US1877337A - Apparatus for preparing highly uniform solutions for the manufacture of artificial products - Google Patents

Description

Sept. 13, 1932.,

A. KAMPF ET AL ,877,337 APPARATUS FOR PREPARING HIGHLY UNIFORM SOLUTIONS FOR THE MANUFACTURE OF ARTIFICIAL PRODUCTS Filed Match 25, 1950 t [as Patented Sept. 13, 1932 ADOLF ,KEMPF, or pnssA -zI Ie -mminarnnnn nAGER; or woman, GERMANY, AssIeNoRs TO I. e. ramarmrunpsgrem l K'rrn1v E sELLscH-AFT, or

v R NKJMRm-o -r s mllv, G RMANY APPARATUS FOR PREPARING HIGHLY nmrorm soLu'r-rons-roa THE MANUFACTURE or ARTIFICIAL rnonucrs' I a v r a Application filed March '25, 1930, Seria1 No 5438 870, and-intfierinany: March 27,1529.

Our present invention relates to a process of preparing spinning solutions asfused in themanufacture of artificial threads, fi-

.bers or films and more particularly tosuch a process carried out on a large scalein which the said solutions prepared in a continuous manner and in a plurality of dissolving vessels are filtered, deaerated and made ready for the coagulation process. Anotherobject of ourinvention is a device for carrying out the saidprocess.

- Thelinjuries to which spinning solutions,

especially viscose, arev exposed when forup of single batches of spinning solutions Ly does not lead to uniform products even if the 7 use of compressed air or the like (is avoided,

as far as this is practically possible, during the manufacturer of the spinning solution. 7 -'-Due to the inevitable changes of the numerous important factors which give rise to constant- -ly occurring greater or smaller difierences be-l tween the single batches, it is diificult to obtain auniform end-product and these difliculties rise whenworking-up a viscose solution to be spun wlth as low a degree ofripeness as possible.

By our present invention thesedisad vantages are avoided by making use essentially of two expedients.

(1). The batches of viscose dissolved more orless at the same time in several dissolving- -"vessels, are not filtered individually each through a separate filter but all of the spin-r ning solutions, ready for filtration, are l; pumped iniknownmanner without using com- 1 pressed air, into a collecting piping which delivers'the solution to a suitable number of filters presses-arranged in, parallel, Pref- .50 -vi ded in excess ofthenumber requ red for erably, atleastlone filter press should be promon ducttwhere they are combined into a sinl s ream. ln-this manner, the iggle batches 1 ;(-2). Thefiltered spinning solution is not r a tedashithe e J f llalkin bafhes each of which is ,charged into difierent collecting v ss ls:fromwh chtmsqlu ic is d aw req ire 1 deae ati aii further treatamen-b.1 12 (it is sq t n q n du into a icmmqn lhemc eni i or equ i selfrem whichattheiop s e i With- F w 117wn ,,.azcanthnaau yan I 1 L un a manner as poss1ble,;to the spinning device.

., Thesai eqommv rvs e rv S t al .urpqse I .Itzse v o ieompen at th a o -;ah e irre u arit e -flame r o pp y of 1:fi i edpinl i sb utionto he v (b The-spinni g s i t o s freed f s in: th homqgenizin vess T i p nn ng; oluti n s c nt n s y subje t d -.-t. a tm chanical ag t n dur g its passage through =the vesseL i "For t purpose in ic ted. under )v the es l. 5 s is itab x dimensioned, fiQrIB P i g y; with t @q anti ypf P i i ql whichfis to pass through it.

x 'With;respect;t0 the feature of the process 1 outlined nd r (6) torie g; the sp nn 7 solution irom; gas on its way through a the .homqgeni ng -.%v sse ,;t ol ow P r Eaular ,measuresjmaytba a opted.

oiSinCetheSPinning.YSQ tiQI is e Stirred in the vesseland withdrawn fromthe outlet to; h spinaing machi by'l an f. ap p it ay h ppen that lrzm yi e d awn r a the stuffing boxes andthe'bearingsof the drivi g zandtubular shaft and absorbedby, the

spinning solution kept ,under a-vacuum.

In order to avoidithis danger, the vessel is prov ded-With. a ver ical t bul eXteIisiOn alrea y tail ate a; i 1 e te ii the. ng operation. i

pieceof such a height that at the lower part of the vesselat which part the stirring mechanism is arrangedthe reduced pressure is approximately compensated by the hydrostatic pressure of the'column'of liquidin the tube. When operating, for instance, under. a reduced pressure of 150 mm. of mercury,

. the pressure due to the head of the spinning solution must correspond with the pressure of about 600 mm. of mercury for viscose,

having a specific gravity off l-.15- this would require a tubular portion having a height of about 7 meters.

In order that the spinning solution enteringthe vessel, may remain therein for the period necessary for a complete removal ofga's,the

vessel bears on the tubular extension piec'e a funnel-shaped or conical head plece. Now,

at'the upper rim of the funnel, which may have a diameter of several meters, the current of filtered spinning; solution is Poured, by

- 'means of a rotary distributing pipe,"onto the not mounted horizontally but somewhat inclined to the discharge pipe.

inner surface of the funnel in such a rate, that the time during which the spinning solutlon flows downwards in a thin layer over the inner wall of the funnel issuflicient for completely liberating the spinningsolutionfrom air or gas; if required, there may be provided in addition to the rotary distributingplpe a scraper which is caused to travel overthe conical surface, thus preventing viscose from remaining on the wall of the funnel'for too long a period. It is a question of the quantities produced whether between the tubular andthe conical member a widened cylindrical partis provided which forms the real homogenizing room of the vessel.

