Experimental investigation of the effect of low-frequency fluctuations of the liquid flow rate on the minimum irrigation density in film flow

1988 ◽  
Vol 55 (1) ◽  
pp. 756-759
Author(s):  
S. E. Shcheklein ◽  
V. I. Vel'kin
Author(s):  
Yoshiyuki Iso ◽  
Xi Chen

Gas-liquid two-phase flows on the wall like liquid film flows, which are the so-called wetted wall flows, are observed in many industrial processes such as absorption, desorption, distillation and others. For the optimum design of packed columns widely used in those kind of processes, the accurate predictions of the details on the wetted wall flow behavior in packing elements are important, especially in order to enhance the mass transfer between the gas and liquid and to prevent flooding and channeling of the liquid flow. The present study focused on the effects of the change of liquid flow rate and the wall surface texture treatments on the characteristics of wetted wall flows which have the drastic flow transition between the film flow and rivulet flow. In this paper, the three-dimensional gas-liquid two-phase flow simulation by using the volume of fluid (VOF) model is applied into wetted wall flows. Firstly, as one of new interesting findings in this paper, present results showed that the hysteresis of the flow transition between the film flow and rivulet flow arose against the increasing or decreasing stages of the liquid flow rate. It was supposed that this transition phenomenon depends on the history of flow pattern as the change of curvature of interphase surface which leads to the surface tension. Additionally, the applicability and accuracy of the present numerical simulation were validated by using the existing experimental and theoretical studies with smooth wall surface. Secondary, referring to the texture geometry used in an industrial packing element, the present simulations showed that surface texture treatments added on the wall can improve the prevention of liquid channeling and can increase the wetted area.


2010 ◽  
Vol 2010 ◽  
pp. 1-5 ◽  
Author(s):  
I. I. Esen

Hydraulic performance of an airlift pump having a rectangular cross-section 20 mm × 80 mm was investigated through an experimental program. The pump was operated at six different submergence ratios and the liquid flow rate was measured at various flowrates of air injected. The effectiveness of the pump, defined as the ratio of the mass of liquid pumped to the mass of air injected, was determined as a function of the mass of air injected for different submergence ratios. Results obtained were compared with those for circular airlift pumps using an analytical model for circular pumps. Effectiveness of the rectangular airlift pump was observed to be comparable to that of the circular pumps. Hydraulic performance of the rectangular airlift pump investigated was then described by a set of semilogarithmic empirical equations.


2011 ◽  
Vol 133 (9) ◽  
Author(s):  
Yoshiyuki Iso ◽  
Xi Chen

Gas-liquid two-phase interfacial flows, such as the liquid film flows (also known as wetting flows on walls), are observed in many industrial processes including absorption, desorption, distillation, and so on. The present study focuses on the characteristics of wetting flows, in particular the drastic transition between the film flow and rivulet flow, as the liquid flow rate and the wall surface texture treatments are varied. The three-dimensional gas-liquid two-phase interfacial flow (wetting flow) simulation is based on the volume of fluid (VOF) model. As the liquid flow rate is increased and then decreased, a hysteresis of the transition between the film flow and rivulet flow is discovered, which implies that the transition phenomenon depends primarily on the history of the change of interfacial surface shape (which affects the process of the flow pattern transition). The applicability and accuracy of the present numerical simulation is validated by using the existing experimental and theoretical studies. Further study on the effect of texture geometry shows that the surface texture treatments added on the wall can impede liquid channeling and increase the wetted area.


Author(s):  
Yoshiyuki Iso ◽  
Xi Chen

Gas-liquid two-phase interfacial flows on the wall like liquid film flows, which are the so-called wetted wall flows, are observed in many industrial processes such as absorption, desorption, and distillation. For the optimum design of packed columns widely used in those kind of processes, the accurate predictions of the details on the small scale behavior of wetted wall flows in packing elements are very important, especially in order to enhance the mass transfer between the gas and liquid and to prevent flooding and channeling of the liquid flow. The present study focuses on the effects of the change of liquid flow rate and the wall surface texture treatments on the characteristics of wetted wall flows which have the drastic flow transition between the film flow and rivulet flow. In this paper, the three-dimensional gas-liquid two-phase flow simulation by using the volume of fluid (VOF) model is applied into wetted wall flows. Firstly, present results showed that the hysteresis of the flow transition between the film flow and rivulet flow arose against the increasing or decreasing stages of the liquid flow rate. It was supposed that this transition phenomenon depends primarily on the history of flow pattern as the change of curvature of interphase surface which leads to the surface tension. Additionally, the applicability and accuracy of the present numerical simulation were validated by using the existing experimental and theoretical studies. Secondary, referring to the texture geometry used in an industrial packing element, the present simulations showed that surface texture treatments added on the wall can improve the prevention of liquid channeling and can increase the wetted area.


1986 ◽  
Vol 51 (10) ◽  
pp. 2127-2134 ◽  
Author(s):  
František Potůček ◽  
Jiří Stejskal

Absorption of oxygen into water and aqueous solutions of poly(acrylamides) was studied in an absorber with a wetted sphere. The effects of changes in the liquid flow rate and the polymer concentration on the liquid side mass transfer coefficient were examined. The results are expressed by correlations between dimensionless criteria modified for non-Newtonian liquids whose flow curve can be described by the Ostwald-de Waele model.


Author(s):  
Svetlana Rudyk ◽  
Sami Al-Khamisi ◽  
Yahya Al-Wahaibi

AbstractFactors limiting foam injection for EOR application are exceptionally low rock permeability and exceedingly high salinity of the formation water. In this regard, foam formation using internal olefin sulfonate is investigated over a wide salinity range (1, 5, 8, 10, and 12% NaCl) through 10 mD limestone. The relationships between pressure drop (dP), apparent viscosity, liquid flow rate, total flow rate, salinity, foam texture, and length of foam drops at the outlet used as an indicator of viscosity are studied. Foaming is observed up to 12% NaCl, compared to a maximum of 8% NaCl in similar core-flooding experiments with 50 mD limestone and 255 mD sandstone. Thus, the salinity limit of foam formation has increased significantly due to the low permeability, which can be explained by the fact that the narrow porous system acts like a membrane with smaller holes. Compared to the increasing dP reported for highly permeable rocks, dP linearly decreases in almost the entire range of gas fraction (fg) at 1–10% NaCl. As fg increases, dP at higher total flow rate is higher at all salinities, but the magnitude of dP controls the dependence of apparent viscosity on total flow rate. Low dP is measured at 1% and 10% NaCl, and high dP is measured at 5, 8, and 12% NaCl. In the case of low dP, the apparent viscosity is higher at higher total flow rate with increasing gas fraction, but similar at two total flow rates with increasing liquid flow rate. In the case of high dP, the apparent viscosity is higher at lower total flow rate, both with an increase in the gas fraction and with an increase in the liquid flow rate. A linear correlation is found between dP or apparent viscosity and liquid flow rate, which defines it as a governing factor of foam flow and can be considered when modeling foam flow.


Author(s):  
N.I. Mikheev ◽  
V.M. Molochnikov ◽  
D.V. Kratirov ◽  
O.A. Dushina ◽  
A.A. Paereliy ◽  
...  

2007 ◽  
Vol 50 (6) ◽  
pp. 641-650
Author(s):  
V. B. Bol’shakov ◽  
N. I. Kosach

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