IMPROVE- MENTS IN THE PROCESS AND APPARATUS FOR CLEARING WOOLLEN MATERIALS FROM VEGETABLE IMPURITIES
Year: 1882

page_text: LETTERS PATENT to Charles Denton Abel, of No. 28, Southampton Buildings,
"
Chancery Lane, in the county of Middlesex, for an Invention of IMPROVE-
MENTS IN THE PROCESS AND APPARATUS FOR CLEARING WOOLLEN MATERIALS
FROM VEGETABLE IMPURITIES." A communication from abroad by La Société
Anonyme La Laine, of Paris, in the republic of France.
PROVISIONAL SPECIFICATION left by the said Charles Denton Abel at
the Office of the Commissioners of Patents on the 27th February 1882.
CHARLES DENTON ABEL of No. 28 Southampton Buildings Chancery Lane in the
County of Middlesex "IMPROVEMENTS IN THE PROCESS AND APPARATUS FOR
CLEARING WOOLLEN MATERIALS FROM VEGETABLE IMPURITIES." [A communication
from abroad by La Société Anonymne La Laine, of Paris, in the republic of
France.]
In the processes employed for destroying the vegetable substances that are mixed
with animal fibres, the action of the acids employed for carbonising the vegetable
matters has an injurious effect on the animal fibres in consequence chiefly of the
heat evolved in the reaction. This invention relates to means of proventing excess
of heat in such operations and to the construction and arrangement of apparatus for
producing and applying the chemicals employed in the process. Excess of heat is
according to this invention prevented by causing the heat generated to be absorbed
in evaporation of the moisture present with the materials operated on. For this
purpose the materials are kept in constant agitation while the acid gas is trans-
mitted uniformly through them, the supply of gas being suspended whenever the
heat tends to exceed the desirable limit. The evaporation is also promoted by
creating a partial vacuum, and in order that the acid may be fully utilised it is
drawn through the materials in one vessel, then through those in another and so
on through a series of vessels each of which is charged with the material, and each
in its turn being the first to receive the acid direct after it has been during a
certain time subjected to the acid and vapour withdrawn from the vessel preceding it

page_text: in order. The vessels are conveniently made as barrels turning on hollow trunnions
through which the acid gas is supplied and withdrawn along with the vapours
generated. In some cases the materials are placed in closed vessels to which the
gas is supplied at the top, and from which the gas and vapours are withdrawn at
the bottom. To preserve the suction pump from the action of the acid several
vessels may be interposed containing fragments of woollen material or leather with
wood charcoal. The passage of the acid may be alternated with that of air through
the material when greater cooling is required. It is desirable that the temperature
should not vary beyond the limits of 75° to 115° Fahr. When the contents of one
of the vessels have been sufficiently treated they are left at rest from 6 to 12 hours
and then exposed to the air, great friability of the carbonised matter being thus
obtained, especially when the material is moist, and when it is not sufficiently
moist it should be moistened with water or steam. The material is then washed
first with water containing lime or carbonates of baryta, strontia or magnesia, and
then with pure water. Natural phosphates of lime may also be used in excess so
that the bath shall not be acid, and the phosphate can afterwards be cleared of the
carbonised matters by levigation. The woollen material after washing is dried and
treated in the ordinary way and it is capable of taking dyes with great facility or
having its colour revived, more especially if the dye be applied before the drying
in the water used for washing slightly heated.
The acid gas employed is hydrochloric, but in cases where salts of iron have
been used in dyeing this should be mixed with 5 to 10 per cent of sulphurous acid
with which the material should be impregnated before the hydrochloric acid is
applied to it. In preparing the hydrochloric acid by subjecting a chloride to the
action of sulphuric acid the vessel in which the reaction takes place besides having
an outlet to the wool vessels, that can be be closed by a cock or valve, should
have a second outlet with a liquid seal to prevent excess of pressure. The gas
produced may be passed through a series of vessels containing hydrochloric acid of
commerce so as to concentrate it up to saturation, the gas finally passing off to
the vessels in which the wool is treated. Instead of producing hydrochloric acid it
may be obtained by treating with sulphuric acid the hydrochloric acid of commerce.
