Improvements in or relating to the Carbonisation of Rags, Wool, or the like.
Year: 1894

page_text: Date of Application, 21st June, 1894-Accepted, 18th Aug., 1894
COMPLETE SPECIFICATION.
Improvements in or relating to the Carbonisation of Rags, Wool,
or the like.
A communication from GEBRÜDER SCHÜLL, of Duren, Rheinland, Germany,
Manufacturers.
1, ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex,
Chartered Patent Agent, 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:-
The process and apparatus hitherto adopted for the destruction of vegetable
matter (cotton etc.), in fabrics for the manufacture of the so-called artificial wool
or shoddy suffer from the following defects and disadvantages:-
:-
1. The warming of the apparatus and of the entire space devoted to the
process, by the ribbed-pipes located under the drum, which are heated directly by
gas-flames, is extremely defective and dangerous; defective, because, by reason
of the large quantities of dust created and flying about, the pipes are 5000
covered with such a thick layer of dust, which is burnt and adheres to them, that there
can be scarcely any question of the heat passing through them. The pipes conse-
quently become red hot the deposited staple or filaments very readily approaching
the kindling point. Thereby favourable opportunity is offered for setting on fire
the coal dust which is floating about in a state of fine comminution and in such
large quantities throughout the entire space being derived from the destroyed
cotton, thus giving rise to the explosions which are so much dreaded; hence the
process is also dangerous.
Hitherto, the attempt has sometimes been made to prevent explosion by
quenching the burning dust by means of sprinkling water over it. This remedy,
besides offering only very feeble security, causes in addition a great loss of heat
and materially increases the wear and tear of the drum. Should the combustion,
however, only be slow, instead of sudden, there is a continual generation of
combustion-gases in large volumes, which mingle with the acid vapours, and
interfere prejudicially with their action, by materially diluting and weakening
their strength, whereby, on their discharge into the open air, an extraordinary
atmospheric oppresion is caused in the vicinity. The unfavourable result is at the
very least, invariably an increased consumption of the necessary acid, inasmuch as
a large proportion of the acid vapours generated is carried off with the combustion
gases given off, and therefore wasted.
2. It is a drawback that the destroyed cotton and consequently the coal-dust
in the wool fabrics, during the whole carbonizing process remain in contact and
alike enfold the same in each individual particle, whether remaining fixed or in
the state of dust flying around. The surrounding walls for the most part closed,
do not permit any escape of the destroyed cotton. Hence results an undue
prolongation of the process, and an increased consumption of muriatic acid,
inasmuch as the fabric, before the acid action, is protected by the quickly solidified
cotton-ash.
All these disadvantages are obviated by my improved process as set forth herein,
by the employment of the apparatus and arrangements hereinafter described.
The drum itself comprises two circular heads or end walls with their appropriate
fixed gudgeons, and on one of these latter which passes right through the end wall,
is mounted the toothed wheel by which the drum is rotated. These end walls are

page_text: united by fixed stays, with which they form the drum-frame. Upon the said
Frame is attached as the shell of the cylinder, a cage of either wire-work or sheet
metal with so many perforations and of such a size that all the dust created
during the carbonising process may throughout fall through with ease.
The
door opening provided in the cylinder casing may consist of a frame covered with
wire-work.
Fig. 1 is a plan view partly in section of the improved apparatus.
Fig. 2 is a section on the fine A B in Fig. 1.
The acid fumes or vapours are generated in a fixed or rotary retort a and first
pass into the superheating apparatus, whence they are conveyed by the bell
mouthed pipe or conduite (Figure 2) into the space surrounding the drum d.
As the drum throughout borders closely on its end walls the acid-gases must
perforce find a passage through the wire lattice and the material to be treated so
as to permeate the latter thoroughly, because the gases are discharged under the
drum, through the outlet e. The drum however remains in continued rotation, and
thus keeps the material in constant movement, so that the resulting dust. is shaken
out of it, and the acid fumes have a perpetually changing surface submitted to
their influence. Thus is attained the utmost possible speed and acid-consumption
in working, as well as a more perfect finished product. The dust falls on the
floor and can from time to time be removed thence. The acid gases are super-
hented, and in consequence thereof in the first place a considerable accession of
heat is introduced into the process, in the place and time where and when it is most
needed, namely coincident with the acid attack on the fabric; in the second place
the acid gases remain in the state of vapour and cease to condense themselves on
the drum walls and to cause their deterioration.
.
The heating of the entire space occupied moreover is no longer effected by means
of the subjacent heating coil, and the direct action of the gas-tlames, but mainly
by heated air conveyed from hot-air chambers located in the enclosing walls. To
this end fresh air is forced by a fan through the heating apparatus (as shown by
the arrow) and there heated to any required temperature by gas or other desired
means which also at the same time heats the pipe 6. Thence the hot air passes
by the conduit g (Figure 2) into the chamber h, diverging therefrom to right and
left to the chambers i am ; after ascending these latter, it crosses over the drum-
chamber, descending on the other side in corresponding chambers, whence it issues
into the open air.
It is obvious that the hot air can be drawn through instead of being driven.
The chambers i& can only part with their heat to the interior space within the
drum chamber as in all other directions the heat is intercepted by bad conductors
of heat (in the walls etc.) while these hot-air passages are only separated from the
space to be heated by iron plates, which are good heat-conductors. These
plates are placed in vertical position and have smooth or polished exterior
surfaces so that no dust and dirt is deposited thereon, to the detriment of heat-
radiation.
In this manner of heating, the cause of exploding as previously mentioned is
entirely eliminated, inasmuch as the possibility of the iron plates becoming hot no
longer exists while on the other hand the heating by radiation in lieu of direct
flame is as far as possible uniform and regular, and can be carried to any desired
temperature. The regulation of the temperature is effected simply by variations
in the velocity and volume of the air-current from the blower, in a
given time.
Thus, explosion becomes impossible with this method of carrying out the heating
and working arrangements, more particularly because the admission of atmo
spheric air into the apparatus is entirely debarred. Nothing but acid-fumes
finds entrance there. during the process. The air initially contained in the
central or working chamber and passages is very quickly dissipated through e
so that in a very brief time nothing remains but the operative acid fumes and
the gases engendered by the process from the materials treated.

page_text: Therefore since air and consequently the oxygen indispensable for an explosion
are absent or only present in small quantities and diluted or restrained by other
antagonistic elements, explosion is rendered impossible; and for the simple reason
that there is no oxygen present.
The apparatus described has yet another advantage namely that during the
carbonising process all the dust is taken out of the wool by the persistent whirling
around to which it is submitted, whereas in the process as now conducted, with
special machines (such as the "Shaker") serious and prejudicial hygienic conditions
are unavoidably created for the workers.
Having now particularly described and ascertained the nature of the said inven-
tion as communicated to me by my foreign correspondent, and in what manner the
same is to be performed, I declare that what I claim is :-
1. A process for the carbonisation of rags wool and the like in which the acid
fumes are conveyed to the material to be carbonised in the interior of a perforated
or wire-latticework covered drum in such manner that they penetrate from outwards
into the interior of the drum while the drum is heated by means of hot-air circulating
around it in a system of passages substantially as described and illustrated in the
accompanying drawings.
2. In an apparatus such as described a perforated or wire-latticework covered
drum filling as far as possible the interior space of a chamber surrounded with a
system of hot-air passages substantially as described and illustrated in the
accompanying drawings.
Dated this 21st day of June 1894.
W. P. THOMPSON & BOULT,
Agents for the Applicant.