Investigation on distribution of particles in inlet region of an FCC external catalyst cooler with different inlet structures

AbstractThe most widespread of all Holocene tephra deposits in the Cook Inlet region of south-central Alaska is a set of deposits from Hayes volcano. Because of their unique phenocryst content—biotite in rare amounts and a high proportion of amphibole to pyroxene—the deposits are readily identifiable at all but the most distant sites where they are very fine grained. Eighteen radiocarbon dates from eight upland sites limit the age of the tephra set to between about 3500 and 3800 yr. The set originated at Hayes volcano in the Tordrillo Mountains 150 km northwest of Anchorage; seven or possibly eight closely succeeding deposits, low-silica dacite in composition, compose two main lobes that extend northeast for 400 km and south for at least 250 km from the vent. We estimate the total tephra volume to be 10 km3; multiple layers imply four to six larger and two or three smaller eruptions. The deposits are a nearly isochronous marker horizon that should be useful in future archeologic, geologic, and palynologic studies in the region.

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The Effects of Artificially-Produced Defects on the Film Thickness Distribution in Sliding EHD Point Contacts

Journal of Lubrication Technology ◽

10.1115/1.3253222 ◽

1982 ◽

Vol 104 (3) ◽

pp. 365-375 ◽

Cited By ~ 34

Author(s):

C. Cusano ◽

L. D. Wedeven

Keyword(s):

Film Thickness ◽

Contact Region ◽

Thickness Distribution ◽

Point Contact ◽

Optical Interferometry ◽

Point Contacts ◽

Thickness Profile ◽

Inlet Region

The effects of artificially-produced dents and grooves on the elastohydrodynamic (EHD) film thickness profile in a sliding point contact are investigated by means of optical interferometry. The defects, formed on the surface of a highly polished ball, are held stationary at various locations within and in the vicinity of the contact region while the disk is rotating. It is shown that the defects, having a geometry similar to what can be expected in practice, can dramatically change the film thickness which exists when no defects are present in or near the contact. This change in film thickness is mainly a function of the position of the defects in the inlet region, the geometry of the defects, the orientation of the defects in the case of grooves, and the depth of the defect relative to the central film thickness.

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Heat transfer in pulsating flow behind a rib in the channel inlet region

Journal of Physics Conference Series ◽

10.1088/1742-6596/1105/1/012018 ◽

2018 ◽

Vol 1105 ◽

pp. 012018

Author(s):

N I Mikheev ◽

I M Gazizov ◽

I A Davletshin

Keyword(s):

Heat Transfer ◽

Pulsating Flow ◽

Channel Inlet ◽

Inlet Region

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Discussion: “Turbulent Flow in the Inlet Region of a Smooth Pipe” (Barbin, A. R., and Jones, J. B., 1963, ASME J. Basic Eng., 85, pp. 29–33)

Journal of Basic Engineering ◽

10.1115/1.3656522 ◽

1963 ◽

Vol 85 (1) ◽

pp. 33-33

Author(s):

Karl Brenkert

Keyword(s):

Turbulent Flow ◽

Inlet Region ◽

Smooth Pipe

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Numerical Simulation of Axial Vortex in a Centrifugal Pump as Turbine with S-Blade Impeller

Processes ◽

10.3390/pr8091192 ◽

2020 ◽

Vol 8 (9) ◽

pp. 1192

Author(s):

Xiaohui Wang ◽

Kailin Kuang ◽

Zanxiu Wu ◽

Junhu Yang

Keyword(s):

Centrifugal Pump ◽

Pressure Fluctuation ◽

Optimization Design ◽

Rotational Frequency ◽

Low Flow ◽

Dissipated Energy ◽

Detached Eddy Simulation ◽

Inlet Region ◽

Axial Vortex ◽

The Impact

Pump as turbines (PATs) are widely applied for recovering the dissipated energy of high-pressure fluids in several hydraulic energy resources. When a centrifugal pump operates as turbine, the large axial vortex occurs usually within the impeller flow passages. In view of the structure and evolution of the vortex, and its effect on pressure fluctuation and energy conversion of the machine, a PAT with specific-speed 9.1 was analyzed based on detached eddy simulation (DES), and the results showed that vortices generated at the impeller inlet region, and the size and position of detected vortices, were fixed as the impeller rotated. However, the swirling strength of vortex cores changed periodically with double rotational frequency. The influence of vortices on pressure fluctuation of PAT was relatively obvious, deteriorating the operating stability of the machine evidently. In addition, the power loss near impeller inlet region was obviously heavy as the impact of large axial vortices, which was much more serious in low flow rate conditions. The results are helpful to realize the flow field of PAT and are instructive for blade optimization design.

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