US1571474A - Apparatus for the manufacture of artificial threads or filaments - Google Patents

Description

Feb. '2 1926. 1,571'-,'474

N. B. GRILLET APPARATUS FOR THE MANUFACTURE OF ARTIFICIAL THREADS 0R FILAMENTS Filed March 5, 1924 a Sheets-Sheet 1 I NICOLAS BEN (TGRILLET, Q @aZn m J Feb. 2 1926.

v N. B. GRILLET APPARATUS FOR THE MANUFACTURE OF ARTIFICIAL THREADS 0R FILAMENTS Filed March 5. 1924 s Sheets -Sheef; 2

Jwv Z9 NmoMsBEw/T BILLET,

* Feb. 2,1926. 1,571,474'.

N. B. GRILLET v APPARATUS FOR THE MANUFACTURE OF ARTIFICIAL- THREADS 0R FILAMENT S J Filed Marcus). 1924 3 sheets-sheet 5 Jrwevndov NIOHLAS BE/von'fimLLET;

Patented Feb. 2, 1926.

UNITED STATES PATENT OFFICE.

NICOLAS BENOIT GRILLET, OF NEUILLY, FRANCE, ASSIGNOR '10 SOCIE'IE POUR LL FABRICATION DE LA SOIE RHODIASETA, OF PARIS, FRANCE.

APPARATUS FOR THE MANUFAGTTJRE or ARTIFICIAL rnminns on rmnmimrs.

Application filed March 5, 1924. Serial No. 697,028.

To all whom it may concern:

Be it known that I, NIcoLAs BENOIT Gun.- LET, residing at Neuilly, Seine, France, a citizen of the Republic of France, have invented certain new and useful Improvements in Apparatus for the Manufacture of Artificial Threads or Filaments, of which the following is a specification.

The present invention relates to improvements in processes and apparatus intended for the manufacture of artificial filaments of all kinds constituted by a single fibre or, on the contrary, by the union of several fibres obtained by flowing or spinning, in a gaseous medium, whether heated; or not, of'a more or less viscous fluid of suitable composition, comprising essentially:

(1) A solvent or solvent mixture (A), volatile in the operating conditions which are selected for spinning the said fluid.

(2) A body or mixture of bodies (B), suitably selected, non-volatile in the operating conditions adopted for spinning, which, when freed by evaporation of the liquid or mixture of liquids (A),-constitutes the substance of the artificial filament issuing after spinning, (B) being constituted, for instance, by an ether, an ester, or another derivative of cellulose, alone or mixed with other ethers, esters, or cellulose derivatives, or else by a derivative or mixture of derivatives of cellulose with substances adapted to impart plasticity or non-volatile solvents of the said derivatives, the mixture (B) being, if desired, such as also to comprise in every one of the above cases one or more definite bodies, added for various purposes, which-will remain in the completed filament or which will be subsequently removed, for instance, to dye it, to dress or finish it, or give it any required useful properties in view of its ultimate use.

In such processes the spinning apparatus properly so-called is constituted by a cage or cell, closed or almost closed, within which is placed at one of its extremities the spinning device or spinning die, which comprises essentially holes or orifices the shape, numher and diameter of which are suited to the kind. of threads or filaments which it is desired to manufacture, the exit orifice or orifices of this or these threads or filaments filaments, or by openings of suitable shape and dimensions provided in the portion of the walls of the cell which is in the neigh borhood of the said issue orifice or orifices. It passes through the cell in the opposite direction to that of the threads or filaments which are being manufactured, and issues from the cell by openings suitably provided n the portion of the walls'of the cell which is in the vicinity of the spinning device. The said gaseous medium is either aspirated from or. forced through the cells by means of any suitable device or propelling apparatus known and in common use.

The said gaseous medium is preferably heated by any suitable means, either outside the cell, before entering the latter, or

in the cell during its assage therethrough, or by these two methods simultaneously, the heating being carried out so as to obtain a suitable regular temperature in the whole of the cell; however, if desired, difierent temperatures may be maintained at difierent levels in the cell, as may be suitable for any desired purpose.

