Unterschiede
Hier werden die Unterschiede zwischen zwei Versionen angezeigt.
| Beide Seiten der vorigen RevisionVorhergehende ÜberarbeitungNächste Überarbeitung | Vorhergehende Überarbeitung | ||
| en:grundlagenhandbuch:mischvorgaenge_im_gleichdrall-doppelschneckenextruder [2026/08/14 14:37] – [References] paal | en:grundlagenhandbuch:mischvorgaenge_im_gleichdrall-doppelschneckenextruder [2026/09/04 11:01] (aktuell) – [References] paal | ||
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| Zeile 30: | Zeile 30: | ||
| ==== Longitudinal Mixing ==== | ==== Longitudinal Mixing ==== | ||
| - | To evaluate an extruder we need values, which are able to describe | + | To evaluate an extruder we need values |
| $$\sigma^2 = \int_{\Theta_1}^{\infty} (\Theta - 1)^2 f(\Theta)d\Theta \tag{1}$$ | $$\sigma^2 = \int_{\Theta_1}^{\infty} (\Theta - 1)^2 f(\Theta)d\Theta \tag{1}$$ | ||
| Zeile 44: | Zeile 44: | ||
| The bold lines represent the values usually found within those machines. Values that are not found within this area are deemed invalid. The minimum dimensionless residence time $Q_1$ takes into account the different geometries of the extruder. If $Q_1 = 1$ we find a bulk flow with a variance $\sigma^2 = 0$, in an ideal mixer we would find $Q_1 = 0$ with a variance $\sigma^2 = 1$ [[en: | The bold lines represent the values usually found within those machines. Values that are not found within this area are deemed invalid. The minimum dimensionless residence time $Q_1$ takes into account the different geometries of the extruder. If $Q_1 = 1$ we find a bulk flow with a variance $\sigma^2 = 0$, in an ideal mixer we would find $Q_1 = 0$ with a variance $\sigma^2 = 1$ [[en: | ||
| - | The variance profile of co-rotating twin screw extruders is almost identical to that of the smooth barrel single screw extruder. The values usually found for co-rotating twin screw extruders are shifted to lower values of the minimum dimensionless residence time. Because of this the variances | + | The variance profile of co-rotating twin screw extruders is almost identical to that of the smooth barrel single screw extruder. The values usually found for co-rotating twin screw extruders are shifted to lower values of the minimum dimensionless residence time. This allows for higher |
| Potente [[en: | Potente [[en: | ||
| Zeile 54: | Zeile 54: | ||
| ==== Axial Mixing Coefficient ==== | ==== Axial Mixing Coefficient ==== | ||
| - | Werner [[en: | + | Werner [[en: |
| $$\sigma_M = \frac{\dot{V}_x}{\dot{V}_z} \tag{3}$$ | $$\sigma_M = \frac{\dot{V}_x}{\dot{V}_z} \tag{3}$$ | ||
| Zeile 74: | Zeile 74: | ||
| [Lap85] Lappe, H.: Untersuchung zum Verweilzeitverhalten von Schmelze- und konventionellen Plastifizierextrudern, | [Lap85] Lappe, H.: Untersuchung zum Verweilzeitverhalten von Schmelze- und konventionellen Plastifizierextrudern, | ||
| - | [OC83] Ottino, J.M.; Chella, R.: Laminar Mixing of Polymeric Liquids; | + | [OC83] Ottino, J.M.; Chella, R.: Laminar Mixing of Polymeric Liquids; |
| [Pah85] Pahl, M.H.: Mischen in Schneckenmaschinen, | [Pah85] Pahl, M.H.: Mischen in Schneckenmaschinen, | ||
| Zeile 94: | Zeile 94: | ||
| [Pot91] Potente, H.: Rechnergestützte Extruderauslegung., | [Pot91] Potente, H.: Rechnergestützte Extruderauslegung., | ||
| - | [Raa61] Raasch, J.: Beanspruchung und Verhalten suspendierter | + | [Raa61] Raasch, J.: Beanspruchung und Verhalten suspendierter |
| [Sch87] Schultheis, S.M.: Approximationsgleichungen zur Auslegung von gegenläufigen Doppelschneckenextrudern, | [Sch87] Schultheis, S.M.: Approximationsgleichungen zur Auslegung von gegenläufigen Doppelschneckenextrudern, | ||