In this case the hydrochloric acid should first be poured into a vessel and then the
sulphuric acid which being heavier will sink mixing with the hydrochloric acid as
it descends. Or the sulphuric acid being first charged into a vessel, the hydro-
chloric acid may be admitted by a pipe entering the vessel at the bottom so that
the hydrochloric acid will mingle with the sulphuric acid in rising through it.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Charles Denton Abel in the Great Seal Patent Office on the
25th August 1882.
CHARLES DENTON ABEL of No. 28 Southampton Buildings Chancery Lane in
the County of Middlesex "IMPROVEMENTS IN THE PROCESS AND APPARATUS FOR
CLEARING WOOLLEN MATERIALS FROM VEGETABLE IMPURITIES." A communication
from abroad by La Société Anonyme La Laine of Paris in the Republic of
France.
In the processes employed for destroying the vegetable substances that are mixed
with animal fibres, the action of the acids employed for carbonising the vegetable
matters has an injurious effect on the animal fibres in consequence chiefly of the
beat evolved in the reaction. This invention relates to means of preventing excess
of heat in such operations and to the construction and arrangement of apparatus
for producing and applying the chemicals employed in the process. Excess of heat
is according to this invention prevented by causing the heat generated to be
absorbed in evaporation of the moisture present with the materials operated on.
For this purpose the materials are kept in constant agitation while the acid gas is
transmitted uniformly through them, the supply of gas being suspended whenever
the heat tends to exceed the desirable limit.
The operation is effected either at ordinary pressure or under considerable
reduction of pressure and either in maintaining the substances to be treated in a
continual state of agitation, or by placing them in vessels where they remain in a
state of rest during the action of the acid.
I. MODE OF OPERATING UNDER ORDINARY PRESSURE WITH AGITATION OF THE
MATERIALS.
Fig. 1 of the drawings shews at A A a wooden cylinder with open sides carried
by a hollow wooden shaft B B. The bydrochloric gas enters this shaft through
the three-way cock R and by means of a stuffing box E. The end B b of the shaft
is closed. The part a a of this shaft has perforations tt through which the
hydrochloric acid gas passes in contact with the wool to be treated, which by the
rotating motion is continually displaced and thus successively comes in contact
with the outer atmosphere, to which it gives off quantities of watery vapour
proportionate to the rise of temperature. If the temperature rises above the
desired degree (from 25° to 45° Cent, but by preference 30° Cent) the cock R is
closed more or less until the temperature has sunk again, and in like manner if
the temperature sinks too low the cock is opened to a greater extent.
When the hydrochloric gas is produced by the decomposition of common salt
under the action of heat in a retort F the use of the three-way cock R is indis-
pensable in order that the gas may not attain a dangerous pressure, as when the
gas is prevented from passing into the cylinder it is led into a number of vessels DD
where it is taken up by water. The cylinder may be confined in a chamber or
box provided with an outlet through which the air of the chamber is exhausted
by any suitable exhauster, and in thus being continually renewed, renders the
operation more rapid. When all parts of the wool under treatment are impreg-
nated with hydrochloric gas the supply of the latter is cut off, and the wool is
removed and is allowed to lie until the vegetable particles are sufficiently friable.
II. MODE OF OPERATING WITHOUT AGITATION OF THE MATERIALS, UNDER THE
INFLUENCE OF A GREAT REDUCTION OF PRESSURE.
