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.

Plate type heat exchanger and method of manufacturing heat exchanger

Abstract: A plate heat exchanger includes a plurality of plates sandwiched between a pair of end plates. Each of the plurality of plates has two passageways defined therein that are not in fluid communication with each other. Alternatively, some of the plurality of plates have a passageway, while some of the remaining plates have another passageway. Two fluids flow through the two passageways in a countercurrent fashion. Because the countercurrent flows are superior in heat transfer efficiency, it is possible to enhance the performance and reduce the size of the plate heat exchangers.

On Bubble Rising in Countercurrent Flow

Abstract: A single bubble of typical volume 20 mm³ ≤ VB ≤ 400 mm³ was placed in downward conically diverging flow of low and moderate viscous liquids (aqueous solutions of glycerine and of electrolytes (NaCl, Na3PO4, MgSO4), and butanol). Experiments were performed over a range of Reynolds number 60≤Re≤2200, Weber number 1≤We≤14, Tadaki number 1≤Ta≤10, Eötvös number 1≤Eo≤22, and bubble aspect ratio 0.4≤b/a≤0.9. The bubble shape, bubble position and motion were investigated by direct observation of two plane projection of bubble by high speed camera. Typical sampling frequency was 150 fps. Relatively long records, (approximately 9000 frames per one bubble observation) allow us to get relevant statistics of treated data. Bubble aspect ratio has been determined from both projection planes. Dimensionless front area of observed bubble has been introduced as suitable parameter for correlation with Eötvös number. Model of static bubble and classical Wellek correlation were employed as asymptotes. Bubble rising velocity has been determined and tested for each single bubble with respect to liquid properties. Velocity data are plotted within the frame given by several theoretical predictions for pure and contaminated liquids. Dimensional analysis is used considering viscosity and surface tension effect. New simple correlation of bubble rising velocity separating the effects of viscosity and surface tension is presented.

Gas‐liquid mass transfer with a tangentially moving interface: Part II. Experimental studies

Abstract: A horizontal, rectangular channel of high aspect ratio has been built for the study of interphase mass transfer in stratified, laminar gas-liquid flow. Cases were examined where the resistance to mass transfer is confined to the gas phase and where the control is distributed between phases. Measurements of the rate of evaporation of ethanol into oxygen and carbon dioxide confirmed that cocurrent interface motion enhances gas phase-controlled mass transfer coefficients substantially. On the other hand countercurrent motion of the interface decreases the coefficient. Agreement with basic convective diffusion theory was found for the evaporation of ethyl ether into helium and carbon dioxide from dilute solutions in ethanol, cases where the mass transfer control is distributed between the phases. Experiments with aqueous solutions were hampered by the accumulation of surfactants at the interface. A diaphragm cell technique was used to measure diffusivities of 0.87 × 10−5 sq.cm./sec. for ethyl ether at high dilution in ethanol and 0.96 × 10−5 sq.cm./sec. for ethyl ether at high dilution in water at 25°C.