IMPROVEMENTS IN APPARATUS FOR BURNING BURNING, CALCINING, OR ROASTING SULPHUR ORES AND OTHER MATERIALS
Year: 1868

page_text: LETTERS PATENT to Arthur McDougall, of the Firm of M°Dougall
Brothers, Manufacturing Chemists, of Manchester and London,
for the Invention of "IMPROVEMENTS IN APPARATUS FOR BURNING,
Sealed the 21st July 1868, and dated the 25th January 1868.
PROVISIONAL SPECIFICATION left by the said Arthur McDougall at
the Office of the Commissioners of Patents, with his Petition, on
the 25th January 1868.
I, ARTHUR MCDOUGALL, of the Firm of McDougall Brothers, Manu-
facturing Chemists, of Manchester and London, do hereby declare the
nature of my said Invention for "IMPROVEMENTS IN APPARATUS FOR BURNING,
CALCINING, OR ROASTING SULPHUR ORES AND OTHER MATERIALS," to be as.
follows, that is to say :-
This Invention relates to an improved construction of apparatus for
the purpose of effecting the burning, calcining, or roasting ores and
other materials, but which is more especially adapted for burning ores
or other. materials containing sulpher. The apparatus employed for

page_text: In and
this purpose is by preference constructed of a circular form, and consists
essentially of a circular horizontal floor of brick, tiles, tiles, fire-clay, or
metal covered with a dome or sperical or arched roof also constructed of
similar materials. The floor of this combustion chamber may be heated
from below by means of flues to any temperature desired.
through the centre of the roof a feeding hopper of convenient form and
dimensions is placed. Through the centre of the hopper a vertical
shaft driven by any convenient motive power is fixed and carries at
its lower extremity cross bars extending nearly the whole of the diameter
of the floor. To these cross bars a number of plates placed vertically
or otherwise are attached so as to form a rake or agitator, and are so
fixed that when the shaft revolves the cross bars are carried with it,
and the materials being operated upon are made to pass from the centre
to the circumference, where they are allowed to pass out of the calciner
by means of tubes or outlets. Upon that portion of the vertical shaft
which passes through the neck of the hopper short projecting arms or
a spiral worm is placed so as to act as feeders to the calciner. The
bearings of the vertical shaft may be upon an adjustable bar so as to
bring the rake or agitator to any desired distance from the floor. In
the lower portion and if necessary in other portions of the apparatus
suitable arrangements may be made for the admission of atmospheric air
and the gasceous products to pass off.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Arthur McDougall in the Great Seal Patent Office
on the 25th July 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ARTHUR
MCDOUGALL, of the Firm of McDougall Brothers, Manufacturing
Chemists, of Manchester and London, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-fifth day of January, in the
year of our Lord One thousand eight hundred and sixty-eight, in the
thirty-first year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Arthur McDougall, Her spécial
license, that I, the said Arthur McDougall, my executors, adminis-
trators, and assigns, or such others as I, the said Arthur M'Dougall;

page_text: my executors, administrators, or 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 APPARATUS FOR BURNING, CALCINING, OR ROASTING SULPHUR
ORES AND OTHER MATERIALS," upon the condition (amongst others) that I,
the said Arthur McDougall, my executors or administrators, by an
instrument in writing under my hand and seal, 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
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Arthur McDougall, do hereby declare
the nature of my said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by
the following statement, reference being had to the accompanying
Drawing, and to the letters marked thereon, that is to say :-
My said Invention relates to an improved construction of apparatus
for the purpose of effecting the burning, calcining, or roasting of ores
and other materials, but which is more especially adapted for burning
ores or other materials containing sulphur. The apparatus employed
for this purpose is by preference constructed of a circular form, and
consists essentially of a circular horizontal floor of brick, tiles, fire-
clay, or metal covered with a flat or other roof also .constructed of
similar materials. The floor of this combustion chamber may be
heated from below by means of flues to any temperature desired. A
feeding hopper or spout of convenient form and dimensions passes.
through the roof at or near the centre thereof. A central vertical shaft
driven by any convenient motive power carries at its lower extremity
cross bars or arms extending nearly the whole of the diameter of
the floor. To these cross bars or arms a number of plates, placed
vertically or otherwise, are attached so as to form a rake or agitator,
and are so fixed that when the shaft revolves the cross bars or arms.
are carried round with it, and the materials being operated upon are
made to pass from the centre to the circumference of the floor,
where they are allowed to pass out of the calciner by means of
tubes or outlets. The central vertical shaft transmits motion to a