The fluid to be spun is brought to the spinning dies at a suitable pressure and by any known means, after having through, if thought advisable, any esired apparatus such as filters, regulators for the temperature or the pressure, and the like. It issues by the orifices of the spinning dies and passes through the cell inthe opposite direction to the aforesaid current of the gaseous medium, either in a natural manner, when the spinning takes place in a. downward direction, or by any suitable arrangements in the other cases. As the volaassed tile body or mixture of bodies (A) gradually evaporates, the thread or threads, filament or filaments, issuing from the orifice or orifices of the spinning device, solidify and acquire consistency. As soon as this consistency is suflicient, and particularly as soon as the threads or filaments are dry or nearly dry, they are ready to be made to pass out of the cell by any suitable orifices, after having united them, if required, into one single thread or filament. From this point, this or these threads or filaments proceed to any further desired apparatus or plant in order to receive any suitable treatment, such as, for instance, stretching, 11npregnation with any substance for any desired purpose, twisting, bobbining, etc.

The whole or part of the said treatments may, however, take place either entirely or partially within the cell, before the threads or filaments issue therefrom.

Finally the cell may be provided with any accessory apparatus or plant which may be' necessary or desired, either to facilitate the spinning or to allow the control and the regulation ofthe process, or for any other purpose, such, for instance, as those described for the sole case of the downward spinning in the co-pending application No. 667,872 of 11th October, 1923, or in any other suitable or usual and known apparatus or plant.

The present invention is more particularly applicable to the industrial manufacture of artificial threads or filaments of all kinds by the process called dry spinning, the principal characteristics of which are 1nd]- cated by the foregoing description.

In this industrial manufacture a very large number of cells of the type described above is, of course, employed. They are usually arranged in such a way as to occupy the least possible area of the shed, every one of them being employed in the manufacture of a similar commercial grade of products, or else, more frequently the cells being distributed in a certain number of groups of cells, more or less important,'each one employed in the manufacture of a different kind.

By similar commercial grade is meant not only products of the same kind, such, for instance, as silk. wool, horse-hair, or any other artificial filament, but for each of these kinds products of the same commercial quality are meant, and particularly having the same number of fibres of the same standard, excepting naturally such qualities as torsion, dyeing,

preparation, etc., which are, or may be,

given to the threads or filaments'after their complete formation and outside the manufacturing cell.

At is natural, it will be necessary that the commercial quality of the products manufactured by each cell of the same group be as uniform as possible,'not only in space, that is, for the several cells of the group, but also in time, that is, for the same cell, at the various moments of the manufacture.

The standard and the. qualities of each elementary fibre which is manufactured depend on a great number of variable factors, among which may be mentioned: the composition of the fluid to be spun, its viscosity, and therefore its temperature, the form and the dimension of the spinning die or dies, the spinning pressure, the speed of spinning, and therefore the tractive efforts which are exerted upon the thread at the moment of its formation, and, finally, to a very great extent, the nature and the properties of the medium in which spinning takes place, particularly at the beginning, when the elementary fibres are still plastic and devoid of solidity, and the time during which this medium acts, that is, the length of the cell. This medium,-tl1at is, the gaseous atmosphere selected, exerts a special influence by its temperature and its rate of flow, apart from any chemical action.

The temperature of the said atmosphere affects the viscosity of the fibre being formed and therefore the shape which is assumed by this fibre; it also affects the speed of evaporation, and therefore the speed of formation of the fibres. The rate of flow will affect-the speed of evaporation on one hand for a well-known purely mechanical reason, on the other hand in determining, together with the temperature, the successive proportions of volatile solvents in the said atmosphere, and, therefore, its evaporating properties.

All these variable factors on which depend the standard and the properties of each elementary fibre are not, of course, independent of one another, and it would be possible, at least theoretically, to regulate or modify one or some of them, so as to compensate the variations of one or of some others, and to obtain, in spite of these variations, a uniform manufactured product.

The only practical and known means for en surmg the required uniformity is, however,

to maintain as strictly constant as possible, in space and in time, all the conditions governing the spinning of a cell of the same group.

The cells are preferably uniform in shape and dimensions, the spinning device or the whole of the spinning dies of each cell being similarly placed and as identical as possible. The fluid to be spun utilized for feeding the group is of constant composition and is brought to the spinning dies by means of any suitable usual or known apparatus or arrangement, under a regular and constant pressure and either at a constant temperature or at a temperature such that the viscosity of the said fluid is constant. Finally, it will be spun at a constant speed in a medium of constant composition and temperature, constant in time and for regions similarly placed, that is, occupying the same level in each cell of the group, the said me dium being either forced through or aspirated from the cell with a rate of flow which is maintained constant and uniform.

