Improved Process and Apparatus for Retting and Drying Flax and other Textile Materials.
Year: 1895

page_text: Compla
Date of Application, 1st May, 1895
OFIL
1.000
Aantal
7th Mon 1906
PROVISIONAL SPECIFICATION.
Improved Process and Apparatus for Retting and Drying Flax and
other Textile Materials.
A communication by ROMAIN CHARLES LOUIS EDOUARD DE SWARTE and
JEAN MARIE EMMANUEL DOUMER, both of 13 Rue de Fleurus, Lille, in
the Republic of France, Engineers.
I, WILLIAM PHILLIPS THOMPSON F.C.S. M.I.M.E. of The Agency for
Foreign Patent Solicitors, 6 Lord Street, Liverpool, and 6, Bank Street,
Manchester, both in the County of Lancaster, 118 New Street, Birmingham in
the County of Warwick and 31 High Holborn in the County of Middlesex,
Civil Engineer, do hereby declare the nature of this invention to be as follows:-
The reiting of flax is produced by a fermentation, the agent of which is a
microbe which develops itself in hot water. In order to rationally accomplish this
operation, my correspondents have sought to find what was the medium most
favourable to the vitality of this microbe, and it has been found that such was
water in a closed vessel at a temperature varying from 30° to 38° C. according to
the nature of the material to be treated.
Starting from this principle an improved process of retting flax and other textile
materials has been conceived operating in a closed vessel either under the action of
heat and vacuum or under the action of water, heat and air.
This process is applicable not only to flax but also to all the textile materials
baving an analogous texture, such as hemp, ramie, jute, phormium-tenax and the
like.
The method of treatment when the material is treated by the action of heat and
vacuum will first be described and then the steps to be taken when it is a question
merely of the action of water, heat and air.
The vacuum has for its object to remove in the retting process, as far as possible
the air contained in the substance which is to be treated, either between the stems
themselves or in the inside of the stems in order by afterwards re-establishing
atmospheric pressure to enable the water which covers these stems to penetrate
thoroughly into all their parts which does not take place so completely in the case
of immersion in the open air. There is thus obtained a more complete retting or
steeping. The vacuum has also for its object to obtain, in the drying process, a
rapid operation without raising the temperature, and at small cost.
Various kinds of apparatus, according to the different cases, may be utilised for
these various operations. The one hereinafter described and which is shown on
the accompanying drawing gives every satisfaction.
With an apparatus of suitable dimensions, it is possible to treat about
500 kilogrammes of raw flax at a time.
A cylindrical basin or pan 3, Figure 1, hermetically closed, is arranged in an
external cylindrical open sheet metal tank 1, provided at the bottom with a tap 2.
The lower part of this cylindrical basin 3 is curved and it is closed above by
means of a movable curved lid or cover surmounted by a pipe 4 provided with a
lateral arm; this lid has, further, several engaging or fastening flanges. In the
interior of this basin are two partitions or screens one at the level of the curved
bottom, the other at that of the lid. They are intended to compress the substance
which is to be treated and to maintain it immersed. The basin 3 communicates at

page_text: its bottom with a pipe 5 provided with two taps 6 and 7, which is in turn connected
by a lateral joint with the tap 2 of the outer tank; this pipe 5 which passes through
the sheet metal wall of the tank 1 must be capable of easily expanding without
causing play at 8 and 9, for which purpose it suffices to provide it with a stuffing
box or any other suitable arrangement. The pipe 10 must also be able to expand
without difficulty and for this purpose it suffices to bend it. The latter may be of
copper or other suitable material. The basin 3 is of iron, tinned or varnished on
the inside to prevent it from becoming oxidised. It may be also constructed of
any other suitable material.
·
The body of the basin must be attached to the upper cover by means of a
perfectly hermetic joint. This is obtained by using two flanges of sheet steel 11
and 12 which are pressed one against the other by means of screws 13.
Between
the plates 11 and 12 there is an indiarubber washer 14 which is strongly pressed
between these plates or flanges.
The method and operation of retting and drying the textile material by this
improved process will now be described:-
The basin or pan 3 being filled with the substance which is to be treated (the
figures relating to flax) and the tank 1 being filled with hot water of a temperature
of about 50° C. so as to completely immerse the pan 3, the discharge tap 7 is
closed and the taps 2 and 6 opened. The pipe 4 is placed in communication with
the vacuum pump and water from the tank is drawn into the basin or pan until the
textile substance is completely covered therewith. The taps 2 and 6 are then
closed, and for about an hour the process of forming a vacuum is continued in
order to remove the remaining air; the taps 2 and are then opened and the
process of filling the basin or pan with water, the level of which has been lowered
during the operation by the departure of the air, is completed and then the tap 2
is closed.
By detaching the pipe 4 from the vacuum pump, atmospheric pressure is
re-established in the basin or pau, which reduces the volume of air remaining in
the substance in the proportion of its proper value to that of the vacuum obtained
thus increasing considerably the contact of the water with the said material. The
retting is then allowed to commence. After 36 hours the water in the basin is
renewed by fresh water at a temperature of about 48°. In order to do this the
pan or basin is emptied by opening tap 7 and it is again filled by closing tap 7
and opening tap 2. Tap 2 is afterwards closed. Three or four days after the
commencement of the operation, the basin .or pan is emptied (by closing 2 and
opening tap 7). Hot water is then inserted for rinsing (by opening 2 and closing
tap 7) and the pan is then again emptied (by closing tap 2 and opening tap 7).
