Improvements in Apparatus for the Dry Distillation of Wood, Wood Refuse, Coal, Peat, and the like, and for the Treatment of other Substances.
Year: 1898

page_text: Date of Application, 27th Dec., 1898-Accepted, 25th Feb., 1899
COMPLETE SPECIFICATION.
Improvements in Apparatus for the Dry Distillation of Wood,
Wood Refuse, Coal, Peat, and the like, and for the Treatment
of other Substances.
I, EDUARD MARTIN JOHAN LARSEN, of 12, Norrwoldgade, Copenhagen, in the
Kingdom of Denmark, Engineer, do hereby declare the nature of this 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 accompany-
ing drawings and to the letters and figures marked thereon, that is to say.
This invention relates to apparatus for the dry distillation of wood, wood refuse,
peat, and the like, also for carbonizing and decomposing other substances, such for
instance as limestone
Apparatus and retorts as heretofore employed for this purpose are, as a rule,
stationary, and are heated either externally, or by means of heating pipes arranged in
the retort. Now in the operation of carbonizing wood, a number of defects have
presented themselves, due to the use of stationary retorts, and to their poor conducting
capacity, whereby the carbonization of the materials takes place irregularly. The outer
portions which are most exposed to the heat become carbonized first, and then offer a
considerable resistance to the heat penetrating the inner or more centrally located
portions of the material, such resistance being the greater in proportion as the
material under treatment 18 of a closer grain oi texture. Consequently, in order to
obtain a complete carbonization of the contents of the retort, a larger supply of heat
is required, and a longer time is necessary, the result being that the retorts can only
be utilized to a limited extent.
The
With a view to improving the action, the capacity of the retorts has been reduced,
and the retorts have been subjected to an increased temperature, There are, however,
other disadvantages which render the use of stationary retorts undesirable.
employment of small retorts involves the handling of a large number of such retorts,
so that the whole operation becomes more expensive than it would be if large retorts
were employed, whilst, owing to the higher temperature employed, the retorts are
quickly attacked and soon become destroyed.
A further objection is, that, in the case of stationary retorts, the material must be
supplied in a fairly homogeneous condition, and the mixing of large pieces of material
with small pieces, or with pulverized material cannot be restorted to, because the
latter would entirely prevent the carbonization of the large pieces. Thus with these
defects inherent to them, the yield with stationary retorts is uneconomical both as
regards quantity and quality.
Now, the present invention is designed to obviate these defects, and to this end
the retort, during the carbonizing process, is caused to rotate, suitable means being
provided for heating it either from the outside, or internally by pipes, or by both
methods combined. Suitable means are also provided for the discharge of the
distillation products.
Owing to the notation of the retort during the operation, all portions of the
material are brought into contact with the heating surfaces, and any sticking together
of the carbonized material is prevented, so that the carbonization is perfect, and the

page_text: duration of the operation is materially reduced. Moreover, the products of distillation
become, owing to the perfectly uniform temperature in the interior of the retort,
superior, as regards quantity as well as quality, to those obtained by means of
apparatus of former constructions.
Another advantage obtained is that sorting of the material, according to size is
rendered entirely unnecessary, as any material may be mixed with any other for
carbonization, and the carbonization takes place quite uniformly. In addition,
retorts of large dimensions can be employed having for example a diameter of
from 2 to 3 metres, without the carbonization being thereby, in any way, deteriorated,
this being a special advantage. Retorts of such great diameter and capacity could
not heretofore be employed for carbonizing wood.
The retorts are generally of cylindrical form, although they may be spherical, and
are suitably arranged either on pivots, or are supported by rollers, so as to permit of
their turning around a horizontal, or an inclined, axis. The heating may be effected
either externally, or by means of appropriate heating pipes traversing the retort, or
by means of a source of heat arranged in a furuace or flue. In case, when using very
high temperatures, the iron casing or jacket should not offer sufficient resistance, the
interior of the retort may be provided with a lining of fine-proof material
Various alternative forms of apparatus are represented in the accompanying
drawings, all of which are capable of being rotated, and are provided with means for
the permanent discharge of the products of distillation from the upper part of the
retort which, for the time being, is free from material. Appropriate screw conveyors
may also be provided whereby the material can be conveyed to, or discharged from,
the retort, whilst stirring devices may be arranged in the interior for the purpose of
obtaining an increased loosening action during the rotation of the material in the
retort.
