Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Four-roll mill

Fig. 21. Schematic drawing of the Taylor four-roll mill with the created flow field. The 2-dimensional velocity gradient can be represented by the tensor A ... Fig. 21. Schematic drawing of the Taylor four-roll mill with the created flow field. The 2-dimensional velocity gradient can be represented by the tensor A ...
This flow field can be maintained in a steady state, at least in the Eulerian sense, either by use of a four-roll mill [18] as in Figure 2.8.4(a) or by means of opposed jet flow as in Figure 2.8.4(b). However, it is important to note that the flow is still transient in the Lagrangian sense. That is, pure planar extension is confined to the central stagnation... [Pg.189]

Fig.2.8.4 Geometry pertaining to (a) four-roll mill and (b) opposed jet flow. Fig.2.8.4 Geometry pertaining to (a) four-roll mill and (b) opposed jet flow.
Fig. 2.8.8 (a) Implementation of four-roll mill device, (b) Speed image obtained across a horizontal slice by combining separate x- and y-velocity images, (c) Velocity profile taken across the x-axis of the cell showing the uniform extensional strain rate 8, such that x= ex (adapted from Ref. 15]). [Pg.194]

Bentley, B. J., and Leal, L. G., A computer-controlled four-roll mill for investigations of particle and drop dynamics in two-dimensional linear shear flows. J. Fluid Mech. 167, 219-240 (1986). [Pg.199]

Figure 10.3 Schematic diagram for a four-roll mill flow device. Figure 10.3 Schematic diagram for a four-roll mill flow device.
D. P. Pope and A. Keller, Alignment of macromolecules in solution by elonga-tional flow a study of the effect of pure shear in a four roll mill, Coll. Polym. Sci., 255, 633 (1977). [Pg.253]

In order to describe more general flow gradients, such as those generated near the stagnation point of a four-roll mill, some mathematics must be introduced in particular, tensors (which can be represented as matrices) are needed, namely the velocity gradient tensor. [Pg.21]

Figure 3.17 Birefringence as a function of the eigenvalue of the velocity gradient tensor, G, for planar flows generated in a four-roll mill, for dilute solutions of polystyrenes of three different molecular weights in polychlorinated biphenyl solvent. Here G is the strain rate and a the flow type parameter. For planar extension, a — 1 and G = is the extension rate for simple shear, a = 0 and G = y is the shear rate. The different symbols correspond to a values of 1.0 (0)> 0.8 (A), 0.5 (-1-), and 0.25 (diamonds). The curves are theoretical predictions from the FENE dumbbell model, including conformation-dependent drag (discussed in Section 3.6.2.2.2). (From Fuller and Leal 1980, reprinted with permission from Steinkopff Publishers.)... Figure 3.17 Birefringence as a function of the eigenvalue of the velocity gradient tensor, G, for planar flows generated in a four-roll mill, for dilute solutions of polystyrenes of three different molecular weights in polychlorinated biphenyl solvent. Here G is the strain rate and a the flow type parameter. For planar extension, a — 1 and G = is the extension rate for simple shear, a = 0 and G = y is the shear rate. The different symbols correspond to a values of 1.0 (0)> 0.8 (A), 0.5 (-1-), and 0.25 (diamonds). The curves are theoretical predictions from the FENE dumbbell model, including conformation-dependent drag (discussed in Section 3.6.2.2.2). (From Fuller and Leal 1980, reprinted with permission from Steinkopff Publishers.)...
Bentley and Leal have measured droplet shapes and critical conditions for droplet breakup over a wide range of capillary numbers, viscosity ratios, and flow types. The flow type is conveniently controlled in an apparatus called a four-roll mill, in which a velocity field is generated by the rotation of four rollers in a container of liquid (see Fig. 1-15). By varying the rotation rate of one pair of rollers relative to that of a second pair, velocity fields ranging from planar extension to nearly simple shear can be produced near the stagnation point. [Pg.401]

Figure 9.9 Dimensionless critical droplet size for breakup (capillary number Ca<- = Crj a/r) as a function of viscosity ratio M of the dispersed to the continuous phase for two-dimensional flows in the four-roll mill. The data sets correspond from bottom to top to ff — 1.0(0), 0.8 (A), 0.6 (0), 0.4 (V), and 0.2 ( ), with a defined in Eq. (9-17). The fluids are those described in Fig. 9-7. The solid lines are the predictions of a small-deformation theory, while the dashed lines are for a large-deformation theory. The closed squares are from Rallison s (1981) numerical solutions (see also Rallison and Acrivos 1978). (From Bentley and Leal 1986, with permission from Cambridge University Press.)... Figure 9.9 Dimensionless critical droplet size for breakup (capillary number Ca<- = Crj a/r) as a function of viscosity ratio M of the dispersed to the continuous phase for two-dimensional flows in the four-roll mill. The data sets correspond from bottom to top to ff — 1.0(0), 0.8 (A), 0.6 (0), 0.4 (V), and 0.2 ( ), with a defined in Eq. (9-17). The fluids are those described in Fig. 9-7. The solid lines are the predictions of a small-deformation theory, while the dashed lines are for a large-deformation theory. The closed squares are from Rallison s (1981) numerical solutions (see also Rallison and Acrivos 1978). (From Bentley and Leal 1986, with permission from Cambridge University Press.)...
Lee JS, Dylla-Spears R, Teclemariam NP, Muller SJ (2007) Microfluidic four-roll mill for all flow types. Appl Phys Lett 90 074103... [Pg.2451]

Hudson SD, Phelan FR, Handler MD, Cabral JT, Migler KB, Amis EJ (2004) Microfluidic analog of the four-roll mill. Appl Phys Lett 85 335-337... [Pg.2451]

Currently Performed Experiments. Flow experiments with equipment similar to the Schlumberger elongational viscometer have been attempted, but encountered many difficulties an elongational cross cell system (same flow as the Taylor four-roll-mill) is being developed Shear flow has been studied more extensively in a Couette viscometer (see Ref. for review). A periodic oscillatory uniaxial deformation has been recently started on PDMS rubbers . Up to now the range of available time... [Pg.53]

The yam is then drawn on four rolling mills (godets) the hot godet causes some fumes that must be collected and sent to the treatment plant. [Pg.148]


See other pages where Four-roll mill is mentioned: [Pg.113]    [Pg.190]    [Pg.192]    [Pg.203]    [Pg.203]    [Pg.199]    [Pg.200]    [Pg.200]    [Pg.202]    [Pg.203]    [Pg.209]    [Pg.210]    [Pg.210]    [Pg.255]    [Pg.3104]    [Pg.20]    [Pg.22]    [Pg.24]    [Pg.141]    [Pg.156]    [Pg.194]    [Pg.146]    [Pg.2448]    [Pg.765]    [Pg.5342]    [Pg.1485]   
See also in sourсe #XX -- [ Pg.189 , Pg.203 ]

See also in sourсe #XX -- [ Pg.416 ]




SEARCH



Four-roll mill birefringence

Milling roll mill

Roll mill

Roll-milling

Rolling mills

© 2024 chempedia.info