Dynamic processes in a free granular layer during gas filtration with a sudden pressure drop

1991 ◽  
Vol 31 (6) ◽  
pp. 874-881
Author(s):  
V. A. Antipin ◽  
A. A. Borisov ◽  
A. P. Trunev
Author(s):  
A.N. Kharkhardin ◽  
◽  
I.Yu. Markova ◽  

Concludes combined equation for the pressure drop in the apparatus with stationary and fluidized granular layer, and the resulting recursive equation is used to calculate phase transitions of matter, from the atomic granularity of matter to granular (particulate) material.


2016 ◽  
Vol 87 (2) ◽  
pp. 208-215 ◽  
Author(s):  
Li-Hua Lou ◽  
Xiao-Hong Qin ◽  
Hongnan Zhang

In this paper, patterned nanofibrous membranes were fabricated for air filtration. Polyacrylonitrile was employed as the electrospinning material as its fluffy property and bulged bubble template served as collector to prepare the patterned membrane. With this special structure, the pressure drop significantly declined from 151.7 to 24.7 mmH2O, although the filtration efficiency of nanofiber membranes exhibited a slight decline from 99.94% to 96.33% compared to traditional electrospinning nanofibrous membranes. These sharp declines of the pressure drop while retaining the filtration efficiency imply that it could have more extensive applications.


2008 ◽  
Vol 2 (1) ◽  
pp. 87 ◽  
Author(s):  
T. G. Chuah M ◽  
J. P.K Seville

Rigid ceramic filters have been proven to be highly efficient gas filtration devices. However, they must be cleaned periodically for maximum efficiency. This is done by applying a pulsed reverse flow. The cleaning mechanism by which the deposited dirt is removed from the filter surface is still not fully understood. Experiments were carried out to measure pressure drop along the axis of two different candle geometry, cylindrical and tapered. For the cylindrical filter, the reverse pulse pressure was not uniformly distributed along the element. Generally, the pressure difference across the wall of the element is highest at the close end, and lowest, sometimes close to zero, at the open end. Pressure drop across the tapered filter was more uniform compared to that of the cylindrical filter. Hence, it should demonstrate better filter dirt removal. The authors have written a computer program that models the flow of the reverse pulse from the cleaning bar nozzle to the dirty side of the filter. It uses the iterative calculation mode and allows variables such as reverse pulse pressure and filter geometry to be changed. The calculations demonstrate fair agreement with the experimental results.


Author(s):  
H.H. Rotermund

Chemical reactions at a surface will in most cases show a measurable influence on the work function of the clean surface. This change of the work function δφ can be used to image the local distributions of the investigated reaction,.if one of the reacting partners is adsorbed at the surface in form of islands of sufficient size (Δ>0.2μm). These can than be visualized via a photoemission electron microscope (PEEM). Changes of φ as low as 2 meV give already a change in the total intensity of a PEEM picture. To achieve reasonable contrast for an image several 10 meV of δφ are needed. Dynamic processes as surface diffusion of CO or O on single crystal surfaces as well as reaction / diffusion fronts have been observed in real time and space.


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