Referring to the various forms of apparatus, Figs 1 and 2 represent in longitudinal
and transverse section, respectively, a rotary retort, A arranged on 1olleis a, and pro-
vided with a double heating pipe or flue K B, in such a manner that the products of
combustion from the furnace I first traverse the outer tube or flue B in order to
subsequently enter the inner tube or flue K, as indicated by the arrows, and thence
to escape into the chimney. Vanes or stirrers b are provided for the purpose of
acting on and further loosening the material duung the rotation of the retort.
Through the front wall of the retort A an outlet pipe R for the distillation products
18 tightly inserted in such a manner as not to partake of the rotary movement of the
retort, and so that its mouth is always turned towards the upper part of the retort,
as shewn in Figs. 1 and 2, which, for the tune being, is free from material.
A right and left hand screw conveyor S passing through stuffing boxes and pro-
vided with a crank handle e, serves for discharging the carbonized material at a
central opening g, after the operation 18 finished and the retort stopped.
According to the arrangement shewn in Figs. 3, 4 and 5, a group of heating pipes C
18 arranged regularly around the central flue K which serves for the discharge of the
heating gases. The said gases coming from the furnace L first pass into these
heating pipes, after which they meet in the central tube or flue K, and subsequently
escape into the chimney.
In the aarangement shewn in Figs. 3 and 5, the discharge of the products of
distillation is not effected by means of a stationary outlet pipe, but by a collecting
chamber & in communication with the interior of the retort by a sieve-like or
perforated wall.
In the arrangement shewn in Fig 4, the discharge of the products of distillation,
instead of taking place through a perforated wall, takes place through tubular
perforated cages E which, at the same time, establish communication between the
collecting chamber d and the interior of the retort. In order to prevent the
perforations of the cages E becoming obstructed by material, steel wire brushes e,
(Fig. 4,) are provided, and are adapted to be actuated, when required, from outside.
The method of discharging the products of distillation, as illustrated in Figs. 3, 4,
and 5 18 preferred when treating comparatively coarse material.

page_text: In Figs. 6 and 7, a retort is shewn in which there is also a central tube or flue K,
to receive the heating gases from a surrounding set of tubes C, and to carry them off
into the chimney. In this arrangement, the discharge of the products of distillation
18 effected by means of radiating pipes on conduits G which terminate at the periphery
of the retort near one of its ends, where they open into its interior, and are furnished
with suitable valves F. These valves are kept closed by the action of a spring, or
the like, until they reach the upper part of their circulai movement, when they strike
against a stationary segmental piece O, by which they are opened and kept so until
the retort has turned to such an extent that the material' again gradually commences
to cover the valve. The products of distillation passing out through the tubes G,
enter a collector H and thence escape by the pipe R.
Fig. 8 and 9 represent a retoit varying from the preceding in that instead of the
heating pipes traversing the same axially, diametrically arranged heating pipes C¹
are employed. The gases coming from the furnace Ltiaverse these heating pipes
or dues in various directions and then collect in their upper part and pass into the
chimney
Fig. 10 represents, in cross section, a pair of retorts which admit of being alter-
nately employed for drying and carbonizing.
The furnace L is here arranged between the retorts in such a manner that on
suitable dampers m, n, being properly adjusted, the fire gases are first utilized for
heating one retort, and then subsequently serve for the preliminary drying of the
contents of the second retort. If, for example, the carbonization has been completed
in retort A¹ (which, according to the position of the dampers shewn in Fig. 10 is
heated first) the dampers m and n are reversed. and while A¹ is being discharged
the carbonization of the contents of A is completed, whereupon the contents of the
newly charged retort A' can be subjected to a preliminary diying.
Figs. 11, 12, and 13 represent another arrangement suitable for a continuous car-
bonizing operation. The retort in this case is considerably longer than the other
retorts, previously illustrated, and 13 provided with diaphragmns Ň, and with screw-
conveyors S3 arranged between them. The diaphragms are themselves provided with
openings a though which the material gradually passes from one end to the other.
