IMPROVEMENTS IN FURNACES FOR BURNING PYRITES
Year: 1880

page_text: LETTERS PATENT to James Mason, of Eynsham Hall, near Witney, in the
County of Oxford, for an Invention of "IMPROVEMENTS IN FURNACES FOR
BURNING PYRITES."
PROVISIONAL SPECIFICATION left by the said James Mason at the Office
of the Commissioners of Patents on the 4th August 1880.
1 JAMES MASON, of Eynsham Hall, near Witney, in the County of Oxford.
"IMPROVEMENTS IN FURNACES FOR BURNING PYRITES."
The object of this Invention is to effect the burning of pyrites ore for the
production of sulphurous acid with the view of its conversion principally into
sulphuric acid, and to manipulate the ore during the process of burning without
the aid of manual labor.
The furnace I employ for this purpose is of rectangular section at the sides and
floor and closed with a straight or arched roof. In this furnace I place a series of
fluted cylinders, all of similar size and form, with their axes parallel to each other,
and one behind the other a short distance apart, and placed in an incline plane, the
space between each and the inclination being regulated according to the size and
description of the ore to be dealt with. The cylinders may be of any material
which suffers little or no deterioration from moderate friction at a red heat whilst
in contact with the gases set free during the process. The axles of the fluted
cylinders project through both sides of the fire brick furnace, and are carried in
suitable bearings outside, the whole of the bearings being secured to strong iron
plates or girders bolted to the sides of the furnace and rigidly held in position.
One end of each axle is furnished with a cog wheel, and into each of these wheels
is geared the thread of a screw or worm. All the screws are fixed upon a revolving
shaft carried in bearings along the furnace, the rotation of which shaft produces a
corresponding and simultaneous revolution of the cylinders all in the same direction.
At one end of the furnace, above and in front of the first cylinder, is fixed a hopper
containing the pyrites ore reduced to the desired size for feeding on to the cylinders.
At its lower end the hopper carries a slit placed across the furnace, and of a length
equal to that of the above mentioned fluted cylinders, whilst a feed roller inside
the hopper, fitted with a regulating slide and rotated mechanically by means of
Dis 31

page_text: gearing from the main driving shaft, delivers the ore on to the cylinders in the
desired and regular quantity. The whole may be driven by any convenient power.
The upper surface of the cylinders is made to move during rotation from the
first towards the second, from the second towards the third, and so on, and the ore
delivered upon the first by the hopper is thus carried towards the second and
deposited in a heap in front of the latter, which picks it up and carries it forward
towards the 3rd, and so on through the whole series, until the last cylinder drops
the ore in its final depository. Thus the upper surface of the cylinders forms an
artificial bed, upon which the usual calcining action is carried out at the same time
that the material is gradually and regularly fed into, through, and out of the furnace
without the aid of manual labor.
The quantity of pyrites passed through the furnace in a given time will depend
on the speed given to the cylinders, their length, the size or depth of the flutes,
and on the inclination of the plane through the axes of the cylinder.
The gearing driving the main shaft, as also the part which rotates the feed
roller, should be arranged to admit of different speeds. There will be no particular
limit to the size of the ore used in this process so long as it can be fed mechanically
through the hopper.
The following is the method of using the furnace :--The prime mover is first
connected with the countershaft giving motion to the fluted cylinders and to the
feed roller in the hopper. The air valves in the final depository for the burnt
pyrites and the damper in the flue are closed, whilst the damper in the uptake and
that in the down flue are opened. The fire is then lighted in the grate and allowed
to heat the calcining chamber and the cylinders to a red heat. Ore is then admitted
into the hopper, the fire withdrawn, the fire door and ash pit closed, also the damper
in the down flue and in the uptake, whilst the damper, as well as the air valves,
are opened to allow the gas to pass to the sulphuric acid chambers. As the ore
descends through the hopper on to the fire plate, it ignites and passes on to the
cylinders, whence it is gradually carried forward over the whole length of the bed,
as previously described, carrying out the process of burning in a thoroughly regular
manner without further manual labor and without any additional fuel. As the
burned ore arrives at the far end of the chamber it falls into the final depository,
and is drawn off through a slide regulated so as to keep always a certain depth of
ore over the opening to prevent the ingress of air at that point. Arrangements
are made to withdraw any fluted rollers if necessary for repairs, either through
openings in the sides of the chamber or by lifting them bodily out with their axles
after the removal of one of the roof sections.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said James Mason in the Great Seal Patent Office on the 22nd December
1880.