The material is then allowed to drain for an hour or two and then the drying is
proceeded with.
For this latter operation taps 7 and 6 are closed and the basin or pan is again
placed in communication with the vacuum pump. This latter is formed of a
suction pump communicating with the basin by a tube in which cold water is
injected in order to condense the vapour drawn off. The vacuum produced by this
pump in conjunction with the heat imparted to the basin or pan by the enveloping
tank dries the retted material. This drying takes place in about 25 hours.
The material is retted and dried in 5 to 6 days from the commencement of the
operation. It is then removed from the pan by lifting the lid.
The right is reserved of applying to the apparatus and the method of treatment
hereinbefore described all the changes and modifications which practice suggests.
In order to facilitate the retting operation hereinbefore described it is
preferable to
1st. Fill the basin or pan with water charged with suitable ferments in order
to assist the cominencement of the retting;
2nd. To maintain at the commencement of the operation the temperature of
the water at about 48° during one or two hours, and then it may be allowed
to fall without inconvenience down to 35° as the minimum.

page_text: The water need not be removed during the retting if the whiteness of the fibre
is not a matter of importance. Duration of the retting varies according to the
substances, it may be two, three or four days.
In order to dry the material, the stems must be placed upright in the basin or
pan without intermediate bands under a maximum pressure in order to have a
uniform distribution. When the retting is terminated the water is discharged and
the material is strained by draining or vacuum. The material is then dried by a
current of air blown in at a temperature of 20° to 30° arriving by the bottom of
the basin or pan in order that the draught of air may pass parallel to the length of
the fibres.
In basins or pans of large diameter, it is preferable to watch the upper layer of
the material, and as soon as dry parts become visible to cover them with frames or
other suitable covering in order that the air shall only pass over the parts which
are still undried, and so on successively until the desiccation is complete.
In order to produce a simultaneous drying in all the parts of the basin or pan
air may be introduced into the lower part by a metallic distributor such as is
shown in Figure 2. It is formed of a mushroom-shaped piece perforated with
holes of such diameter with regard to the pressure that the air is distributed
uniformly in the mass which is to be dried.
The air may also be brought by means of a laterally flattened cone, as shown in
Figure 3 as a side view and Figure 4 a plan view, provided with guides 15 curved
and placed in such a way that however much the pressure varies according to the
inclination of the jet the air comes into the bottom of the basin or pan at a
uniform constant pressure.
The air flowing into the basin, the false bottom 16, 17 and 18 of which is perforated,
encounters the baffle plates shown in plan view by concentric arcs of a circle
perpendicular to the jets of air emerging from the guides and shown in dotted
lines in such a way that they divide the surface of the circle forming the plane of
the basin into equal parts. In elevation these baffle plates have the form
shown, 16, 17 and 18 of Figure 3. They are bent or curved in an arc of a circle
to 90° towards the bottom and the side from which the wind comes. These arcs of
a circle descend so far that the volume of air deviated upwards by each of the
baffle plates shall be the same in the same time.
The apparatus for retting and drying may represent two principal arrangements:
the same basin or pan may serve for retting and for drying, or distinct basins or
pans may be employed for the two operations.
A. In case the same basin or pan serves for retting and drying, a pan or basin
may be employed having one or several stages for stems as will be now described.
Firstly, a pan or basin with a single stage. The basin Figure 5 is composed of an
upright cylinder of about 1.20 metres in height and a diameter varying according
to the capacity which it is desired it should have. It is covered by a curved lid
from the top of which the pipe for forming the vacuum in the apparatus debouches.
Below it is terminated by another curved surface. The latter has in its lower
part a nozzle or socket 19 on which the tube for supplying air is connected. The
tube for bringing the water is also connected with the same socket or nozzle on the
one side and on the opposite side the pipe for discharging a steam pipe passing
through the middle of the curved bottom is attached to the basin or pan in order
to allow of a suitable temperature being maintained in the latter by means of
injections, a thermometer 20 enabling this internal temperature to be ascertained.
The entire external surface of the basin or pan is coated with a good insulating
substance. The cylindrical part has two partitions, the one at the top, the other
at the bottom, between which the substance to be treated is held during the
retting. The bottom of the nozzle or socket 19 is closed by a solid joint 21.
When the straining is terminated and the water therefrom run off, this solid joint
is removed, and the solid substances remaining in the bottom of the pan or basin
fall below into a trough arranged for the purpose.
When it is desired to dry the material, the pipe 21* of the suction apparatus or

page_text: fan is connected at 21. This pipe is bent at right angles and returns to the main
air pipe 22. At 23 and 24 there is a joint hinged on 23 on which the pipe 21*,
may turn in order to assume a vertical position, so that its opening avoids coming
in contact with the substances discharged from the pan or basin when the solid
joint 21 is opened.
In case the air circulation is effected at one side of the bottom, the tubes for
water discharging steam and the thermometer are placed on the other side.
In the preceding arrangement the stems must be brought into the basin or pan
and removed therefrom by hand.
If it be desired to bring them into it or remove them from it en bloc, a mechanical
arrangement such as is shown diagrammatically in Figure 6 may be employed.
