IMPROVEMENTS IN FURNACES FOR CALCINING ORES CONTAINING SULPHUR
Year: 1871

page_text: LETTERS PATENT to John Berger Spence, of Manchester, in the
County of Lancaster, Manufacturing Chemist, for the Invention of
"IMPROVEMENTS IN FURNACES FOR CALCINING ORES CONTAINING SULPHUR."
PROVISIONAL SPECIFICATION left by the said John Berger Spence
at the Office of the Commissioners of Patents, with his Petition,
on the 28th April 1871.
I, JOHN BERGER SPENCE, of Manchester, in the County of Lancaster,
Manufacturing Chemist, do hereby declare the nature of the said Inven-
tion for "IMPROVEMENTS IN FURNACES FOR CALCINING ORES CONTAINING SULPHUR,"
to be as follows:-
My improved furnace consists of two or more beds on which the ore
to be calcined is distributed. These beds are made of tiles supported on.
hollow cast-iron girders which pass through the side walls of the furnace
and are open at each end in order that a current of air may pass through
the girders to keep them cool. Beneath the lowest bed is a heating
chamber. The orc to be calcined is supplied through a hopper on to

page_text: the top bed, and it is gradually raked to the end thereof, as now
customary, from whence it drops on to the bed below, along which it is
also raked. When more than two beds are used the ore drops from the
second to the third bed, and so on if more than three are required.
In calcining ores containing sulphur it is generally sufficient only to
light the fire in the heating chamber until the sulphur is ignited on the
the
lowest bed, as the heat from that ignites the sulphur on
bed
upper
or beds, but in calcining poor ores the fire is kept up in the heating
chamber.
The sulphurous acid gas may be made to travel in the same direction
as the ore, or in the contrary direction, by making the entrance air
passages either near the point where the ore is discharged from or
supplied to the furnace.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Berger Spence in the Great Seal Patent
Office on the 28th October 1871.
-TO-ALL-TO-WHOM-THESE PRESENTS SHALL COME, I, JOHN
BERGER SPENCE, of Manchester, in the County of Lancastor, Manu-
facturing Chemist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-eighth day of April One
thousand eight hundred and seventy-one, in the thirty-fourth year of
Her reign, did, for Herself, Her heirs and successors, give and grant
unto me, the said John Berger Spence, Her special license that I, the
said John Berger Spence, my executors, administrators, and assigns,
or such others as I, the said John Berger Spence, 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 FOR CALCINING ORES CONTAINING SULPHUR," upon the condition
(amongst others) that I, the said John Berger Spence, 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

page_text: be calcined is passed. At o, p, are passages or flues, the one proceeding
from the top floor j and the other from the bottom floor c. Both of
these passages are in communication with the vitriol chamber, but
either the one or the other may be shut off therefrom by a suitable
door, and air allowed to pass into the said passage through another door
which is then opened for that purpose.
The mode of operating is as follows:-A charge of the material to be
calcined is admitted by the hopper at n to the floor ;, and raked along
thereon by any convenient instrument, passed successively through the
doors m, fresh quantities of the material being passed through the
hopper to take the place of those which have been raked onward.
When the floor ; has been filled to the depth of about three inches the
material begins to fall through the aperture k on to the floor f, upon
which it is passed onward by raking through the doors, subsequently
to fall through the aperture i on to the bottom floor c, upon which it
is in like manner raked onward through the doors d, and thus the three
floors are charged. The heat arising from the burning fuel in the fire-
place and from the flue heats the bottom floor c, and this by the
-burning-mass-thereon-heats-the-floor-above-it,-and-so-on-to-the-top-
floor, and when this condition is established no further charge of fuel
is generally required to be added to the fire a, but in cases of poor ores
it may be desirable to continue the said fire, and thus the operation
continues, the calcined ore being raked out through the passage e, and
fresh charges supplied through the hopper n.
By the process above described sulphurous acid gas arises, which is
to be conducted to the vitriol chamber along with a current of air, and
I propose to cause this air to travel in the direction of the material
which is being calcined or in the opposite direction at pleasure, and in
the following manner:-The chamber above the top floor j is continued
until it is capable of being closed by a door 9; and leading from the
said continued part is a channel, leading to the vitriol chamber, and
provided with a door s. In like manner the bottom floor is continued
until it arrives at a door 2*, within which is a channel * leading, as
well as that shewn at r, to the vitriol chamber, and provided with a
door s*. I will now suppose it to be desired that the air shall travel
in the same direction as the material being calcined; in that case
the doors will be closed and the air door 9 opened, while the door >*
leading to the vitriol chamber is open and the air door q* closed. If the

page_text: air is desired to pass in the contrary direction then the positions of the
doors have simply to be reversed.
I have above mentioned that the whole of the floors are charged to
begin with, but according to the Specification of the said Peter Spence
above referred to one quantity is calcined, or partially so, before
another is passed on, and this plan may be adopted in my furnace if
desired.
Another part of my Invention consists in a method of constructing
and supporting the floors of the furnace. For this purpose I employ
hollow iron girders u, which extend through the side walls of the
furnace, and are thus provided with air passages through them by
which they are kept cool; upon these girders are placed fire-brick tiles
to form the floors of the furnace.
I have above described my improved furnace as provided with
three floors, but two or more than three may in like manner be
employed.
Having thus described and ascertained the nature of my said Invention,
and the manner in which the same is to be performed, I desire it to be
understood that I claim as secured to me under the above in part recited
Letters Patent,-
Firstly, and for the purpose above set forth, the use of a furnace
provided with two or more floors, substantially as described.
Secondly, the use of hollow iron girders for supporting the floors
of such furnaces as aforesaid.
In witness whereof, I, the said John Berger Spence, have here-
unto set my hand and seal, this Twenty-seventh day of October,
in the year of our Lord One thousand eight hundred and seventy-
one.