Results 211 to 220 of about 81,208 (258)

Determination of the gas chromatographic gas hold-up time

Chromatographia, 1988
New versions are suggested for the gas hold-up time calculation in gas chromatography. The results are compared with those obtained by using other methods. The advantages of the suggested ways of calculation are pointed out.
M S Vigdergauz
exaly   +2 more sources

Estimation of gas hold‐up in aerated vessels

The Canadian Journal of Chemical Engineering, 2000
AbstractAn attempt to produce a simple equation for gas hold‐up in stirred tank reactors has been made. This new semi‐empirical equation, based on the mass balance for the gas phase, predicts the observed effem due to the tank and impeller diameters and physical properties reasonably well.
Paglianti A., Takenaka K., Bujalski W., Takahashi K.   +3 more
openaire   +2 more sources

Gas hold-up in aerated reactors

The Chemical Engineering Journal, 1979
Abstract An experimental study has been carried out on the gas content of the aerated layer in the physical model of a vertically sectioned commercial bubble reactor. On the basis of the results obtained, we derived a second-degree polynomial relating the gas content to the factors of influence: depth of the non-aerated liquid layer, gas velocity ...
P.S.T. Petrov, A.A. Petkov, E.N. Panayotova, D.I. Dimitrov, M.P. Popangelova   +4 more
openaire   +1 more source

The hold-up time in gas chromatography

Journal of Chromatography A, 1998
Abstract Three arguments are presented to show that the plot of the logarithms of the adjusted retention times of n -alkanes eluted under isothermal conditions versus their chain length is not a straight line, as generally accepted, even for n -alkanes of seventeen carbon atoms.
José Antonio Garcı́a-Domı́nguez, Jesús Eduardo Quintanilla-López, Rosa Lebrón-Aguilar   +2 more
openaire   +1 more source

Gas hold-up in bubble columns

The Chemical Engineering Journal, 1980
Abstract Experimental data on the fractional gas hold-up in a 10 cm I.D. bubble column with a single-nozzle gas sparger were obtained with various gases and pure liquids or aqueous solutions of non-electrolytes and the effect of the physical properties of the gas and the liquid on the gas hold-up was studied.
H. Hikita, S. Asai, K. Tanigawa, K. Segawa, M. Kitao   +4 more
openaire   +1 more source

A Gas hold‐up model for slurry bubble columns

AIChE Journal, 2007
AbstractA phenomenological model of the gas bubble hold‐up in slurry bubble columns is presented. The slurry moves upward in the core of the column and downward in the annulus, resembling the riser and downer of an air‐lift loop reactor, respectively. The model virtually divides the column in a riser and a downer. The cross‐sectional areas of the riser
Chilekar, V.P., Singh, C., Schaaf, van der, J., Kuster, B.F.M., Schouten, J.C.   +4 more
openaire   +1 more source

Characterizing Frothers using Gas Hold-Up

Canadian Metallurgical Quarterly, 2007
AbstractA way to characterize (classify) frothers using gas hold-up as a surrogate for bubble size was explored. Nine surfactants with a range in chemical structures were selected and tested in a bubble column instrumented to measure gas hold-up and superficial gas velocity. A correlation between frother type and gas hold-up was observed: for alcohols,
F. Azgomi, C.O. Gomez, J.A. Finch
openaire   +1 more source

Solid hold up in gas fluidised beds

Chemical Engineering and Processing: Process Intensification, 2002
Abstract The hold-up of particles has been studied in two gas fluidised beds of 89 and 290 mm diameter. Particles of different materials, density from 1228 to 11 400 kg/m3 and size from 50 μm to 1 mm were fluidised. Four distributors were examined in the larger diameter bed. Power law and exponential correlation of the expansion were examined. All of
N Hilal, D.J Gunn
openaire   +1 more source

Gas hold-up measurements in bioreactors

Trends in Biotechnology, 1988
Abstract The gas hold-up of a gas-liquid dispersion is an important parameter in the fermentation industry. If it is too low, or too high, productivity can be adversely affected. Gas hold-up in fermentors cannot be calculated from physico-chemical correlations and, therefore, must be measured accurately for each fermentation.
openaire   +1 more source

Consistency of gas hold-up determinations

Journal of Chromatography A, 1999
Abstract The retention of methane on poly(dimethylsiloxane) capillary columns was studied focusing its relation with the gas hold-up time t M , which was derived from the retention of n -alkanes. The [ideal gas/Van der Waals fluid] partition equation was applied in order to provide the mathematical expression for the retention factor of the n ...
openaire   +1 more source