The furnace is located near the discharge opening g, so that the material 18 first
dried in the left portion of the retort, and is then, during the rotation, carried
gradually by the screw conveyors through the openings of the diaphragins to the
right, where the final carbonization takes place.
The rotation of the retort is then stopped, and the carbonized material is drawn
from the farthest right hand chamber N through the discharge opening, while upon
the left at f fresh materul 18 admitted. In this arrangement the fire gase, pass
through diametrically arranged pipes C¹ terminating in a central collecting channel or
flue K, whence they pass off into the chimney.
In Figs. 14 and 15, a still further arrangement is illustrated, in which a group of
heating pipes C 18 circularly arranged around the axis of the retort, and the retort
is heated only by means of these pipes. The end of the retort next to the furnace 18
provided with a conical cover or cap, furnished with radial diaphragms Z. and
terminating in a cylindrical neck which is located in the wall of the furnace flue.
Into this neck projects a tongue or baffle P of masonry, so that the gases coming
from the furnace L are forced to pass through the lower heating pipes C, the front
collecting box, and the upper heating pipes or flues C, and are thus compelled to
traverse a given path through the retort prior to being discharged therefrom.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is
1. An apparatus for carbonizing wood, peat, coal, and the like, in large quan-
tities, and for simultaneously treating disintegrated and undisintegrated materials,
consisting of a rotatable retort adapted to be heated either from the outside, or
from the inside by means of internal heating pipes, or both from the inside and

page_text: outside, and in which the generated gaseous products are caused to escape into
a chamber arranged at the front, and communicating with the interior of the
retort, and froin which chamber they are discharged through a pipe, arranged
axially but not participating in the rotary motion of the retort, substantially as
described.
2. In combination with apparatus such as above claimed, the employment of a
right and left hand screw conveyor passing through stuffing-boxes and capable of
being rotated so as to effect the discharge of the matenal, substantially as
described with reference to Figs. 1 and 2 of the drawings.
3. The arrangement in which, for carrying off the gases of distillation, the front of
the retort has double walls, the space between which communicates with the interior
of such retort either by means of a perforated diaphragm, or by perforated tubular
cages fitted with brushes adapted to be actuated from the outside, for keeping them
clear, substantially as described with reference to Figs 3 to 5 of the drawings.
4. The modified arrangement in which the discharge of the gases is effected by
means of radially arranged tubes fitted with valves adapted to be opened by a
segmental piece directly they reach the upper empty part of the retort, substantially
as described with reference to Figs. 6 and 7 of the drawings.
5. The arrangement comprising perforated diaphragms situated transversely of the
axis of the retort, and screw conveyors located in the compartments thus formed,
whereby such retort can be utilized for continuous distillation, and need only be
interrupted when material is to be supplied, or to be discharged, substantially as
described with reference to Figs. 11 to 13 of the drawings.
6. The arrangement in which one of the ends of the retort is provided with a
conical cover or cap terminating in a cylindrical neck located in the masonry, and a
tongue o baffle is arranged in the furnace flue so as to project into the neck and
compel the furnace gases to first traverse the lower heating tubes of the retort and
then the upper ones, substantially as described with reference to Figs. 14 and 15 of
the drawings.
7. The arrangement in which the heating tubes are arranged diametrically so as
not to obstruct the ends of the retort which receive the devices for discharging the
products of distillation. substantially as described with reference to Figs. 8 and 9 of
the drawings.
8 The combination of a pair of retorts of this kind first above claimed, in such a
manner that the furnace gases are first used for carbonizing the contents of one retort
and for drying the contents of the other, and then, by a reversal of dampers, aie
caused to traverse the retorts in the opposite direction, whereby the carbonizing and
drying operations are effected simultaneously, substantially as described with reference
to Fig. 10 of the drawings.
Dated this 27th day of December 1898
ERNEST DE PASS,
Chartered Patent Agent,
78, Fleet Street, London, and 5*, Market Street, Nottingham,
Agent for the Applicant.