The material to be treated is placed in a cylinder having open sides and bottom
of a diameter less than that of the interior of the basin or pan to such an extent as
to allow of it being easily inserted.
This cylinder should have a metallic bar placed according to its axis, the lower
end of which is screwed or threaded and carries a nut which sustains the bottom
piece. This rod is provided in its upper part with a somewhat strong hook in order
to raise the cylinder filled with material.
If the diameter of the basin or pan is such that the charge is too heavy for one
rod, several rods uniformly distributed and connected by cross pieces may be
employed. The frame thus formed is provided with a hook for raising the
material.
With this arrangement in which the current of air may pass between the
open-worked cylinder and the basin or pan three elastic flanges may be arranged
for the drying as is shown in the figure by 25, 26, 27. Any material than the
textiles which is in the pan or basin must be unattackable by water or the products
of fermentation.
Secondly. A pan or basin having several stages.
The apparatus may comprise several tiers of material with the object of
economising space and the expense of basins, because for several stages or tiers
there only one cover and one furnace, the outer cover and the bottom being like
those of the basin or pan having only the single tier.
It will suffice to describe the
special arrangement for multiplication of the stages.
As may be seen in Figure 7 each stage will be about 1.20 metres in height, and
each partition must be strong enough to support with safety the corresponding
loaded stage above it. The material may be brought into the vessel or removed
therefrom by hand. All the stages already loaded may also be brought or inserted
and with this object the same arrangement as was described in Figure 6 may be
employed in a similar case.
B. When distinct basins or pans are employed for the retting and the drying,
the latter are always in several stages. The retting basins are divided into two
categories, those in which the material is supplied and removed by hand and those
where this work is done by mechanical means.
When the material is manipulated by hand the basin or pan, Figure 8,
resembles the one shown in Figure 5 with this simplification that the air-pipe
is dispensed with and replaced by a discharging pipe; the basin or pan has several
stages.
When the material is treated by mechanical means the arrangement is the same
as that shown in Figure 6 with a number of stages, the air-tube being dispensed
with and replaced by a discharging pipe. Drying pans or basins are intended to
methodically dry the retted fibre.
The fibre when it has been strained is inserted at the top and the dried fibre
withdrawn from the bottom. The air flows in from below and passes out from
above. This arrangement is shown in Figure 9.
The basin or pan of itself is very simple. It is composed of a straight cylinder
of equal diameter to that of the retting pans with which it is employed and of
such a height that the air passes out saturated for the greater economy of the

page_text: heating and motive power. The bottom of the basin or pan is curved terminated
below by the pipe supplying the air. In this case as all the operation is
performed mechanically a special arrangement is necessary for this purpose. It is
necessary that one tier when dried must be able to be withdrawn from below and a
freshly retted tier be inserted above. For this purpose the bottom of the basin.
has a door 28, 29, 30 semi-circular, of the same height as a stage carried on a
carriage, capable of turning on hinges 28 in such a way as to open half the lower
part of the basin or pan. Two rails are placed transversely to the commencement.
of the bottom serving for guiding the carriage sustaining the lower stage of fibre.
These rails are extended at this level to 31 outside of the pan or basin and there is
a shunting place at 32 in order that an empty carriage may be held in readiness.
there.
Above the basin or pan a trolley is arranged travelling on rails intended to bring
to the top of the apparatus the tiers of fibre coming from the retting process.
During the aeration all the tiers except the last at the bottom are maintained in
equilibrin by the upper crane. For this purpose a bisected rod passes through
all the stages in the direction of their axis. Each section has the ring at the
bottom and a hook at the top so that it can be connected with the one above it and
to the one below it, the last section at the bottom resting merely on the carriage.
If the diameter of the basin or pan is such that the charge is too heavy for one rod,.
several rods uniformly distributed may be employed. They are connected above
by cross pieces at each tier and a single hook is attached to each of these frames.
thus formed.
The operation for withdrawing from below a dry tier and introducing above
a tier coming from the retting is effected as follows. The stages or tiers 33,
34, 35 are first suspended by means of a transverse bar by passing it into the
hook 37, then the chain of the travelling crane is detached from this hook, the
lower door of the pan or basin is opened, hook 38 is detached from its ring and
the lowest dry tier will be drawn out of the basin or pan on its carriage and the
empty carriage re-inserted.
At this moment there must be inserted at the top another tier fresh from the
retting, and in order to do this, it is brought to the top of the pan or basin by
means of the travelling crane. The lower ring of its rod is passed into the
hook 37 and the transverse bar is withdrawn. The fresh tier is then caused
to descend by the trolley and the tiers 33, 34, 35 until 35 rests on the carriage.
The circular door of the pan or basin is closed by stopping the free space
below the door occasioned by the passage of the rails and air is driven in until the
tier 35 is completely dried. Each tier will have elastic supports or flanges.
The arrangement of pans or basins with separate stages for the retting and
the drying is suitable for large factories in which the necessary first cost may
be incurred in order to obtain greater results.
It has the advantage of reducing to a minimum the number of basins or pans
which have to be worked because the methodical drying effects a considerable
saving of time.
It withdraws from the drying action of the current of air, which otherwise might
be prolonged, the fibre immediately it has become dried, and this is favourable to
maintaining the quality of the textile fibre.
Finally it reduces to a minimum the expense of motive power and all heat.
to be supplied to the air current for a given weight of material to be treated.
