Effect of agitation

As would be expected, agitation increases the heat transfer rate for nucleate boiling. Schweppe and Foust (S2) pumped saturated water through a heated tube to obtain the boiling curves in Fig. 34. Note the 

The constancy of the critical AT agrees with the equation-of-state explanation of superheated liquids and with the reaction-rate view of nucleation. It means there is an upper temperature limit above which a superheated liquid cannot exist (at a stated pressure) regardless of agitation. 

The fact that an ordinary degree of agitation causes only a negligible 

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Table 2.3. Effect of agitation rate on baker s yeast production...

Effects of agitator size and speed on bead size (microns). 

Figures 12 and 13 show the effects of agitation and time of exposure on suspensions of biological materials in bioreactors [61]. In turbulent flow the energy dissipation rate per unit mass, e, of a stirred bioreactor is normally expressed by the following equation ...

Effect of agitation The CHF of pool boiling can be increased considerably by introducing agitation, as shown by Pramuk and Westwater (1956) in experiments with boiling methanol at 1 atm (Fig. 2.35). 

Figure 2.35 Effect of agitation in methanol boiling at 1 atm. (From Pramuk and Westwater, 1956. Copyright 1956 by American Institute of Chemical Engineers, New York. Reprinted with permission.)... 

Figure 4 Effect of agitation speed on reaction rate.

FIGURE 3.8. Effect of Agitation and Surface Fouling on Heat Transfer and Stability. 

Ramtoola Z, Corrigan 01. Effect of agitation intensity on the dissolution rate of indomethacin and indomethacin-citric acid compressed discs. Drug Dev Ind Pharm 1988 14(15-17) 2241-2253. 

The process must be developed and tested for die efficacy of submerged-bath dilute nitric acid treatment for metals parts, including die effects of agitation and temperature. 

The effect of agitation, as produced by a rotary stirrer, for example, on mass transfer rates has been investigated by Hixson and Baum 2-1 who measured the rate of dissolution of pure salts in water. The degree of agitation is expressed by means of a dimensionless group (Nd2p/fx) in which ... 

Figure 13.31. Effect of agitator speed on efficiency for the system acetone-xylene-ester ...

Z., and Chen, J. (2005) Effect of agitation on the synthesis of zeolite beta and its synthesis mechanism in absence... 

In a mixer-settler, the effect of agitation speed on the extraction or stripping... 

In brief, deposited metal distribution depends on the shape and dimensions of the object, the geometry of the plating cell, the conductivity of the bath, the shapes of the polarization curves, CE-current density (or similar) curves, and the effect of agitation. 

Smith JJ, Lilly MD, Fox Rl, The effect of agitation on the morphology and penicillin production of Penicillium chrysogenum, Biotechnol Bioeng 35 1011— 1023, 1990. 

For crystallization by cooling, the effects of agitation, impurity concentration, and time after nucleation were examined. The experimental apparatus used was the same as shown schematically in Figure 3 except that acid was not added to the solution. 

Figure 6. Effect of Agitation on L-Leu and L-Val Purification Factors in Recovered L-Ile Hd H2O Crystals...

Figure 10. Effect of Agitation on the Purity of L-Ile Crystals Recovered by Cooling Crystallization...

Platen, G.E., Skar, M., Luthman, K. and Brandi, M. (2007) Drug permeability across a phospholipid vesicle based barrier 3. Characterization of drug-membrane interactions and the, effect of agitation on the barrier integrity and on the permeability. European Journal of Pharmaceutical Sciences, 30, 324—332. 

In the case of solid diffusion control, even in the absence of agitation where the mass transfer coefficient is at its minimum value, sufficient agitation should be provided in order to avoid the negative effect of the liquid-film resistance. The effect of agitation should be taken into account in both the design and application stage. 

Fig. 34. Effect of agitation on nucleate boiling. Saturated water was pumped through a heated vertical tube, 0.62 to 1.05 in. in diameter, at the indicated flow rates. Pressure = 15 to 36 lb./sq. in. abs. (S2).

Fig. 35. Effect of agitation. Methanol was agitated with a three-blade propeller while boiling at 1 atm. on a %-in. horizontal, steam-heated, copper tube. The shaft speed is indicated (P5).

Any other data which the customer feels would be of help such as heat transfer data present conditions under which the product is produced and type of equipment used present crystal size and effects of agitation, additives and/or temper ature on crystal size, shape, recovery, or purity. 

Yuguchi, S and M. Watanabe Studies on acrylic fiber. X. Effect of agitation on polymerization of acrylonitrile in aqueous and emulsion phase initiated by persulfate-triethanolamine redox system and persulfate alone. Chem. High Polymers 17, 108—114 (1960). See also previous papers in this series. 

When stirred-tank bioreactors started to be used for animal cell cultivation, many problems related to deleterious effects of agitation on cell viability were observed. Flowever, it was noted that the use of large impellers rotating at low speeds could minimize mechanical damage to the cells. The most widely used impeller types are marine (Chisti, 1993)... 

Fig. 10. Effect of agitation speed on cell concentration (A) and regeneration frequency (B) of rice calli in TBR without (o, ) and with (a, ) supports. Dotted lines show the results of the control culture...

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