IMPROVEMENTS IN THE SEPARATION OF ANIMAL SUBSTANCES FROM RAGS OF MIXED FABRIC
Year: 1864

page_text: PROVISIONAL SPECIFICATION left by Arthur Thomas Weld and John
Folliott Powell at the Office of the Commissioners of Patents, with
their Petition, on the 7th June 1864.
We, ARTHUR THOMAS WELD, of Gravesend, in the County of Kent, Civil
Engineer, and JOHN FOLLIOTT POWELL,, of Albion Place, Hyde Park, in the
County of Middlesex, Gentleman, do hereby declare the nature of the Inven-
tion for "IMPROVEMENTS IN THE SEPARATION OF ANIMAL SUBSTANCES FROM RAGS
OF MIXED FABRIC," to be as follows:-
The Invention consists in a mode of treating rags of mixed fabric by which
we separate the substances of animal origin in the form of a dry nitrogenous
powder and the substances of vegetable origin in a condition peculiarly
suitable for the use of the paper maker. In most of the plans which have
been from time to time proposed for rendering available for paper-making
the vegetable portions of rags and mixed fabric the matters of animal origin
are dissolved or washed out; generally by the use of alkalies or of alkaloid
earths, and the resulting product being in a liquid or viscid condition has
been found of little or no commercial value. It has been proposed to obtain
the animal matter in the condition of a dry powder, and for that purpose
Frederick Oldfield Ward obtained Letters Patent bearing date the 5th day
of December 1857, No. 3028. By that patented process the mixed rags
are exposed to a high temperature in a dry state and the colors of the
vegetable portions become so fixed that bleaching is effected with much
difficulty and the value of the material for paper-making is found to be
seriously impaired.

page_text: Our improved mode of treatment entirely obviates this objection to the
process above referred to, at the same time that the materials of animal origin
are obtained in the form of a dry powder richer in nitrogen because retaining
all or most of that portion which in the process referred to escapes in com-
bination with the acid gases produced in the steam digesters employed, and
which are found also injuriously to affect the interior of the digesters and
their brass fittings.
In carrying out our process we first wash or steep the mixed fabrics in
water, either hot or cold, giving preference to the former, and to the distilled
water obtained by condensation of steam; whilst in a saturated condition we
subject the material in suitable chambers to the action of steam, either
ordinary or superheated, at a pressure varying according to the time of
treatment and the nature of the material. We find that with ordinary steam
at a pressure from 4 to 5 atmospheres the animal matter of mixed woollen
rags will have undergone the requisite chemical change in 30 minutes, and
that the time may be reduced by superheating the steam. When the animal
matter is silk a longer period of exposure is required, and the process is
accelerated by the use in the wash or steep water of a small quantity of soap
or alcohol. When the animal matter has become sufficiently disintegrated
the material is to be removed from the steam chambers and dried. by any
convenient mode of desiccation, such as by a hydro-extractor and the drier
known as Norton's stove, and when dry the animal matter may be separated
from the vegetable fibre by an ordinary willow or beating machine, and
collected as a dry manure containing from 11 to 13 per cent. of readily
available nitrogen, equal to from 14 to 16 per cent. of ammonia. The
vegetable fibre will be found clear of animal matter and the colors so much
loosened as to bleach with the greatest facility.