The process which has just been described may be slightly modified by
suppressing the use of vacuum. The material is then merely treated with water,
heat and air. In this case the material to be treated is first immersed in closed
vats or basins filled with water at a temperature varying between 30° and 38° C.,
according to the quality of the material and it is left therein until the retting is
terminated which is ascertained when the textile fibre when dry is easily detached
from the stems which surround it.

page_text: The retting is carried out to a greater or lesser extent according to the nature of
the material and the number of the threads which it is desired to draw therefrom.
When the retting is completed, the water in the pan or basin is discharged to the
outside and the material is allowed to drain. Then without removing it, it is dried
by means of a current of hot air as has been already described.
In order to proceed to the retting of textile materials by this process a special
apparatus shown in Figure 10 of the accompanying drawings is employed. This is
composed of a cylindrical vessel 39, 40, 41, 42, which may be of various heights
according to the quantity or weight of material which is to be placed therein.
It may be divided into several stages.or comprise only one. In the accompanying
drawing the pan is only assumed to be divided into two stages by a perforated
partition 43, 44 placed on a movable frame.
In the interior of this pan or basin several horizontal movable partitions or
screens placed on equally movable frames are employed. There is always one
frame more than the number of tiers or stages employed so that the material
is enclosed or contained at each stage between two consecutive frames. There
are the same number of screens or partitions as stages because there is not one
above the upper frame. Thus in a five tier pan there are six frames and five
screens there being no screen on the top frame. The pan or basin 39, 40, 41, 42
has five lateral orifices. The orifices 45 and 46, the one above and the other below,
are intended to receive thermometers and three orifices 47 (only one is visible in the
drawing) below arranged at equal distances round the circumference of the pan or
basin under the material to be treated serve for injecting steam in order to maintain
the temperature to a suitable degree.
The basin is fitted with a cover having a hole in the centre for discharging the
gases from the fermentation, and an arm hole near the edge in order to allow
samples of the material to be withdrawn by means of it in order to be examined for
the purpose of seeing how far the retting is advanced, and is completed at its lower
part by a conoid trunk the surface of which is represented by the curved
line 42, 48, 49, 50. This curve is formed of two arcs of circles 42-48, and 49-50
connected together by means of a common tangent 48-49. These ares are
perpendicular, the first to the horizontal plane, 41-42, the second to the horizontal
plane 50-51. The arc 42-48 turns its concavity towards the axis of the
apparatus, and the are 49-50 turns its convexity towards the same.
The bottom of this conoid trunk is connected with a vertical tube 52 (Figure 11)
of the same diameter by means of a register 53 which may produce or interrupt the
communication with it as may be desired. It has at the side a discharge tube 54
provided with a register 55 and several armholes for cleaning purposes. A tube 56
connected to the pipe 52 serves to bring air into the apparatus. In the interior of
the conoidal trunk is a series of convidal trunks of smaller diameter or air guides 57.
They have for their object to distribute the air uniformly in all the parts of the
stems treated. These air guides which may vary in number according to the size
and diameter of the apparatus are concentric to its axis and such that their superior
sections at 41, 42 intercept between them exactly equal annular surfaces and that
their lower sections at 50, 51 intercept among them increasing aunular surfaces from
the centre to the circumference.
Figure 10 of the accompanying drawing shows that the lower part of the conoidal
trunk is horizontal. This arrangement is sometimes employed but in order to
facilitate the working it is preferable to arrange it at an angle of about 20° as
shown in Figures 11 and 12. This inclination may of course be varied. The
distance of the horizontal plane 50 from the surface of the ground may be evidently
greater or smaller.
This improved apparatus may be constructed of any suitable substance or
material so long as they are not attacked by water and the products of fermentation.
It may more particularly be constructed entirely of metal or in metal and concrete.
This is bow the operation is carried out. The husked green flax (or any other

page_text: suitable textile material) is placed vertically in each of the stages of the cylindrical
part of the basin without bands, the bottom of the stem below and the head above.
Each stage is arranged in such a way as to have the height of the stems which are
to be treated. It is completely immersed in water, the temperature of which varies
between 30 and 38° C. according to the material.
When it is found that the retting is completed (this operation may be more or
less prolonged as has been herein before explained) the apparatus is emptied by the
lower lateral opening 54, and the material is allowed to drain for a longer or shorter
time, remaining in its place. Then the drying is proceeded with. For this purpose
the cover plate over the basin is removed, the discharge opening is closed and the
register 53 of the air pipe 56 is opened. A current of hot air, the temperature of
which may vary between 30° and 50° is then passed into the textile mass.
When the desiccation is completed, the current of air is shut off and the flax is
withdrawn and made into bundles.
In the case of large installations, the retting and the drying may be performed in
separate apparatuses.
Dated this 30th day of April 1895.
WM. P. THOMPSON & Co.,
Agents.
Improved Process and Apparatus for Retting and Drying Flax and
other Textile Materials.
A communication by ROMAIN CHARLES LOUIS EDOUARD DE SWARTE aud
JEAN MARIE EMMANUEL DOUMER, both of 13 Rue de Fleurus, Lille, in
the Republic of France, Engineers.
