IMPROVEMENTS IN THE TREATMENT OF WOOL, AND APPARATUS FOR THE SAME
Year: 1876

page_text: LETTERS PATENT to Alexander Melville Clark, of 53, Chancery Lane, in the
County of Middlesex, Patent Agent, for the Invention of "IMPROVEMENTS IN
THE TREATMENT OF WOOL, AND APPARATUS FOR THE SAME.” A communication
from abroad by Jules Raulin, Professor of Chemistry at the Faculty of Sciences,
of Lyons, France.
Sealed the 20th May 1877, and dated the 20th December 1876.
PROVISIONAL SPECIFICATION left by the said Alexander Melville Clark
at the Office of the Commissioners of Patents on the 20th December 1876.
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
Patent Agent.
"IMPROVEMENTS IN THE TREATMENT OF WOOL, AND APPARATUS
FOR THE SAME.
This Invention relates to the treatment of wool by means of gases and liquids.
The following are the principles on which this improved treatment is based :-
1st. If raw wool, such as noils for example, be placed in a glass tube of say two
inches in diameter by thirty-six inches in length, and compressed to correspond to a
weight of 190 kilogrammes of wool per cubic metre (wool uncompressed represents
about 30 kilos. per cubic metre). The tube being completely filled, one end is placed
in communication with a gas pipe, the gas being at a pressure of from one and a
half to two inches of water. On opening the cock, the gas passes through the wool
and out at the other open end of the tube, where it may be ignited and burned at
the end of a tapered tube. The flame is weaker than that of a similar burner
placed on the pipe before the gas passes through the layer of wool, but on gradually
closing a cock placed on the pipe before both flames, they become gradually smaller,
and die out at almost the same time. It is thus apparent that gaseous currents
under the influence of a very slight excess of pressure (amounting to a few
millimetres of water only) are able to traverse a thick layer of firmly compressed
wool.
2ndly. If the lower end of the tube containing the wool be connected with a
water supply pipe, and the cock be opened, the water will be seen to rush into the
tube, slowly rise through the wool, and flow out at the upper end, even with a
pressure of but a few decimetres of water. It is thus evident that liquid currents

page_text: may by a slight increase of pressure be made to traverse thick layers of firmly
compressed wool.
3rdly. If the tube containing the wool be held in a vertical position, and the water
be allowed to run out at its bottom end, the water will gradually drain from the
upper part of the column of wool, and after a few hours the proportion of water
with which the wool remains impregnated is gradually greater towards the bottom,
and the bottom portion for a height of 10 to 20 centimetres remain visibly moist
to such an extent that the water is expressed on applying the least pressure, but the
wool at the upper part will present the aspect and the elasticity of wool dried in a
centrifugal machine. The proportion of water remaining in wool when wrung by 1
hand, being about one hundred per cent., may be readily reduced to seventy-
five per cent., or less when the wool is dried by capillary action in the manner
described.
4th. The column of wool thus dried, especially if the lower part be removed, may
be then again traversed by a weak current of gas, as in the first experiment, but at 1
a slightly slower rate, all other things being otherwise equal.
5th. The same results are obtained on repeating the foregoing experiments with a
mass of wool of prismatic or cylindrical form, contained in a tube without any inter-
vening space between them, and whose bases are open and of such a size that the
gas or liquid may enter at one base and escape at the other. Moreover (and this is a s
result which is essential for deriving a practical benefit from the four principles
above stated) all points of the same section parallel to the bases are traversed by an
equal quantity of gas or liquid, or are equally dried in a given time, provided that
the wool be homogeneous and uniformily packed, and that the pressure of the gas
or liquid on each base is equal at all points of the same base, but slightly greater at 2
one base than at the other.
Before describing the application of the above principles to the treatment of wool,
I would remark that there are a certain number of treatments which may be
reduced to the three following operations, viz., submitting the wool to the action of
a gas, submitting the wool to the action of a liquid, and afterwards drying it. The
chemical cleansing of the wool is a good example of the kind of treatment to which I
refer. Now these several operations are severally performed as though the wool
offered great resistance to penetration either by gases or liquids, and as though the
gases and liquids could only be with difficulty extracted from the wool which
they impregnated. Thus, when it is sought to treat wool by means of a gas, for
example, hot air in order to deprive it of any moisture which remains after drying
mechanically, the wool flock spread out in thin layers, and even opened out if
required, and exposed to the action of a considerable volume of heated air.
In some cases the action of the air current is facilitated by keeping the wool in
movement in the air chamber in order to continually renew the surface of the flocks
in contact with the air, as it is as much by its contact with the surface as by its
penetration that the gas acts in this method of treatment. Moreover, the gaseous
currents circulate in all directions relatively to the wool without any effort to
regulate either their direction or rate of motion. This remark will also apply to the
usual mode of treating wool with liquids, as for instance in washing wool with water
for the purpose of removing the soluble substances with which it may have been
previously impregnated.
Further, in order to mechanically extract from wool the greater part of the
liquid with which it is impregnated, the wool after being drained is generally
subjected to the action of a hydro extractor in order that it may be afterwards
dried by means of hot air. This mode of treatment necessitates a considerable ex-
penditure of motivo power, and the employment of complicated and costly machinery
which is subject to rapid wear, while a great portion of the gases, and also of the
liquids employed, is lost without producing any useful effect. The labor required
to pass the wool from one machine to the other, in order that it may undergo the
several treatments, is also very considerable, and the wool also becomes deteriorated
in its external physical qualities. On the other hand, the principles before enunci

page_text: ated show that wool is readily permeated by or deprived of liquids and gases under
the action of the slighest pressure, and that by a proper method of treatment the
machinery employed for these purposes may be simplified, and an economy
effected in the re-agent's motive power and labor without prejudicially affecting
the appearance of the wool. Such is the object of this Invention.
Suppose, for example, a cylindrical or other vessel, as shewn in vertical and
horizontal section at Figures 1 and 2 of the accompanying Drawings, provided with
a false bottom of wire cloth at C, D, upon which is placed the wool to be treated in
its ordinary hygrometric condition, or after it has been dried by capillary action if it
has been treated with a liquid. The wool is to be packed more or less closely
together, so as not to leave any vacant spaces in its interior or between it and the
sides of the vessel, and then covered with wire cloth A, B, suitably secured to the
sides of the vessel. In order to treat this layer of wool by a gas, the latter is
introduced by a pipe E for a proper length of time and at a suitable pressure. The
spaces C, E, and F, B, are large enough, and so arranged that the pressure shall be
uniform at all points of C, D, and also of A, B, and that the pressure shall be slightly
greater on C, D, than on A, B. The gascous current passes through the mass of
wool, and escapes freely at F, and when the wool is sufficiently treated, the opera-
tion is arrested. The treatment is the same if a liquid be employed as a substanco
for the gas. To dry the wool after being thus treated with a liquid by capillary
action, it is allowed to drain for some hours, and the upper part only removed for
further treatment, this portion in its present condition possessing all the qualities of
wool dried in hydro-extractors. The lower layer of wool, which contains more
moisture, is left, and for this lower portion T generally use waste of but little value,
which is left at the bottom of the chamber, to serve for drying successive quantities
of wool placed upon it. These three operations inay be carried on in succession in
the same or in different vessels, according to requirements and the conditions of
operating.
The nature, proportions, and time of action of the gases or liquids with which the
wool is to be treated do not differ essentially from those used in the ordinary
processes.
The features of distinction between these and other processes are that according
to this Invention the wool is always treated in a dense homogeneous mass more or
Jess closely packed, which remains unstirred in all its parts throughout each of the
three operations mentioned, and is in form as nearly that of a cylinder or prism as
possible, and there are no vacant spaces between the wool and the sides of the
container. Each of the two parallel bases of the cylinder is freely and uniformly
pressed on by the gaseous or liquid current at all points, the pressure on one of the
bases being however greater than that on the other; thus all points of the same
section parallel to the bases are traversed perpendicularly thereto by the streams of
liquid or gas identical to one another, having the same speed, the whole of the
liquid or gas being made to pass through the wool.
In order to dry the wool by capillary action after moistening, it is allowed to
drain for a few hours, care being taken to place beneath it another layer of wool
upon the guage bottom, the underlayer serving the purpose of absorbing the
moisture contained in that placed upon it, which alone is to be used.
The Invention thus consists,―
First. In the industrial application of the principles before stated as to the high
degree of permeability of wool for treating the same by means of gases or liquids,
and also for obtaining a thorough drying by capillary action.
Second. In combining two and generally three of the above treatments so as to
form a complete process, and the application and employment of this combination
process in the ordinary industrial operations of treating wool with liquids and
gases.
I will now proceed to describe the nature of the operations and the varieties to
which these processes are applicable.
I will first remark that the mass of wool treated under these conditions forms

