Wyniki wyszukiwania - BazTech

1

Stopnie zapełnienia faz wznoszącego przepływu mieszaniny wodno-olejowej w rurze pionowej

Troniewski L., Mydlarz-Gabryk K.

Inżynieria i Aparatura Chemiczna

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2006

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Nr 6s

241-242

EN

An attempt of adopting and examination of methods permitting the calculation of a very viscous phase fraction was undertaken in the paper. The methods applied are correct for up-ward adia-batic gas - liquid flow. A comparison of the oil volume fraction with the one resulting from mutual relation between streams of phases was executed. An influence of velocities of both phases on the oil fraction in flowing mixture was discussed.

2

Prediction of holdup in liquid slugs

Brauner N., Ullmann A.

Transactions of the Institute of Fluid-Flow Machinery

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2003

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nr 112

75--90

EN

Correlations and models from the literature for the prediction of void fraction in liquid slugs are reviewed. It is shown that a mechanism that can explain the slug aeration in vertical, horizontal and inclined tubes has not yet been established. A new model that attributes the aeration of the liquid slug to a recurrent bubble entrainment from the Taylor bubble (TB) tail is introtuced. The bubble fragmentation is related to the rate of turbulent kinetic energy in the shear layer, which is formed at the TB wake as the liquid film plunges into the slug front. The model has been tested against experimental data available from the literature and was found to predict the effects of liquid and gas flow rates and physical properties, as well as tube diameter and inclination on the void fraction.

3

Metodyka badań przepływów mieszanin wielofazowych

Fidos H., Dziubiński M.

Inżynieria i Aparatura Chemiczna

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2003

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Nr 6

6-10

PL

Przedstawiono własne konstrukcje czujników pomiarowych oraz opracowaną metodykę badań wybranych parametrów przepływów wielofazowych takich jak spadki ciśnienia i udziały faz oraz parametrów charakteryzujących strukturę przepływu - szczególnie przepływu rzutowego - a mianowicie średnich długości pęcherzy gazowych i rzutów cieczy oraz średnich prędkości i częstotliwości rzutów.

EN

Measuring sensors of our own construction and methods for the investigation of selected multi-phase flow parameters such as pressure drop, phase structure, and also the parameters characterising the flow structure, in particular slug flow, namely, mean gas bubble lengths and liquid slugs liquid as well as mean velocities and frequencies of slugs.

4

Radioisotope tracer study in an indirectly heated rotary dryer

Pant H.

Nukleonika

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2002

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Vol. 47, nr 4

173-176

EN

A radioisotope tracer study was carried-out in a pilot scale indirectly heated rotary dryer to measure residence time distribution (RTD) of sand particles. Lanthanum-140 labeled sand was used as a tracer. Mean residence time (MRT) and variance of the tracer distribution curves were calculated from the measured RTD curves. From the calculated MRTs, solid holdup in the dryer was estimated. The qualitative comparison of the dimensionless variance with the data published in the literature led to the conclusion that the rotary dryer behaves as a plug flow system. The results of the study were used to design a full-scale industrial rotary dryer.

5

Measurement of liquid holdup and axial dispersion in trickle bed reactors using radiotracer technique

Pant H., Saroha A., Nigam K.

Nukleonika

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2000

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Vol. 45, nr 4

235-241

EN

The holdup and axial dispersion of aqueous phase has been measured in trickle bed reactors as a function of liquid and gas flow rates using radioisotope tracer technique. Experiments were carried out in a glass column of inner diameter 15.2´10-2 m column for air-water system using three different types of packings i.e. non-porous glass beads, porous catalysts of tablet and extrudate shape. The range of liquid and gas flow rates used were 8.3´10-5-3.3´10-4 m3/s and 0-6.67´10-4 m3/s, respectively. Residence time distributions of liquid phase were measured and mean residence times were determined. The values of liquid holdup were calculated from the measured mean residence times. It was observed that liquid holdup increased with increase in liquid flow rates and was independent of increase in gas flow rates used in the study. Two-parameter axial dispersion model was used to simulate measured residence time distribution data and values of mean residence time and Peclet number were obtained. It was observed that values of Peclet number increases with increase in liquid flow rate for glass beads and tablets and remains almost constant for extrudates. The values of mean residence time obtained from model simulation were found to be in good agreement with the values measured experimentally.