AN IMPROVED FURNACE FOR SUBLIMING OR REDUCING TO A METALLIC STATE THE ORES OP ZINC
Year: 1843

page_text: AFF
CLEAVER, of Ripley, in the County of Derby, send greeting.
power, sole
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent under the Great Seal of the United Kingdom of Great Britain and
Ireland, bearing date at Westminster, the Twelfth day of October, in the
seventh year of Her reign, did give and grant unto me, the said John Cleaver,
my executors, administrators, and assigns, Her especial licence, full
privilege and authority, that I, the said John Cleaver, my executors, adminis-
trators, and assigns, and such others as I, the said John Cleaver, 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 of years
therein mentioned, should and lawfully might make, use, exercise, and vend,
within that part of the United Kingdom of Great Britain and Ireland called
England, the Dominion of Wales, and the Town of Berwick-upon-Tweed,
and in the Islands of Jersey, Guernsey, Alderney, Sark, and Man, and in
all Her Majesty's Colonies and Plantations abroad, my Invention of "AN
IMPROVED FURNACE FOR SUBLIMING OR REDUCING TO A METALLIC STATE THE ORES
OP ZINC;" in which said Letters Patent there is contained a proviso, that
I, the said John Cleaver, shall particularly describe and ascertain the nature.
of my said Invention, and in what manner the same is to be performed,
by an instrument in writing under my hand and seal, and cause the same

page_text: to be enrolled in Iler said Majesty's High Court of Chancery within two
calendar months next and immediately after the date of the said in part
recited Letters Patent, as by the said Letters Patent, reference being thereunto
had, will more fully and at large appear..
NOW KNOW YE, that in compliance with the said proviso, I, the said
John Cleaver, 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, and the Drawings to these Presents annexed,
which may be taken as the working Drawings, for the construction of an
improved furnace for subliming or reducing to a metallic state the ores of zinc,
the same being adapted and arranged as a ten-pot furnace, according to my
Invention.
Figure 1, which is the front elevation, shows, as follows, five openings,
marked with the letter O, in the front of the furnace, over the centre of each of
the smelting pots, to enable the superintendant to determine upon and regulate
the heat of the furnace. (These openings are closed up or left open, so as to
regulate the heat of each pot, as occasion may require.) Five condensers
leading from five of the pots in the furnace, marked with the letter B, to
pans for receiving the metal marked with the letter P in Figure 5. Six
spaces marked with the letter C, to enable the superintendant to ascertain
the state of the pots in the furnace, and repair them in case they should
have become damaged, and which openings are kept closed, except when
the pots require examination or repair. Five spaces in the front wall, marked
with the letter D, in each of which spaces three bricks can be taken out,
opposite to the bottom of each pot, in order to extract the cinders and refuse
from the pots, through the openings of which, one is shewn in the section
of a pot, marked A 2 in Fig. 5.
Figure 2, which is the longitudinal section of the furnace, shows the ends
of five smelting pots in the furnace marked A. In this Figure the parts
marked X are sections of the arches, composed of fire bricks, called slap-jacks,
which arches are more fully shown and described at letter X in Figure 3,
and compose the pot hearth, or place upon which the smelting pots stand.
These arches are separated from each other by the spaces marked S, which
are left for the purpose of enabling the flames and heat to ascend and
surround the pots in the furnace. The spaces marked C are openings in the
middle of the crown of the arch of the furnace, to allow the superintendant to
get at the back of the smelting pots in order to repair them, which spaces are
covered over, unless required to be opened for the purpose last above mentioned.