page_text: perfect filter through which only gases and liquids can pass, and which arrests even
the very finest solid substances. For this reason the processes of this Invention are
not applicable where gases and liquids are employed for effecting the mechanical
separation of solid matters however sinall from wool. Thus a current of air has
been sometimes employed for depriving wool of dust and other fine matters, as well
as for removing the "yolk" or grease, and also the earthy matters adhering thereto.
For these purposes the wool requires to be opened as much as possible to the action
of the gases or liquids, and recourse should therefore be had to the ordinary methods
of treatinent. When however it is desired to treat the wool with a liquid or gas
for the purpose of exerting either a chemical a dissolvant or diffusive action in
the interior of the mass, the processes of this Invention may be employed, and this is
more especially the case with regard to the operation of cleansing wool. All kinds
of wool capable of being formed into a homogeneous mass may be thus treated,
whether new or old, noils, waste, shoddy, rags, &c., and even new woollen fabrics
may be thus treated.
The machinery and apparatus suited to the application of these processes may be
greatly varied, and I shall here give some examples only, which will serve as types,
but it should be remarked that the choice of one apparatus determines to a certain
extent that of the others employed in the series of operations.
Wool in the course of treatment ordinarily requires to be subjected to the action
of hot air, which for the purposes of this Invention may be produced in the ordinary
manuer.
Figures 3 and 4 of the Drawings show a simple and economical arrangement of
coke oven employed in the chemical treatment of wool, in which the products of
combustion are conducted direct to the wool-drying stoves.
The motors usually employed for supplying hot air from the heater to the wool-
drying stove are of two kinds, videlicit, the fan by which only low pressures are
obtainable and the force pump, the double acting arrangement, Figure 5, being
capable of producing considerable pressure. Both these kinds of machines inay be
used either for extracting the hot air from the heater, and forcing it into the drying
stove, and so into the atmosphere, or for pumping it into the stove, and then discharg-
ing it; or they may be made to force air into the heater, and thence into the drying
stove, and discharge into the atmosphere. In the first place the motor would be
placed between the heater and the drying stove; in the second case the stove
would be placed between the heater and motor; and in the third case the heater
would be placed between the motor and the stove.
These machines as applied to the purposes of this Invention should be driven at a
moderate speed, and be of such dimensions with regard to that of the stoves and the
quantity of wool to be treated as to never develop their maximum pressure, as the
useful effect fails from various causes to keep pace with the increase of pressure.
For the purposes of this Invention it is suitable when the ordinary fans are used
that the guage placed in the stove M, at Figure 1, where the air is forced in, should
indicate a pressure of from two to four inches of water, and that when force pumps
are used a pressure of 2 to 4 inches of mercury should be indicated.
The hot air is usually intended to act on the damp wool, and serves among other
purposes to evaporate the water therein. In this case it is preferable that the
operation be not too extended, otherwise the prolonged action of the heat upon the
wool would be liable to affect its qualities. For this reason the apparatus should be
differently arranged, according as a fan or a pump is used, the thickness of wool
being reduced in the case of the fan.
The following are convenient arrangements of apparatus, applicable in each of the
above cases:―
Figures 6 and 7 show vertical and horizontal sections of a wool drying stove
adapted for receiving a supply of hot air from a fan. The stove may be constructed
of bricks and mortar, or preferably of wood lined with lead or other suitablo
material. a, a, strong iron wire net or cloth on which the wool is placed, and then
covered with a framing c, c, covered with wirework, and secured by pins to the

page_text: sides of the chamber. The wool should be regularly laid so as not to leave any
vacant spaces in its interior, or between it and the sides of the chamber for the
passage of the air, and it should also in addition be more or less closely packed. It
is sufficient that the wool when packed should possess a density corresponding to
60 kilos. per
cubic metre, which can be obtained by simply treading it, and without
the aid of a press. This condition also applies to the wool placed in the liquid vats.
A water gauge M, Figure 6, communicating with bindicates the pressure therein,
and a thermometer T the temperature of the hot air. The water is evaporated from
the wool placed in the stove by passing hot air therein from the heater by means of
the fan, the operation being continued for a sufficient length of time. With a pressure
of two inches of water indicated on the gauge M the wool may be about one foot in
depth, and of a density corresponding to 60 kilos. per cubic metre. An ordinary
fan of about four feet outside diameter driven at a moderate speed will suffice to
produce this pressure in three of these stoves, having an area of about ten feet
operated simultaneously.
In order to economize the heat and obtain more uniform results it is sometimes
of advantage to use a stove similar to the above, but provided with a cover sealed
by a water joint, as shown in vertical section, Figure 8, and during the first part of
the operation to introduce air below the wool and discharge it above, and during
the latter half of the time to reverse the direction of the air current; A, A', are the
air inlets, alternately used, as indicated.
With the same object I may also adopt the arrangement shown in horizontal
section in Figure 15, which consists of a combination of four stoves of the kind
shown in Figures 6 and 7. In this case the stove A contains a layer of wool placed
in the same position as in the above-mentioned Figures, but of slightly less depth.
The same arrangement is adopted for the second and third stoves B, C. When the
wool in stove A is almost dried, and the air leaving the same still possesses a high
temperature, an additional quantity of wool equal to that already contained is
placed thereon, but without being so closely packed, and the wirework cover
applied over all; the same is done in the case of the stoves B and C. When the
under layer in the first stove is sufficiently treated, according to the results desired
to be obtained, the damper by which hot air is admitted into this stove is closed,
and the upper layer of wool is introduced into the fourth stove D and a lot air
supply opened, after which another layer of wool is placed thereon, as in other
compartments, and the under layer is removed from the first stove; similarly the
upper layer of stove B is introduced into the first stove, and covered with another
layer, and so on, the wool passing in this order throughout the series of chambers.
To facilitate the transfer of the wool from one chamber to the other, as also the
removal of the same, it is convenient to place each layer of wool upon four woollen
nets or other open fabric which will not impede the passage of the hot air, the edges
of each net being folded over upon the wool, so that two men holding the four
corners of each net may carry one-fourth of the layer at a time.
The stoves above described are little suited for treating wool with liquids or for
drying. For these latter purposes large wooden vessels, such as shown in Figures 9
and 9a, may be used, each vessel being fitted with a stout lead coated iron wire false
bottom a, a, upon which is placed a layer of waste wool a, b, of from 28 to 32 inches
in depth, covered with a few inches of course wool, and intended to absorb the
moisture. Upon this is placed the wool to be treated, as described with reference
to the stoves, and packed to a corresponding degree until the container is filled.
The different lots of wool are divided by woollen nets, and it is prevented from
being raised by the liquid by placing upon it two semicircular frames covered with
wirework, which are firmly secured to the sides of the container by clamps m.
The packing of the wool may be effected in various ways, as for example, by
temporarily fixing on the container a cylinder provided with a screw, as shown in
Figure 16. The container and cylinder, being both filled with wool, wire cloth is
placed upon it, and then two bars placed crosswise, and the screw is then turned so
as to press upon the bars where they cross one another until the wire cloth is brought

page_text: below the level of the clamps, when the latter are slid forward in order to hold the
wool down, and the screw is then removed.
A simpler method consists in introducing from one to two hundredweight of wool
into the container, and then watering each layer by means of a rose adapted to a
cock placed at the top of the vessel, as shown in Figure 19, the same liquid being
afterwards used to act on the wool. An escape may be provided at the bottom for
the liquid. The liquid falling in the form of rain serves to consolidate the wool,
which is still further assisted by treading down the fresh layer of wool, which is
superposed upon the wetted portion. The water is then introduced into the vessel,
either from above by the cock above mentioned, or from below through a pipe at
the bottom part of the container until the latter is filled with water. The supply
of liquid is still maintained at one end, the excess flowing out at the other. The
outflow is so regulated as to keep the container constantly full. When the flow of
liquid has continued for a sufficient time the supply is cut off, and an opening made at
the bottom of the vessel for draining off the wool, after which it is left for some
hours in this state, so as to dry by capillary action. The wool may then be placed
in baskets, and raised out of the vessels by means of chains and pulleys mounted
thereon.
In order to ensure a rapid and uniforin drying of the wool it is of advantage to
treat several containers at a time, and instead of removing the whole of the dried
wool from the first vessel and then that from the second vessel, and so on, to first
remove the upper layer from each of the vessels, and after a time another, and then
another layer, and so empty all the vessels simultaneously, a saving of time being
thereby ensured, especially in dealing with large quantities of wool.
The upper surface of the wool which is in contact with the air always dries
quicker and better than the underneath layers, while the second layer dries during
the subsequent treatment of the first, the third while treating the second, and so on.
In operating in this manner by successive layers the vessels should also be filled in
layers, so that the wool will form a layer of same depth at the bottom of the whole
This method
series, and another layer of equal depth be placed thereon, and so on.
of operation also permits of considerably diminishing the thickness of the layer of
waste and of reducing it to from 12 to 16 inches only, or this waste layer may be
altogether dispensed with on condition that the bottom layer of wool which always
remains wet is reserved and withdrawn for the purpose of being placed upon the
wool, being drained in another series of vessels for the purpose of completing the
drying before it is removed for subsequent treatment. To facilitate this method of
treatment, which consists in removing the wool from a series of vessels by successive
layers at equal intervals of time, each series of vessels may be replaced by one large
vat made of wood or brickwork, and lined either with lead or cement on its interior.
This vat would be of a capacity to contain as much wool as the whole series of
vessels treated together and be also of the same depth as the same vertical and
horizontal sections, Figures 10 and 11.
The wool is introduced and removed from the vat by successive layers at regular
intervals as in the case of the vessels above described, and if it is desired that the
wool should pass from the vat to the stoves, or vice versa, it is convenient to place
the vat in juxtaposition with two, three, or more stoves serving for the sole purpose
of treating the wool from the vat.
The openings of the vat A, Figure 15, and the stoves B, C, D, should be the same
horizontal plans, so that the wool may be discharged direct from the vat into one or
other of the stoves, or vice versa, the latter being worked by double layers and the
vat by successive layers at equal intervals as before explained. The stoves should
be of sufficient capacity to empty or fill the vat in one or two days' labor.
Under the second head of this Invention which relates to the use of force pumps
in the treatment of wool the system herein described may be applied with advantage
in manufactories where a force pump is available, but as higher pressures are obtain-
able by a pump than by a fan the treatment with gases, more particularly the
drying, may be performed on thicker layers of wool, and the several drying and

