Multistage mixing

In fact viscosity reduction of diene elastomer blends with QDI show an optimum based on mixer discharge temperature. Figure 16.13 shows the results of two experiments done on the 16 L scale. The viscosities represent the viscosity of the fourth stage of a multistage mixing experiment. These compounds were 60/40 blends of either BR or SBR with NR and contained 50 phr of N-234 carbon black. 

FIGURE 16.13 Fourth pass viscosity of a multistage mixing experiment of butadiene rubber-natural rubber (BR-NR) and styrene-butadiene rubber (SBR)-NR blends (60/40) with 50 pbr of N-234 carbon black. 

Figure 6-26 Backflow rate in a multistage mixing tank.

Figure 6-27 Backflow velocity as a function of forward flow velocity in a multistage mixing tank where Vb is the backflow velocity, Vbo the backflow velocity at zero throughput, and Vf the forward flow velocity.

The RTD is a distinctive characteristic of mixing behavior. In Fig. 7-2>e, the CSTR has an RTD that varies as the negative exponential of the time and the PFR is represented by a vertical line at = 1. Multistage units and many packed beds have beU-shaped RTDs, like that of... 

FIG. 10-46 Vertical multistage turbine, or mixed-flow, pump. 

Refer to Fig. 15-41. The extrartor is an extension of the simple baffled mixing vessel into a multistage column. Although commercial apphcation has been made, data are scarce and are limited to towers of small diameter. The preferred proportions are Zt = 0.5df, d, > dj. 

Figure 3-56. Viscosity performance correction chart for centrifugal pumps. Note do not extrapolate. For centrifugal pumps only, not for axial or mixed flow. NPSH must be adequate. For Newtonian fluids only. For multistage pumps, use head per stage. (By permission. Hydraulic Institute Standards for Centrifugal, Rotary, and Reciprocating Pumps, 13th ed.. Hydraulic Institute, 1975.)...

Multistage counter-current liquid-liquid extraction is a typical continuous process. Fig. 121 shows a schematic diagram of the process. The slope of the line depends on the volumetric ratio of the aqueous and organic phases. The aqueous and organic phases move through the system as two counter currents. The raffinate from a specific extraction stage moves on to the next stage, to be mixed with a relatively fresh portion of the extract, i.e. extractant that was previously mixed with a low-concentration aqueous solution. 

Double suction, 166, 167 Efficiency, 200 High speed, 169 Illustrations, 161, 164 Impellers, 164, 170 In parallel, 177, 178 In series, 176, 178 Liquid horsepower, 200 Materials of construction, 211 Mixed flow, 169 Multistage, 167 Operating curves, 180 Packing, shaft, 170... 

The sample volume initially introduced onto the sorbent, the choice of sorbent and solvent system and careful control of the amount of solvent used are of paramount importance for effective pre-concentration and/or clean-up of the analyte in the sample. The number of theoretical plates in an SPE column is low (/V = 10-25). SPE is a multistage separation method and as such requires only a reasonable difference in extractability to separate two solutes. In SPE concentration factors of 1000 or more are possible, as compared to up to 100 for LLE with vortex mixing. 

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