Mass transfer and pressure drop in a cocurrent reciprocating plate extraction column

Noh, Sung Hyun; Baird, M. H. I.

doi:10.1002/aic.690300117

Cited by 29 publications

(21 citation statements)

References 11 publications

(17 reference statements)

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“…These effects are all comparable with a derivation by Noh and Baird (1984) based on the quasi-steady flow assumption, namely that the orifice coefficient C, for the perforations retains a constant value throughout the reciprocation cycle. AP,, = (Np, U:/2 C,")…”

Section: Sign Convention For Maysupporting

confidence: 79%

“…When D> 1, Equation ( 2 ) predicts a linear dependence of pressure drop on 4f: Equation ( 2 ) has been reasonably well confirmed by the single phase data of Noh and Baird ( 1984) and by Rama Rao and Baird (1988) The curves through the data points on Figure 2 have been calculated from Equation (2) using the applicable values ofAf; N, S and U,. The value of C , has been set at 0.79; this is the value found by Rama Rao and Baird (1988) to give the best fit in a 5 cm diameter KRPC using plates similar to type I.…”

Section: Sign Convention For Maysupporting

confidence: 60%

“…The prediction of time-average pressure drop can be important in estimating pumping power requirements for cocurrent flow at high throughputs. For example, Noh and Baird ( 1984) operated a column at superficial velocities up to 26 c d s and time-average frictional pressure drops up to 6 kPa. More typically, and under countercurrent two-phase conditions, the superfical velocities are in the order of a few c d s and frictional pressure drops are much smaller than the hydrostatic pressure drop.…”

mentioning

confidence: 99%

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Pressure drops in gas—liquid flow in a 15 cm reciprocating platecolumn

Baird

Rao

1997

Can J Chem Eng

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Time-averaged pressure drops have been measured in a 15 cm internal diameter reciprocating plate column, using the wateriair system under conditions of cocurrent, countercurrent and single phase (water) flow. The reciprocation frequency was varied from 1 to 4 Hz, while the stroke (peak to trough amplitude) was set at 2.54 cm. Two types of perforated plate were used, having perforation diameters 14.3 and 6.35 mm.Under single phase flow conditions, the pressure drops were in agreement with an earlier model due to Noh and Baird ( I 984). Under cocurrent conditions the gas flow had the effect of increasing the pressure drop, particularly at low reciprocation rates; this was interpreted in terms of has been developed for industrial applications in diameters up to 1.7 m. Other industrially important types of RPC are the Prochazka column (PRPC) featuring smaller perforations and downcomers for the continuous phase, and the KRIMZ and other types developed in the U.S.S.R. Detailed reviews of the extraction characteristics of RPCs are available (Lo et al., 1992;Baird et al., 1994).Research activity on gas-liquid contact in W C s has been relatively slow to develop. In the 197Os, Miyanami and coworkers operated a vibrating disk contactor (the MVDC) containing a series of reciprocating disks driven from a vertical central shaft, interspersed with donut-shaped stator plates. Hydrodynamic data (Tojo et al., 1974a) and mass transfer data (Tojo et al., 1974b) were reported. Brauer and Sucker (1979) operated a gas-liquid 30 cm diameter Karr column as a fermentor. This led to the development of a reciprocating-jet gas-liquid reactor which has been successfully applied to waste water treatment (Brauer and Hennig, 1986) and the production of antibiotics (Brauer, 1989).The pressure drop in an oscillatory flow system comprises a fluctuating component and a time-average value. The fluctuations in pressure are of obvious practical importance. The maximum (peak) pressure affects the safe mechanical design of the column, including seals. The minimum 'Author to whom correspondence should be addressed. E-mail address:bairdmhi@mcmaster.ca (trough) pressure may lead to local cavitation in cases of intense oscillation (Baird and Stonestreet, 1995). In reciprocating-plate columns, the pressure fluctuations can be measured with a transducer and recorder. When these variations are integrated with the displacement, values of the energy dissipation rate in the column can be calculated (Hafez and Baird, 1978; Baird and Rama Rao, 1995). Attention must also be given to the time-average pressure drop in a reciprocating plate column. This is usually different under oscillatory flow conditions than under steady conditions at the same time-average flows. Noh and Baird ( I 984) showed that in single-phase flow conditions the time-average pressure drop was significantly increased by reciprocation, so that additional power would be needed to pump the feeds through the system. This additional energy input is different from that needed to reciprocate the p...