I, WILLIAM PHILLIPS THOMPSON F.C.S., M.1.M.E., of The Agency for
Foreign Patent Solicitors, 6 Lord Street, Liverpool, and 6, Bank Street,
Manchester, both in the County of Lancaster, 118 New Street, Birmingham in
the County of Warwick and 31 High Holborn in the County of Middlesex
Civil Engineer, do hereby declare the nature of this invention and in what mauner
the same is to be performed, to be particularly described and ascertained in and by
the following statement:-
The retting of flax is produced by a fermentation, the agent of which is a
microbe called "amylo bacteria" which develops itself in hot water. In order to
rationally accomplish this operation, my correspondents have sought to find what
was the medium most favourable to the vitality of this microbe, and having found
that such was hot water in a closed vessel at a temperature varying from
30° to 38° C. according to the nature of the material to be treated; their
idea is to impregnate this hot water with pure cultivations of these amylo
bacteria.
Starting from this principle an improved process of retting flax and other
textile materials has been conceived operating in a closed vessel, either under the
action of heat and vacuum, or under the action of water, heat and air.
This process is applicable not only to flax but also to all the textile materials
having an analogous texture, such as hemp, ramie, jute, phormium-tenax and the
like.
The method of treatment when the material is treated by the action of heat and
vacuum will first be described and then the steps to be taken when it is a question
merely of the action of water, heat and air.
The vacuum has for its object to remove in the retting process, as far as possible
the air contained in the substance which is to be treated, either between the stems

page_text: themselves or in the inside of the stems, in order by afterwards re-establishing
atmospheric pressure to enable the water which covers these stems to penetrate
thoroughly into all their parts which does not take place so completely in the case
of immersion in the open air. There is thus obtained a more complete retting or
steeping. The vacuum has also for its object to obtain, in the drying process, a
rapid operation without raising the temperature, and at small cost.
Various kinds of apparatus, according to the different cases, may be utilised for
these various operations. The one hereinafter described and which is shown on the
drawing accompanying the Provisional Application gives every satisfaction.
With an apparatus of suitable dimensions, it is possible to treat about
500 kilogrammes of raw flax at a time.
A cylindrical basin or pan 3, Figure 1, hermetically closed, is arranged in an
external cylindrical open sheet metal tank 1, provided at the bottom with a tap 2.
The lower part of this cylindrical basin 3 is curved and it is closed above by means
of a movable curved lid or cover surmounted by a pipe 4 provided with a lateral
arm; this lid has, further, several engaging or fastening flanges. In the interior
of this basin are two partitions or screens, one at the level of the curved bottom,
the other at that of the lid. They are intended to compress the substance which is
to be treated and to maintain it immersed. The basin 3 communicates at its
bottom with a pipe 5 provided with two taps 6 and 7, which is in turn connected
by a lateral joint with the tap 2 of the outer tank; this pipe 5 which passes
through the sheet metal wall of the tank 1, must be capable of easily expanding
without causing play at 8 and 9, for which purpose it is sufficient to provide it with
a stuffing box or any other suitable arrangement. The pipe 10 must also be able
to expand without difficulty and for this purpose it is sufficient to bend it. The
latter may be of copper or other suitable material. The basin 3 is of iron, tinned
or varnished on the inside to prevent it from becoming oxidised. It may be also
constructed of any other suitable material.
The body of the basin must be attached to the upper cover by means of a
perfectly hermetic joint. This is obtained by using two flanges of sheet steel 11
and 12 which are pressed one against the other by means of screws 13. Between
the plates 11 and 12 there is an indiarubber washer 14 which is strongly pressed
between these plates or flanges.
The method and operation of retting and drying the textile material by this
improved process will now be described:-
The basin or pan 3 being filled with the substance which is to be treated (the
figures relating to flax) and the tank 1 being filled with hot water of a
temperature of about 50° C. so as to completely immerse the pan 3, the discharge
tap 7 is closed and the taps 2 and 6 opened. The pipe 4 is placed in communication
with the vacuum pump and water from the tank is drawn into the basin or pan
until the textile substance is completely covered therewith. The taps 2 and 6
are then closed, and for about an hour the process of forming a vacuum is continued
in order to remove the remaining air; the taps and 6 are then opened and the
process of filling the basin or pan with water, the level of which has been
lowered during the operation by the departure of the air, is completed and then
the tap 2 is closed.
By detaching the pipe 4 from the vacuum pump, atmospheric pressure is
re-established in the basin or pan, which reduces the volume of air remaining in
the substance in the proportion of its proper value to that of the vacuum obtained,
thus increasing considerably the contact of the water with the said material. The
retting is then allowed to commence. After 36 hours the water in the basin is
renewed by fresh water at a temperature of about 48°. In order to do this, the
pan or basin is emptied by opening tap 7 and it is again filled by closing tap 7.
and opening tap 2. Tap 2 is afterwards closed. Three or four days after the
commencement of the operation, the basin or pan is emptied (by closing 2 and
opening tap 7). Hot water is then inserted for rinsing (by opening 2 and closing
tap 7) and the pan is then again emptied (by closing tap 2 and opening tap 7).

page_text: The material is then allowed to drain for an hour or two and then the drying is
proceeded with.
For this latter operation, taps 7 and 6 are closed and the basin or pan is again
placed in communication with the vacuum pump. This latter is formed of a
suction pump communicating with the basin by a tube in which cold water is
injected in order to condense the vapour drawn off. The vacuum produced by
this pump in conjunction with the heat imparted to the basin or pan by the
enveloping tank dries the retted material. This drying takes place in about
25 hours.
