IMPROVEMENTS IN THE MODE OF AND APPARATUS FOR CARBONIZING SAWDUST AND OTHER VEGETABLE SUBSTANCES
Year: 1861

page_text: Sealed the 11th March 1862, and dated the 13th September 1861.
PROVISIONAL SPECIFICATION left by the said Henry Dixon and John
Robinson Renner at the Office of the Commissioners of Patents, with
their Petition, on the 13th September 1861.
We, HENRY DIXON, of Pendleton, in the County of Lancaster, Gentleman,
and JOHN ROBINSON RENNER, of Liverpool. in the said County. Artificial
Manure Manufacturer, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN THE MODE OF AND APPARATUS FOR CARBONIZING SAWDUST
AND OTHER VEGETABLE SUBSTANCES," to be as follows:-
Our Invention relates to the carbonization of vegetable substances by steam,
and consists in the employment of rotating or other moveable pipes or agi-
tators, perforated so as to allow steam to flow into contact with the material
to be carbonized. These pipes or agitators we provide with angular vanes or
scrapers, and enclose them within a perforated vessel, through which the steam

page_text: is allowed to escape into an outer chamber. Having carbonized the material,
we shut off the steam, and admit steam of a lower temperature, by which
means it becomes cooled, and gases are driven off.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Henry Dixon and John Robinson Renner in the Great Seal
Patent Office on the 13th March 1862.
TO ALL TO WHOM THESE PRESENTS SHALL COME. we. HENRY
DIXON, of Pendleton, in the County of Lancaster, Gentleman. and Joux
ROBINSON RENNER. of Liverpool, in the said County, Artificial Manure Manu-
facturer, send greeting.
WHEREAS ller most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Thirteenth day of September, in the year of our Lord
One thousand eight hundred and sixty-one. in the twenty-fifth year of Her
reiga, did. for Herself. Her heirs and successors. give and grant unto me. the
said Henry Dixon and John Robinson Renner. Her especial licence that we,
the said eary Dixon and John Robinson Renner. our executors. adminis-
trators, and assigns. or such others as we. the said Henry Dixon and John
Robinson Renner. our executors, administrators, and assigns, should at any
time agree with, and no others. from time to time. and at all times there-
after 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 CARBONIZING SAWDUST AND OTHER VEGETABLE SUBSTANCES." upon the
condition, amongst others. that we, the said Henry Dixon and John Robinson
Renner, by an instrument in writing under our hands and seals. (or under the
hand and seal of one of us.) should particularly describe and ascertain the
nature of the said Invention, and in what manner the same was to be per-
formed, and cause the same to be filed in the Great Seal Patent Oflice
within six calendar months next and immediately after the date of the said
Letters Patent.
NOW KNOW YE, that we, the said Henry Dixon and John Robinson
Renner, do hereby declare the nature of our 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 accompanying Drawings
(that is to say):-
Our Invention relates to the carbonization of vegetable substances by steam,

page_text: and consists in the employment of rotating or other moveable pipes or agi-
tators perforated so as to allow steam to flow into contact with the material to
be carbonized. These pipes or agitators we provide with angular vanes or
scrapers, and enclose them within a perforated vessel, through which the steam
is allowed to escape into an outer chamber. The material having been car-
bonized, we shut off the steam, and admit steam of a lower temperature, by
which means the material becomes cooled, and certain gases are driven out.
The mechanical arrangements by which these general features of our Inven-
tion may be carried into effect may be varied to a considerable extent: but
we will describe certain suitable apparatus which we adopt.
In the accompanying drawing. Fig. 1 is a vertical section of a refort con-
structed according to our Invention: Fig. 2 is a horizontal section thereof:
Fig. 3 is an external top view: Fig. 4 is a plan of the bottom. The retort
itself being shown by blue lines; and Fig. 5 is a section thereof. The retort
is at a, within which is placed a cylinder b. the circumference of which is
perforated, or it may be of wire gauze, varying in its meshes according to the
size of the pieces of material to be operated upon. In the centre of the retort
is a hollow shaft c, turning at bottom in a step d. and carried at top by the
cover e. This hollow shaft carries a number of arms formed of tubes, which
communicate with the shaft c. such tubes being provided with a number of
perforations. Upon the arms or tubes are placed angular blades /*. At g
is a steam pipe receiving steam from any ordinary generator. and communi-
cating with the hollow shaft c and tubes f. The upper part of the shaft c is
furnished with a nut working upon a screw i. which screw carries at its
lower end a piston k. In the Drawing this screw, and the upper part of
the shaft care shewn as broken off. but they are made of such a length that
by the turning of the nut the piston may be raised above the top arm f.
Upon the shaft c is a worm wheel i. taking into a worm m upon a shaft n, by
the turning of which shaft, therefore, the hollow shaft c and arms may be
caused to revolve. In the retort cover e are doors m, which are kept closed
when desired by screws n working in cross bars o. At the bottom of the retort
are two doors p, which are opened for the discharge of the charred material,
but which are at other times kept firmly closed. A method which may be
adopted for opening and closing these doors is shewn at Figs. 4 and 5. The
doors p are hinged to shafts r, which turn in bearings carried by the bottom
of the retort. The shafts r are provided with wheels s, taking into worms
fixed upon shafts u, upon the turning of which, therefore. the doors may be
opened upon their hinges r; it being desirable, however, that these doors shall
fit the bottom of the retort steam-tight, or nearly so, the following contrivance