JAMES MASON, of Eynsham Hall, near Witney, in the County of Oxford.
"IMPROVEMENTS IN FURNACES FOR BURNING PYRITES."
My said Invention, which relates to improvements in furnaces for burning
pyrites, has for its object effecting the burning of pyrites ore for the production of
sulphurous acid, with the view to its conversion principally into sulphuric acid,
and the manipulation of the said ore during the process of burning without the aid
of manual labour.
The furnace employed for carrying out these operations is constructed with a
long narrow inclined chamber of fire brick or other suitable material, and is
preferably of rectangular section at the sides and the floor, and is closed at its top
with a straight or arched roof.
Within the said chamber are arranged a series of fluted cylinders, all of similar
size and form, with their axes parallel to each other, and with a suitable space
intervening between each two consecutive cylinders.
The row or series of cylinders is inclined in accordance with the inclination of
the chamber, the amount of inclination depending upon the description of ore to be
operated upon. The cylinders are by preference made either of cast iron or of fire
clay, but may be of any other material which suffers little or no deterioration from
moderate friction at a red heat whilst in contact with the gases set free during the
process. The shafts of the fluted cylinders, made of wrought iron or other suitable
material, project through both sides of the chamber and are carried in suitable
bearings outside of the same, the whole of the bearings being secured to strong
iron plates or girders bolted to the sides of the furnace and rigidly held in position.
One end of each shaft is furnished with a toothed wheel, and into each of these
wheels is geared the thread of a worm. All the worms are fixed upon a revolving
shaft carried in bearings along the surface of the bed, the rotation of which shaft
produces a corresponding and simultaneous revolution of the cylinders all in the
same direction. At one end of the furnace above and in front of the first cylinder
is fixed a hopper containing the pyrites ore reduced to the desired size for feeding
on to the cylinders. At its lower end the hopper is formed with a slit placed
across the furnace and of a length equal to that of the above mentioned fluted
cylinders, whilst a feed roller inside the hopper, provided with a regulating slide
and rotated mechanically by means of gearing from the main driving shaft
delivers the ore onto the cylinders in the desired and regular quantity.
The upper surface of the cylinders is caused to move during rotation from the
first towards the second, from the second towards the third, and so on, and the ore
delivered upon the first by the hopper is thus carried towards the second and deposited
in a heap in front of the latter, which picks it up and carries it forward towards
the third, and so on through the whole series until the last cylinder, which drops
the ore into the final depository. Thus the upper surface of the cylinders forms
an artificial bed and laboratory of the furnace upon which the usual calcining
action is carried out, at the same time that the material is gradually and regularly
fed into, through, and out of the furnace without the aid of manual labour.
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 several Figures on the annexed Sheet of Drawings, the same letters of reference
indicating corresponding parts in all the corresponding Figures.
Figure 1 of the accompanying Drawings represents a side elevation of a furnace
constructed according to my said Invention; Figure 2 is a longitudinal section of

page_text: the same; Figure 3 is a transverse sectional elevation taken along the line 1, 2,
Figure 2, and Figure 4 is a transverse sectional elevation take along the line 3, 4,
Figure 2.
Within the inclined calcining chamber A is arranged the inclined row of fluted
cylinders B keyed upon the shafts b which are carried in bearings b¹ outside the
heating chamber, the said bearings being supported on the longitudinal plates or
girders C.
Motion is imparted to the said cylinder from the main shaft D by the worms d
gearing with the wheels 62 keyed upon the cylinder shafts b; the main shaft D is
supported upon the brackets d¹ and has motion imparted to it from the engine or
prime mover through the intervention of the worm wheel d² gearing with the
worm upon the counter shaft d'.