The present invention relates more particularly to improvements in the usual or known arrangements in order to ensure the uniformity of the heating of the gaseous medium before or while passing through all the cells of the same group, together with the regularity of the rate of flow of the said medium through the said cells. This result, to my knowledge, has hitherto not been obtained, no one having succeeded in ensuring the automatic regulation of the heating, in a simple manner, simultaneously in a very great number of enclosures.

The idea which occurs quite naturally is to regulate individually the heating in each of these chambers by means of suitable taps or any other devices. This regulation, however, is laborious, it uselessly occupies a great number of hands, and cannot be, in any case, strictly uniform. Former operators have also been satisfied with the heating in series of a relatively small number of these chambers with the same heating device (coil with steam or hotwater circulation, for'instance) or with other similar methods. In this manner of heating in series, mentioned above, it is evident that the number-of heat units supplied to the apparatus situated at the end of the piping is very interior, for an equal heating surface, to the number of heat units received by the apparatus at the beginning of the piping.

Generally no account is taken of this irregularity or else it is diminished by suitably modifying the intensity of the heating arrangement for each chamber, according to its rank in the series of chambers to be heated, which, for a great number of chambers, complicates extremely the heating installation.

- I have found that one can obtain in a very simple manner a heating which is as strict ly uniform as may be desired, in a number, however great it may be, of similar chambers provided with identical heating apparatus, by operating according to the principles mentioned hereafter, which I shall first set forth in res ect of a heating coil with hot water circu ation. This hot water is provided, for instance, with a suitable tank or reservoir, where its temperature is maintained uniformly at the required degree by any usual or known means.

If the heating coils of all the chambers.

are placed in series on this hot-water tank, the chambersv which are situated farthest from the reservoir will receive, as has been explained above, less heat units than the chambers which are nearer to the said reservoir.

A compensation to these. differences in the heating of chambers placed at dilferent ranks is obtained by providingthem with a second heating arrangement, arranged in series, identical with the first (the coils having the same dimensions) which is the seat of a current flowing in the opposite direction to the former, either a current of hot water at the same temperature as for the first heating and having the same rate of flow, or, more simply, by the hot water itself which has been used for this heating and which returns in this manner to the head of the series of chambers after having passed through each of them twice in opposite directions.

The scientific study of the problem shows that the compensations will not be absolutely strict, but that the maximum departure is independent of the number of chambers to be heated and is a function only of the differences between the temperature of the heating water at the beginning and at the end of its circuit and the temperature, suppoi'ed constant, of the chambers to be heated. It shows, moreover, that whatever may be the latter temperature, the diflerence between the extrcme temperatures of the heating water may alwaysbe chosen so that the maximum departure from the average heating may be inferior to any desired" value.

\Vhatever may be the value of these theoretical considerations, I have actually verified in practice that, for a very great number of cells arranged according to the above principles with double heating coils identi- .cal with one another, and designed so as to provide an ample allowance, for all the ells the heating is practically strictly uniform for a difference of temperature between the incoming and the outgoing heating water approximating to 5 to 10 C. for instance.

The water having been used for the heating, can of course-be utilized again, and, for instance, may go back to the feed reservoir where it will receive by any suitable means only the heat units lost during its journey. so that the important condition mentioned above that only arelatively small difference can be allowed between the extreme temperatures does not involve any supplementary consumption of fuel.

It is superfluous to insist upon the em ciency, the certaintv and the simplicity of installation or of wo'king of the arrangement which I have discovered compared with all the processes hitherto known or at into practice, but it will be understood t at the form under which this arrangement will be put into operation may depart considerably from that which has been described above for the ,clearness of the demonstration only, without departing from the spirlt of the present invention.

Instead of water, one may use for this heating any liquid, any solutions, or even any fluids, gas or vapor, which may be deemed suitable or desirable. The said fluids may be used over again as ithas been said above or in any other manner, in wggole or in part, or, on the other hand, it may not be so used again. It may be heated at any desired. temperature: electrically, by a flame, hot gases, steam coils or steam bubbling, or by any other suitable, usual or known means. It may be purified or not, or may be mixed or not with any substances, for instance, to avoid its thickening or the for mation of deposits, or for any other reason.

The heating plant for the said fluid, outside the group of chambers, may be of any kind and may comprise any apparatus or necessary arrangements which may be desired, for instance, for storing reserves of hotor coldfluid, fresh or already used, for

' controlling and regulating its rate of flow through the group or its temperatures, avoidlng any unnecessary heat losses, or for any other purpose.