Referring to purpose v(c), the vessel shall further serve for mechanically agitating the spinning solution. For this purpose, the lower part of the vessel is provided with a longitudinal shaft carrying-mixingarms', so that the spinning liquid flowing through the lower part of the vessel is continuously; mixed by stirring. Preferably the said lower part is In working-up anunripened viscose, it is desirable to use a homogenizing vessel which is not excessively large, in' order that theviscose may not remaln for too long a per od 1n the vessel and ripen in an undesired degree. In using ripened viscose, the buffer vessel may be of a correspondingly larger size. At the, outlet of the buifer vessel the spinning li'quid is received, as above stated, by a pump for- 1 mixing of the spinning liquid.

warding it in known manner'tothe spinning machine.

Anessential feature of the invention conand f sists in. the continuous'remo'val of The annexed drawing illustrates diagrammatically byway of'example a device suitable for executing the invention.

The spinning solution prepared in the, dis- Levies? solving vessels 1 flows under its own weight through the common pipe 2 to the eccentric pump 3 by which the crude spinning solution is forwarded through the common connecting pipe '5'to the filter presses 6. In order that the filtration may be conductedunder constant pressure, a return-flow pipet is providedby which anyliquid deliverel by the e'ccentric pump 3 in excess of the quantity capable of passing through the filter presses, is returned to the sucking side of the pump. he filtrates from the several presses are combined in the common pipe 7 and-flow through a rotary swivel-tube 9 driven at 10, whichdelivers the solution to the upper conical portion of the surface of an exhausted equalizing vessel 8. The solution flows in the form of a thin layer downwardly on the inner wall of the funnel, is removed therefrom by. a

scraper 21 and collects in the cylindrical part the homogenizing vessel 8 bears a branch 2O through which the air is exhausted.

The spinning solution is slowly but continuously mixed by means of a stirring de vice 15 in an extension 1 1' of the portion 13, slightly inclined to the horizontal. From the lowest point of theextension 14:, the spinning solution passes the feeding eccentric pump;

16 having a return flow-pipe 17 provided with a' pressure regulator, and is forwarded under ing to the spinning machines. V v It is recommendable to provide all the parts 11, 13 and 14 of the buffer Vessel 8 and,if

' required, also the feed pumps 8 and 16 with .a jacket as indicated at 19 for the purpose of maintaining the solution in the vesseliat a constant temperature.

Obviously, our present invention is not limited to the foregoing statements. 7

. As known in the art, spinningsolutions may also be deaerated, for instance, by admixing volatile solvents and by evaporating the same.

In this case, it is preferable to operate without evacuation of the homogenizing vessel, but to heat feebly the wall of its conical part.

Numerous other embodiments are possible and we contemplate as included within our invention all such modifications and equiva *lents as-fall within the scopeof the appended claims. What we claimisz-s i r I I 1. Ina machine for producing highlyuni form solutions for the manufacture of artificial products consisting of cellulose derivaconstant pressure through the piping 181eadtives a homogenizing and deaerating means comprisinga vesselwith a furinel-shapedw head part, a circularly. rotary;.-.swivel tube adapted to distribute the spinning solution in the form of a thin layer on the funnelshaped head part, means to evacuate the said vessel, a cylindrical collecting part, a tubular 5 extension piece of substantial height, a slightly inclined almost horizontally mounted receptacle and in the latter a mixing device.

2. In a machine for producing highly uniform solutions for the manufacture of artificial products consistingof cellulose derivatives a homogenizing and deaerating means comprising a vessel with a funnel-shaped head part, a circularly rotary swivel-tube adapted to distribute the spinning solution in the form of a thin layer on the funnel-shaped head part, means to evacuate the said vessel, a cylindrical collecting part, a tubular exten- V sion piece of a height balancing when filled with spinning solution by the hydrostatic 29 pressure of the latter the action of the vacuum on the parts mounted on its lower end, a slightly inclined almost horizontally mounted receptacle and in the latter a mixing dee vlce.

3. A machine for producing highly uniform solutions for the manufacture of artificial products consisting of a cellulose derivative comprising a plurality of dissolving vessels, a pump provided with a return flux,

30 a plurality of filter presses, a common piping. through which the contents of the dissolving vessels is forwarded to the pump and from the pump to a plurality of filter presses, a second common pipe collecting the filtrates of the different filter presses, a homogenizing and deaerating means comprising a vesfisel provided with a funnel-shaped head part, a circularly rotary swivel-tube adapted to distribute the spinning solution in the form of a thin layer on the funnel-shaped head part, means to evacute the said vessel, a cylindrical collecting part, a tubular extension piece of a height balancing when filled with spinning solution by the hydrostatic pressure of the latter the actionof the vacuum on the parts mounted on its lower end, a slightly inclined almost horizontally mounted receptacle and in the latter a mixing device, and a second pump provided with a return flow and adapted to forward the solution under constant pressure to the spinning machine. 7

In testimony whereof, we afiix our signatures.

ADOLF' KAMPF. ARNULF HAGER.

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