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Section: Sign Convention For Maysupporting

confidence: 79%

Section: Sign Convention For Maysupporting

confidence: 60%

mentioning

confidence: 99%

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Pressure drops in gas—liquid flow in a 15 cm reciprocating platecolumn

Baird

Rao

1997

Can J Chem Eng

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“…f Dp q c gz Dp Dp empty (16) A light attenuation technique was used for measuring the specific interfacial area since it was found to be in good agreement with the results obtained using the chemical and photographic techniques and was by far the most convenient of the three. The light source and photocell were mounted diametrically opposite each other on a Plexiglas ring clamped around the column, and measurements were taken at the mid-point between adjacent plates to reflect average conditions throughout the stage.…”

Section: Energy Dissipation Rate Due To Gas Flow E Gmentioning

confidence: 72%

“…This may be estimated based on the conventional pressure drop relations for fluid flow across a perforated plate [16]:…”

Section: Energy Dissipation Rate Due To Liquid Flow E Nmentioning

confidence: 99%

Dispersion Characteristics and Mass Transfer in a Pilot‐Scale Gas‐Liquid Oscillatory‐Plate Column

Gomaa¹,

Hashem²,

Al‐Taweel³

2012

Chem Eng & Technol

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Mass transfer and hydrodynamic characteristics of an oscillatory-plate column (OPC) and their relation to energy dissipation were investigated using a 0.1-m diameter pilot-scale unit. The column is characterized by having plates with a small hole diameter (1.6-3.2 mm) oscillating at 180°out of phase at higher frequencies (0-30 Hz) and small amplitudes (0-3.2 mm). Using this design, it was possible to achieve gas holdup and specific interfacial areas as high as ∼0.8 and 400 m -1 , respectively. The maximum gas superficial velocity achieved reaches as high as 1.7 m/s, while the axial dispersion coefficient ranged from ∼10 -4 to over ∼3 × 10 -3 m 2 s -1 , which is almost one order of magnitude lower than that in bubble columns under similar flow rates. The value of gas velocity of ∼0.1 m s -1 seems to mark a transition beyond which interfacial area, holdup, and axial mixing become practically unchanged. Keeping in view its performance characteristics, the column can satisfactorily meet many of the demands posed by intensified wastewater treatment processes, namely high rates of oxygen transfer, multistage operational mode, uniform distribution of small-scale turbulence structure, and the ability to handle sludge with relatively high concentrations of suspended solids.

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Direct measurement of droplet breakage in a pulsed disc and doughnut column

et al. 2017

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The lack of experimental data for the droplet breakup has been one of the limitations for the application of population balance model (PBM). In this work, a high‐speed camera was used to directly measure the droplet breakup frequency and daughter size distribution in a pulsed disc and doughnut column. It was found from the captured video that multiple breakup events were more frequently observed than binary breakup. The multiple breakup was treated as an original breakup and several intermediate breakups to characterize the process quantitatively. The effects of pulsation intensity, dispersed phase flow rates, and the spatial locations were investigated in detail. Empirical correlations were finally established for both the breakup frequency function and the daughter droplet size distribution function and fitted well with the experimental data. The correlation equations were then used in a simplified PBM to calculate the droplet number density, which further proved the feasibility of the correlations. © 2017 American Institute of Chemical Engineers AIChE J, 63: 4188–4200, 2017

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Mass transfer and pressure drop in a cocurrent reciprocating plate extraction column

Cited by 29 publications

References 11 publications

Pressure drops in gas—liquid flow in a 15 cm reciprocating platecolumn

Pressure drops in gas—liquid flow in a 15 cm reciprocating platecolumn

Dispersion Characteristics and Mass Transfer in a Pilot‐Scale Gas‐Liquid Oscillatory‐Plate Column

Direct measurement of droplet breakage in a pulsed disc and doughnut column

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