
which water is caused to circulate in contact with the outer portions of
the rotating annular bed in such manner as to prevent its being injured
by excessive heating. In the arrangement illustrated the chamber or
vessel t consists of an annular tank constructed of wrought iron. This
tank extends some distance up the sides of the annular rotating bed.
The chamber t is provided with an inlet t¹ for cold water, and an outlet (
for water that has taken up heat from the annular bed. I prefer to
place a wall or division across the chamber t, and to arrange the inlet
near one side of such division or wall, and the outlet at the other side of
the division or wall. By this arrangement, as will be seen, the water is
caused to circulate in contact with the outer sides of the lateral portions
of the annular bed as well as in contact with the outer sides of the
bottom of the annular rotating bed, and the bearings of the antifriction
wheels are kept well lubricated. The annular bed is guided when
travelling within the annular chamber by wheels c** carried by sliding
journal boxes arranged under the inner wall plates and made adjustablo
by screws c¹³, as shewn.
Figs. 9 and 10 illustrate in cross section and in plan respectively the
third part of my Invention as applied to furnaces designed for the
roasting of ores or other analogous purposes. a is the rotating annular
bed having only one raised side a* which in this case is on the inner or
smaller side of the bed. In the wall ₁ at the outer side of the bed is an
opening or way 62 through which materials that have been operated
upon may be discharged. This opening is provided with a guide plate b³
(Fig. 10) slightly overlapping the annular bed, as shewn. v¹, 02, 0³, 01,
v, v, v, vs, are plates or deflectors arranged parallel to each other, but.
in an angular direction relatively to the course of the rotating annular
bed (indicated by the arrows), so that at each rotation of the annular
bed the positions of the particles of ore or other material that
may be
under treatment in the bed will be changed, and not only will such
particles of ore or other material be turned over, but the entire contents of
the annular bed will be by each rotation moved nearer to the outer side,
and finally will be caused after due treatment to pass out of the furnace

page_text: by the opening 6. For example, supposing the particles of ore to be
fed on to the rotating annular bed by the hopper w, the particles of ore
contained on the inner part of the bed will towards the completion of
the first rotation be brought into contact with the deflector v¹, and will be
deflected into the course indicated by 2
their place being supplied
by fresh particles fed in by the hopper w continuously. Towards the
completion of the second rotation a similar change of position of the
particles then situated at the inner side of the bed will take place, and
the particles which at the conclusion of the first rotation were moved by
the deflector v¹ into the course 2
will now come in contact with :
the deficctor v² and be thereby moved into the course 3
By the next rotation the particles just mentioned will be moved by the
deflectors into the course 4 and so on during each succeeding
rotation, until finally the particles in question will be brought in contact
with the deflector v³, and by it will be deflected into the exit passage
and so ejected from the furnace. By this arrangement as already stated
ores or other materials may be fed constantly on to the bed at one of its
sides, and as the bed rotates will be gradually roasted and turned over, and
moved towards the opposite side of the bed, whence after being under
treatment for the requisite time they will be ejected from the furnace,
and this operation will take place continuously or approximately; so if
the feeding of the furnace with material to be operated upon be con-
ducted in a continuous manner, it will be evident that by adjusting the
speed of the rotating bed and the number of deflectors, as also the
angles at which the deflectors are arranged relatively to the course in
which the bed travels, the period during which the materials to be
operated upon shall remain under treatment may be regulated with the
greatest nicety.
The deflectors are passed through slots in a plate v where they are
held by pins.
It will be evident that the arrangement shewn in Figs. 9 and 10, and
just above described may be modified to suit circumstances without
departing from the distinctive character of this part of my Invention as
herein-before set forth.
Having described the nature of my said Invention and having
explained the manner of carrying the same into practical effect, I

page_text: declare that I do not claim as of my Invention, or the exclusive use of,
any of the mechanical parts herein-before mentioned or referred to
when used separately or otherwise than according to and for the purposes
of my said Invention as herein-before set forth, but that what I consider
to be novel and original, and therefore claim as the Invention secured to
me by the herein-before in part recited Letters Patent is,-
First. The application and use, in combination with an annular
rotating furnace bed, of apparatus constructed, arranged, and operating
substantially as respectively shewn in and described with reference to
Figs. 1, 2, 3, and 4, and with reference to Figs. 5, 6, and 7 of the
accompanying Drawings for actuating, stirring, or agitating implements,
lowering the same into position for operating upon the materials in or
upon the rotating bed, and raising the said implements out of working
position to facilitate changing the same as required.
Secondly. The adaptation and use in combination with a rotating
annular bed of a chamber or vessel in which water is caused to circulate,
in contact with the outer portions of the rotating annular bed to prevent
its being injured by excessive heating, substantially as herein-before
described and illustrated by Fig. 8 of the Drawings.
Thirdly. The application and use in combination with a rotating
annular furnace bed of plates or deflectors, arranged in sets or series
parallel to each other, but in an angular direction relatively to the course
of the rotating annular bed, in such manner as at each rotation of the
annular bed to change the position of the particles of material under
treatment in or upon such bed, and to move the entire contents of the
annular bed nearer to the opposite side to that at which such material
was originally fed in; and finally, after due treatment to eject the treated
material from the furnace, as herein-before described with reference to
Figs. 9 and 10 of the Drawings.
In witness whereof, I, the said Christopher James Schofield, have
hereunto set my hand and seal, this Twenty-eighth day of July,
in the year of our Lord One thousand eight hundred and seventy-
fire
C. J. SCHOFIELD. (L.S.)