page_text: washing operations may be effected in the same apparatus, which should be made
sufficiently strong to resist the pressure, and be either of wood, lead-lined, or of
metal.
The apparatus which is shown in Figure 12 consists of a large vat fitted with a
screw-down cover closing an opening of sufficient size for introducing and removing
the wool, or the vat may be open at top and fitted with a removable cover as
shown in Figure 17, the rim of which dips into a trough containing mercury, by
preference, or it might be water, so as to form a seal similar to that of the stove,
Figure S. The layer of waste wool which assists in the drying is placed at a, b,
Figure 12, and upon it a homogeneous layer of wool a, c, which is more or less
closely packed and arranged in layers, as in the case of the fan, and covered with
strong wire work; m, n, passages at which the gasos or liquids are introduced and
expelled.
To treat the wool with a liquid the cock R is shut and a stream of liquid intro-
duced from a reservoir above by the pipe m which flows down through the wool
and escapes at pipe n.
In drying the wool the flow of liquid is cut off at same time that cock R and
pipe mare opened, and the wool is allowed to drain a suitable time. To complete
the drying or to treat it with a current of hot air or gas the hot air or gas is intro-
duced under pressure by the pipe 22 which communicates with the force pump or gas
producing apparatus, and the passage of the current is continued until the air or gas
escaping from the pipe m, which is open, is found to be hot or found to possess its
characteristic qualities, as the case may be. For this apparatus may also be sub-
stituted that shown in vertical and horizontal section at Figures 13 and 14, a, b,
being the waste wool, b, c, the wool to be treated, and c, d, a thin layer of wasto,
upon which is placed a plate m, n, covered with cloth around its edges and held
down by cross bars h. The gases and liquids circulate laterally in the direction of
the arrows, the drying action being from the bottom upwards. With these slight
distinctions the operations are effected in the same manner as in the apparatus
before described, and if the wool is to be completely dried the current of air may be
forced through a thickness of three feet of wool compressed to a density of 60 kilos.
per cubic metre, with a pressure at the pump of 4 inches of mercury.
A gauge M and thermometer T, Figures 12 and 13, should, as in the case of the
fan, be placed in communication with that part of the stove at which the air or
gases arrive under pressure.
The excess of gas or liquid escaping from one apparatus may be utilized for
treating the wool in a second apparatus when the gas or liquid is only partly
utilized in the first, and afterwards that in a third apparatus when the first is cut
off. These processes may also be applied to the chemical purification of wool. The
explanations already given are sufficient to give a general idea of the method to be
adopted and to avoid unnecessary repetitions.
I will here describe in detail one example only of the chemical treatment of wool
with sulphuric acid and using a fan. For this purpose the wool acidulated by
steeping in a series of wooden vessels similar to those shown at Figures 9 and 9ª,
placed in a row above a shallow trough P, Figure 18, of large area sufficient to
contain as much liquid as three or four of the vessels combined. A pump A, the
interior of which is lined with lead and india-rubber, is employed to raise the liquid
from the trough P into another trough B of wood, lined with lead, which rests upon
the ends of all the vessels, and is made of a size to contain from 2 to 3 cubic metres
of liquid. The bottom of the trough is pierced with a hole O above each vessel,
which is closed by a wood plug C, the liquid being discharged by the pump through
the holes into each vessel in the form of rain by means of the nozzle, shown at A,
Figure 19. The liquid in the trough is composed of sulphuric acid and water in the
proportion of from one to one and a half pints of acid at 60° Baumé to one hundred
pints of water. Each vessel B, Figure 19, is pierced with a hole at bottom for
running off the liquid into the trough, and they are also provided with wire cloth
divisions like those before mentioned. Other wooden vessels similar to the above

page_text: are employed for removign the acid from the wool, said vessels being arranged
along a trough into which the waters may be discharged. Above the vessels is a
water pipe provided with a cock and rose for each vessel, and at the bottom of
each is a cock for discharging the water into the trough.
For carbonising the vegetable matters a series of stoves similar to those shown in
Figures 6 and 7, and combined as in Figuro 15, are employed, which stoves receive
a supply of hot air at the under part of the same pressure and temperature as that
produced by the heater, Figures 3 and 4, the heated air being supplied by means of
a fan. An opening is made in the pipe which supplies the air from the heater to
the fan, in proximity to the latter, provided with a register for admitting external
air to mix with the hot air and regulate the temperature.
Another series of similar stoves, also fed by a fan and provided with a regulator,
supplies air from the same heater for drying the wool after the acid has been
climinated. Each stove is also provided with a damper for shutting off or opening
the hot air supply. A sufficient number of acidulating vessels are employed for a
day's supply of wool for the carbonising stoves. The vessels are filled with
successive layers of wool which is consolidated with acidulated water sprinkled
thereon as before explained. The vessels being filled with wool, which is held in
position by the wire cloth, they are then filled with acidulated liquid by means of
the pump, and when full the supply of liquid is still continued for about fifteen
minuites and allowed to run out at the bottom, after which the supply is cut off
and the vessels drained of the liquid, the wool being dried by capillary action.
A second series of vessels are then treated in a similar manner, and then a third
series identical with the first, after which the operation is recommenced. In this first,
when all the wool has been removed, twenty-four hours or even less after coin-
mencing to drain the first series of vessels, the wool is removed therefrom by layers
at regular intervals as before explained, and placed in the carbonising stoves where
it is treated in double layers according to the method above described. The hot air
should be of a temperature of from 90 to 95 degrees centigrade when it arrives
beneath the wool. It is preferable to make the under layers about fourteen inches
in depth, and to gradually reduce the same to ten inches by trampling when
employing hot air at a pressure of from two to two and a half inches of water.
This degree of compression, which corresponds to a density of about 60 kilos. of wool
per cubic metre, may however be slightly varied, as although it is suited for wool
properly so called, which is little liable to become felted, and for colored waste,
which needs fewer precautions, it is preferable in the case of noils to compress
them to a lesser degree, as they are more liable to felt.
It is preferred to employ woollen nets upon which to support the wool when
removing the same, as vegetable fibres would become carbonised after lengthened
contact with the acid. A suitable time at which to place a fresh layer upon the
wool is when the wire cover becomes hot at some points, while the rest of its
surface is but moderately warm, and the moment at which the under layer is
purified is indicated by the wire becoming hot at all points, this being an indication
that all the water in the wool is evaporated. On leaving the stoves the purified
wool is conveyed to a series of vessels corresponding in number to the acidulating
vessels for eliminating the acid as before described. The vessels being filled
with wool, and the cock at bottom closed, water is introduced from above until the
vessels are filled, when the cock is opened, and the supply of water still maintained
so as to keep the vessels constantly full until the whole of the acid is eliminated
from the wool. This result is ascertained by testing the liquid from time to tiine
with litmus paper as it issues from a small test tube x, Figure 9, communicating
with the bottom part of the vessel, and when the litmus paper no longer reddens
the operation is complete. The water supply then cut off and the liquid in the
wool allowed to drain off through the cock at bottom.
The elimination of the acid may be acclerated by adding lime water or a
solution of carbonate of soda or soap, especially towards the end of the operation.
The drying of the upper layers of wool will be sufficiently complete in about

page_text: 12 hours, after which it is transported at regular intervals, a layer at a time, into the
drying stoves to be there treated in successive double layers as already described. The
heat required is less than that used in carbonising, and it is preferable to pack the
wool a little less closely in order to avoid its becoming felted; for example, instead
of reducing a layer of 34 centimetres to a thickness of 28 cenitimetres only, while
noils are always compressed to a lesser extent than wool. The woollen nets may be
economically replaced by very coarse canvas. A temperature below 90 degrees
centigrade is preferable in order that the wool may retain its original suppleness
and softness. 70 degrees cent. is a suitable temperature for the wool, 60 degrees cent.
for noils, and 40 degrees c. for woollen matters intended to be used for white
fabrics.
It is unnecessary to carry the drying beyond a certain point, as when the wire
which covers the under layer becomes hot at certain points another layer may be
superposed, and when the wire is hot over its whole surface, or the steam escaping
from the upper layer las considerably diminished, the under layer will be sufficiently
dried for ordinary purposes and may then be removed. Noils which are required
to preserve their whiteness may be dried in special stoves, above which would be
placed a conical top, whose base is equal to the diameter of the stove, this conical
part being surmounted by a chimney for carrying off the products.
When the drying of a layer is almost completed, a vessel filled with burning
sulphur in the proportion of 500 grammes or more per 100 kilos. of wool, is lowered
into the pipe which conducts hot air into the stove. The sulphurous acid will
preserve the original color of the wool.
By following the method herein-before described, the several portions of the
same lot of wool will, at the termination of the chemical treatment, be again collected
in the same order as at starting. It will be evident from what has been before
stated that each series of vessels may be replaced with advantage by a single vat,
such as in Figures 10 and 11.
The following is the arrangement, as shown in Figure 20-A, asidulating vat to
contain a sufficient quantity of wool for at least one day's supply for the stoves B,
C, D, into which the wool is introduced from said vat and treated in double
layers; E, de-acidulating vat in which the wool is placed on leaving the stoves;
F, G, H, drying stoves. The upper ends of all the vats and stoves are all in the
same plane. As many separate series of vats and stoves A, B, C, D, E, F, G, H, are
employed as are required.
The whole of the operations comprised in the chemical treatment may be effected
when a pump is made use of in a single vessel, Figure 12, lined with lead, and
provided with an air-tight cover. The wool is laid upon a layer of waste, as before,
to a depth of about three feet, when an air pressure of four inches of mercury is
used, and an upward current of acidulated water, of similar composition to that
before described, is here introduced by pipe m which escapes at pipe n, after which
the liquid in the wool is drained off by opening passage m and cock K. A current
of hot air at 90 degrees centigrade is next passed through in a downward direction, as
before described, until the air escapes in a heated condition from m. The wool is
then washed by passing a current of water through it in an upward direction until
the liquid no longer contains any traces of the acid. The wool is then again drained
and dried by passing through it in a downward direction a current of hot air at
70 degrees cent. or less, until it escapes in a heated state at m; the wool is then fit
to be removed; the same treatment may also be operated in the apparatus shown
in Figures 13 and 14.
The operations above described would be carried out in an exactly similar
manner, if for the sulphuric acid there used be substituted ordinary hydrochloric
acid of commerce in the proportion of four parts of acid for every 100 parts of
water or thereabouts, of chloride of aluminum may be used for the purpose in
solution in water marking 5 to 6 degrees Beauté, but when the chloride is used it
is necessary to carbonize at from 120 to 130 degrees cent.