page_text: second vertical shaft which carries a number of revolving tappets or
short projecting arms for imparting a vibratory or shaking motion to
the feeding hopper or spout, or a revolving spiral worm may be
placed in the spout so as to act as a feeder to the calciner. The
vertical shaft may be made adjustable so as to bring the rake or
agitator to any desired distance from the floor; in the lower portion
and if necessary in other portions of the apparatus suitable arrange-
ments may be made for the admission of atmospheric air and for
allowing the gaseous products to pass off.
And in order that my said Invention may be fully understood I
shall now proceed more particularly to describe the same, and for
that purpose shall refer to the accompanying Drawing, which represents
a sectional elevation of one form of my improved apparatus as
adapted for the burning of materials containing sulphur in the manu-
facture of vitriol and for the like purposes.
In the Drawing A represents a horizontal floor constructed by
preference of fire-clay tiles supported on a number of cross walls B of
open brickwork in order to permit the passage of flame and products
of combustion from the fire-place C. In fact the floor is heated after
the manner (well known to manufacturing chemists) of heating the iron
pot in a salt cake furnace; this floor is provided with a discharge pipe D
at its circumference to allow the burnt or calcined material to pass out.
The floor is surrounded and supported by a wall E, which carries a roof
or covering of fire-clay tiles F supported upon transverse cast-iron beams
or girders. Through the centre of the roof or covering a vertical
shaft G passes supported in bearings H bolted to the cast-iron beams I, I.
These beams are secured to the column K, the arrangement of which
will be clearly understood on reference to the Drawing. The shaft G
is driven by a pair of bevel wheels L, M, from any convenient prime
mover, and imparts a rapid rotary motion by a spur wheel and
pinion N, O, to a countershaft P, which carries a beater or set of
tappets these tappets by revolving and beating against the oscillating
incline spout R insure the feeding of the material to be operated upon
on to the floor A through the covering or roof F as near to the centre
as possible. The spout R is fed from above by a small feeding hopper S
and large store hopper T. At the lower extremity of the vertical
shaft G a cross arm U is fixed which carries a number of vertical plates
or stirrers a, a, placed not at right angles to the longitudinal centre
;

page_text: line of the arm U, so as to form a rake or agitator, which, by the
irregular position of the stirrers a, tends when the shaft revolves in the
proper direction to gradually urge or move the material operated upon
lying on the floor A from the centre to the circumference thereof, where
it falls through the outlet D, and at the same time tends to turn over
such material after the manner of the turnfurrow of a plough. In
this way a complete stirring or turning over of the material will be
accomplished, and it will be caused to be piled on the floor in a number
of circular furrows, thereby greatly increasing the amount of surface
of the material exposed to the action of the surrounding gases. Also
a fresh supply of material will be made to pass continuously through
the apparatus, the rate of such supply being regulated by the speed
at which the shaft G is driven, and also by regulating the inclination
of the shoe spout R by a cord and pulley V. Through the surrounding
wall E are made a number of holes W fitted with regulators in order
to admit a supply of air to the material operated upon. The products of
combustion from the calcined material pass off through a flue X fixed
on the roof or covering F leading to the vitriol chamber, or wherever
the sulphurous acid is needed, and ultimately to a chimney or other
suction draught. Should it be found that one such floor is not sufficient
to complete the roasting of the material, other similar floors may be
placed immediately beneath, each floor being provided with its rake
fitted to an extension or continuation of the shaft G. The rakes on the
alternate floors must have their plates a inclined in one direction, while
those of the intermediate floors must be in a reversed direction, so as to
drive the material from the centre to the circumference of one series
of floors from the circumference to the centre of the other series
alternately. The lowest floor only of such a series need be heated from
below, as the heated gaseous products of the roasted material passing
upwards through the holes through which the material falls will heat
all the upper floors.
When employed for vitriol making I find it most convenient to use
a small separate engine to drive the apparatus, the waste steam of
which supplies the necessary steam for the vitriol chamber. I also
pass the waste heat from the heating flues of the apparatus through
a steam boiler in order to generate steam to drive the engine.
Having now described and particularly ascertained the nature of my
said Invention, and the manner in which the same is or may be used or

page_text: carried into effect, I would observe in conclusion 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 to and in the burning, calcining, or
roasting of ores and other materials of a self-acting rake or stirrer
arranged, combined, and operating substantially as herein-before
described and illustrated by my Drawings.
Second. The general combination and arrangement of apparatus to
be employed in the burning, calcining, or roasting of sulphur ores and
other materials, substantially as herein-before described and illustrated
by my Drawings.
In witness whereof, I, the said Arthur McDougall, have to this
my Specification set my hand and seal, the Twentieth day of
July One thousand eight hundred and sixty-eight.
ARTHUR MCDOUGALL. (L.S.)