The material is retted and dried in 5 to 6 days from the commencement of the
operation. It is then removed from the pan by lifting the lid.
The right is reserved of applying to the apparatus and the method of treatment
hereinbefore described all the changes and modifications which practice suggests.
In order to facilitate the retting operation herein before described it is
preferable to
1st. Fill the basin or pan with water charged with suitable ferments in order to
assist the commencement of the retting;
2nd. To maintain at the commencement of the operatiou the temperature of the
water at about 48° during one or two hours, and then it may be allowed to fall
without inconvenience down to 35° as the minimum.
The water need not be removed during the retting if the whiteness of the fibre
is not a matter of importance. Duration of the retting varies according to the
substances, it may be two, three or four days.
In order to dry the material, the stems must be placed upright in the basin or
pan without intermediate bands under a maximum pressure in order to have a
uniform distribution. When the retting is terminated, the water is discharged
and the material is strained by draining or vacuum.
The material is then dried
by a current of air blown in at a temperature of 20° to 30° arriving by the bottom
of the basin or pan in order that the draught of air may pass parallel to the length
of the fibres.
In basins or pans of large diameter, it is preferable to watch the upper layer of
the material, and as soon as dry parts become visible to cover them with frames
or other suitable covering in order that the air shall only pass over the parts
which are still undried, and so on successively until the desiccation is complete.
In order to produce a simultaneous drying in all the parts of the basin or pan,
air may be introduced into the lower part by a metallic distributor, such as is
shown in Figure 2. It is formed of a mushroom-shaped piece perforated with holes
of such diameter with regard to the pressure that the air is distributed uniformly in
the mass which is to be dried.
The air may also be brought by means of a laterally flattened cone, as shown
in Figure 3 as a side view and Figure 4 a plan view, provided with guides 15
curved and placed in such a way that however much the pressure varies according
to the inclination of the jet, the air comes into the bottom of the basin or pan at a
uniform constant pressure.
The air flowing into the basin, the false bottom 16, 17 and 18 of which is
perforated, encounters the baffle plates shown in plan view by concentric arcs of
a circle perpendicular to the jets of air emerging from the guides and shown in
dotted lines in such a way that they divide the surface of the circle forming the
plane of the basin into equal parts. In elevation these baffle plates have the form
shown, 16, 17 and 18 of Figure 3. They are bent or curved in an arc of a circle
to 90° towards the bottom and the side from which the wind comes.
These arcs
of a circle descend so far that the volume of air deviated upwards by each of the
baffle plates shall be the same in the same time.
The apparatus for retting and drying may represent two principal arrangements:
the same basin or pan may serve for retting and for drying, or distinct basins or
pans may be employed for the two operations.
A.-In case the same basin or pan serves for retting and drying, a pan or basin
K

page_text: may be employed having one or several stages for stems as will be now
described.
Firstly, a pan or basin with a single stage. The basin Figure 5 is composed of an
upright cylinder of about 1.20 metres in height and a diameter varying according
to the capacity which it is desired it should have. It is covered by a curved lid
from the top of which the pipe for forming the vacuum in the apparatus debouches.
Below, it is terminated by another curved surface. The latter has in its lower
part a nozzle or socket 19 on which the tube for supplying air is connected. The
tube for bringing the water is also connected with the same socket or nozzle on the
one side, and on the opposite side is the pipe for discharging. In order to allow of
a suitable temperature being maintained, steam is injected by means of three taps
arranged in the bottom of the pan at equal distances apart in the space below the
lowest screen supporting the stalks. These taps are placed in the same horizontal
plane and are connected by a circular or curved tube which receives steam from a
suitable supply.
A thermometer 20 is fixed in the bottom of the pan, and
another may be placed at the top below the water level but above the topmost
screen. By observing these thermometers, the desired temperature may be easily
maintained by regulating from time to time the steam supply.
The entire external surface of the basin or pan is coated with a good insulating
substance. The cylindrical part has two partitions, the one at the top, the other
at the bottom, between which the substance to be treated is held during the retting.
The bottom of the nozzle or socket 19 is closed by a solid joint 21. When the
straining is terminated and the water therefrom run off, this solid joint is removed,
and the solid substances remaining in the bottom of the pan or basin fall below
into a trough arranged for the purpose.
When it is desired to dry the material, the pipe 21* of the suction apparatus or
fan is connected at 21. This pipe is bent at right angles and returns to the main
air pipe 22. At 23 and 24 there is a joint hinged on 23 on which the pipe 21*
may turn in order to assuine a vertical position, so that its opening avoids
coming in contact with the substances discharged from the pan or basin when the
solid joint 21 is opened.
In case the air circulation is effected at one side of the bottom, the tubes for
water discharging, steam and the thermometer are placed on the other side.
In the preceding arrangement the stems must be brought into the basin or pan
and removed therefrom by hand.
If it be desired to bring them into it or remove them from it en bloc, a
mechanical arrangement such as is shown diagrammatically in Figure 6 may be
employed.
The material to be treated is placed in a cylinder having open sides and
hottom, of a diameter less than that of the interior of the basin or pan to such
an extent as to allow of it being easily inserted.
This cylinder should have a metallic bar placed according to its axis, the
lower end of which is screwed or threaded and carries a nut which sustains
the bottom piece. This rod is provided in its upper part with a somewhat
strong book in order to raise the cylinder filled with material.