The materials to be tranted a wlosed
An
the Sala hathama
A
A 1

page_text: •
then closed hermetically. They are connected by tubes b, and the vat A¹ is con-
nected by a pipe with an exhaust pump P which draws in at p and delivers at p¹
the gases and vapours from the vats A A'. The vat A is also in communication
with a source of bydrochloric gas, which is here shewn produced in a retort F as
in Fig. 1, but in this case the retort has a second outlet 8¹ in order that the gas
may escape through it when by closing the cock R or by stopping the pump P the
pressure in the retort rises, the escaping gas being condensed in the usual manner
in the vessels D D', a tube T T being provided of sufficient length (about 36 feet)
to prevent the aqueous hydrochloric acid from the vessel D from re-entering the
retort when the pump is in action and the cock R open. The gas before entering
the vat A passes through the vessel B where it is cooled and separates from the
aqueous particles carried along with it. The vessels D D¹ &c. become saturated
by degrees and as a considerable number are employed, no gas escapes into the
atmosphere. When no more gas is produced from the retort F the rarefaction
produced by the pump carries off a great portion of the gas dissolved in the water
of the vessels D D¹ &c. and causes it to pass in contact with the material under
treatment in the vat A. The liquid thus dis-saturated in the vessels D is now
again capable of absorbing fresh quantities of hydrochloric gas, and these vessels
are consequently capable of serving for an indefinite time, the quantity of water
lost by evaporation being however made good. The cock R is in communication
with a second retort arranged exactly like F and connected in the same manner
with a series of vessels similar to D'D' &c. The pump P is set to work with the
cock R closed until the greatest possible reduction of pressure has been attained
in the vats A A'. When the pressure has sunk to about 1.5 inches of mercury, the
cock R is opened and the gas flowing into A acts upon the material under
treatment. The heat disengaged by this union (about 500 calories per 2lbs. of gas)
is instantaneously absorbed by the water of hydration of the wool; and under the
influence of the low pressure a quantity of steam is generated containing a large
portion of these calories. This vapour of water or steam, the temperature of which
is about 35° cent. at 1.5 ins of mercury pressure passes through the contents of the
vat A and into the vat A' the contents of which are traversed and heated thereby,
and eventually it passes to the pump P. When the temperature of the material
rises, the cock R is closed whereupon the temperature may be reduced to any
required degree, the gas is then again admitted and the regulation continued until
the whole of the material in A is saturated with gas. As some gas will pass
through A towards the end of the operation the vat A' is interposed between it
and the pump in order to prevent any gas from passing into the latter. When
about one fourth or one third of the material in A' has thus become acidulated, by
the excess of gas from A, the cock R is closed, the vat A is removed and A¹³ is
made to occupy its place, while a fresh vat is added in the place of A' and the
above described operation is continued until A¹ has received sufficient gas, and so
on. When for a certain reason all the vats of the series require to be saturated
with gas, there are interposed between the last of the series and the pump, two or
more other vats charged with material of a nature that will not be damaged by long
continued contact with the gas, for instance offal of wool or hides for manure or
charcoal. In this latter case the material is rendered again applicable by washing
it in water. By this means the pump is prevented from injury by the gas, and
the excess of the latter is not lost. A current of air may also be made to pass
through the vats alternately with a current of the gas, the air being made to take
up the aqueous vapor from the wool, but it is preferred to use the evaporation at
very low pressure. The temperatures at which it is preferred to operate are from
25° to 30°, 35°, 40° and 45° Cent, or from 77° to 86°, 95°, 104° and 113° Fah*.
On the removal of the saturated vats it is preferred to let them rest about 6 to 12
hours, after which the contents are spread out in the open air in order to render
the cotton fibre more friable, the operation taking place in well ventilated
workshops. Should the friability be obtained too slowly the materials may be
agitated in an atmosphere moistened by means of steam or water spray, such

page_text: agitation being effected either by forks, on the floor, or in revolving cylinders
similar to those above described for the first process. The required degree of
friability of the cotton being obtained, the material may be washed by means of
any suitable known apparatus, but by preference the washing is effected by means
of carbonate of baryta, strontia, magnesia and in particular of lime, dissolved in
the washing water, the last rinsings being effected in pure water, in place of
ordinary carbonate of lime it is advantageous to use phosphate of lime which is
rich in carbonate; in this case the excess of the phosphates should be such that
the bath can never become acid.
The removal of the carbonate of lime by means of the hydrochloric acid is not
new, but the novelty consists in the combination of the neutralisation of the wool
with this operation, obtaining thus by the washing a saving of chalk, and in the
enrichment of the phosphate, a saving of hydrochloric acid, water, and manual
·labor. As organic particles exist in the phosphates thus enriched, they are
removed by levigation, an operation which has not before been employed under
these circumstances. It has been found that under the influence of the acid during
the above treatment the various metals, that have served as mordants in the
dyeing of the materials, and which in consequence of the various treatments with
lime to which the wool is subjected before the said treatment are rendered less
effective for re-dying, will combine with the hydrochloric acid in the form of
chlorides or oxichlorides, which the above described neutralisation by the alkaline
carbonates reconvert in mordants that are very efficacious for dyeing in the hot or
the cold way. This discovery is utilised for additionally dyeing the purified wool
that has been previously dyed. For this purpose the necessary quantity of
colouring matter is added to the last baths, for instance a weak solution of extract
of logwood may be used when it is desired to increase the intensity of color of
wool originally dyed black and which has lost color in the treatment with hydro-
chloric acid.
