IMPROVEMENTS IN THE CONSTRUCTION OF RETORTS FOR MANUFACTURING AND RE-BURNING ANIMAL CHARCOAL
Year: 1867

page_text: LETTERS PATENT to John Fletcher, of Bow, in the County of Middlesex,
Engineer, for the Invention of "IMPROVEMENTS IN THE CONSTRUCTION OF
RETORTS FOR MANUFACTURING AND RE-BURNING ANIMAL CHARCOAL."
PROVISIONAL SPECIFICATION left by the said John Fletcher at the Office
of the Commissioners of Patents, with his Petition, on the 11th June
1867.
I, JOHN FLETCHER, of Bow, in the County of Middlesex, Engineer, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN THE CONSTRUCTION
OF RETORTS FOR MANUFACTURING AND RE-BURNING ANIMAL CHARCOAL," to be as
follows, that is to say:-
My Invention consists of improvements in the construction of retorts for
manufacturing and reburning animal charcoal, and is as follows:-
In one arrangement my improved retort is of a cylindrical form at each end
for a short distance, the intermediate portion being cast with grooves or channels
both internally and externally, the grooves or channels running in the direction
of its length. One or more or all of the inner grooves or channels is or are pro-
vided with fillets or ribs placed at intervals through the whole length of the
groove or channel, which fillets or ribs are placed at an angle to the centre or
axis of the retort, and as the retort revolves the grooves carry up on the ascending
side a portion of the charcoal to a certain height, when it falls; this height
may be more or less great according to the angles of the sides of the grooves, and

page_text: as the charcoal (which is introduced into the retort in the ordinary way) falls
from the grooves a portion of it is advanced a distance towards the discharge
end of the retort, which distance varies according to the angle of the fillets or
ribs before-mentioned. At the discharge end of the retort, where the longi-
tudinal grooves or channels terminate, is fixed an internal projecting ring or
flange which serves to keep the charcoal at a uniform level in the retort.
When the charcoal reaches a certain height it falls over the projecting ring
or flange into a chamber from which it is raised and discharged through the
opening at the end of the upper retort into the retort beneath, or in the case
of the under retort into the cooler. For the purpose of raising the charcoal
from the bottom of the retort or chamber, and discharging it through the hole
in the centre of the end of the retort, I use a pipe or pipes of a square or
rectangular shape, which I attach to the end plate of the retort on the inside;
one end of this pipe extends to the side of the retort or chamber, and the
other end to the centre of the hole in the end plate of the retort, the end of
the pipe nearest to the side of the retort or chamber has an opening on its
side, and as the retort revolves and the pipe passes through the .charcoal at
the lower side of the retort or chamber, it becomes charged through the
opening on the side with charcoal which is carried up as the retort revolves,
and discharged through the hole in the centre; the pipe at this end is curved
so as to form a right angle and carry the charcoal through and clear of the
end plate of the retort. "The internal ring or flange above mentioned may if
desired .be dispensed with, in which case the opening in the pipe for taking
up the charcoal for discharging it must be nearer the centre, in which case
it will leave a certain quantity of charcoal at the bottom of the retort, which
will be greater or less according to the distance the hole is from the side of
the retort or chamber. This arrangement will answer the same purpose as
the internal flange or ring before mentioned. The hole in the end plate
through which the charcoal is discharged is fitted with a pipe through which
the charcoal passes from one retort to the second or third retort, according to
the number of retorts employed, a similar pipe is also used for conducting the
charcoal from the last retort to the cooler, the retort or retorts is or are fitted
on one end with a spur wheel into which works a pinion wheel which gives motion
to the retort or retorts. When more than one retort is used the pipion is
so placed that it will gear with one or two retorts at the same time. In
case three retorts are employed an additional pinion and spur, wheel are
required,
Another arrangement of retort which I consider preferable is as follows :-
I construct a retort of a cylindrical form externally, each end of same