If the diameter of the basin or pan is such that the charge is too heavy for one rod,
several rods uniforinly distributed and conuected by cross pieces may be employed.
The frame thus formed is provided with a hook for raising the material.
With this arrangement in which the current of air may pass between the open-
worked cylinder and the basin or pan, three elastic flanges may be arranged for the
drying as is shown in the figure by 25, 26, 27. Any material other than the
textiles which is in the pan or basin must be unattackable by water or the products
of fermentation.
Secondly. A pan or basin having several stages.
The apparatus may comprise several tiers of material with the object of
economising space and the expense of basins, because for several stages or tiers
there is only one cover and one furnace, the outer cover and the bottom being like

page_text: those of the basin or pan having only the single tier. It will be sufficient to
describe the spécial arrangement for multiplication of the stages.
As may be seen in Figure 7, each stage will be about 1.20 metres in height, and
each partition must be strong enough to support with safety the corresponding
loaded stage above it. The material may be brought into the vessel or removed
therefrom by hand.. All the stages already loaded may also be brought or inserted
and with this object the same arrangement as was described in Figure 6 may be
employed in a similar case.
B. When distinct basins or pans are employed for the retting and the drying,
the latter are always in several stages. The retting basins are divided into two
categories, those in which the material is supplied and removed by hand and those
where this work is done by mechanical means.
When the material is manipulated by haud the basin or pan, Figure 8, resembles
the one shown in Figure 5 with this simplification that the air-pipe is dispensert
with and replaced by a discharging pipe; the basin or pan has several stages.
When the material is treated by mechanical means, the arrangement is the same
as that shown in Figure 6 with a number of stages, the air-tube being dispensed
with and replaced by a discharging pipe. Drying pans or basins are intended to
methodically dry the retted fibre.
The fibre when it has been strained is inserted at the top and the dried fibre
withdrawn from the bottom. The air flows in from below and passes out from
above. This arrangement is shown in Figure 9.
The basin or pan of itself is very simple. It is composed of a straight cylinder
of equal diameter to that of the retting pans with which it is employed and of such
a height that the air passes out saturated for the greater economy of the heating
and motive power. The bottom of the basin or pan is curved, terminated below by
the pipe supplying the air. In this case as all the operation is performed
mechanically a special arrangement is necessary for this purpose. It is necessary
that one tier when dried must be able to be withdrawn from below and a freshly
retted tier be inserted above. For this purpose the bottom of the basin has a
door 28, 29, 30 semi-circular, of the same height as a stage carried on a carriage,
capable of turning on hinges 28 in such a way as to open half the lower part of the
basin or pan.
Two rails are placed transversely to the commencement of the
bottom, serving for guiding the carriage sustaining the lower stage of fibre.
These rails are extended at this level to 31 outside of the pan or basin and there
is a shunting place at 32 in order that an empty carriage may be held in readiness
there.
Above the basin or pan a trolley is arranged travelling on rails intended to
bring to the top of the apparatus the tiers of fibre coming from the retting process.
During the aeration, all the tiers except the last at the bottom are maintained in
equilibrium by the upper crane. For this purpose a bisected rod passes through
all the stages in the direction of their axis. Each section has the ring at the
bottom and a hook at the top so that it can be connected with the one above
it and to the one below it, the last section at the bottom resting merely on the
carriage. If the diameter of the basin or pan is such that the charge is too
heavy for one rod, several rods uniformly distributed may be employed. They
are connected above by cross pieces at cach tier and a single hook is attached
to each of these frames thus formed.
The operation for withdrawing from below a dry tier and introducing above
a tier coming from the retting is effected as follows. The stages or tiers 33,
34, 35 are first suspended by means of a transverse bar by passing it into the
hook 37, then the chain of the travelling crane is detached from this hook,
the lower door of the pan or basin is opened, hook 38 is detached from its ring
and the lowest dry tier will be drawn out of the basin or pan on its carriage
and the empty carriage re-inserted.
At this moment there must be inserted at the top another tier fresh from the

page_text: retting, and in order to do this, it is brought to the top of the pan or basin by
means of the travelling crane. The lower ring of its rod is passed into the
hook 37 and the transverse bar is withdrawn. The fresh tier is then caused to
descend by the trolley and the tiers 33, 34, 35, until 35 rests on the carriage. The
circular door of the pan or basin is closed by stopping the free space below the
door occasioned by the passage of the rails and air is driven in until the tier 35
is completely dried. Each tier will have elastic supports or flanges.
The arrangement of pans or basins with separate stages for the retting and the
drying is suitable for large factories in which the necessary first cost may be
incurred in order to obtain greater results.
It has the advantage of reducing to a minimum the number of basins or pans
which have to be worked, because the methodical drying effects a considerable
saving of time.
It withdraws the fibre from the drying action of the current of air, (which
otherwise might be prolonged,) immediately it has become dried, and this is
favourable to maintaining the quality of the textile fibre.
Finally it reduces to a minimum the expense of motive power and all heat to be
supplied to the air current for a given weight of material to be treated.
The process which has just been described may be slightly modified by
suppressing the use of vacuum. The material is then merely treated with water,
heat and air. In this case the material to be treated is first immersed in closed
vats or basins filled with water at a temperature varying between 30° and 38° C.
according to the quality of the material and it is left therein until the retting is
terminated which is ascertained when the textile fibre when dry is easily detached
from the stems which surround it.