page_text: may be adopted. At are shafts, provided with lugs or short levers we, bearing
against the doors as seen at the right hand end of Fig. 5, and forcibly pressed
thereon by means of shafts c. which act through worms upon worm wheels .
The left hand side of Fig. 5 shews the door open.
The method of operating
is as follows: The doors in the retort cover having been opened, the sow-
dust, or other vegetable substance to be charred is placed within the perforated
cylinder b, the covers are then replaced, and the piston k drawn upwards until
its lower end is above the top arm or tube f. Steam being now admitted to
the pipe g. and having been superheated on its passage in any ordinary manner
to a sufficient temperature. will flow through the hollow shaft c. and through
the arms or lubes into the bulk of the substance under operation. during
which flow of steam the shaft n is turned at intervals either by power or by
hand. so as to cause the said arms or tubes to revolve, and thus effect a stirring
operation, and bring the steam into contact with different particles of material
composing the mass. This action is materially assisted by the vanes . which
by their revolution remove the material from the periphery of the perforated
cylinder, and cause it in a certain degree to circulate. As the steam passes
through the material it carries with it the gases evolved, and both escape
through the perforations in the cylinder b. and afterwards through the pipe z
to a condenser if desired, for the manufacture of pyroligneous acid. As the
charring proceeds, the sawdust or other material sinks into a smaller compass,
and the steam therefore would escape from the upper arms or tubes / without
effect; in order to prevent this, the piston is lowered as the said sinking takes
place, so as gradually to close up the communication with the upper part of
the hollow shaft c. The rate at which this piston must be shifted will depend
upon the shrinking character of the material under operation, and this we
ascertain by using an experimental charge, and opening the cover of the retort
at intervals, so as to ascertain how far it has shrunk in a given time, this is a
guide for future operations. The degree of carbonization of the material
is indicated by the temperature of the gases evolved, and this will therefore
inform the attendant when the desired operation is complete. The steam used
for that purpose is then shut off, and steam of a lower temperature, say,
20lbs. pressure is admitted, by which means the material becomes cooled, so
as to avoid the risk of ignition when discharged, and the gases remaining in
the retort are driven out, such second application of steam being sufficiently
low in temperature to prevent their continued generation, after which the
doors p are opened as above described for the withdrawal of the charge, which
is allowed to fall into any air-tight receptacle placed beneath the retort. The
apparatus above described may be set in brickwork in any convenient manner,

page_text: and if desired, there may be fire flues surrounding it in order to maintain the
heat of the steam. We have not shewn in the Drawing the bearings for the
shafts used for opening and closing the doors p. but they may be carried by
any ordinary means depending upon the method which is adopted for setting
the retort.
Having thus described and ascertained the nature of our said Invention, and
the manner in which the same is to be performed, we desire it to be understood
that we do not intend to limit ourselves to the precise arrangement of appa-
ratus above shewn and described; but we claim as secured to us under the
above in part recited Letters Patent:-
Firstly, the use of moveable perforated pipes or agitators which convey the
steam to the material.
Secondly, enclosing such pipes or agitators within a perforated cylinder, as
illustrated at b.
Thirdly, the use of a second application of steam in the manner and for the
purpose aforesaid:
In witness whereof, I, the said Henry Dixon, have hereunto set my
hand and seal, this Twelfth day of March, in the year of our Lord
One thousand eight hundred and sixty-two.
HENRY DIXON. (L.S.)