page_text: They are further shown in Figure 6, letter C. The space marked E is the fire-
place, which is lined throughout with the fire bricks called slap jacks. The
letter F marks the feeding mouth; G, the fire bars of the furnace, supporte
on bearing bars; and II, the ash-pit. The letter I shows two of the four
chimmies attached to the furnace, as shewn at letter I in Figure 6, for the
purpose of carrying away the smoke from the interior of the furnace into t'he
air. The letter K shows one of two flues, or ventilators, also marked K in
Figures 3 and 6, for the purpose of carrying off the fumes and vapours from the
condensers, and also the smoke and heat proceeding from the openings, marked
with the letter O in Figure 1. The letter W points out a wall built rather
higher than the tops of the chimnies, and ventilating flues, for the purpose of
shielding them from the action of the wind.
Figure 3 is a sectional elevation of the furnace, in which the letter A points
out two smelting pots, to which are connected the condensers, marked with the
letter 1, the ends of which are shewn at B in Figure 1, and a section of one
at A 1 in Figure 5. The letter P shews the receiving pans, further noticed
in Figure 5; V. V, are plates of iron for supporting the condensers, more fully
described in Figure 5; and U and T two bars of iron, likewise mentioned in
the same Figure. The letter C shews the openings, described by the same
letters in Figures 1 and 2. The letter D shows the spaces, described more
particularly in Figure 1 by the same letter, as openings to extract the cinder
and refuse from the pots. The letter X shows the elevation of one of the five
arches composing the pot hearth, before described in Figure 2 at letter X.
S, S, S, S, show the form and extent of the spaces leading from the fire-place
into the furnace between the arches composing the pot hearth. E is the
section of the fire-place; G the fire bars, and II the ash-pit; I, I, are the
chimnies for carrying off the smoke, &c. of the furnace, described particularly
in Figures 2 and 6; and K, K, the section of the two flues, also more
particularly described in Figures 2 and 6; W is the wall, before mentioned in
Figure 2.
Figure 4 is a plan of the fire bars or grate, marked G, and the feeding mouth,
marked F; the remaining part of the plan being that of the foundations.
Figure 5 is a plan of the interior of the furnace, with the position of the
smelting pots upon the pot hearth. In this plan the pots and condensers, ten
in number, are shewn, as in the previous Figures, by the respective letters
A and B. Two of the pots are shewn in sections; the one marked A 1 is a
section near the top, through the pot and condenser; the other, marked A 2, is
a section through the bottom of the pot, showing the opening in the pot

page_text: fronting the space marked D in Figure 1, by means of which the cinder and
refuse are extracted from the pots. P, P, are two of the pans, fixed below the
ends of the condensers for the purpose of receiving the metal, which comes in
vapour from the pots, and being converted into metal in the condensers flows
from them into the pans; S shews the spaces, described in Figures 2 and 3,
for the passage of the heat between the pots; V, V, is a plate of cast iron to
support the condensers, one end of which is built into the front wall of
the furnace, and the other end of which is supported upon a flat bar of iron,
marked U, which extends across the front of the furnace. The pans P rest on
a round bar of iron T at the bottom and the flat bar U at the top.
Figure 6 is a plan of the exterior of the furnace top, showing the four
chinnies, two ventilating flues, the five spaces through the crown of the arch
for inspecting the pots, and the surrounding wall, all of which are fully
described in the several preceding Figures.
Figure 7 is a longitudinal elevation of the pot with the condensing pipe
attached; Figure 8 is a sectional elevation of the same; Figure 9 is an end
elevation of the pot, and Figure 10 is a cross section. These pots are made
of fire clay, or such earth as will stand the heat of the furnace.
Figure 11 is a front view of the clay stopper of the condensing pipe, shewing
at a the hole through which the metal passes from the condensing pipe.
Such being the construction and arrangement of my improved furnace, the
following particulars and directions must be attended to with respect to the
working and managing the same:-In placing the pots in the furnace care
must be taken that each pot is firmly seated on the pot hearth, and to ensure
which, I cause a quantity of finely-powder'd Stourbridge brick to be placed under
each pot, and the pot to be firmly bedded in it. The pots I use are narrow
oblong pots, three feet long, three feet nine inches high, and twelve inches wide,
outside measure; the thickness of the pot is five inches at bottom, three inches
on the sides and ends, the thickness gradually reducing until it comes to two
inches at the top. The length and height of the pot is not material; but I
find that if the pot is increased in width, a larger consumption of coal with a
less quantity of metal is the result; 1 therefore prefer the pots being of the
width here described.
In working my improved furnace I proceed as follows:-I cause the tops
of the four chimnies to be securely closed and a small fire to be placed
in the fire-place; this is to be gradually increased for the first forty-eight
hours, so that at the expiration of that time the whole length of the fire
bars are covered with hot coal. During the next forty-eight hours the fire is

