Improved Conductivity System for Measurement of Turbulent Concentration Fluctuations

Torrest, Robert S.; Ranz, W. E.

doi:10.1021/i160032a035

Cited by 22 publications

(11 citation statements)

References 8 publications

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“…Thus, we used a microprobe similar to those described by Manning and Wilhelm [8] and by Torrest and Ranz [9]. A 0.2mm diameter platinum wire was soldered into a stainless steel hypodermic needle (0.45mm in diameter), which was extended by a second needle, itself soldered to the first needle.…”

Section: Conductimetric Methodsmentioning

confidence: 99%

Mixing characteristics in the torus reactor

1992

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The hydrodynamic characteristics of propeller-induced toroidal flow in a loop reactor were investigated by performing an RTD analysis. The experimental determination of circulation time allows the calculation of the mean axial velocity with respect to the rotational speed of the impeller. RTD measurements are interpreted with the aid of the dispersion plug flow model, and it is shown that axial dispersion is relatively weak in the torus reactor. The mixing time was also determined experimentally and related to the circulation time. A direct relationship between mixing time and axial dispersion coefficient has been established, leading to a correlation for the mixing time in a torus reactor.

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Section: Conductimetric Methodsmentioning

confidence: 99%

Mixing characteristics in the torus reactor

1992

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“…The active area of the probe is the tip section of a 30 lam diameter platinum wire as in the work of Brodberger et al (1983). After polishing, this area is coated with platinum following the procedure of Torrest and Ranz (1969). The uniformity of the coating is controlled through a microscope.…”

Section: Conductivity Probe and Conductivity Metermentioning

confidence: 99%

“…The spatial resolution of such probes has been improved over the years up to cell volumes of 10 -4 mm 3 magnitude (Prausnitz andWilhelm, 1956, 1957;Cairns and Prausnitz, 1960;Lamb et al, 1960;Gibson and Schwartz, 1963;Torrest and Ranz, 1969).…”

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confidence: 99%

Concentration fluctuations in a stirred reactor

Mahouast

1991

Experiments in Fluids

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Turbulent mixing of tap-water with salt-water in a 6.3 dm 3 Continuous Stirred Tank Reactor is analyzed from concentration measurements obtained by a conductivity micro-probe. The frequency response of the instrument has been tested previously by specific dynamic trials. As well as the field of mean concentration C and the degree of segregation x//~/C, the Eulerian length macroscales of concentration in the tank and characteristics of the turbulent diffusion in the discharge flow are deduced from spectral analysis of the fluctuations and from the turbulent velocity field measured by laser Doppler velocimetry.

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“…To characterize mixing and the influence of flow rates and geometries, several experimental methods, either physical or chemical, have been developed: (1) injection of an electrolyte and use of a conductivity probe [14], (2) visualization of a dye along the mixing device [15], (3) use of reactions generating colored species or a color change [15], (4) use of two consecutive or parallel competitive reactions with different characteristic time and the determination of the concentration of the product obtained by the slowest reaction [16]. Nowadays, the system of parallel competitive reactions proposed by Guichardon et al [17], the so called the Villermaux-Dushman reaction and the one proposed by Baldyga et al [18] are widely used.…”

Section: Introductionmentioning

confidence: 99%