page_text: I further propose to substitute for the mixture of liquid hydrochloric acid of
commerce and water a mixture of vapors of the said acid and air, also in suitable
proportions. For this purpose hydrochloric acid of commerce marking the same
strength of Benumé's hydrometer may be placed in a vessel of suitable capacity, a
Mariotte bottle, for example, from which it is caused to flow at a constant rate by
means of a regulating cock into the pipe which conducts the hot air into the wool
stove, see Figure 21. The acid falls upon earthenware or other plates placed one
above the other in the pipe in positions slightly inclined oppositely one to the
other, as shown, the evaporating surface being sufficient to volatilize the whole of
the acid falling upon the said plates. The wool being always disposed in the same
manner in the stove the pressure of air beneath the wool is constant, and it will
flow at a constant rate, the mixture of acid vapors and air being in the proportion
stated. The mixture arriving in the wool-drying stove at a temperature of about
90° should be produced from 1 litre of acid of commerce, inarking about 22° Baumé
for every 15 to 20 cubic metres of air.
The quantity of acid expended per hour should, other things being equal, be
proportional, the sectional area of the stove to the square root of the pressure
indicated by the gauge and inversely to the square root of the thickness of the wool.
It may also be determined in each case by the number of cubic metres of air
expended per hour, measured in the ordinary manner.
From experiments made I have ascertained that the volume of air which, at a
pressure of four inches of water, passes in an hour through an area of one square
inetre of wool, packed to correspond to 60 kilos. per cubic metre and one metre in
thickness, is about 200 cubic metres.
The above mixture may be employed with advantage for carbonizing the
vegetable matters contained in the wool, a stove being used similar to that shown
in Figures 6 and 7, except that it is of increased height, and lined with lead, and
also provided with a conical hood, through which the gases are discharged; the
wirework used would also be coated with lead. The wool may be of a thickness
of from one to one and a half metres, and have a density equal to 60 kilos. per
cubic metre, the pressure of the gaseous mixture being four inches of water. The
operation is complete when the upper wire covering of the wool becomes heated all
over. The flow of gas is then cut off, and a current of water is passed either in
an upward or downward direction through the wool to climinate the acid until the
liquid becomes neutral to litmus. The wool is then allowed to drain, and after the
lapse of from 15 to 20 hours is removed, a layer at a time, and dried in stoves similar
to those shown in Figure 6, as before described.
The under layer of wool, which contains a greater amount of moisture, is placed
on the top of the wool which has been put to drain in another casing in order to
facilitate the drying.
These two successive operations may also be effected in a single apparatus, such
as shown in Figure 12, provided a machine be employed to compress the gas. This
mixture of vapors of liquid hydrochloric acid and air may also be replaced by a
inixture of gaseous anhydrous hydrochloric acid and air in suitable proportions.
The gaseous acid is produced in the ordinary manner, for example, by the action
of sulphuric acid on sea salt, in any of the apparatus usually employed for this
purpose. The gas is conducted from the producing apparatus into a small gas
holder A, Figure 2, similar to those of gas works, but dipping into sulphuric acid,
for instance, and of such size that by suitably regulating the production of gas the
gas holder shall never quite reach the top or bottom of its course.
The acid gas is
thence conducted, as well as the hot air, into a reservoir B, having a capacity of
about ten cubic metres, where the mixture of the two gases is effected before it
passes to the wool stove. The gas holder is provided with a gauge M, as likewise
the mixing reservoir, and another gauge is placed at that part of the stove C at
which the mixture of gases is introduced.
The gas holder is so balanced that the excess of pressure of the gas in the holder

page_text: over that in the mixing reservoir shall equal the excess of pressure of the mixture
in the reservoir over the pressure in that part of the stove at which the mixture is
introduced. Further, the proportion of the sectional area of the pipe through which
the acid gas passos to the reservoir to that of the pipe by which the mixture is
conducted to the stove should be equal to the constant proportion of the volumes of
acid gas and of air which should exist in the mixture in order that the wool may
be properly purified (see Figure 22).
The proportions of the volumes of acid gas and air depend on the temperature of
the latter when it enters the stove, the proportion of acid diminishing as the
temperature increases, thus with air at 20° centi. nearly three volumes of acid gas
will be required to 100 volumes of air; if at 40° 2 volumes of gas for 100 of air;
and if at 70° or 80° from 1 to 11, volumes of gas to 100 of air.
The above proportions, whether of acid gas and air or of acid vapors and air,
although the most suitable, may yet be varied under certain circumstances, and
after having operated under the conditions above indicated, which give good
practical results, it may be necessary to slightly increase or diminish the proportion
of acid in succeeding operations, according to the results obtained.
The method of operation is the same with acid gas as with the vapors of tho
liquid acid of commerce.
After the greater part of the chemical treatment of wool has been effected, viz.,
removing the grease, sulphuring, dyeing, &c., the wool requires to be washed and
dried, and for these purposes the processes of this Invention are also applicable, but
it will be unnecessary to repeat the description of these operations, which are the
same as those following the purification.
The processes herein described may also be applied in the sulphuring of wool for
bleaching the same, it being simply necessary to burn the sulphur in a vessel placed
in the passage conducting cold air from the fan to the wool stove, and to pass the
current of air mixed with sulphurous acid until the acid freely disengages from the
wool. This operation may be performed in the stove shown in Figures 6 and 7,
for which purpose it is provided with a hood for discharging the gases on a
thickness of one and a half to two metres of wool for a pressure of four inches
of water.
The proportion of acid absorbed by the wool may be increased by impregnating
the wool with water by injecting stream or a current of water, allowing it to drain
before treating it with the acid gas.
In operating in the humid way a solution of sulphurous acid in water or n
solution of sulphite of soda mixed with hydrochloric acid is passed through the
wool. This operation is effected in the apparatus shown in Figure 9.
The proportions of the re-agents and the duration of their action are the same as
in the ordinary process.
The subsequent washing and draining of the wool are also effected in the manner
already described, and the reagents climinated by the washing may be recovered
and utilized.
The processes of this Invention are attended with still further advantage by
combining the several operations of scouring, purifying, and sulphuring under the
same roof, thus the wool after it has been scoured in the ordinary manner would
be introduced into the apparatus, and there purified in the manner herein-before
described in the humid way, without being previously dried, and then sulphured
after eliminating the acid or after carbonizing the vegetable matters previous to
washing, draining, and finally drying by the processes described.
The Invention is also applicable for dyeing wool, for which purpose the chambers
in which the wool is placed are covered with a non-conducting material to prevent
cooling, and the wool is treated successively with solutions of the mordants and
dyeing matters as ordinarily used. This operation is effected in the same manner
as the treatment with sulphuric acid or with water for eliminating the acid, as
above described in the same apparatus, as well as the subsequent washing.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Alexander Mevlille Clark in the Great Seal Patent Office on the
19th June 1877.
ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
Patent Agent. "IMPROVEMENTS IN THE TREATMENT OF WOOL, AND APPARATUS
FOR THE SAME." A communication from abroad by Jules Raulin, Professor of
Chemistry at the Faculty of Sciences, of Lyons, France.
This Invention relates to the treatment of wool by means of gases and liquids.
The following are the principles on which this improved treatment is based.
1st. If raw wool, such as noils for example, be placed in a glass tube of, say, two
inches in diameter by thirty-six inches in length, and compressed to correspond to
a weight of 190 kilogrammes of wool per cubic metre (wool uncompressed
represents about 30 kilos. per cubic metre), the tubo being completely filled, one end
is placed in communication with a gas pipe, the gas being at a pressure of from one
and a half to two inches of water. On opening the cock the gas passes through
the wool and out at the other open end of the tube, where it may be ignited and
burned at the end of a tapered tube; the flaine is weaker than that of a similar
burner placed in the pipe before the gas passes through the layer of wool, but on
gradually closing a cock placed on the pipe, so as to cut off the gas from both flames,
they become gradually smaller, and die out at almost the same time. It is thus
apparent that gaseous currents under the influence of a very slight excess of
pressure (amounting to a few millimetres of water only) are able to traverso a layer
of firmly compressed wool, as much as a metre iu thickness.
2nd. If the lower end of the tube containing the wool be connected with a water
supply pipe, and the cock be opened, the water will be seen to rush into the tube,
slowly rise through the wool and flow out at the upper end even when the excess
of pressure is but a few decimetres of water. It is thus evident that liquid currents
can under the influence of a slight excess of pressure traverse a thick layer of firmly
compressed wool.
3rd. If the tube containing the wool be held in a vertical position, and the water
be allowed to run out at its bottom end, the water will gradually drain from the
upper part of the column of wool, and after a few hours the proportion of water
with which the wool remains impregnated is gradually greater towards the bottom,
and the bottom portion for a height of 10 to 20 centimetres remains visibly moist
to such an extent that the water is expressed on applying the least pressure, but the
wool at the upper part will present the aspect and the elasticity of wool dried in a
centrifugal machine. The proportion of water remaining in wool when wrung by
hand being about one hundred per cent. may be readily reduced to seventy-five
per cent. or less when the wool is dried by capillary action in the manner
described.
4th. The column of wool thus dried, especially if the lower part be removed, may
be then traversed by a weak current of gas, as in the first experiment but at a
slightly slower rate, all other things being equal.
5th. The same results are obtained on repeating the foregoing experiments with
a mass of wool of prismatic or cylindrical form contained in a vessel of corresponding
form without any vacant space between, and whose bases are open and of such a
size that the gas or liquid may enter at one base and escape at the other. Moreover
(and this is a result which is essential for deriving a practical benefit from the four
principles above stated) all points of the same section parallel to the bases are in a
given time traversed by an equal quantity of gas or of liquid, and are also equally

