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Showing papers on "Slug flow published in 1983"


Journal ArticleDOI
TL;DR: A series of equations based on the physical processes thought to take place during slug flow were developed in this paper to predict the hydrodynamic character of this complex flow pattern, which appeared to validate the model.
Abstract: A series of equations are developed based on the physical processes thought to take place during slug flow which are used to predict the hydrodynamic character of this complex flow pattern. New experimental results are reported which appear to validate the model.

262 citations


Journal ArticleDOI
TL;DR: In this article, an analytical solution for the transient behavior of heat transfer in vertical upward gas-liquid slug flow is presented, which allows the prediction of the temperature variation with time and location and the wall temperature fluctuations, as well as the average heat transfer coefficients.

15 citations


Book ChapterDOI
01 Jan 1983
TL;DR: In this paper, the authors focus on recent publications about methods used for two-phase mass flow rate measurements, and present a combination of several methods for steady-state and transient flow conditions.
Abstract: This article concentrates on recent publications about methods used for two-phase mass flow rate measurements. Most of these methods need several measured quantities. Therefore, in the first part, the advances are described which can be achieved by the use of single techniques only. Combinations of several methods are discussed next, and mass flow rate results are presented, which were obtained in different experimental facilities for steady-state and transient flow conditions.

14 citations


Journal ArticleDOI
TL;DR: In this article, a series of high-pressure pneumatic dense-phase flow experiments were conducted using pulverized coal as the granular solids, and a detailed analysis of the system was performed.
Abstract: A series of high-pressure pneumatic dense-phase flow experiments were conducted using pulverized coal as the granular solids. This granular material was transported by nitrogen gas out of a conical feeder tank, through a length of stainless-steel tubing and into a pressurized receiver tank. Only the nitrogen gas trapped in the interstices of the coal particles inside the feeder tank was used to transport the coal. Six different transport stainless-steel tube geometries were used. A detailed analysis of the system is performed. This analysis reasonably predicts the expected solids flow rate for a given set of operating conditions and the minimum pressure drop required to maintain flow.

12 citations


Journal ArticleDOI
TL;DR: In this paper, a simple one-dimensional model of the single-sided linear induction pump is presented, and the electromagnetic fields and forces (thrust and lift) are obtained by using a semi-infinite geometry that neglects pump edge and end effects.
Abstract: A simple one-dimensional model of the single-sided linear induction pump is presented. The electromagnetic fields and forces (thrust and lift) are obtained by using a semi-infinite geometry that neglects pump edge and end effects. The forces are subsequently derated for edge effects by means of correction factors. The field solution is also used to determine the air gap impedance, while conventional expressions from electric machine theory are used to determine the stator impedance. The throughput produced by a given thrust is determined by assuming turbulent slug flow. Throughput versus kVA characteristics are presented for a variety of pump operating conditions.

6 citations


Journal ArticleDOI
TL;DR: In this paper, a unified flow model using a liquid wall-climbing algorithm to describe the transition from stratified to annular flow, and an enhanced interface friction factor was developed for slug flow.
Abstract: Two-phase flow in pipelines is described by separate equations of motion for the gas and liquid with frictional coupling at the interface. Solutions are obtained for steady-state flow by numerical integration. A unified model is developed which gives results for the liquid holdup and the pressure gradient agreeing with available data for the stratified, annular, and slug flow regimes. The unified flow model uses a liquid wall-climbing algorithm to describe the transition from stratified to annular flow, and an enhanced interface friction factor to describe the effects of slug flow. In applying the model to the study of pipelines, it is found that small uphill inclinations tend to cause large liquid holdups, increased pressure gradients, and/or slug formation over a wide range of flow conditions. For low flows, the liquid holdup and pressure gradient tend to be independent of the flowing liquid gas ratio. These results are significant to the operation of pipelines bringing gas with condensible hydrocarbons onshore from offshore fields.

4 citations


01 Jan 1983
TL;DR: In this article, the authors simulated inverted annular flow with turbulent water jets, issuing downward from long aspect nozzles, enclosed in gas annuli Velocities, diameters, and gas species were varied, and core jet length, shape, break-up mode, and dispersed-core droplet sizes were recorded at approximately 750 data points.
Abstract: In experiments, inverted annular flow was simulated adiabatically with turbulent water jets, issuing downward from long aspect nozzles, enclosed in gas annuli Velocities, diameters, and gas species were varied, and core jet length, shape, break-up mode, and dispersed-core droplet sizes were recorded at approximately 750 data points Inverted annular flow was observed to develop into inverted slug flow at low relative velocities, and into dispersed droplet flow at high relative velocities For both of the above transitions from inverted annular flow, a correlation for core jet length was developed by extending work done on free liquid jets to include this new, coaxial, jet disintegration phenomenon The result, showing length dependence upon diameter, jet Reynolds number, jet Weber number, void fraction, and gas Weber number, correlates the data well, especially at moderate-to-large relative velocities

4 citations


Journal ArticleDOI
TL;DR: In this article, the decay heat removal capability under boiling condition was studied using an LMFBR fuel subassembly mock-up loop, where the sodium flow was driven by natural convection through the loop in which was installed a 37-pin bundle heated electrically over a length of 45 cm.
Abstract: Decay heat removal capability under boiling condition was studied using an LMFBR fuel subassembly mockup loop. The sodium flow was driven by natural convection through the loop in which was installed a 37-pin bundle heated electrically over a length of 45 cm. The heat flux furnished by the pins was increased stepwise, upon which the two-phase flow regime changed from bubble to slug flow and then to annular or annular mist flow. Dryout occurred even in slug flow regime, but only momentarily, and permanent dryout was not observed before establichment of annular flow. A suitable criterion for permanent dryout is considered to be 0.5 average exit sodium vapor quality. The results indicated that upon occurrence of sodium boiling, the coolability of fuel subassembly would be maintained by natural convection after reactor shutdown.