The said installation may be single for the whole group or, on the contrary, the latter may comprise, if it is desired, several similar or identical installations. All the chambers of the group may be in series upon the same installation, or, on the contrary, may be distributed in sub-groups of chambers in series, these sub-groups being themselves arranged in parallel on the said installation or installations and all usual or known precautions being taken, with the help, if necessary, of any useful accessory apparatus or devicesato ensure in spite of this the uniformity of the heating in all the chambers of the group.

On the contrary, two or more groups of cells employed for different manufactures may be connected as stated above upon the same heating installation, arrangements being made by means. if necessary, of any apparatus or suitable accessory devices, known or usual, so that each of these groups should receive the rate of flow of heating fluid which is useful for the best possible working of the manufacture in which it is employed.

The fluid utilized for the heating may be driven at any desired speed through the heating "-il;=by any means or suitable usualor known apparatus, for instance, mechanical, such as pumps. 'or physical, such as thermo-siphons, or both mechanical and ph sical. or based on any other principle.

The heating coils, identical for each chamber, may be cylindrical, or. on the con-.

trarv, may have any other suitable or desired shape. 1 They may be replaced by any similar arrangement, such as heating jackets or any other arrangement, be provided with vanes or any other radiating members for heat, and be placed 1n such zones of the chamber which may be deemed advisable. Similar arrangements may, of course, be used for cooling instead of heating.

In the manufacture of artificial threads or filaments which specially concerns me, the above described arrangement which I have discovered may be used as well for the heating of the groups of cells as for the heating or cooling of the selected gaseous atmosphere, eitherbefore its entrance into the cells, or after it has come out of same, whatever may be the purpose in view in performing these operations.

The use of these arrangements will therefore permit, all other spinning conditions remaining the same, the obtainment at the exit of each of the cells of the group of a gaseous atmosphere of strictly constant composition and temperature, which will allow the regulation of its rate of flow in a manner also strictly uniform, as will be described hereafter.

Concerning the regulation of the rate of flow, when it was not neglected, which could only lead to unsatisfactory results, as I have shown above, it has hitherto been performed by means of regulating arrangements individually provided for each cell. These arrangements, very simple apparently, so that they presented themselves at once to the mind, have in practice serious inconveniences.

Although it is obviously easy to regulate two or a small number of taps placed upon pipings connected to the same general collector, in such a way that the gaseous flow through each of them is approximately the same for all, it is evident that the problem becomes much more delicate and laborious to solve if it is a question, as is the case industrially, of a very great number. for example a thousand or more taps, to be regulated in a uniform manner, even if these thousand or more taps are each provided with a flow meter, the thousand or more flow meters being carefully compared and standardized;

In spite of the high cost of such an illstallation, it will be very diflicult to obtain by this process a strictly uniform regulation, particularly if the temperature of the gaseous medium issuing from the cell is not strictly the same for all the cells of the group and, moreover, during the course of manufacture itself, it will not be possible to desired, by observing the following d1rections which I shall first set forth in the supposition that the gaseous atmosphere 1s aspirated through the cell.

Each of the cells of the group is connected by an individual pipe or passage to a collector which may be either a general collector, common to the whole group, or a secondary collector, common 'to a portion of themselves connected to collectors of a more general kind, and so on, so that all the groups are finally in communication with a general collector to which are connected the aspirating device or devices associated with the said group of cells.

It will be essential that all these individual passages, secondary or general, have a large diameter, so that the loss of head produced by them is negligible, or very small, compared to the difference of pressure obtained by means of the aspirating device.

In this manner the fall of pressure will he the same in the individual outlet pipings conducting from each cell to the corresponding collector. If this group is very important and therefore the losses of headin the above described system of piping not negligible, although very small, the same result will be obtained, namely, uniform fall of pressure at the. exit ofthe cell for all the.

cells of the group, by a. suitable arrangement, for instance one which is perfectly symmetrical, of this system of'piping, or by any other suitable usual device or any device known by technical experts. WVith the above described arrangement, and if the inlet orifices to each cell for the selected gaseous medium have been also designed with an ample allowance, together with the section of the parts or apparatus through which the said medium may be made to pass for various purposes before entering the cell, the rate of flow of this medium through each cell will be strictly the same for all the cells of the group. It may be adjusted to any desired value by creating in the general collector, by any suitable or known means, exactly the fall of pressure which, taking into account the dimensions of the plant, precisely corresponds to this desired rate of flow.