page_text: gradually increased, by which time the pots will have become of a dull red
heat; in this state they must remain for the next twelve hours, the chimneys
being all the time closely covered down; much care should be taken in
bringing up the fire, for if brought up too quick or allowed to slacken during
this period, it would be likely to crack the pots, and occasion much trouble
afterwards. The next thing to be attended to is to place the condensing pipe
in its chamber, which should be done soon after the first fire is placed in the
fire-hole. The condensing pipe is formed of fire clay, and is two feet six inches
long, seven inches in diameter, the thickness of the clay being one inch, and
made perfectly dry; before being placed in the chamber it is to be placed in its
proper situation in the pot (but not luted in); in this position it is to remain
until the pots are required for usc. When the pots have attained a red heat
they will have contracted in size; a space will thus be left between the fire-
brick wall, forming (in part) the chamber for the condensing pipe and the pot;
through this the fire will force it way, and passing along the chamber, cause the
condensing pipe to be annealed or burnt. I now gradually increase the fire by
removing by degrees the dampers placed on the tops of the chimnies, and
proceed to fix the condensing pipe in the pot; this I do by luting it in the pot
with a mixture of fire-brick clay and Stourbridge brick, both reduced to a fine
powder; the proportions I find best for this purpose is a mixture of equal
parts, Stourbridge clay and fire brick, well mixed together, and made into a
stiff luting with water. The pots being brought to a bright red heat, I then
proceed to charge the same, having first luted a stopper made of fire clay into
the bottom opening in the pot; the luting employed for this purpose is the
same as that used in fixing the condensing pipes in the pots. For the first
charge of the pots I mix equal measures of calcined zinc ore and small coke,
charcoal, or other carbonaceous substance. With this mixture the pots are
charged; the condensing pipe is then closed by the lid, shewn in Figure 11,
and the fire increased, until the zinc begins to rise in vapour..
At this point
the fire is steadily maintained; the zine being thus volatilized is forced through
the condensing pipe, and there collected in a fine metallic powder, which
being melted by the heat arising from the connection of the condensing pipe
with the pot, runs down the condensing pipe, and is discharged through the
small opening in the lid (shewn at a, Figure 11), and collected in the receiving
pans, from which it is remove as the pans become filled; the metal is after-
wards cast in the ordinary way for sale. After the first charge is worked off,
which will be in forty-eight hours if due attention has been paid to the fire, the
pots are emptied, by breaking the stopper at the bottom of the pots, and

page_text: removing the refuse by an iron rake. I then charge the pots with a mixture
of three parts calcined ore and two parts (both by measure) small coke,
charcoal, or other carbonaceous matter; this forms the charge afterwards
used. Before the pots are emptied, the lid of the condensing pipe should be
removed, and the fine metallic zinc, mixed with oxide of zinc, cleaned out with
an iron rake; this is mixed with the next charge.
In charging the pots I use the charger shewn in Figure 12, which is a half
cylinder of wrought iron, twenty inches long and four inches over, stopped at
both ends; this is fixed at the end of a wrought-iron bar; the cylindrical
part, being filled with the mixture of calcined ore and carbonaceous substance,
is passed through the condensing pipe and emptied int the pot. This is
repeated until the pots are full; the lid of the condensing pipe is then luted
on, and the process procceds. If duc attention is paid to the fire, the charge
will be worked off' in forty-eight hours, including the time occupied in charging
and discharging the pots. During the working of the pots a light blue flame
will be seen to issue through the opening a (Figure 11), in the lid of the con-
densing pipe, of from one to two inches in length; this should be steadily
maintained, and will regulate the workman in supplying the fire with coal; if it
slackens the fire must be increased; it will likewise indicate when the pots are
worked off, by altogether ceasing or becoming very weak.
Having now described the nature of my said Invention, and in what manner
the same is to be performed, I wish it to be understood that I do not claim as
of my Invention, or the exclusive use of the said several well-known processes
herein-before described and referred to in the manufacture of zinc, except when
the same are used and applied with and by my said improved furnace. And I
declare my Invention to consist in the construction and arrangement of an
improved furnace for subliming zinc, in which the heat of the fire circulates
freely about the sides of the pots, standing side by side on a pot hearth, as
above described.
In witness whereof, I, the said John Cleaver, have hereunto set my hand
and seal, this Twelfth day of December, in the year of our Lord One
thousand eight hundred and forty-three.

page_text: AND BE IT REMEMBERED, that on the same Twelfth day of December
in the year above mentioned, the aforesaid John Cleaver came before our
Lady the Queen in Iler Chancery, and acknowledged the Specification afore-
said, and all and every thing therein contained, in form above written. And
also the Specification aforesaid was stamped according to the tenor of the
Statute in that case made and provided.
Inrolled the same Twelfth day of December, in the year above written.