Interfacial area of mellapak packing: Absorption of 1,1,1‐trichloroethane by Genosorb 300

Abstract

In this work a Sulzer structured packing, Mellapak 250Y, was studied for applications in the field of absorption. A new model was proposed which makes it possible to estimate the packing surface that actually takes part in the process. In the course of these studies, new experimental data were obtained relating to the absorption of 1,t, t -trichloroethane using Genosorb 300, a mixture of polyethylene glycol dimethyl ethers produced by Hoechst S.p.A., as absorption liquid. The results obtained with the proposed model are in agreement both with the experimental measurements made in the course of the work and with experimental absorption measurements reported by other authors on water systems.

Mechanistic pressure drop model for columns containing structured packings

“…The reason for this is that, according to the present hydraulic model, shear stresses both at the channel walls and at the gas-liquid interface contribute to the frictional losses, and to evaluate them, knowledge of both the gas-liquid interfacial area and of the unwetted fraction of the channel wall is necessary. As shown by Brunazzi et al (1995) for Mellapak packing, and by Nardini et al (1996) for BX packing, this information is related to the dynamic liquid holdup measured in the absence of the gas load. The starting point of those models is the assumption that the liquid phase flows on the structured packing as a falling film.…”

“…Due to the geometric and hydrodynamic characteristics, and according to previous work concerning mass transfer in structured packings (Brunazzi et al, 1995;Nardini et al, 1996), channels within the packing have been drawn as…”

“…The acceleration term is related to gas expansion effects and can be expressed by Eq. 4, where V, must take into account the presence of the liquid phase, and can be computed as (20) where hL,= is the dynamic liquid holdup with reference to the channel and is related to the liquid holdup in the column by means of the simple relation (Brunazzi et al, 1995),…”

“…Until now the approach commonly followed by various workers has been to develop distinct models to predict pressure drop (Stichlmair et al, 1989;Bravo et al, 1986;Billet, 1989;Rocha et al, 1993;Robbins, 1991;Spiegel and Meier, 1992) and mass-transfer efficiency (Bravo et al, 1985;Spiegel and Meier, 1987;Brunazzi et al, 1995;Nardini et al, 1996). Recently, Bravo et al (1992) proposed a comprehensive model that allows global evaluation of the performance of columns equipped with this type of interior.…”

HETP evaluation of structured packing distillation column

“…Several mechanistically-based models have also been developed to help the design and optimization of CSSP distillation columns [Linek et al (1984); Bravo et al (1992); Fair (1993, 1996); Brunazzi et al (1995); Olujić (1997); Nicolaiewsky et al (1999); Olujić, Seibert and Fair (2000)], not only in terms of HETP evaluation, but also on the development of effective interfacial area correlations.…”