DE312393C

DE312393C -

Info

Publication number: DE312393C
Application number: DENDAT312393D
Authority: DE

Description

AUSGEGEBEN AM 15. JUNI 1922ISSUED ON JUNE 15, 1922

KLASSE 29 b GRUPPECLASS 29 b GROUP

(V I₄₄2₅ IV\2₉b)(VI ₄₄ 2 ₅ IV \ 2 ₉ b)

Bekanntlich besteht ein ,sehr großer Unterschied in der Trockendauer eines frisch gefällten Zellulosefadens und eines solchen, der nach dem ersten Trocknen erneut mit Wasser durchtränkt unter sonst gleichen Trockenbedingungen (Temperatur und Luftwechsel) getrocknet wird. Es liegt dies daran, daß das Wasser aus dem einmal fest gewesenen Kunstseidefaden viel rascher herausdiffandiert als aus dem kolloiden Gebilde, wie' es der frisch gefällte Faden vorstellt — oder gar erst aus dem Gebilde, welches sich bei fortschreitender Trocknung dem festen Körper nähert.It is well known that there is a very large difference in the drying time of a freshly felled one Cellulose thread and one that is washed again with water after the first drying soaked under otherwise identical drying conditions (temperature and air change) is dried. This is because the water from the once solidified Artificial silk thread diffuses out much more quickly than out of the colloidal structure like 'it the freshly felled thread introduces - or even from the structure that emerges as it progresses Drying approaches the solid body.

Der Diffusionswiderstand des frischen Fadens, der das Wasser von der Oberfläche fernhält und der Kapillarwiderstand des sich dem festen Aggregatzustand nähernden Fadens wirken in gleichem Sinne verzögernd.The diffusion resistance of the fresh thread, which the water from the surface and the capillary resistance of the thread approaching the solid state of aggregation have a retarding effect in the same sense.

· Es wird aber die das Wasser an die Oberfläche des Fadens treibende Kraft wachsen, je größer die Feuchtigkeitsdifferenz ist zwischen Oberfläche des Fadens und dem Fadeninnern. Je rascher daher ständig der Fadenoberfläche das Wasser entzogen! wird, je trockner sie gehalten wird, je rascher erfolgt die Verdampfung des im Faden enthaltenen Wassers. Die ungenügende Beachtung dieser Überlegungen hat unter anderem Anlaß gegeben zu den bisherigen ganz unökonomischen und langsam arbeitenden Trockeneinrichtungen für solche Fäden, die zumeist auf Glaswalzen, Pappspulen o. dgl. in verhältnismäßig dünnen Schichten aufgewickelt und in etwa 6o° warmen ventilierten Räumen aufgestapelt waren. : · However, the force driving the water to the surface of the thread will increase, the greater the difference in moisture between the surface of the thread and the inside of the thread. The faster the water is constantly withdrawn from the thread surface! the drier it is kept, the faster the evaporation of the water contained in the thread takes place. Insufficient attention to these considerations has given rise, among other things, to the previously uneconomical and slow-working drying devices for such threads, which were mostly wound up in relatively thin layers on glass rollers, cardboard bobbins or the like and stacked in ventilated rooms with a temperature of about 60 °. :

Wohl hatte man daran gedacht, die Aufstapelung in verschiedenen Kammern vorzunehmen und die aus einer Kammer austretende durch die Wasserdampfung abgekühlte Luft durch erneutes Erhitzen zur weiteren Verdampfung und Aufnahme von Wasser in einer folgenden Kammer weiter nutzbar zu machen, auch das Gegenstromprinzip war selbstverständlich angewendet worden, aber das Trocknen dauerte tagelang und war schon darum unökonomisch.One had probably thought of stacking them in different chambers and the air emerging from a chamber, which has been cooled by the water vapor, is heated again for To make further evaporation and absorption of water in a subsequent chamber further usable, also the countercurrent principle had been used, of course, but drying took days and was therefore uneconomical.

Das Zögern, andere Wege zu suchen, ist darauf zurückzuführen, ,daß der weiche Faden sich rasch verfärbte und braun wurde (ähnlich einem mit einem zu heißen Eisen berührten feuchten weißen Baumwollstoff, womit eine durch Ausfärbung mit passenden Farbstoffen nachweisbare chemische Veränderung eintrat an den betreffenden Stellen, die oft sehr unangenehm war), wenn der betreffende Faden zu nahe an einem Heizkörper gestanden hatte. Man folgerte daraus, daß das weiche Gebilde eine höhere Temperatur nicht vertrage, während nach heutigen Ermittlungen die Schuld wohl an ungenügend rascher Verdampfung liegt.The hesitation to look for other avenues is due to the fact that the soft thread quickly discolored and turned brown (similar to one touched with an iron that was too hot damp white cotton fabric, with which one by coloring with suitable dyes detectable chemical change occurred in the affected areas, which are often very uncomfortable was) if the thread in question was too close to a radiator. It was concluded from this that the soft structure A higher temperature cannot be tolerated, while according to current investigations the This is probably due to insufficiently rapid evaporation.

Eine etwas raschere Trocknung ergab sich wohl, wenn man die Gebilde nach Patentschrift 121430, ähnlich wie man dies mit anderen reichlich Wasser haltenden Gebilden,Somewhat faster drying was probably obtained if one looked at the structure according to the patent specification 121430, similar to how this can be done with other structures that hold abundant water,

Claims

like mushrooms or green beans wont do, with boiling water or even under 4 to 5 atmospheric pressure with flowing saturated steam, .but the profit Time was not worth it, effort.

Only the mass production of such threads in recent times as so-called »staple fiber, Wool substitute, Neuschappe and the like drove up again after better drying methods To look for thorough new considerations.

Surprisingly, tests with 100 to 130 ^° C. and more hot air showed that you have it completely in your hand, as quickly as you like

'5 to dry, and that the dreaded browning does not occur if one is in the air or gases that are even more indifferent to cellulose based on the principle of countercurrent in exchangeable chambers, z. B. of channel shape, which leads to the thread masses and meticulously ensures that the air flow in as intimate as possible Comes into contact with the threads. It is useful to heat the emerging from a chamber, as a result of the release of heat of evaporation, the temperature has decreased and at the relevant setting temperature Water fully saturated air by air heater back to the high temperature before they enter a new chamber for further evaporation work and saturation leaves. The dimensions of the chambers and the limit of the utilization of the air are calculated from purely professional further considerations.

It is in the first chamber z. B. the setting temperature when using 100 ° C hot air about 35 ⁰ . The cubic meter of air, which fell from ioo ° to 35 ⁰ in temperature was 65 X 0.30: = 1.9,5 thermal units on the other hand is able to air containing already normal το grams of water in cubic meters at full saturation at 35 ⁰ to take up a further 42-10 = 32 grams of water, whereby 0.032 X 600 = 19.2 thermal units could again be consumed. Exact measurements give full agreement with the calculated result.

It is noteworthy that the fiber was not noticeable during this intensive drying process Skill is weakened when the fiber has been washed well and the hot air was in thermal equilibrium.

Ρλ τ ε ν τ claim:

Quick drying process for freshly precipitated cellulose threads, consisting in that the threads, expediently according to the principle of countercurrent, a 100 ° to 130 ⁰ C and more hot, more or less strong and in thermal equilibrium flow of air or cellulose-inert gases in the best possible way Distribution will be suspended.