page_text: dried, provided that the wool be homogeneous and uniformly packed, and that the
pressure of the gas or liquid on each base is equal at all points of the same base,
but slightly greater at one base than at the other.
Before describing the application of the above principles to the treatment of wool,
I would remark that there are a certain number of treatments, which may be
reduced to the three following operations, vis:-Submitting wool to the action of
a gas, submitting wool to the action of a liquid, and extracting the liquid from the
wool. The chemical cleansing of wool froin mechanical impurities is a good example
of the kind of treatment to which I refer. Now these several operations are
generally performed as though the wool offered great resistance to penetration,
either by gases or liquids, and as though the gases and liquids could only be with
difficulty extracted from the wool which they impregnate. Thus when it is sought
to treat wool by means of a gas, hot air for example, in order to deprive it of any
moisture which remains after drying mechanically, the wool flock is spread out in
thin layers, and even opened out if required and exposed to the action of a con-
siderable volume of heated air.
In some cases the action of the air current is facilitated by keeping the wool in
movement in the air chamber in order to continually renew the surfaces of the
flocks in contact with the air, as it is as much by its contact with the surface as by
its penetration that the gas acts in this method of treatment. Moreover the gaseous
currents circulate in all directions relatively to the wool without any effort to
regulate either their direction or rate of motion. This remark will also apply to
the usual mode of treating wool with liquids, as for instance in washing wool with
water for the purpose of removing the soluble substances with which it may have
been previously impregnated.
Further, in order to mechanically extract from wool the greater part of the liquid
with which it is impregnated, the wool after being drained is generally subjected to
the action of a hydro-extractor, and afterwards dried by means of hot air. This
mode of treatment necessitates a considerable expenditure of motive power, and the
employment of complicated and costly machinery which is subject to rapid wear,
while a great portion of the gases, and also of the liquids employed is lost without
producing any useful effect. The labor is very great, that required to pass the wool
from one machine to the other in order that it may undergo the several treatments,
being alone very considerable, and the wool also becomes deteriorated in its external
physical qualities. On the other hand the principles before enunciated show that
wool is readily permeated by or deprived of liquids and gases under the action of
the slightest pressure, and that by a proper methodical treatment the machinery
employed for these purpose may be simplified, and an economy effected in the
re-agents, motive power, and labor, without prejudicially affecting the appearance
of the wool, such is the object of this Invention.
Take for example a cylindrical or other vessel, as shown in Figures 1 and 2 of the
accompanying Drawings, provided with a false bottom of wire cloth at C, D, upon
which is placed the wool to be treated in its ordinary hygrometric condition, or
after it has been deprived of liquid by capillary action if it has been treated with
a liquid. The wool is to be packed more or less closely together so as not to leave
any vacant spaces in its interior or between it and the sides of the vessel, and then
covered with wire cloth A, B, suitably secured to the sides of the vessel. In order
to treat this layer of wool by a gas, the latter is introduced by a pipe E for a proper
length of time and at a suitable pressure. The spaces C, E, and F, B, are large
enough, and so arranged that the pressure shall be uniform at all points of C, D,
and also of A, B, and that the pressure shall be slightly greater on C, D, than
on A, B. The gaseous current passes through the mass of wool, and escapes freely
at F, and when the wool is sufliciently treated the operation is arrested. The treat-
ment is the same for a liquid, the liquid being merely substituted for the gas. To
dry the wool [after treatment with a liquid] by capillary action, it is allowed to
drain for some hours, and the upper part only removed for further treatment, this
portion in its present condition possessing all the industrial qualities of wool dried

page_text: in hydro-extractors. The lower layer of wool which contains more moisture is left,
and for this lower portion I generally use waste of but little value, which is always
left at the bottom of the chamber to serve for drying successive quantities of wool
placed upon it. These three operations may be carried on in succession in the
same or in different vessels, according to requirements and the conditions of
operating.
The nature, proportions, time, and action of the gases or liquids with which
the wool is to be treated do not differ essentially from those used in the ordinary
processes.
The features of distinction between these and other processes arc, that according
to this Invention the wool is always treated in a dense homogeneous mass, more or
Jess closely packed, which remains undisturbed in all its parts throughout each of
the three operations mentioned, and is in form as nearly that of a cylinder or prism
as possible, and there are no vacant spaces between the wool and the sides of the
container. Each of the two parallel bases of the cylinder or prism is freely and
uniformly pressed on by the gaseous or liquid current at all points, the pressure on
one of the bases being however greater than that on the other. Thus all points of
the same section parallel to the bases are traversed perpendicularly thereto by
streams of liquid or gas identical to one another and having the same speed, the
whole of the liquid or gas being made to pass through the wool.
In order to extract the liquid from the wool by capillary action after moistoning,
it is allowed to drain for a few hours, care being taken to place beneath it in
contact with the lower base another layer of wool upon the gauze bottom, the
underlayer serving the purpose of absorbing the moisture contained in that placed
upon it, which alone is to be used. The Invention thus involves,―
1st. The discovery by experience of the principles above specified relative to the
permeability of wool.
2nd. The application and embodiment of the said principles in three practical
means for tronting wool, viz., the methodical treatment by gases and by liquids, and
the complete and uniform extraction of liquid by capillary action.
3rd. The combining two and generally three of the above treatinents so as to
form a completo and methodical process.
And, 4thly. The application and employment of this combination process in
the ordinary and industrial operations of treating wool with liquids and gases.
I will now proceed to describe the nature of the operations and the varities of
wool to which these processes are applicable.
I will first remark that the mass of wool treated under these conditions forms a
perfect filter, through which only gases and liquids can pass, and which arrests even
the very finest solid substances. For this reason the processes of this Invention are
not applicable where gases and liquids are employed for effecting the mechanical
separation of solid matters, however small, from wool. Thus a current of air has
sometimes been employed for depriving wool of dust and other fine matters; again,
in removing the yolk or grease not only the latter but also the carthy inatters
adhering thereto have to be removed. For these purposes the wool requires to be
opened as much as possible to the action of the gases or liquids, and recourse should
therefore be had to the ordinary methods of treatinent. When however it is desired
to treat the wool with a liquid or gas for the purpose of exerting either a chemical
or a dissolvent action or a diffusion effect in the interior of the mass, the processes
of this Invention may be employed, and this is more especially the case with regard
to the operation of cleansing wool from straw, burrs, &c. All kinds of wool capable
of being formed into a homogeneous mass, whether new or old, noils, wasto, shoddy,
rags, &c., and even new woollen fabrics may be thus treated.
The machinery and apparatus suited to the application of these processes may be
greatly varied, and I shall here give some examples only which will serve as types,
but it should be remarked that the choice of one apparatus determines to a certain
extent that of the others employed in the same series of operations.
Wool in the course of treatment ordinarily requires to be subjected to the action

page_text: of hot air, which for the purposes of this Invention may be produced in the ordinary
inanner.
Figures 3 and 4 of the Drawings show a simple and economical arrangement of
coke oven employed in the chemical treatment of wool in which the products of
combustion are conducted direct to the wool stoves.
The motors usually employed for supplying hot air from the air-heating apparatus
to the wool stove are of two kinds, vis, the fan by which only low pressures are
obtainable, and the force pump which, particularly the double-acting arrangement
shown in Figure 5, is capable of producing considerable pressure. Both those kinds
of machines may be used so as to act, say, by drawing the hot air from the air-
heating apparatus and forcing it into the stove and thence into the atmosphere, or
by drawing it from the stove and then discharging it; or they may be made to
force air into the air heater and thence into the stove, whence it is discharged into
the atmosphere. This latter arrangement is preferably employed when using the
force pump and coke oven above described. In the first case the motor would be
placed between the air heater and the stove; in the second caso the stove would be
placed between the air heater and the motor; and in the third case the air beater
would be placed the motor and the stove.
These machines as applied to the purposes of this Invention should be driven at
a moderate speed, and be of such dimensions with regard to that of the stoves and
the quantity of wool to be treated as to never develop their maximum pressure, as it
has been found that the useful effect fails from various causes to keep pace with the
increase of pressure.
The best effect is obtained when ordinary fans are used, the manometer placed on
the stove at M (Figure 1), where the air is forced in indicates a pressure of from two
to four inches of water, and if force pumps are used a pressure of two to four inches
of mercury.
The hot air is usually intended to act on damp wool, and serves among other
purposes to evaporate the water therein. In this case it is preferable that the
operation be not too extended, otherwise the prolonged action of the hont upon the
wool would be liable to affect its qualities. For this reason the apparatus should be
differently arranged, according as a fan or a pump is used, in order that the
thickness of the wool may be reduced in the case of the fan.
The following are convenient arrangements of apparatus applicable in each of the
above cases:-
Figures 6 and 7 show vertical and horizontal sections of a wool stove adapted for
use with a fan. The stove may be constructed of brickwork plastered, or preferably
of wood, lined with lead or other suitable material. By employing hollow bricks
in the construction of the stoves and air passages loss of heat is avoided. c, cb,
strong iron wire net or cloth on which the wool is placed, a removable framing c, c,
covered with wirework being then placed on the wool and secured by iron pins to
the sides of the chamber. The wool should be laid so as not to leave any vacant
spaces in its interior or between it and the sides of the chainber through which the
air would find an easy passage, and it should be more or less closely packed
according to circumstances. It is generally sufficient if the wool when packed has a
density corresponding to 60 kilos. per cubic metre, which can be obtained by simply
treading it without the aid of a press; this condition also applies to the wool placed
in the liquid vats. A water manometer M, Figure 6, communicating with b, into
which the hot air is introduced indicates the pressure therein, and a thermometer T
the temperature of the hot air. The moisture is evaporated from the wool (from
which the liquid has been previously extracted) in the stove on establishing a
current of hot air from the air heater through the stove by working the fun for a
sufficient length of time. With a pressure of two inches of water indicated on the
manometer M the wool may be 30 centimetres in depth aud of a density correspond-
ing to 60 kilos. per cubic metre. An ordinary fan of about four feet outside
diameter driven at a moderate speed will suffice to produce this pressure in three of
these stoves, measuring about ten feet across, operated simultaneously.

