Topic
Countercurrent exchange
About: Countercurrent exchange is a research topic. Over the lifetime, 2255 publications have been published within this topic receiving 28687 citations. The topic is also known as: Countercurrent exchange.
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TL;DR: In this paper, the authors investigated the hydrodynamic behavior of countercurrent gas-liquid flow and the gas- liquid mass transfer characteristics in an internally finned monolith and concluded that countercurrent flow is possible at industrially relevant flow rates and that the limitations are mainly engendered by the liquid outlet.
33 citations
TL;DR: In this article, the effect of heat transfer rates of swirl generators with holes for the entrance of fluid were investigated by placing them at the entrance section of inner pipe of heat exchanger, where hot air and cold water were passed through the inner pipe and annulus respectively.
33 citations
TL;DR: In this article, the authors evaluated axial dispersion of gas and solid phases in a gas-solid packed column at trickle flow using residence time distribution (RTD) experiments.
33 citations
TL;DR: In this paper, a countercurrent column, filled with structured gauze packing, was measured for the separation of a mixture of terpenes (d-limonene/1,8-cineole) by supercritical carbon dioxide, at 313 and 318 K and pressures up to 9 MPa.
Abstract: Supercritical fluid extraction (SFE) is an alternative separation method to more conventional processes such as liquid extraction and distillation. However, up to now, few works have been devoted to the investigation of the efficiency of countercurrent packed columns under supercritical conditions from a mass transfer point of view. Mass transfer in a countercurrent column, filled with structured gauze packing, was measured for the separation of a mixture of terpenes (d-limonene/1,8-cineole) by supercritical carbon dioxide, at 313 and 318 K and pressures up to 9 MPa. The extraction efficiency was determined in terms of the overall mass transfer coefficient. Operating lines for this process had an appreciable curvature due to a high miscibility of the two contacting phases. The real slope of these lines had to be estimated. Available mass transfer models for packed columns predicted efficiencies diverging to a great extent from the experimental results.
33 citations
TL;DR: In this paper, both theoretical and experimental determination of the hydrodynamics of drying air in an industrial countercurrent spray dryer was presented. But the results were limited to no-swirl operation and 3D CFD calculations showed high instability of the air flow in the dryer.
Abstract: This article presents both theoretical and experimental determination of the hydrodynamics of drying air in an industrial countercurrent spray dryer. Air velocity measurements were performed in selected areas of the tower to determine the flow pattern in the dryer and to collect data to validate the computational fluid dynamics (CFD) modeling and verify the results. For no-swirl operation mode, 3D CFD calculations showed high instability of the air flow in the dryer. A bent, pillow-shaped flow above the drying air inlet, which promotes deposition of particles in this area of the wall, was detected. CFD calculations also proved that when drying air was introduced to the tower tangentially; from 20° to 30° in relation to the initial air flow configuration in the spray-drying tower, the air flow was stabilized and air velocity near the wall increased, which might reduce wall deposition of particles. Comparison of experimental and theoretical results showed that the CFD model of countercurrent spray-drying pr...
33 citations