Mixing studies

There are many nonintrusive experimental tools available that can help scientists to develop a good picture of fluid dynamics and transport in chemical reactors. Laser Doppler velocimetry (LDV), particle image velocimetry (PIV) and sonar Doppler for velocity measurement, planar laser induced fluorescence (PLIF) for mixing studies, and high-speed cameras and tomography are very useful for multiphase studies. These experimental methods combined with computational fluid dynamics (CFDs) provide very good tools to understand what is happening in chemical reactors. 

The solids mixing study by injection of tracer particles indicated that the axial mixing of solids in the bubble street is apparently very fast. Radial mixing flux depends primarily on the bubble size, bubble velocity, and bubble frequency, which in turn depend on the size of the jet nozzle employed and the operating jet velocity. 

NIRSy stems, Inc., Application Note, Following the progress of pharmaceutical mixing studies using near-infrared spectroscopy, Silver Spring, Md. 

Full scale mixing studies were conducted without incident using 100, 250, 500, and 1,000 pound batch sizes. Electrostatic charge generation during the blending cycle was several orders of magnitude below that required for initiation. 

SUTHERLAND, K. S. Trans. Inst. Chem. Eng. 39 (1961) 188. Solids mixing studies in gas fluidised beds. Part 1. A preliminary comparison of tapered and non-tapered beds. 

This maximum is thought, from viscosity and enthalpy of mixing studies (Fig. 5.42), to be due to the formation of a H-bonded monomer-water complex. Previous investigations of the solvolysis of 2-chloro-2-methylpropane had led us to conclude that low intensity ultrasound (< 2 W cm ) was capable of destroying H-bonds and if this were... 

Ng and Assirelli have carried out a mixing study in batch stirred vessels with working volumes of 3 L to 20L using a fiber-optic UV-vis monitoring technique. Bromophenol blue sodium salt was used as a non-reactive tracer. The results on traditional Rushton turbines and 45° angled pitched blade turbines showed good agreement with a typical conductivity technique and a correlation proposed in literature. 

D.J.W. Ng, M. Assirelli, Mixing study in batch stirred vessels using a fibre-optic UV-VIS monitoring techniqne a novel method, Chem. Eng. Res. Des., 85(10), 1348-1354 (2007). 

E.W. Ciurczak, Eollowing the progress of a pharmaceutical mixing study via near-infrared spectroscopy, Pharm. Tech. 15, 140 (1991). 

Ogilvie, J. P, Plazanet, M., Dadusc, G., and Miller, R. J. D. 2002. Dynamics of ligand escape in myoglobin Q-band transient absorption and four-wave mixing studies. J. Phys. Chem. 109 10460-67. 

Mixing Studies. The typical steps in preparing a gelled slurry system may be summarized as follows ... 

Absorption spectroscopy, quartz crystal microbalance and electrical measurements and femtosecond degenerate four-wave mixing studies of third-order optical non-linearity... 

Shilstone Test Lab., Inc., "Rep. Cone. Mix Studies for Coll. Petrol, and Min., Saudi Arab.", Houston, 1967. 

Second, encapsulation of 2-ethylpolyaniline has been achieved. Degenerate four-wave mixing studies have been carried out, but the observed signal cannot be unambiguously attributed to %(3) effects. 

Michael BD (1984) Kinetics and mechanisms of the oxygen effect in radiobiology. In Breccia A, Greenstock CL, Tamba M (eds) Advances on oxygen radicals and radioprotectors, pp 53-63 Michael BD, Adams GE, Flewitt FIB, Jones WBG, Watts ME (1973) A posteffect of oxygen in irradiated bacteria A submillisecond fast mixing study. Radiat Res 54 239-251... 

Whillans DW, Hunt JW (1978) Rapid-mixing studies of the mechanisms of chemical radiosensitization and protection in mammalian cells. Br J Cancer 37 38-41 Whillans DW, Hunt JW (1982) A rapid-mixing comparison of the mechanisms of radiosensitization by oxygen and misonidazole in CHO cells. Radiat Res 90 126-141 Whillans DW, Adams GE, Neta P (1975) Electron-affinic sensitization. VI. Pulse radiolysis and ESR comparison of some 2- and 5-nitroimidazoles. Radiat Res 62 407-421... 

Pullin, M. J., and S. E. Cabaniss. 1997. Physiochemical variations in DOM-synchronous fluorescence Implications for mixing studies. Limnology and Oceanography 42 1766-1773. 

Other studies were conducted by the FS in 1976 to expand the data base on the size of drops which deposited on Douglas-fir needles. These studies provided an opportunity to determine if the drop size distribution would be similar to drop size distributions of tank mixes studied earlier. The 1976 study involved aerial application of acephate and trichlorfon, and the 1981 study involved Bacillus thuringiensis (Dipel 4L and Thuricide 16B). These data have not been published or reported previously. The chemical tank mixes were applied by helicopter and the B.t. tank mixes were applied by fixed-wing aircraft. 

R. Potluri, D. B. Todd, and C. G. Gogos, Proc. 1 l,h Polymer Mixing Study Semi-annual Meeting, Polymer Processing Institute, Hoboken, NJ (1995). 

The TSMEE is an experimental device developed to study melting and mixing in twin rotor mixers during the Polymer Mixing Study conducted at the Polymer Processing Institute (95). 

Fig. 11.31 Schematic representation of the Twin Screw Mixing Element Evaluator (TSMEE) in (a) the melt-melt (M-M) mode, and (b) the dissipative mix-melting (DMM) mode. The last section of both the M-M and DME modes consists of two separate HBRs. The mixing element sequences are a design variable. [Reprinted with permission from Proceedings of the Sixth Semi-annual Meeting of the Polymer Mixing Study, Polymer Processing Institute, Hoboken, NJ (1993).]...

---