Migration behavior of two-component gases among CO2, N2 and O2 in coal particles during adsorption

In this paper, we consider the three dimensional flow of granular materials and a viscous fluid in a channel. We use Mixture Theory to treat this problem as a two-component system [1]: One component is the solid particles (granular materials), such as sand, coal particles or red blood cells; the solid particles are modeled as a generalized Reiner-Rivlin type fluid derived by Massoudi [2], which not only considers the effects of volume fraction but also has a viscosity which is shear rate dependent. The other component, the host fluid, is assumed to behave as a linear viscous fluid, such as water, oil or plasma. For the interaction forces, the effect of different hindrance functions for the drag force is studied; moreover a generalized form of the expression for the hindrance function is suggested. For studying this two-component system numerically, a three dimensional CFD solver based on OpenFOAM® has been developed. Applying this solver, a specific problem (blood flow) has been studied for which our numerical results and experimental data [3] show good agreement.

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ON SOME ASPECTS OF THE STUDY OF PULVERIZED COAL AND FUEL MIXTURES COMBUSTION IN A DROP TUBE FURNACE

Modern Problems of Metalurgy ◽

10.34185/1991-7848.2021.01.12 ◽

2021 ◽

pp. 119-131

Author(s):

Yurii Stupak ◽

Tatyana Khokhlova

Keyword(s):

Blast Furnace ◽

Combustion Process ◽

Pulverized Coal ◽

Tube Furnace ◽

Drop Tube ◽

Drop Tube Furnace ◽

Coal Particles ◽

Two Component ◽

Tube Furnaces ◽

Fuel Mixtures

The article considers some aspects of the pulverized fuel combustion modelling in the laboratory on installations called vertical tube furnaces (referred to as drop tube furnaces in scientific periodicals). We have considered the scheme of the installation to study the process of pulverized coal (PС) combustion in conditions similar to the conditions of heating and ignition of coal particles in the blast flow of the blast furnace and their subsequent gasification in the raceway. We have formulated the basic requirements for ensuring the reliability of modelling results. We have examined the methods of combustion completeness (burnout) estimation used in similar studies. We have proposed a convenient method for the estimation of the burnout of two-component fuel mixtures. According to this method, the estimation can be performed for any ratio of components in a two-component fuel mixture with the use of data on the initial ash content in each of them and the relevant burnout. We have obtained the estimated data on the dependence of the burnout of PC (anthracite, lean coal) with fuel additives. It has been shown that the proposed approach can be used to evaluate experimental data regarding the study of the combustion completeness of fuel mixtures. It has been established that for the initial stages of PC combustion (heating, emission and ignition of volatile matters), which occur before the fuel particles enter the blast furnace raceway, the fuel mixtures burnout values recorded in the experiments do not differ significantly from the estimated ones. For the final stages of PC combustion (heating and burnout of char), which occur mainly in the raceway and outside, the combustion completeness determined in laboratory studies was significantly higher than the estimated one. The obtained results confirmed the efficiency in the use of drop tube furnace to model the PC combustion process during the fuel injection with the heated blast flow in the blast furnace raceways and study of the influence of various factors on the combustion process. The results of such studies can be used to improve the design of PC injection units in the blast furnace and to study the possibilities for improving the coal particles combustion completeness and the specific consumption of PC.

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Spectroscopic Observations of Visual Double Stars

International Astronomical Union Colloquium ◽

10.1017/s0252921100027536 ◽

1965 ◽

Vol 5 ◽

pp. 109-111

Author(s):

Frederick R. West

Keyword(s):

Radial Velocity ◽

High Dispersion ◽

Velocity Difference ◽

Spectrograph Slit ◽

Spectroscopic Observations ◽

Double Stars ◽

Visual Double Stars ◽

Relative Orbit ◽

Two Component ◽

Star Images

There are certain visual double stars which, when close to a node of their relative orbit, should have enough radial velocity difference (10-20 km/s) that the spectra of the two component stars will appear resolved on high-dispersion spectrograms (5 Å/mm or less) obtainable by use of modern coudé and solar spectrographs on bright stars. Both star images are then recorded simultaneously on the spectrograph slit, so that two stellar components will appear on each spectrogram.

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A technique for protecting delicate specimens during processing

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100156894 ◽

1989 ◽

Vol 47 ◽

pp. 982-983

Author(s):

R.J. Mount ◽

R.V. Harrison

Keyword(s):

Basilar Membrane ◽

Low Cost ◽

Organ Of Corti ◽

Region Of Interest ◽

Sensory Epithelium ◽

Physical Damage ◽

Air Drying ◽

Specimen Handling ◽

Two Component

The sensory end organ of the ear, the organ of Corti, rests on a thin basilar membrane which lies between the bone of the central modiolus and the bony wall of the cochlea. In vivo, the organ of Corti is protected by the bony wall which totally surrounds it. In order to examine the sensory epithelium by scanning electron microscopy it is necessary to dissect away the protective bone and expose the region of interest (Fig. 1). This leaves the fragile organ of Corti susceptible to physical damage during subsequent handling. In our laboratory cochlear specimens, after dissection, are routinely prepared by the O-T- O-T-O technique, critical point dried and then lightly sputter coated with gold. This processing involves considerable specimen handling including several hours on a rotator during which the organ of Corti is at risk of being physically damaged. The following procedure uses low cost, readily available materials to hold the specimen during processing ,preventing physical damage while allowing an unhindered exchange of fluids.Following fixation, the cochlea is dehydrated to 70% ethanol then dissected under ethanol to prevent air drying. The holder is prepared by punching a hole in the flexible snap cap of a Wheaton vial with a paper hole punch. A small amount of two component epoxy putty is well mixed then pushed through the hole in the cap. The putty on the inner cap is formed into a “cup” to hold the specimen (Fig. 2), the putty on the outside is smoothed into a “button” to give good attachment even when the cap is flexed during handling (Fig. 3). The cap is submerged in the 70% ethanol, the bone at the base of the cochlea is seated into the cup and the sides of the cup squeezed with forceps to grip it (Fig.4). Several types of epoxy putty have been tried, most are either soluble in ethanol to some degree or do not set in ethanol. The only putty we find successful is “DUROtm MASTERMENDtm Epoxy Extra Strength Ribbon” (Loctite Corp., Cleveland, Ohio), this is a blue and yellow ribbon which is kneaded to form a green putty, it is available at many hardware stores.

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