Without excluding the possibility of proceeding as described above, I prefer, however, to create in the general collector'a fall of pressure which is greater or much greater than that which would be necessary according to the above method. The desired rate of flow in each cell is then,-in this latter case, obtained by providing the individual outlet piping of each cell with individual devices causing a loss of head. These devices may be of any kind, for instance, they may be constituted by tubes of small diameter and of definite length inserted in the said outlet individual pipings or else definite constrictions of the said pipings or else diaphragms constituted by holes of definite diameter pierced in plates of definite thickness and placed in said pipings or else, finally, any I other suitable usual or known system.

The said arrangement is constructed or the rates of flow approximating to a desired rate, a notable or even very marked loss of head in comparison with the loss of head for the same rate of flow corresponding to the whole of the remaining pipings for the gaseous medium or the variations of the losses of head caused by any manipulation which may be performed on the gaseous stream or, more generally, to any cause whatever. I

In this manner, the variations in the design of the said whole of the pipings, unavoidable in practice when it concerns a group comprising a very large number of cells, will only have an importance which may be as small as may be desired on the course of the process which is the object of the present invention- These arrangements may be strictly identical for all the cells (for instance, diaphragms with holes ofthe'same diameter pierced through plates of the same thickness) if the above indications have been borne in mind. They can also differ, for instance, for one or some portions ofthe group, in order to allow for the different losses of head in the pipings corresponding to this or these portions of groups and resulting either, for example, from a nonstrictly symmetrical installation, or from any other cause.

It is well understood that the loss of head caused by the individual devices above provided'for each cell, and therefore also the fall of pressure to generate in the general collector, will be selected in such a manner that, hearing in mind the importance and the irregularities of the whole of the pipings of the group or the possible irregularit1es in the working of the aspirating apparatus used, the variation of the rates of flow, either in the same time for the same cell, or in space for all the cells of the group, will not, in the most unfavourable case, exceed the required value, as-determined in advance,

whatever may be the gaseous rate of flowwhich passes through the cells, bearing in .mind all the contemplated changes in manufacture.

' In all cases itis an extremely simple matter to vary these rates of flow to pass from one manufacture to another or in any other desired purpose, since it is suflicient for this to cause a variation of the fall of pressure arranged in such a manner as to create, for the group only, the secondary collectors being provided with a suitable The apparatus used for generatin thegaseous stream through the cell may of any kind; it may be connected to a single group, or, on the other hand, may be connected to several groups each of WlllCh 1s eneral collector, by any suitable usual or own means or arrangements.

The pipings connecting the cells to the pumping arrangement may be provided with any suitable accessory organs to fulfil the required purposes. For instance, in the case of the generation of the gaseous stream by aspiration, if it is desired to recover the -'volatile solvents contained in the gaseous medium issuing from the cells, the installation necessary for this recovery is preferably located after the aspiratlng devices, but, in order to perform this recovery in good working conditions, the said pipings may be then provided with any suitable a.r rangements, for instance, for OOOllIlg or otherwise for any desired purpose. One may also in this case foresee the possibility of isolating any cell or any group or any portion of a cup. of cells Whlch is momentarily not 1n operation for any reason, for instance, for repairs, this bein obtained by means of any suitable usual or own arrangement. If the arrangement which causes the loss of head is a diaphragm introduced in a joint of the individual pipings, one may, for instance, arrange that the plate in which the whole of this diaphragm is pierced is adapted to slide in the joint so as to block it. v

If the gaseous medium issuing from the cells and carrying volatile solvents is inflammable or explosive or adapted to' become so, one may introduce, if convenient, on the individual outlet pipings of each cell, or on the secondary or general collectors, safety devices of any known ty but preferably not causin any loss of ead except losses of head w ich are very small or constant.

-These devices may comprise, for instance,

metallic uzes in combination with sudden changes 1n the shape of'the section or in the direction of said pipings and with portions of their wall which are either fragile or mobile, adapted to come apart or to open in the case of fire or explosion within said pipings to bring their contents in ample contact with the surrounding atmosphere.

In the case of generation of the stream by forcing the gaseous medium through the cell, this gaseous medium may be submitted, be tween the pump and the cells, to an suit able or desired treatment such as ing, moistening, heating, or cooling, or othe In both cases, the gaseous medium may in whole or in part after recovery of the solvent, or after having been freed from the whole or part of the latter, by any suitable means or process, and restored to the condition whereit is desired to use it in normal circumstances b or, on the contrary, molstening, heating or cooling, partial exhaust to the atmosphere and in production of new aseous medium or generally any other suita le operation.

