Unterschiede

Hier werden die Unterschiede zwischen zwei Versionen angezeigt.

Link zu dieser Vergleichsansicht

Beide Seiten der vorigen RevisionVorhergehende Überarbeitung
Nächste Überarbeitung
Vorhergehende Überarbeitung
en:grundlagenhandbuch:berechnung_der_dispergierguete [2026/05/28 09:34] deppe2en:grundlagenhandbuch:berechnung_der_dispergierguete [2026/05/28 09:35] (aktuell) – [Agglomerate Disintegration] deppe2
Zeile 37: Zeile 37:
 In addition to the power, the stresses to which a sphere is subjected in a shear flow are considered in the next step, analogous to [[en:grundlagenhandbuch:berechnung_der_dispergierguete#references |[Raa61]]], [[en:grundlagenhandbuch:berechnung_der_dispergierguete#references |[BT74]]] with regard to the energy input. The particle rotates in the shear flow and is thereby subjected to alternating tensile and compressive stresses. According to Raasch [[en:grundlagenhandbuch:berechnung_der_dispergierguete#references |[Raa61]]], the angular velocity $\omega$ is derived from the prevailing shear velocity of the surrounding flow: In addition to the power, the stresses to which a sphere is subjected in a shear flow are considered in the next step, analogous to [[en:grundlagenhandbuch:berechnung_der_dispergierguete#references |[Raa61]]], [[en:grundlagenhandbuch:berechnung_der_dispergierguete#references |[BT74]]] with regard to the energy input. The particle rotates in the shear flow and is thereby subjected to alternating tensile and compressive stresses. According to Raasch [[en:grundlagenhandbuch:berechnung_der_dispergierguete#references |[Raa61]]], the angular velocity $\omega$ is derived from the prevailing shear velocity of the surrounding flow:
  
-$$\omega = \frac{1}{2} \dot{\gamma} \tag{1} \tag{6}$$+$$\omega = \frac{1}{2} \dot{\gamma}  \tag{6}$$
  
 The power at the sphere’s surface, as shown in Figure 10.2, is formulated as follows according to Raasch [[en:grundlagenhandbuch:berechnung_der_dispergierguete#references |[Raa61]]] when considering a pure shear flow: The power at the sphere’s surface, as shown in Figure 10.2, is formulated as follows according to Raasch [[en:grundlagenhandbuch:berechnung_der_dispergierguete#references |[Raa61]]] when considering a pure shear flow:
Zeile 117: Zeile 117:
 Due to the high pressures occurring in continuous mixers, shear failures are more than likely to occur. From this follows: Due to the high pressures occurring in continuous mixers, shear failures are more than likely to occur. From this follows:
  
-$$\tau_{Sch} = \frac{1}{2} \sigma_v = \sigma_3 - \sigma_1 \tag{10} \tag{23}$$+$$\tau_{Sch} = \frac{1}{2} \sigma_v = \sigma_3 - \sigma_1 \tag{23}$$
  
 With σ1 and σ3 being the maximum principle stresses. We assume the hoop stress σv to be almost equal to the tensile strength σz, which we predict using Rumpf's [[en:grundlagenhandbuch:berechnung_der_dispergierguete#references |[Rum61]]] equation: With σ1 and σ3 being the maximum principle stresses. We assume the hoop stress σv to be almost equal to the tensile strength σz, which we predict using Rumpf's [[en:grundlagenhandbuch:berechnung_der_dispergierguete#references |[Rum61]]] equation:
  
-$$\tau_{Sch} = \frac{1}{2} \sigma_z = \frac{(1 - \varepsilon_A) \overline{F_{adh}}}{2\pi \cdot d_p^2} \tag{11} \tag{24}$$+$$\tau_{Sch} = \frac{1}{2} \sigma_z = \frac{(1 - \varepsilon_A) \overline{F_{adh}}}{2\pi \cdot d_p^2} \tag{24}$$
  
 Inserting the agglomerate strength according to Rumpf (eqn. (11) results in the following differential equation for the agglomerate rupture: Inserting the agglomerate strength according to Rumpf (eqn. (11) results in the following differential equation for the agglomerate rupture:
  
-$$\frac{\partial \bar{d}}{\partial t} = \frac{5}{64} \cdot \frac{\tau_{Fluid} \cdot \dot{\gamma}}{\tau_{Sch} \cdot \pi} \cdot \bar{d} \tag{12} \tag{25}$$+$$\frac{\partial \bar{d}}{\partial t} = \frac{5}{64} \cdot \frac{\tau_{Fluid} \cdot \dot{\gamma}}{\tau_{Sch} \cdot \pi} \cdot \bar{d} \tag{25}$$
  
 ==== Erosion ==== ==== Erosion ====