page_text: being of a cylindrical form- internally for a short distance only. The space
between these internal cylindrical parts is formed with sector shaped com-
partments in the direction of its' length, with a space between each of such
compartments extending to the periphery of the retort. The ends of these
spaces are closed so as to stop communication with the inside of the retort.
The sector shaped compartments do not thus join each other at the axis
or centre of the retort, and the part of such compartments nearest to the axis
or centre of the retort is made of a curved form; so as to leave a larger space
in the centre of the retort. This centre space has a partition or partitions
through its whole length. In case of only one partition being used, the
exterior of one-half of the sector shaped compartments is divided from the
other, or if more than one partition be used, the communication between the
spaces is entirely closed. Each end of the centre space is provided with a
close fitting cap or plate which closes the communication between the outside
of the sector shaped compartments and the inside of the retort; these caps
are secured in their places by. screws. Each end of the sector shaped com-
partment's is open to the cylindrical ends of the retort, and is provided with
an internal flange serving to keep the charcoal at a uniform height from one
end of the compartiments to the other. The curved parts of the inside of the
sector shaped compartments nearest to the centre are provided with ribs or
fillets placed at intervals through their length. These ribs are placed at an
angle to the centre; and as the retort revolves they pass through the charcoal
and advance it towards the discharge end of the retort a greater or less.
distance according to the angle of such ribs or fillets. The charging' and
discharging of the retort are effected as herein-before described.
077
SPECIFICATION in pursuance of the conditions of the Letters Patent, fed
by the said John Fletcher in the Great Seal Patent Office on the To
December 1867:
auoitevole
110 noitos
TO ALL TO WHOM THESE PRESENTS SHALL COMELJOHN
FLETCHER, of Bow, in the County of Middlesex; Engineer, send greeting hari?
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Lettersie
Patent, bearing date the Eleventh day of June, in the year, of our Lord
One thousand eight hundred and sixty-seven, in the thirtieth year of Her reign
did, for Herself,. Her heirs-and successors, give and grant upto me, the said
John Fletcher, Her special. licence, that I, the said John, Fletcher, my i
executors, administrators, and assigns, or such others as I, the said.

page_text: John Fletcher, 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 "IMPROVE-
MENTS IN THE CONSTRUCTION OF RETORTS FOR MANUFACTURING AND REBURNING
ANIMAL CHARCOAL," upon the condition (amongst others) that I, the said John
Fletcher, 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 immediately after the date of the
said Letters Patent.
NOW KNOW YE, that I, the said John Fletcher, do hereby declare
the nature of the 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 Drawings hereto .annexed, and to the
figures and letters marked thereon, that is to say:-
My Invention consists of improvements. in the construction of retorts for
manufacturing and reburning animal charcoal.
In order to make the Invention better understood I will proceed to describe
the same by reference to the accompanying Drawings, which shew two forms
of construction of retort..
In Sheet 1, Figure 1 is a longitudinal section of one arrangement, shewing
two retorts, one above the other, with the ordinary furnace beneath; Figures 2
and 3 front and back elevations of same; and Figure 4, transverse section of
one retort.
In Sheet 2, Figure 5 is a longitudinal section on line A, B, of Figure 8,
shewing the second arrangement of retort; Figures 6 and 7, front and back
elevations of same; Figure 8 transverse section, and Figure 9 longitudinal
section on line C, D, of the upper retort; and Figure 10 similar section of the
lower retort.
Similar letters of reference in all the Figures represent parts which are
similar.
In one arrangement shewn in Sheet 1 my improved retort a, a, is. of a
cylindrical form at each end for a short distance, the intermediate portion
being cast with grooves or channels. b, b, both internally and externally (that
is to say corrugated); these grooves or channels run in the direction of its
length and increase the heating surface, and ensure a better distribution of

page_text: the charcoal; one or more or all of the inner grooves or channels, is or are.
provided with fillets or ribs c, c, (in the Drawing they are all shewn so pro-
vided) placed at intervals along the whole length of the groove or channel,
which fillets or ribs c, c, are placed at an angle to the centre or axis of the
retort, and as the retort revolves the grooves carry up on the ascending side a
portion of the charcoal to a certain height, when it falls; this height may be
more or less great according to the angles of the sides of the grooves, and as
the charcoal (which is introduced into the retort in the ordinary way by the
pipe c) falls from the grooves a portion of it is advanced a distance towards
the discharge end d, d, of the retort, which distance varies according to the
angle of the fillets or ribs herein-before described. Near the discharge end of
the retort, where the longitudinal grooves or channels terminate, is fixed an
internal projecting ring or flange e, e, which serves to keep the charcoal at a.
uniform level in the retort. When the charcoal reaches a certain height it,
falls over the projecting ring or flange e, e, into a chamber f, f, from which it.
is raised and discharged through the openings 9, 9, at the end of the upper:
retort into the retort beneath, or in the case of the under retort into the cooler..
For the purpose of raising the charcoal from the bottom of the retort or:
chamber and discharging it through the holes g, g, in the centre of the end d, d,,
of the retort I use a pipe or pipes i, i, of a square or rectangular shape, which,
I attach to the end plate of the retort on the inside; one end of this pipe.
extends to the side of the retort or chamber f, f, and the other end extends to..
the centre of the hole 9 in the end plate d of the retort. The end of the pipe.
nearest to the side of the retort or chamber has an opening k, k, in its side,.
and as the retort revolves and the pipe passes through the charcoal at: the
lower side of the retort or chamber it becomes charged through the opening k, k,.
in its side with charcoal, which is carried up as the retort revolves, and
discharged through the hole g in the centre; the pipe at this end is curved
so as to form a right angle as shewn and carry the charcoal through and clear.
of the end plate of the retort. The internal ring or flange e may if required
be dispensed with, in which case the openings k, k, in the pipes i, i, for taking
up the charcoal for discharging it must be nearer the centre, so as to leave ȧ.
certain quantity of charcoal at the bottom of the retort, which will be greater..
or less, according to the distance which the hole is from the side of the retort
or chamber. This arrangement will answer the same purpose as the internal
ring or flange e. The hole g in the end plate & through which the charcoal.
is discharged is fitted with a pipe l, through which the charcoal passes from
the first retort to the second retort. (or to the third if three retorts are
employed); a similar pipe l'is also used for conducting the charcoal from the
d