2 citations


Journal Article
TL;DR: In this article, a hydrodynamic study of a slug catcher system is presented, which is a reservoir provided at the downstream end of a pipeline carrying wet gas to separate and collect slugs of liquid.
Abstract: A slug catcher is an important part of an increasing number of gas pipeline systems. It is a reservoir provided at the downstream end of a pipeline carrying wet gas to separate and collect slugs of liquid. These slugs may be received regularly as a result of passing spheres down the line to reduce the liquid hold-up and thus increase the capacity for gas flow. Slugs may also emerge from wet gas pipelines on an irregular basis, as a result of liquid accumulation, to the point that the gas flow causes slug displacement. Choosing a slug catcher system depends on such factors as maximum slug size and plot size limitations. This article will discuss one system and the role played by a hydrodynamic study in designing it.

1 citations


Journal ArticleDOI
TL;DR: In this article, a quantitative description of non-uniform, dilute-phase, volume fraction and superficial velocity in two-phase bubble-slug-flow, fluidized beds is presented.
Abstract: A quantitative description of non-uniform, dilute-phase, volume fraction and superficial velocity in two-phase, bubble-slug-flow, fluidized beds is presented. The appropriate expression for absolute slug velocity is where the distribution coefficient, Co takes on a value of 1.20, and ūs is a weighted-mean value over the bed cross-section. Only if the slug flow profile were uniform would the distribution coefficient be unity, and this is shown not to be the case. These results quantify the absolute slug velocity relationship proposed by Nicklin et al4.

1 citations


Patent
31 Oct 1983
TL;DR: In this article, the authors describe a continuous flow system in which successive liquid segments are established containing different related components of a fluid package, separated by at least one immiscible segment, passed along a first section of a conduit, combined in a second section of the conduit and mixed while passing along a third section, so as to provide a completely mixed segment.
Abstract: SINGLE CHANNEL CONTINUOUS FLOW SYSTEM ABSTRACT OF THE DISCLOSURE A continuous flow system is disclosed in which successive liquid segments are established containing different related components of a fluid package, such as an anlaysis mixture, separated by at least one immiscible segment, passed along a first section of a conduit, combined in a second section of the conduit and mixed while passing along a third section of the conduit, so as to provide a completely mixed segment. This system permits the delayed on-line mixing of different components of an analysis mixture, such as samples with reagents or dilu-ents, as well as mixing and interaction of such components in a single conduit.


Book ChapterDOI
01 Jan 1983
TL;DR: In this paper, gas/liquid mass transfer at non-Newtonian flow occurring, e.g., in aerobic fermentation is studied using highly viscous pseudoplastic solutions of sodium carboxymethylcellulose (CMC) as a model medium.
Abstract: Gas/liquid mass transfer at non-Newtonian flow occurring, e.g., in aerobic fermentation is studied using highly viscous pseudoplastic solutions of sodium carboxymethylcellulose (CMC) as a model medium. Aeration measurements have been carried out in a 14 cm (I.D.) bubble column, 270 cm in height, operated cocurrently at bubbly and slug flow conditions. Volumetric mass transfer coefficients are evaluated by fitting the measured profiles of the oxygen liquid phase concentration to the predictions of the dispersion model. Interfacial areas have been measured by the sulfite oxidation method. Simple correlations describe eG, kLa and a in the slug flow regime. Since the kLa correlation holds also for a CMC/Na2SO4 solution the results on the interfacial area make it possible to evaluate kL. Volumetric mass transfer coefficients reported for fermentations of penicillium chrysogenum are in striking agreement with the suggested correlation.

Journal ArticleDOI
TL;DR: In this paper, the conditions necessary for the existence of slug flow are considered and the boundary of the region of its existence is constructed and compared with the author's own data and published experimental data reveals agreement of the results.
Abstract: The conditions necessary for the existence of slug flow are considered and the boundary of the region of its existence is constructed. Comparison with the author's own data and published experimental data reveals agreement of the results.

Journal ArticleDOI
TL;DR: In this article, the velocity of a water jet formed at the spherical top surface of a slug bubble is measured on high-speed photographs, and it is confirmed that the velocity is less than 10m/s even in the case of a vapour slug bubble, and that the pulsation of the gas slug bubble in the pressure waves is treated as an adiabatic one.
Abstract: By means of high-speed photography and pressure transducers, the motion of a gas- or a vapour-slug bubble is observed in pressure waves. The velocity of a water jet, formed at the spherical top surface of a slug bubble, is measured on the high-speed photographs, and it is confirmed that the velocity is less than 10m/s even in the case of a vapour slug bubble, and that the pulsation of the gas slug bubble in the pressure waves is treated as an adiabatic one. Moreover, the impact pressure of the water jet against the pressure transducer, set in the gas slug bubble, is measured, and it is also confirmed that the value is the same as the one, estimated by the stagnation pressure. of the water jet.