Temperature equalizers may be provided if desired and accordin to any known or suitable arrangements, tween the warm gaseous medium issuing from the cells and the whole or part of the medium intended for the supply of the said cells."

It is understood that the arrangement which constitutes the object of the present invention may be used, whatever may be the type of the cells adopted, their form and the manner in which they are constituted or united in groups, the number and the dimensions of the elementarv fibres, in each thread or filament, as also the nature of the cellulose derivatives, of the solvent or solvent mixture, and of the various additive substances which constitute the fluid to be spun, the nature of the composition of the atmosphere in which the spinning takes place, and whether the spinning 1s performed upwards or downwards or many other manner. i

The treatments to which the threads or filaments which have been manufactured are subjected, after their formation, either in "or may not be sent again through the cells means of drying the cells or outside the latter, such as supplementary stretching, impregnation by any compound and for any desired purpose, torsion or winding or any other treatment, may be ofany kind and even varv fronr one priii-tion to another of the same group of ce s.

In order to illustrate the present invention, I describe hereafter its application to a group of 500 cells in each of which a solution of cellulose acetate in a mixture of acetone and methyl alcohol is spun upwardly to form artificial silk in a current of air from the atmosphere of the shed, aspirat ed through the cells, which are internally heated by circulation of hot water.

It will be understood that this description is given as an exampleonly, and does not in any way limit the invention as described above.

. In the appended diagrammatic draw- 1ngs:-

Fig. 1 represents in plan the heating diagram for the group, the cover of the upper half group of cells being withdrawn to show in plan the arrangementof the-heating elements, the distribution piping being indicated for one half of a group only, and all accessory organs being supposed omitted;

Fig. 2 represents, in plan and in elevation, the detail of a heating element;

Fig. 3 represents in plan the diagram for the whole of the pipings for the aspiration of the air through one half of a group (not shown) Figs. 4 and 5 represent the front elevation and end view of a portion of a group, showing in a more detailed manner the application of the heating and aspirating arrangement to one cell.

1, 1, 1 represent single parallelopiped shaped cells, united to one another so as to form partial groups 2, 2, 2 of 50 cells.

In each cell 3 is a glass door allowing the spinning performance to be supervised, and to remedy all incidents of manufacture. 4 represents the spinning die of each cell, which die is supplied with the fluid to be spun by means of any suitable device. 5, 5 are the elementary fibres produced by each hole, orifice or spinneret of the spinning de, and united into one thread 6 which issues from the cell b a suitable orifice 7 to proceed to any furt 181 suitable apparatus or plant (notshown) 8, 8, represent return heating elements, all identical among themselves, for all the cells, and constituted by semi-cylindrical double-walled vessels, illustrated with greater details in Fig. 2.

- The heat ng elements of two neighbouring cells are connected together, internally of the cell, by short pipes 9 of large diameter, passing through their common Wall, in any easily conceived manner;

The series of elements forthe outgoing hot water are connected to the series of elements for the ingoing water by elbows 10, 10 external to the cells, situated at the end of the sub-groups of cells opposite to the hot water inlet. These elbows are very carefully lagged with a heat insulating material.

The hot water issues from a reservoir 11, very carefully lagged with a layer 12 of heat insulating material, and rovided with a thermometer 13, a. level lndicator 14, an overflow 15 and any other desired auxiliary apparatus.

Preferably, condensation water, or carefully purified water, will be used to avoid deposits.

The water is heated in the reservoir 11 by means of steam jets 16, the output of which can be regulated by cocks 17. It proceeds to the several subgroups of cells by the systems of piping 18, its supply being ensured by a pump 19, placed at. the head of the .piping system, and the output of which is adapted to be varied.

Perforated diaphragms 20, the orifices of which are carefully determined, are placed at the head of the'piping of each sub-group heat'ng system, so that the rate of flow of the water is the same in all these systems, or else one uses for this purpose any other simple device. At the end of its journey, the water is sent back in the reservoir 11 by the piping system 21. These piping systems 18 and 21 are very carefully coated with a thermal insulating lagging. Thermometers 22 are placed at the inlet and at the outlet of each sub-group heating system; and also, if desired, in the cells, in order to allow the control of the temperature at various levels. The latter thermometers may be fixtures or removable.