page_text: In order to economize the heat and obtain more uniform results it is sometimes
of advantage to use a stove similar to the above, but provided with a cover sealed
by a water joint, as shown in vertical section, Figure 8; and during the first part
of the operation to introduce air below the wool and discharge it above, and during
the latter half of the time to reverse the direction of the air current. A, A¹, are
the air inlets alternately used as indicated.
With the same object I may also adopt the arrangement shown in horizontal
section in Figure 15, which consists of a combination of four stoves of the kind
shown in Figures 6 and 7. In this case the stove A contains a layer of wool
placed in the same position as in the above-mentioned Figures, but of slightly less
depth, say, 20 centimetres. The same arrangement is adopted for the second and
third stoves B, C. When the wool in stove A is almost dried, and the air on
leaving the same still retains a high temperature, an additional quantity of wool,
equal to that already contained, is placed on the wire cloth, covering the latter, but
without being so closely packed, and another wirework cover laid on the top. The
same is done in the case of the stoves B and C. When the underlayer in the first
stove is sufficiently treated according to the results desired to be obtained the
damper in the pipe by which hot air is admitted into this stove is closed, and the
upper layer of wool is transferred to the fourth stove D, where it occupies the
position of the under layer, and a hot air supply opened, after which a fresh layer
of wool is placed thereon, as in the other compartments and the under layer is
removed from the first stove. Similarly the upper layer of stove B is then trans-
ferred to the first stove and covered with a fresh layer, and so on continuously, the
wool passing in this order throughout the series of chambers.
To facilitate the transfer of wool from one chamber to the other, as also the
removal of the same, it may be convenient to place each layer of wool upon four
woollen nets or other opon fabric which will not impede the passage of the hot air;
the edges of cach net being folded over upon the wool, so that two men holding the
four corners of cach net may carry one fourth of the whole layer at a time.
The stoves above described are little suited for treating wool with liquids, or for
draining or extracting the liquid therefrom. For these latter purposes large
wooden vessels, such as shown in Figures 9 and 9ª, may be used, each vessel
being fitted with a stout lead-coated iron wire false bottom a, a, upon which is
placed a layer of waste wool a, b, of from 28 to 32 inches in depth, covered with a
few inches of coarse wool and intended to absorb the moisture. Upon this is
placed the wool to be treated as described with reference to the stoves, and packed
to a corresponding degree until the container is full.
The different lots of wool are divided by woollen nets, and the wool is prevented
from being raised by the liquid by placing upon it two semicircular frames c, c,
covered with wirework, which are firinly secured to the sides of the container by
clamps m.
The packing of the wool may be effected in various ways, as for example, by
temporarily fixing on the container a cylinder provided with a pressure screw, as
shown in Figure 16. The container and cylinder being both filled with wool, wire
cloth is placed upon it, and then two bars placed crosswise, and the screw is then
turned so as to press upon the bars where they cross one another until the wire
cloth is brought below the level of the clamps, when the latter are slid forward in
order to hold the wool down, and the screw and cylinder are then removed.
A simpler method consists in introducing from one to two hundredweight of
wool into the container, and then watering each layer by means of a rose fitted to
a cock placed at the top of the vessel, as shown in Figure 19, the same liquid being
afterwards used to act on the wool. An escape may be opened at the bottom for
the liquid if necessary. If possible it is preferable to place the rose in the axis of
the vessel a few inches above its upper edge, and so that the conical part of the
rose would if prolonged meet the edge; the perforated part having the form of a
segment of a sphere, of which the apex of the cone is the centre. The liquid falling
in the form of rain serves to consolidate the wool, which is still further assisted by

page_text: treading down the fresh layer of wool which is superposed upon the wetted portion.
All being prepared, the water is then introduced into the vessel, either from above
or from below, through a pipe connected to the container until the latter is filled
with water. The supply of liquid is still maintained at one end, the excess flowing
out at the other; the outflow is so regulated as to keep the container constantly
full. When the flow of liquid has continued for a sufficient tine the supply is
cut off and an opening made at the bottom of the vessel for draining off the wool,
after which it is left for some hours in this state, so as to drain or extract the
moisture by capillary action. The wool may then be placed in baskets and raised
out of the vessels by means of chains and pulleys placed above.
In order to ensure a rapid and uniform draining or drying of the wool it is of
advantage to treat several containers at a time, and instead of removing the whole
of the wool from the first vessel and then that from the second vessel, and so on,
to first remove the upper layer from each of the vessels, and after a time another,
and then another layer, and so empty all the vessels simultaneously; the operation
being extended over a sufficient length of time, a working day at least.
The upper portion of the wool, which is in contact with the air, always dries
quicker and better than the underneath layers, so that the second layer drios
quickly after the removal and during the subsequent treatment of the first, the
third while treating the second, and so on. In operating in this manner by
successive layers the vessels should also be filled in layers, so that one lot of wool
will form a layer of uniform depth at the bottom of all the vessels of one serics, and
another lot form another layer of uniform depth placed on the first, and so on.
This method of operation also permits of considerably diminishing the thickness of
the layer of waste used, and of reducing it to from 12 to 16 inches only; or this
waste layer may be altogether dispensed with on condition that the bottom layer
of wool, which always remains too moist, is reserved and withdrawn for the purpose
of being placed upon the top of the wool being drained in another series of vessels
for the purpose of completely drying it before it is removed for subsequent treat-
ment. To facilitate this method of treatment, which consists in removing the wool
from a series of vessels by successive layers at equal intervals of time, each series
of vessels may be replaced by one large vat made of wood or brickwork, set in
hydraulic lime or cement, and lined with lead, or cemented on its interior. This
vat would be of a capacity to contain as much wool as the whole series of vessels
employed together, and be also of the same depth, see Figures 10 and 11.
The wool is introduced and removed from the vat by successive layers at regular
intervals, as in the case of the series of vessels above described; and if it desired
that the wool should pass from the vat to the stoves, or vice versa, it is convenient
to place the vat in juxtaposition with two, three, or more stoves, serving for the
sole purpose of treating the wool from or for the vat.
The openings of the vat A. and the stoves B, C, D, should be in the same hori-
zontal plane, so that the wool may be discharged from the vat into one or other of
the stoves, or vice versa, the latter being worked by double layers and the vat by
successive layers at equal intervals of time, as before explained. The stoves should
be of sufficient capacity to empty or fill the vat in one or two day's labor.
I will now refer to the use of compression pumps in the treatment of wool:-
The system above described may doubtless be employed in manufactories where a
compression pump is available, but as higher pressures are obtainable from a pump
than from a fan the treatment with gases, more particularly the drying, may be
performed on thicker layers of wool, and the several drying, draining, and washing
operations may be effected in the same apparatus, which should be made sufficiently
strong to resist the pressure, and be either of wood or brickwork, lead lined, or of
metal, &c.
The apparatus which is shown in Figure 12 consists of a large vat fitted with a
screw-down cover closing an opening of sufficient size for introducing and removing
the wool, or the vat may be open at top and fitted with a removable cover, as
shown in Figure 17, the rim of which dips into a trough containing mercury by
R

page_text: preference, or it might be water, so as to form a seal similar to that of the stove,
Figure 3. The layer of waste wool which assists in the drying is placed at a, b,
Figure 12, and upon it a homogeneous layer of wool a, c, which is more or less
closely packed and arranged in layers, as when using a fan, and held down by
strong wirework; m, n, passages at which the gases or liquids are introduced and
discharged.
To treat the wool with a liquid the cock R is shut, and a stream of liquid intro-
duced from a reservoi" above by the pipe m, which flows down through the wool
and escapes at pipe n. In draining the wool the flow of liquid is cut off at saine
time that cock R and pipe m are opened, and the wool is allowed to drain for a
suitable time. To complete the drying, or to treat the wool with a current of hot
air or gas, the latter is introduced under pressure by the pipe n, which communi-
cates with the compression pump or gas-producing apparatus, and the passage of
the current is continued until the air or gas escaping from the open pipe m is found
to be hot, or found to possess its normal characteristic qualities, as the case may be.
For this apparatus may be substituted that shown in Figures 13 and 14, a to b
being the waste wool; b to c, the wool to be treated; and c to d, a thin layer of
waste, upon which is placed a plate m, n, covered with cloth around its edges, and
held down by cross bars . The gases and liquids circulate laterally in the direc-
tion of the arrows, the draining being downwards. With these slight distinctions
the operations are effected in the same manner as in the apparatus before described,
and if the drained wool is to be completely dried, the current of air may be easily
forced through a thickness of three feet of wool, compressed to a density of 60 kilos.
per cubic metre, if the pressure obtained by the pump equals four inches of
mercury.
A manometer M and thermometer T, Figures 12 and 13, should, as in the case of
the fan, be placed in communication with the casing, in which the air or gases
arrive under pressure.
The excess of gas or liquid escaping from one apparatus may be utilized for
treating the wool in a second apparatus when the gas or liquid is only partly
utilized in the first, and afterwards that in a third apparatus when the first is cut
off. These processes may also be applied for chemically cleaning wool of all kinds
from mechanical impurities of vegetable origin, that is to say, to destroy all straw,
burrs, twigs, threads, pieces of cloth, hemp, cotton, flax, or other vegetable matters
in general, which may be contained in the wool. The explanations already given
are sufficient to give a general idea of the method to be adopted and to avoid
unnecessary repetitions.
I will here describe in detail one example only of the chemical treatinent of wool
with sulphuric acid, a fan being used-For this purpose the wool is acidulated by
steeping in a series of wooden vessels, similar to those shown at Figures 9 and 94,
placed in a row above a shallow trough, P, Figure 18, of large area, sufficient to
contain as much liquid as three or four of the vessels combined. A pump A, the
interior of which is lined with lead and india-rubber, or a rotary pump lined with
copper, is employed to raise the liquid from the trough P into another trough B of
wood lined with lead which rests upon the top of all the vessels, and is made of a
size to contain from 2 to 3 cubic metres of liquid. The bottom of the trough is
pierced with a hole O above each vessel, which may be closed by a wood plug C,
the liquid passing through the holes and being distributed in each vessel in the
form of rain by means of the rose shown at A, Figure 19. The liquid in the trough
is composed of sulphuric acid and water in the proportion of from one to one and a
half pints of acid at 66° Baumé to oue hundred pints of water. Each vessel B, Figure
19, is pierced with a hole at bottom for running off the liquid into the trough, and
they are also provided with wire cloth divisions like those before mentioned, or
preferably copper wire cloth, or simply with a frame composed of wooden bars
about rd of an inch in width with spaces of the same width between them. Other
wooden vessels similar to the above are employed for eliminating the acid from the
wool, said vessel being arranged along a trough, into which the waters may be

