The nature of the flow just above the perforated plate distributor of a gas-fluidised bed, as imaged using magnetic resonance

2006 ◽  
Vol 61 (18) ◽  
pp. 6002-6015 ◽  
Author(s):  
A.C. Rees ◽  
J.F. Davidson ◽  
J.S. Dennis ◽  
P. S Fennell ◽  
L.F. Gladden ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Perforated Plate ◽  
Fluidised Bed

scholarly journals Computational and Experimental Study on Pressure Drop in a Fluidised Bed with Different Air Distributor Designs

2020 ◽  
Vol 17 (2) ◽  
pp. 8043-8051
Author(s):  
A. S. M. Yudin ◽  
A. N. Oumer ◽  
N. F. M. Roslan ◽  
M. A. Zulkarnain
Keyword(s):  
Pressure Drop ◽  
Perforated Plate ◽  
Area Ratio ◽  
Maximum Pressure ◽  
Fluidised Bed ◽  
Key Factor ◽  
Minimum Number ◽  
Maximum Pressure Drop ◽  
Free Area ◽  
Distributor Plate

Fluidised bed combustion (FBC) has been recognised as a suitable technology for converting a wide variety of fuels into energy. In a fluidised bed, the air is passed through a bed of granular solids resting on a distributor plate. Distributor plate plays an essential role as it determines the gas-solid movement and mixing pattern in a fluidised bed. It is believed that the effect of distributor configurations such as variation of free area ratio and air inclination angle through the distributor will affect the operational pressure drop of the fluidised bed. This paper presents an investigation on pressure drop in fluidised bed without the presence of inert materials using different air distributor designs; conventional perforated plate, multi-nozzles, and two newly proposed slotted distributors (45° and 90° inclined slotted distributors). A 3-dimensional Computational Fluid Dynamics (CFD) model is developed and compared with the experimental results. The flow model is based on the incompressible isothermal RNG k-epsilon turbulent model. In the present study, systematic grid-refinement is conducted to make sure that the simulation results are independent of the computational grid size. The non-dimensional wall distance,  is examined as a key factor to verify the grid independence by comparing results obtained at different grid resolutions. The multi-nozzles distributor yields higher distributor pressure drop with the averaged maximum value of 749 Pa followed by perforated, 45° and 90° inclined distributors where the maximum pressure drop recorded to be about one-fourth of the value of the multi-nozzles pressure drop. The maximum pressure drop was associated with the higher kinetic head of the inlet air due to the restricted and minimum number of distributor openings and low free area ratio. The results suggested that low-pressure drop operation in a fluidised bed can be achieved with the increase of open area ratio of the distributor.

scholarly journals HYDROGENATION OF ETHYLENE IN TWO DIMENSIONAL GAS-SOLID FLUIDISED BED WITH PERFORATED PLATE

1977 ◽  
Vol 10 (4) ◽  
pp. 307-313
Author(s):  
RYOZO TOEI ◽  
MORIHIRO OICHI ◽  
HISATAKA HAYASHI ◽  
KIYOKAZU KUBO ◽  
TOSHIHIRO YANAGIDA ◽  
...  
Keyword(s):  
Perforated Plate ◽  
Two Dimensional ◽  
Fluidised Bed ◽  
Hydrogenation Of Ethylene

Magnetic resonance studies of jets in a gas–solid fluidised bed

Particuology ◽  
2012 ◽  
Vol 10 (2) ◽  
pp. 161-169 ◽  
Author(s):  
Meenal Pore ◽  
Thusara C. Chandrasekera ◽  
Daniel J. Holland ◽  
Aining Wang ◽  
Fei Wang ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Fluidised Bed ◽  
Magnetic Resonance Studies

Magnetic resonance studies of a gas–solids fluidised bed: Jet–jet and jet–wall interactions

Particuology ◽  
2010 ◽  
Vol 8 (6) ◽  
pp. 617-622 ◽  
Author(s):  
Meenal Pore ◽  
Daniel J. Holland ◽  
Thusara C. Chandrasekera ◽  
Christoph R. Müller ◽  
Andrew J. Sederman ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Fluidised Bed ◽  
Magnetic Resonance Studies ◽  
Wall Interactions

An emerging technology: Nuclear magnetic resonance microscopy

1988 ◽  
Vol 46 ◽  
pp. 1000-1001
Author(s):  
M.J. Hennessy ◽  
E. Kwok
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Relaxation Times ◽  
Basic Research ◽  
Local Environment ◽  
Magnetic Resonance Images ◽  
Nmr Microscopy ◽  
Mri Scans ◽  
Temperature Relaxation ◽  
Nuclear Magnetic

Much progress in nuclear magnetic resonance microscope has been made in the last few years as a result of improved instrumentation and techniques being made available through basic research in magnetic resonance imaging (MRI) technologies for medicine. Nuclear magnetic resonance (NMR) was first observed in the hydrogen nucleus in water by Bloch, Purcell and Pound over 40 years ago. Today, in medicine, virtually all commercial MRI scans are made of water bound in tissue. This is also true for NMR microscopy, which has focussed mainly on biological applications. The reason water is the favored molecule for NMR is because water is,the most abundant molecule in biology. It is also the most NMR sensitive having the largest nuclear magnetic moment and having reasonable room temperature relaxation times (from 10 ms to 3 sec). The contrast seen in magnetic resonance images is due mostly to distribution of water relaxation times in sample which are extremely sensitive to the local environment.

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