The desired variations of the heating of all the cells of the group are very simply obtained b altering to this end the temperature of t 1e water of the reservoir 11.

The air of the shed enters in each cell by the outlet orifice 7 of the thread, and also by the orifices 23, 23 provfded in the portion of the walls of the cell which is in the vicinity of this outlet 7.

After having become charged with vapours in the course of its journey through the cells, the air issues by the pipings 24, 24 compris'ng each a joint 25 in which is situated a diaphragm 26 of suitable design, the same for all the cells, which diaphragm is adapted to slide to close the joint.

The pipings 24 end in secondary collectors, 27, provided with pressure gauges 28 and any other desired regulation and control apparatus. These secondary collectors 27 are connected to a general collector 29 by me us of pipes 30 whch comprise a fire safety device 31, constituted by metallic gauzes 32 and paper discs supported by metallic gauze-s 34, incombination with sudden changes in the direction of the pipings 30, as shown in Fig. 3.

All these pipings or collectors 24, 27, 29, 30 have an ample allowance of diameter, to ensure the required rate of flow of air without noticeable loss of head, as has been described above.

An aspirating fan with adjustable out-- put- 35 creates, in the general collector 29, the desired fall of pressure, the latter being measured by means of the pressure gauge hat I claim and desire to secure by Letters Patent is 1. In the manufacture of threads by spinning a viscous fluid containing a volatile solvent into elementary fibres in a heated gaseous current passing through a cell, means for causing the said gaseous current to pass through the said cell and means'for regulating the evaporation of solvent in a series of temperature controlling elements identical to one another for'the whole of each group and for each cell of the group, a

current of temperature controlling fluid passing in each said series of elements in opposite directions.

2. In the manufacture of threads as claimed in claim 1, means for further regulating the evaporation of solvent in a great.

number of cells by creating at the head of the system through which the said gaseous current flows a fall of pressure greater than that necessary in each cell.said means comprising devices interchangeable but nonadjustable individually causing a known loss of head placed in the individual piping of each cell.

3. In the manufacture of threads as claimed in claim 1, and means for controlling the temperature internally of the cells.

4. In the manufacture of threads as claimed in claim 1, and meansQfor controlling the temperature externally of the cells.

5. In the manufacture of threads as claimed in claim 1, and means for controlling the temperature internally and externally of the cells, simultaneously.

6. In the manufacture of threads as claimed in claim 1, and means for controlling the temperature by fluid from one source at the head of one of said series of elements passing twice through each enclosure, once in the outgoing portion of the circuit, and again in the return portion of the circuit.

\ claimed in claim 1, the temperature-controlling elements being designed so that the difference between the temperatures of thefluid utilized for temperature control at the inlet and outlet of the group of chambers or cells is from 5 to 10 C.

9. In 'the manufacture of threads as claimed in claim 1, an arrangement of chambers or cells such that the enclosures whose temperature is controlled by the same double series of elements are grouped in subgroups branched on a single temperaturecontrolling system.

10. In the. manufacture of threads as claimed in claim 1, means for causing the passage of the said heated gaseous current through the said enclosures comprising pipings designed for a rate of flow greatly in excess of that required so as to render the loss of head in said pipings negligible in comparison with the head causing the said current.

11. In the manufacture of threads. as claimed inclaim 1, and means for regulating the rate of flow of the said gaseous current by adjusting the head causing the said current.

12. In the manufacture of threads as claimed in claim 1, and means for regulating the rate of flow of the said gaseous current whereby the head causing the said stream is maintained constant and each cell provided with devices adapted to cause a known loss of head.

13. In the manufacture of threads as claimed in claim 1,-and means for regulating the rate of flow of the said gaseous current whereby the head causing the said stream is maintained constant and each cell provided with devices adapted to cause a known loss of head. said devices being identical for all the cells of a group.

14. In the manufacture of threads as"- claimed in claim 1, and means for collecting the gaseous medium pming. through the enclosures so that it may be used again.

15. In the manufacture of. threads as claimed in claim 1, means for recovering the vapors carried by the gaseous medium, and means for collecting said gaseousmedium so hat it may be used again.

16. In the manufacture of threads as claimed in claim 1, accessory means for ascertaining the temperature and rate of flow of the gaseous current in any desir'ed position in the group of enclosures and in individual enclosures.

In testimony whereof, I aflix my signature.

NICOLAS BENoI'r GRILLET.

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