page_text: discharged. Above the vessels is a water pipe provided with a cock and rose for
each vessel, and at the bottom of each is a cock for discharging the water into the
trough.
For carbonizing the vegetable matter a series of stoves similar to those shown in
Figures 6 and 7, and juxtaposed, as in Figure 15, are employed, said stove receiving
a supply of hot air at the under part of the same pressure and temperature as that
produced by the heater, Figures 3 and 4, the heated air being supplied by means of
a fan. An opening is made in the pipe which supplies the air from the heater to
the fan in proximity to the latter provided with a register for admitting the
external air to mix with the hot air and regulate the temperature. This mode of
regulating the temperature is applicable, whatever may be the kind of blower em-
ployed, provided it draws the air from the heater, the register being placed between
the heater and the blower and stoves. If, on the other hand, external air is forced
by the blower into the heater, and thence to the stove, a by-passage should connect
the blower with the hot air pipe between the heater and the stove for the supply of
cool air. By placing a register at the bifurcation of the by-pipe the amount of cold
air introduced may be regulated as desired.
Another series of similar stoves, also fed by a fan and provided with a regulating
opening, draws air from the same heater for drying the wool after the acid has been
eliminated. Each stove is also provided with a damper for shutting off or opening
the hot air supply. A sufficient number of the acidulating vessels are employed for
at least a day's supply of wool for the carbonizing stoves. The vessels are filled
with successive layers of wool, which is consolidated with acidulated water
sprinkled thereon, as before explained. The vessels being filled with wool, which is
held in position by the wire cloth, they are then filled with acidulated liquid by
means of the pump, and when full the supply of liquid is still continued for about
fifteen minutes, the liquid being at same time allowed to run out at the bottom,
after which the supply is cut off, and the liquid run off, that contained in the wool
being drained or extracted from it by capillary action. A second series of vessels is
then treated in a similar manner, and then a third series indentical with the first,
after which the operation is recommenced in the first series when all the wool has
been removed therefrom. Twenty-four hours, more or less, after commencing to
drain the first series of vessels the wool is removed therefrom by layers at regular
intervals, as before explained, and placed in the carbonizing stoves where it is
treated in double layers, according to the method above described. The hot
air should be of a temperature of from 90 to 95° cent. when it arrives beneath
the wool. It is preferable to make the under layers about fourteen inches in
depth, and to gradually reduce the same to ten inches by trampling when
employing hot air at a pressure of from two to two and a half inches of water.
This degree of compression which corresponds to a density of about 60 kilos. of
wool per cubic metre may however be slightly varied, as although it is suited for
wool properly so called which is little liable to become felted, and for colored
waste which needs fewer precautions, it is preferable in the case of noils to compress
them to a lesser degree, as they are more liable to felt.
It is preferred to employ woollen nets upon which to support the wool when
removing the same, as vegetable fibres would become carbonized after lengthend
contact with the acid. The proper time to place a fresh layer upon the first layer
of wool is when the wire cover is about to become hot at some points while the rest
of its surface is but warm, and the moment at which the under layer is purified is
indicated by the wire becoming hot at all points, this being an indication that all
the moisture in the wool is evaporated. On leaving the stoves the purified wool is
conveyed to a series of vessels corresponding in number to the acidulating vessels
for eliminating the acid, as before described. The vessels being filled with wool
and the cock at bottom closed, water is introduced from above until the vessels are
filled, when the cock is opened and the supply of water still maintained so as to
keep the vessels constantly full until the whole of the acid is eliminated from the
wool. This result is ascertained by testing with litmus paper from time to time the

page_text: liquid as it issues from the bottom cock or from a small test tube x, Figure 9, com-
municating with the bottom part of the vessel, and when the litmus paper no
longer reddens the operation is complete. The water supply is then cut off and the
liquid in the wool allowed to drain off through the cock at bottom.
The elimination of the acid may be accelerated by adding lime water or a solution
of carbonate of soda or soap, especially near the end of the operation. The draining
of the upper layers of wool will be sufficiently complete in about 12 hours, after
which it is transported at regular intervals, a layer at a time, as before explained,
into the drying stoves to be there treated in successive double layers, as already
described. The heat required is less than that used in carbonizing, and it is pre-
ferable to pack the wool a little loss closely in order to avoid its becoming felted.
For example, instead of reducing a layer of 34 centimetres to a thickness of 24
centimetres it is reduced to 28 centimetres only, while noils are always compressed
to a lesser extent than wool. The woollen nets may be economically replaced
by very coarse canvas A temperature below 90° cent. is preferable, in order that
the wool may retain its original suppleness and softness. 70° cent. is a suitable
temperature for wool, 60° cent. for noils, and 40° cent. for woolly matters intended
to be used for white fabrics.
It is unnecessary to carry the drying beyond a certain point. When the wire
cloth which covers the first layer becomes hot at certain parts another layer may be
superposed, and when the same wire cloth is hot over its whole surface, or the vapor
escaping from the upper layer has considerably diminished, the under layer will be
sufficiently dried for ordinary purposes and may then be removed. Noils which
are required to preserve their whiteness may be dried in special stoves, above
which would be placed a conical cap or hood whose base is equal to the diameter of
the stove, this conical cap being surmounted by a chimney for carrying off the
products. When the drying of a layer is almost completed a vessel filled with
burning sulphur in the proportion of 500 grammes or more per 100 kilos. of wool is
lowered into the pipe which conducts the hot air into the stove. The sulphurous
acid will preserve the original color of the wool.
By following the method herein-before described the several portions of the same
lot of wool will at the termination of the chemical cleaning be again collected in the
same order as at starting. It will be evident from what has been before stated
that each series of vessels may be replaced with advantage by a simple vat, such as
in Figures 10 and 11.
The following is the arrangement as shown in Figure 20-A, acidulating vat to
contain a sufficient quantity of wool for at least one day's supply for the stoves
B, C, D, into which the wool is introduced from said vat and treated in double
layers; E, de-acidulating vat in which the wool is placed on leaving the stoves;
F, G, H, drying stoves. The upper ends of all the vats and stoves are all in the
same plane. As many separate series of vats and stoves A, B, C, D, E, F, G, H, are
employed as are required.
Figure 23 shows another convenient arrangement. A, B, C, are three acidulating
vats, each containing 2500 kilos. of wool, each sufficient for one day's supply for the
stoves; D, E, F, G, H, are the carbonising stoves; I, J, K, three de-acidulating
vats; L, M, N, O, P, drying stoves. The upper edges of the vats and stoves are all
in the same horizontal plane so that the workmen can walk thereon. The stoves
and pipes are made of hollow bricks and cemented, while the vats are built of stone
and hydraulic lime and lined with lead. The lead trough for the acid may be
placed beneath the vats A, B, C. Intervening spaces should be left between the
brickwork setting of the vats and stoves to prevent the transmission of heat.
The following is the mode of operation:-The vat A is filled with wool in the
first day's work, B in the second, and C in the third. The draining or extraction
of liquid is rapidly effected during the day following the filling, and on the next
day, that is to say, 36 hours after draining, each vat is emptied and the wool placed
in the five carbonising stoves, the vats A, B, C, are then filled again in daily
succession as before, and so on. The wool withdrawn from the five stoves D, E, F,

page_text: G, H, is similarly passed through the series of vats I, J, K, and stoves L, M, N, O, P.
The whole of the operations comprised in the chemical cleaning may when a
pump is made use of be effected in a single vessel [Figure 12] lined with lead and
provided with a cover made air-tight by a hydraulic joint. The wool is laid upon
a layer of waste as before to a depth of about three feet, when an air pressure of
four inches of mercury is used, and an upward current of acidulated water of similar
composition to that before described is introduced by pipe m and escapes by pipe n,
after which the liquid in the wool is drained off or extracted by opening passage m
andcock R. A current of hot air at 90° cent. is then passed through in a downward
direction, as before described, until the air escapes in a heated condition from m. The
wool is then washed by passing a current of water through it in an upward direc-
tion until the liquid no longer contains any traces of the acid. The wool is then
again drained and dried by passing through it in a downward direction a current of
hot air at 70° cent., or less, until it escapes in a heated condition at m. The wool is
then fit to be removed. The same treatment may also be operated in the apparatus
shown in Figures 13 and 14.
Figure 24 shows a container for the wool, which will be found highly convenient
in practice. It is constructed of strong brickwork lined with lead as high as the
point A, and hollow bricks are employed cemented. The wire cloths B, C, are
inade of very stout copper; B, E, is a layer of waste wool for which rags may be
substituted if necessary; E, C, wool packed to a density of 60 kilos. per cubic
metre. On one of the sido faces perpendicular to B, C, is an inner door, secured
from the outside by two screws similar to that shown in Figure 12, except that
they are arranged to draw the door up to the opening instead of pressing on it.
The hot air is forced by the pump or blower in at pipe F and leaves by the lead
lined pipe H. The acid is introduced by pipe I or through cock K. The water
used for de-acidulating is also supplied in the same way. The wool is introduced
and removed by the side door above mentioned. M is a small tube through which
a small quantity of air is allowed to escape during the drying or carbonizing
processes for the purpose of ascertaining the moment when the wool E, C, is suffici-
ently dried, which is indicated by the escaping air being heated. The operation is
then arrested.
It may be of advantage to effect the acidulation and carbonization in one vessel,
and the washing and drying in another. In this case two chambers, identical with
that of Figure 24, are coupled together with an intermediate door, and after car-
bonization the wool is transferred from the one to the other chamber. Each of the
chambers may be of a capacity to contain 800 kilos. of wool, a series of these vessels
being employed.
The operations above described would be exactly similar, if, instead of sulphuric
acid ordinary hydrochloric acid of commerce, be used in the proportion of four
parts of acid to 100 parts of water, or thereabouts, or if chloride of aluminum in
solution in water be used, marking 5 to 6 degrees Beaumé; but when the chloride is
used it is necessary to carbonize at from 120 to 130° cent.
I further propose to substitute for the mixture of liquid hydrochloric acid of com-
merce and water a mixture of vapors of the said acid and air in certain proportions.
For this purpose hydrochloric acid of commerce marking the same strength of Beaume's
areometer may be placed in a vessel of suitable capacity, a Mariotte vase for example,
from which it is caused to flow at a constant rate by means of a regulating cock into
the pipe which conducts the hot air into the wool stove [see Figure 21]. The acid
falls upon a series of earthenware or other plates placed one above the other in
the pipe in positions slightly inclined oppositely one to the other, as shown, the
evaporating surface being sufficient to volatilize the whole of the acid falling upon
the said plates. If [the wool being always disposed in the same manner in the
stovo] the pressure of air beneath the wool is constant, which will be the case if
the fan, pump, or blower works uniformly, the air will flow at a constant rate, and
the mixture of acid vapors and air will be in certain defined proportions. This
mixture having on its arrival in the wool stove a temperature of about 90° cent.