The hopper E through which the ore is delivered into the calcining chamber is
fitted with a slide or valve e and feeding roller e¹, the former being operated by a
screw and hand wheel 1, as shewn clearly in the Drawing, whilst the valve e is
operated from the main shaft D by means of the vertical shaft e², to which motion
is imparted by the bevel wheels es, the top of the said shaft having keyed upon it
a worm e gearing with a worm wheel e, which communicates motion to the
feeding roller by means of the gearing upon the short shaft d', as shewn in
Figures 1 and 3.
The calcining chamber, as shewn in the accompanying Drawing, is formed with
an arched roof made up of sections a, to which lifting handles a¹ are attached in
order that the roof may be removed with facility when an inspection of the interior
of the calcining chamber is rendered necessary.
At one end of the chamber, underneath the hopper, is the fire grate F, which is
provided with an uptake G and damper g, and at the same end is also situate the
down flue H leading into the main flue to the acid chamber, and fitted with the
damper h.
At the other end of the furnace is the receptacle I for the burnt ore, with an
outlet provided with a sliding door C¹; from this receptacle also extends a down
flue J, having a damper j, the said flue leading to the chimney. Two air inlets K
are arranged one on each side of the receptacle I, and are provided with slides or
valves for adjusting the quantity of air to be admitted.
The furnace is operated in the following manner, videlicet:-Motion is first
imparted to the main shaft D from the engine or prime mover through the gearing
herein before described, whereby motion is communicated to the fluted cylinders
within the calcining chamber and to the feed roller in the hopper. The air inlets K
in the receptacle I and the damper h in the flue H are closed whilst the damper g
in the receptacle G and the damper j in the down flue J are opened. The fire is
then lighted in the grate and allowed to heat the calcining chamber and the
cylinders to a red heat. Ore is then admitted into the hopper, the fire withdrawn,
the fire door and ashpit closed, also the damper j in the down flue J, and the
damper g in the uptake G, whilst the damper h is opened as well as the air valves K.
As the one descends through the hopper on to the fore plate or valve, it ignites and
passes on to the cylinders, whence it is gradually carried forward over the whole
length of the bed, as hereinbefore described. The process of burning the ore is
thus carried out in a thoroughly regular manner without further manual labour
and without any additional fuel. As the burned ore arrives at the far end of the
chamber it falls into the receptacle I, and is drawn off through the sliding
door, which is regulated so as to keep always a certain depth of ore over
the opening to prevent the ingress of air at that point. Any of the fluted
rollers may, if necessary, be removed for repairs either through openings in the
sides of the chamber or by lifting them bodily out with their axles after the
removal of one of the roof sections. The quantity of pyrites passed through
the furnace in a given time will depend on the speed given to the cylinders,
their length, the size or depth of the flutes, and on the inclination of the plane
through the axes of the cylinders. When burning small pyrites with cylinders of,

page_text: say, from 12" diameter upwards, about 6 to 8 revolutions per hour will probably
prove a good working speed, but for larger sized ore, and with cylinders of
great diameter, and with deep flutes, a less speed may be advisable. The gearing
driving the main shaft, as also that which rotates the feed roller, may be arranged
to admit of different speeds in order to suit variations in the working. There
is no particular limit to the size of the ore used in the process herein before described
so long as the said ore can be fed mechanically through the hopper, but small ore,
and by preference all below, say, 3 inch cube, will probably produce the best
results, but I do not confine myself to this limit. I prefer using the ore in separate
sizes, that is, each size in a separate furnace, although this is not absolutely
necessary. Thus dust ore or very small may be one class; grains from the size of
a pea to inch cube a second class; and from that to a 3/, inch cube, a third class;
and so on to a larger size, and with even more subdivisions.
The length and diameter of the fluted cylinders will necessarily be varied
according to the dimensions of the furnace, and the flutes of the cylinders may be
made of any suitable shape.
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 carried into
effect, I would observe in conclusion that what I consider to be novel and original,
and therefore claim as the hereinbefore in part recited Letters Patent is,―
The general arrangement and combination of parts constituting a furnace for
burning pyrites, substantially as herein before described.
In witness whereof, I, the said James Mason, have to this my Specification
set my hand and seal, the Seventeenth day of December, One thousand
eight hundred and eighty.
JAMES MASON. (L.S.)