The retting is carried out to a greater or lesser extent according to the nature
of the material and the number of the threads which it is desired to draw
therefrom.
When the retting is completed, the water in the pan or basin is discharged to
the outside and the material is allowed to drain. Then without removing it, it is
dried by means of a current of hot air as has been already described.
In order to proceed to the retting of textile materials by this process a special
apparatus shown in Figure 10 of the accompanying drawings is employed. This
is composed of a cylindrical vessel 39, 40, 41, 42, which may be of various heights
according to the quantity or weight of material which is to be placed therein.
It may be divided into several stages or comprise only one. In the accom-
panying drawing the pan is only assumed to be divided into two stages by a
perforated partition 43, 44 placed on a movable frame.
In the interior of this pan or basin several horizontal movable partitions or
screens placed on equally movable frames may be employed. There is always
one frame more than the number of tiers or stages employed so that the material
is enclosed or contained at each stage between two consecutive frames. There are
the same number of screens or partitions as stages because there is not one above
the upper frame. Thus in a five tier pan there are six frames and five screens,
there being no screen on the top frame. The pan or basin 39, 40, 41, 42 has five
lateral orifices. The orifices 45 and 46, the one above and the other below, are
intended to receive thermometers, and three orifices 47 (only one is visible in the
drawing) below, arranged at equal distances round the circumference of the pan or
basin under the material to be treated, serve for injecting steam in order to
maintain the temperature to a suitable degree.
The basin is fitted with a cover having a hole in the centre for discharging
the gases from the fermentation, and an arm hole near the edge in order to
allow samples of the material to be withdrawn by means of it in order to be
examined for the purpose of seeing how far the retting is advanced, and is
completed at its lower part by a conoid trunk, the surface of which is represented by
the curved line 42, 48, 49, 50. This curve is formed of two arcs of the circles, 42-48

page_text: and 49-50 and connected together by means of a common tangent 48-49.
These ares are perpendicular, the first to the horizontal plane, 41-42, the second:
to the horizontal plane 50-51. The arc 42-48 turns its concavity towards
the axis of the apparatus, and the arc 49-50 turns its convexity towards the
same.
The bottom of this conoid trunk is connected with a vertical tube 52 (Figure 11)
of the same diameter by means of a register 53, which may produce or interrupt
the communication with it as may be desired. It has at the side a discharge tube 54
provided with a register 55 and several armholes for cleaning purposes. A tube 56
connected to the pipe 52 serves to bring air into the apparatus. In the interior of
the conoidal trunk is a series of conoidal trunks of smaller diameter or air guides 57.
They have for their object to distribute the air uniformly in all the parts of the
stems treated. These air guides which may vary in number according to the size
and diameter of the apparatus are concentric to its axis and such that their superior
sections at 41, 42 intercept between them exactly equal annular surfaces and that
their lower sections at 50, 51 intercept among them increasing annular surfaces
from the centre to the circumference.
Figure 10 of the drawing accompanying the Provisional Specification shows that
the lower part of the conoidal trunk is horizontal. This arrangement is sometimes
employed but in order to facilitate the working it is preferable to arrange it at
an angle of about 20° as shown in Figures 11 and 12. This inclination may of
course be varied. The distance of the horizontal plane 50 from the surface of the
ground may be evidently greater or smaller.
This improved apparatus may be constructed of any suitable substance or
material so long as they are not attacked by water and the products of fer-
mentation. It may more particularly be constructed entirely of metal or in metal
and concrete.
This is how the operation is carried out. The husked green flax (or any other
suitable textile material) is placed vertically in each of the stages of the
cylindrical part of the basin without bands, the bottom of th
m below and the
head above. Each stage is arranged in such a way as i ave the height of
the stems which are to be treated. It is completely in ersed in water, the
temperature of which varies between 30° and 38° C. accoring to the material.
When it is found that the retting is completed (this operation may be more or
less prolonged as has been hereinbefore explained) the apparatus is emptied by the
lower lateral opening 54, and the material is allowed to drain for a longer or
shorter time, remaining in its place. Then the drying is proceeded with. For this
purpose the cover plate over the basin is removed, the discharge opening is closed
and the register 53 of the air pipe 56 is opened. A current of hot air, the
temperature of which may vary between 30° and 50° is then passed into the textile
mass.
When the desiccation is completed, the current of air is shut off and the flax is
withdrawn and made into bundles.
In the case of large installations, the retting and the drying may be performed
in separate apparatuses.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, as communicated to me
by my foreign correspondents, 1 declare that what I claim is :-
:-
1. A process for retting and drying textile materials (flax, hemp, ramie,
phormium tenax or the like) which consists in treating the materials in a closed
vessel and under the action of beat and vacuum, irrespective of the kind of
apparatus employed for these operations substantially as described.
2. The retting of flax and other textile materials (hemp, ramie or the like) in a
closed vessel under the action of water at a temperature varying from 30° to 38° C.,
the material being dried by means of hot air either in the retting vessel itself or in
a separate apparatus substantially as described.

page_text: 3. The special apparatus for retting and drying textile materials substantially
as hereinbefore described and illustrated.
ليم
1
J
T
1000
WM. P. THOMPSON & Co.,
Agents.