page_text: lower. retort to the cooler. The retorts are fitted on one end with a spur
wheel m, m, into which works a pinion n, n, which gives motion to the retorts.
When more than one retort is used, as shewn, the pinion is so placed that it
will: gear with one or two retorts at the same time. In case three retorts are
employed an additional pinion and spur wheel are required. The pipes c
and 2, 7, are supported by the rods o, 0, 0, 0, furnished with spiral springs P; P, P, P.
for reducing friction. q, q, are antifriction rollers for supporting the retorts
in the usual manner.
My second arrangement of retort, which I consider preferable, is shewn in
Sheet 2.
I construct the retort a, a, of a cylindrical form externally, each end' a', a¹,
of same being of a cylindrical form internally for a short distance only. The
space between these internal cylindrical parts is formed with sector shaped
compartments r; r; in the direction of its length, with a space s; s; between
each of such compartments extending to the periphery of the retort; these
sector shaped compartments, answer the same purpose as the grooves or
channels described in my first arrangement. The ends t, t, of these spaces!
are closed so as to stop communication with the inside of the chamber f at the
end of the retort. The sector shaped compartments do not thus join. each
other at the axis or centre of the retort as seen in Figure 9; and the part of
such compartments nearest to the axis or centre of the retort is made of a
curved form. as shewn, so as to leave a larger space in the centre of the retort.
this centre space s has partitions v, v, through its whole length; these
partitions may be dispensed with, in which case the fire will have a thorough-
fare through the spaces s, s. Each end' of the centre space s¹ is provided with
a close-fitting cap or plate u, u, which closes the communication between the
centre space and the circular chamber at the end of the retort; these
'caps are secured in their places by screws. Each end of the sector shaped
compartments rr is open to the cylindrical ends of the retort, the discharge
end. being provided with an internal flange e, e serving to keep the charcoal at
a uniform height from one end of the compartment to the other. The curved
parts of the inside of the sector shaped compartments nearest to the centre
are provided with ribs or fillets c, c, placed at intervals through their length;
these ribs are placed at an angle to the centre; and as the retort revolves they
pass through the charcoal, and advance it towards the discharge end' of the
retort a greater or less distance, according to the angle of such ribs or fillets,. in.
a manner similar to that described in my first arrangement shewn in Sheet. 1.
The charging and discharging of the retort is effected as berein-before
described for my first arrangement.

page_text: Having now, described the nature of my Invention, and the manner of
performing the same, I wish it to be understood that I do not confine myself
to the precise details of construction herein laid down; but what I claim
is,―
Firstly, the construction and employment of a retort or retorts with longi-
tudinal grooves or corrugations, as herein-before described and represented in
Figures 1, 2, 3, and 4, Sheet 1, of the accompanying Drawings.
Secondly, the construction and employment of a retort or retorts with
sector shaped compartments, as herein-before described and represented in
Figures 5, 6, 7, 8, 9, and 10, Sheet 2, of the accompanying Drawings.
Thirdly, the peculiar construction of the nozzle or end of the retort or
retorts, by which the charcoal is discharged through a hole or holes in the
centre of the retort or retorts, as herein-before described and represented in
the accompanying Drawings.
Fourthly, the employment of an internal ring or flange at the discharge
ends of retorts, as and for the purpose herein-before described and represented
in the accompanying Drawings.
Fifthly, the driving a retort or retorts by means of a spur wheel fixed
directly on the end of the retort or retorts, and a pinion gearing into same, as
herein-before described and represented in the accompanying Drawings.
In witness whereof, I, the said John Fletcher, have' hereto set my
hand and seal, this Ninth day of December, in the year, of our Lord
One thousand eight hundred and sixty-seven.
Witness,
GEORGE MAIR.
JOHN FLETCHER. (L.S.)