page_text: should be produced from one litre of acid of commerce marking about 22° Beaumé
for, say, 15 to 20 cubic metres of air.
The quantity of acid expended per hour should, other things being equal, be pro-
portional to the sectional area of the stove to the square root of the pressure indicated
by the manometer, and inversely to the square root of the thickness of the wool.
It may also be determined in each case by the number of cubic metres of air
expended per hour, measured in the ordinary manner.
From experiments made it has been ascertained that the volume of air, which at
a pressure of four inches of water passes in an hour through an area of one square
metre of wool packed to correspond to 60 kilos. per cubic metro, and one metre in
thickness, is about 200 cubic metres.
The hydrochloric acid of commerce employed may, if necessary, be diluted with
water, so that it may always mark the same degree of strength. It may be diluted
so as to bring it to a density of from 10 to 13° Beaumé, in which condition it no
longer gives off acid gas. The action may thus be rendered perfectly regular with
the acid, whose boiling point is 110°.
The above mixture may be employed with advantage for carbonizing the vegetable
matters contained in the wool, a stove being used similar to that shown in Figures 6
and 7, except that it is of increased height and lined with lead, and also provided
with a conical hood through which the gases are discharged. The wirework used
would also be of iron coated with lead, or preferably made of copper. The wool
may be of a thickness of from one to one and a half metres, and have a density
equal to 60 kilos per cubic metre, the pressure of the gaseous mixture being four
inches of water. The operation is complete when the upper wire covering of the
wool becomes heated all over. The flow of gas is then cut-off, and a current of
water is passed either in an upward or downward direction through the wool to
eliminate the acid until the liquid becomes neutral to litmus. The wool is then
allowed to drain, and after the lapse of from 15 to 20 hours is removed, a layer
at a time, and dried in stoves similar to those shown in Figure 0, as before
described.
The under layer of wool, which contains a greater amount of moisture, is placed
on the top of the wool which has been put to drain in another casing, in order to
more completely drain the former layer.
Instead of the acidulated liquid being made to fall upon plates, as described, and
evaporated by the current of hot air passing to the stoves; the plates may be dis-
pensed with, and the liquid allowed to fall upon a fire-brick sole plate at the bottom
of the channel. This sole is highly heated by a furnace beneath it to vaporize the
liquid, the vapors immediately mixing with the air, and passing into the stove.
The sole may also be heated by the furnace supplying the hot air for drying the
wool, whereby the vapors are immediately mixed with the air. When using a
compressing pump or blower it is preferable to perform the whole series of opera-
tions in the apparatus shown in Figure 24. The wool is first placed therein, as
before described, after which the mixture of acid and air is passed in a downward
direction, and then the water used for washing also in the same direction. The
wool is then drained, and the drying completed by passing hot air through it in a
downward direction, as before explained.
The two successive operations may also be effected in a single apparatus, such as
shown in Figure 12, if a machine be employed to compress the gas. This mixture
of vapors of liquid hydrochloric acid and air may also be replaced by a mixture
of gaseous anhydrous hydrochloric acid and air in definite proportions.
The gaseous acid is produced in the ordinary manner, for example, by the action of
sulphuric acid on sea salt in any of the apparatus usually employed for this purpose.
The gas is conducted from the producing apparatus into a small gas holder A,
Figure 22, similar to those of gas works, but dipping into sulphuric acid, for
instance, and of such size that by suitably regulating the production of gas the
holder shall never quite reach the top or bottom of its course.
The acid gas is
gas

page_text: thence conducted, as well as the hot air, into a reservoir B having a capacity of
about 10 cubic metres, where the mixture of the two gases is effected before it
passes to the wool stove, Figure 22. A manometer M is provided on the gas holder,
as likewise on the mixing reservoir, and that part of the stove C at which the
mixture of gases is introduced.
The gas holder is so balanced that the excess of pressure of the gas in the holder
over that in the mixing reservoir shall equal the excess of pressure of the mixture
in the said reservoir over the pressure in that part of the stove at which the mixture
is introduced. Further, the proportion which the sectional area of the pipe through
which the acid gas passes to the reservoir bears to that of the pipe by which the
mixture is conducted to the stove should be equal to the constant proportion of the
volumes of acid gas and of air which should exist in the mixture, in order that the
wool may be properly cleaned (see Figure 22).
The proportions of the volumes of acid gas and air depend on the temperature of
the latter when it enters the stove, the proportion of acid diminishing as the tem-
perature increases; thus with air at 20° cent. nearly three volumes of acid gas will
be required to 100 volumes of air; if at 40°, 2 volumes of gas for 100 of air; and if
at 70° or 80°, from one to one and a half volumes of gas to 100 of air.
The above proportions, whether of acid gas and air or of acid vapors and air,
although the most suitable, may yet be varied under certain contingent circum-
stances. Thus after having operated under the conditions above indicated, which
give good practical results, it may be necessary to slightly increase or diminish the
proportion of acid in succeeding operations, according to the results obtained.
The method of operation, as also the apparatus, are the same with acid gas as
with the vapors of the liquid acid of commerce.
After the greater part of the chemical treatment of wool has been effected, viz.,
removing the grease, sulphuring, dyeing, &c., the wool requires to be washed, drained,
and dried; and for these purposes the processes of this Invention are applicable, but
it will be unnecessary to repeat the description of these operations, which are the
same as those following the cleansing.
The processes herein described may also be applied in the sulphuring of wool
for bleaching the same, it being simply necessary to burn sulphur in a vessel placed
in the passage conducting cold air from the fun to the wool stove, and to pass the
current of air mixed with sulphurous acid through the wool until the acid freely
disengages from the wool. This operation may be performed in the stove shown in
Figures 6 and 7 for which purpose it is provided with a hood for carrying off
the gases from a thickness of one and a half to two metres of wool, and at a
pressure of four inches of water.
The proportion of acid absorbed by the wool may be increased by impregnating
the wool with water by a jet of steam or a current of water, and allowing it to drain
before treating it with the acid gas.
In operating in the humid way a solution of sulphurous acid in water, or a
solution of sulphite of soda, mixed with hydrochloric acid, is passed through the
wool. This operation may be effected in the apparatus shown in Figure 9.
The proportions of the re-agents and the duration of their action are the same as
in the ordinary processes.
The subsequent washing and draining of the wool are also effected in the manner
already described, and the re-agents eliminated by the washing may be recovered
and utilised.
In cleansing the wool by a mixture of hot air and vapors of hydrated hydro-
chloric acid I have indicated a simple method of producing these vapors in deter-
mined proportions relatively to the volume of air expended, and the following is
another equally simple mode of obtaining the same result:-Dissolve about 38
kilos. of sea salt of commerce in 100 kilos. of hot water, and add 32 kilos. of sul-
phuric acid. The liquid thus composed is placed in a Mariotte's bottle, for example,
whence it is allowed to run at a regular rate into the hot air channel upon inclined
plates heated by the air, or upon an inclined sole forming the bottom of the channel

page_text: heated by a small furnace. The acid vapors disengage and mix with the air, the
surface upon which the liquid is received being of sufficient area to enable all the
hydrochloric acid to disengage during the traverse of said liquid. The sulphate of
soda which forms is removed from time to time by means of a scraper through an
opening closed by a door.
The processes of this Invention are attended with still further advantage by com-
bining the several operations of scouring, purifying, and sulphuring under the same
roof, thus the wool after it has been scoured in the ordinary manner would be
introduced into the apparatus, and there cleaned in the manner herein-before
described in the humid way without being previously dried, and then sulphured
after de-acidulation or after carbonization of the vegetable matters previous to
washing, draining, and finally drying by the processes described.
The Invention is also applicable for dyeing wool, for which purpose the chambers
in which the wool is placed are covered with a non-conducting material to prevent
cooling, and the wool is treated successively with solutions of the mordants and
dyeing matters, having the composition and temperature of the mordanting and
dyeing baths generally used, and for the usual length of time. This operation is
effected in the same manner as the treatment with sulphuric acid or with water for
eliminating the acid, as above described, in the same apparatus, as well as the sub-
sequent washing.
These processes are also applicable for any other treatment of wool coming within
the conditions defined at the commencement of this Specification.
Having described the nature of the said Invention and the manner of performing
the same, I declare that what I claim as the Invention to be protected by the herein-
before in part recited Letters Patent is,-
1st. The practical application of the principles specified (relative to the per-
meability of wool), and their embodiment in the three industrial methods of treating
wool, viet, the methodical treatment of gases, the methodical treatment by liquids,
and the draining or extraction of liquid in a complete and regular manner by
capillary action, all as herein described.
2nd. The employment conjointly of two or of all three of these methods, as
the case may be, to constitute a complete and methodical process, as herein
described.
3rd. The application and employment of these conjoined methods to the principal
industrial treatments of wool by liquids or gases, as specified.
In witness whereof, I, the said Alexander Melville Clark, have hereunto set
my hand and seal, this Nineteenth day of June, in the year of our Lord One
thousand eight hundred and seventy-seven.