Wool dyed with a ferric base being affected by the hydrochloric gas, this is
prevented by acting on the same with sulphurous acid gas at the same time as with
hydrochloric acid. The sulphurous gas is used in the proportion of from 5 to 10
per cent. of the other gas; it is prepared by any known method but by preference by
the combustion of sulphur, and it is absorbed by the material to be treated before this
is subjected to the hydrochloric acid. Good results are obtained by saturating
several series of vessels D D¹ &c. Fig 2 with hydrochloric gas and successively
placing each of these series in communication with the vats A. Fig 2. By this
means the passage of the gas to the wool is more regular than if it were made to
pass directly from the retort F, the gas is always cold and there are always
in reserve sufficient quantities of supersaturated aqueous acid, of which the
desaturation alone is sufficient. In this case the gas instead of passing to the wool
from the retort as in Fig. 2 passes to the cock R from the pipe t.
The carbonising process may also be effected by mixing commercial hydrochloric
acid with sulphuric acid. In this case the difficulty arising from the great
difference of density of the two acids is obviated by causing the aqueous hydro-
chloric acid to pass into the sulphuric acid chamber, to the top of which it rises in
disengaging the hydrochloric gas. For this purpose sulphuric acid is poured from
the cock M and funnel N into the vessel O which is connected at R to the vessel Q
by the pipe P. The vessel O communicates by the pipe S with the vats A A¹ so
that the gas passes into these vessels by the pipe S. The hydrochloric acid passes
into Q from the vessel U through the pipe V provided with a cock T.
W W is a
safety pipe passing from the top of Q into the bottom of the vessel X filled with
aqueous hydrochloric acid. The length of this tube from the vessel X to its
highest point should be about 36 feet. Y is a discharge cock. The aqueous
hydrochloric acid in falling on to the sulphuric acid in Q disengages a portion of
its gas and produces a pressure that forces the whole of the liquid into O where
the mixture and the disengaging of the remainder of the gas is effected.
The above described improved processes may be combined in part or in whole

page_text: with the processes now employed for erecting the destruction or carbonisation
the vegetable matter in wool.
Having thus described the nature of the said Invention and in what manner the
saine is to be performed as communicated to me by my foreign correspondents; I
claim,―
First. The herein described processes for effecting the destruction or carbonization
of cotton fibre in wool.
Second. The method of reducing the temperature during the action of the acid
by causing the heat to be absorbed by the evaporation of the moisture contained
in the wool, substantially as herein described.
Third. The method of agitating the wool for facilitating the evaporation referred
to in the preceding claim by bringing the various parts of the wool successively in
contact with the atmosphere, also the use of cylinders with open sides for this
purpose, substantially as berein described.
Fourth. The method of increasing the said evaporation by exhausting the gas so
as to produce a reduction of pressure by which the boiling point of the water is
proportonally reduced; also by causing a current of air to pass in contact with
the wool alternately with the exhaustion of the gas, substantially as herein
described.
Fifth. The method of assisting the destruction of the vegetable matter by
allowing the wool saturated with gas to lie by and if necessary moistening the
same, substantially as herein described.
Sixth. The method of absorbing the excess of hydrochloric acid by means of
substances that can retain it, in order to prevent loss of gas and deterioration of
the apparatus substantially as herein described.
Seventh. The use of the carbonates and phosphates herein described for
neutralising the acid of the materials treated and for washing the same.
Eighth. The method of separating the destroyed vegetable matter by levigation.
Ninth. In combination with the process herein described for removing the
vegetable matter from wool, the method of restoring the color of the wool by
additional dyeing, substantially as herein described.
Tenth. The use of sulphurous acid for the two purposes herein described.
Eleventh. The safety appliances herein described for preventing dangerous
pressures from occurring in the apparatus for producing the hydrochloric acid gas.
Twelfth. The method of extracting by means of rarefaction alone of one part of
the gas contained in the saturated hydrochloric acid, and of heating this hydrated
acid during such extraction.
In witness whereof I the said Charles Denton Abel have hereunto set my
hand and seal this Twenty fifth day of August in the year of Our Lord
One thousand eight hundred and eighty two.