scholarly journals Investigation of Hydrodynamic Behavior of Alginate Aerogel Particles in a Laboratory Scale Wurster Fluidized Bed

Molecules ◽  
2019 ◽  
Vol 24 (16) ◽  
pp. 2915
Author(s):  
Işık Sena Akgün ◽  
Can Erkey
Keyword(s):  
Fluidized Bed ◽  
Residence Time ◽  
Laboratory Scale ◽  
Tube Length ◽  
Operating Parameters ◽  
Hydrodynamic Behavior ◽  
Particle Residence Time ◽  
Upper Limit ◽  
Gap Height ◽  
Circulatory Motion

The effects of design and operating parameters on the superficial velocity at the onset of circulatory motion and the residence time of alginate aerogel particles in a laboratory scale Wurster fluidized bed were investigated. Several sets of experiments were conducted by varying Wurster tube diameter, Wurster tube length, batch volume and partition gap height. The superficial velocities for Wurster tube with 10 cm diameter were lower than the tube with 8 cm diameter. Superficial velocities increased with increasing batch volume and partition gap height. Moreover, increasing batch volume and partition gap height led to a decrease in the particle residence time in the Wurster tube. The results showed that there is an upper limit for each parameter in order to obtain a circulatory motion of the particles. It was found that the partition gap height should be 2 cm for proper particle circulation. Maximum batch volume for the tube with 10 cm diameter was found as 500 mL whereas maximum batch volume was 250 mL for the tube with 8 cm diameter. The fluidization behavior of the aerogel particles investigated in this study could be described by the general fluidization diagrams in the literature.

Particle Residence Time and Particle Mixing in a Scaled Internal Circulating Fluidized Bed

2002 ◽  
Vol 41 (11) ◽  
pp. 2637-2645 ◽  
Author(s):  
Ralf Kehlenbeck ◽  
John G. Yates ◽  
Renzo Di Felice ◽  
Hermann Hofbauer ◽  
Reinhard Rauch
Keyword(s):  
Fluidized Bed ◽  
Residence Time ◽  
Circulating Fluidized Bed ◽  
Particle Residence Time ◽  
Particle Mixing

Influence of operating parameters on the fate and removal of three estrogens in a laboratory-scale AAO system

2015 ◽  
Vol 71 (11) ◽  
pp. 1701-1708 ◽  
Author(s):  
Zhaohan Zhang ◽  
Yujie Feng ◽  
Hui Su ◽  
Lijun Xiang ◽  
Qiuyan Zou ◽  
...  
Keyword(s):  
Residence Time ◽  
Biological Treatment ◽  
Laboratory Scale ◽  
Operating Parameters ◽  
Removal Mechanism ◽  
Excess Sludge ◽  
Hydraulic Residence Time ◽  
17Β Estradiol ◽  
Removal Efficiencies ◽  
Biological Treatment System

A laboratory-scale anaerobic-anoxic-oxic (AAO) process was constructed to investigate the influence of hydraulic residence time (HRT) and sludge retention time (SRT) on the removal and fate of estrone (E1), 17β-estradiol (E2) and 17α-ethinylestradiol (EE2), and their removal mechanisms in a biological treatment system. In an HRT range of 5–15 h, the highest removal efficiencies for E1, E2 and EE2 were obtained at an HRT of 8 h, with values of 91.2, 94.6 and 81.5%, respectively. When the SRT was increased from 10 to 20 d, all three estrogen removal efficiencies stayed above 80%, while the optimal SRT for each estrogen was different. The contribution of each tank for removal of the three estrogens was in the order of aerobic tank > anoxic tank > anaerobic tank. The optimal HRT and SRT for the removal of both the three estrogens and nutrients were 8 h and 15d, respectively. At this condition, respectively, about 50.7, 70.1 and 11.3% of E1, E2 and EE2 were biodegraded, 28.8, 17.2 and 50% were accumulated in the system, 8.3, 5.4 and 17.3% were discharged in the effluent, and 12.2, 7.3 and 20.34% were transported into excess sludge. It indicated that biodegradation by sludge microorganisms was the main removal mechanism of E1 and E2, while adsorption onto sludge was the main mechanism for EE2 removal.

scholarly journals Study of particle residence time in a pressurized fluidized bed with in-bed heat exchanger tubes

2019 ◽  
Vol 355 ◽  
pp. 201-212 ◽  
Author(s):  
M.-A. Séguin ◽  
R.W. Hughes ◽  
M. Fitzsimmons ◽  
A. Macchi ◽  
P. Mehrani
Keyword(s):  
Heat Exchanger ◽  
Fluidized Bed ◽  
Residence Time ◽  
Particle Residence Time

scholarly journals The Non-Stationary Metal Vapour Arc

1973 ◽  
Vol 28 (3-4) ◽  
pp. 428-437
Author(s):  
G. Ecker
Keyword(s):  
Residence Time ◽  
Critical Currents ◽  
Theoretical Studies ◽  
Velocity Dependence ◽  
Metal Vapour ◽  
Energy Characteristics ◽  
Upper Limit ◽  
Physical Background ◽  
Experimental And Theoretical Studies ◽  
Spot Motion

AbstractThe motion is depicted as a sequence of steps of a finite residence time.The spot motion affects essentially only the energy characteristics Te which in comparison to the stationary characteristics Tes are shifted to smaller values. Hereby the critical currents I0, I1 are raised in comparison to the corresponding stationary limits I0s, I1s. Particularly attractive are the phenomena found in connection with the dependence of the spot velocity ʋ on the spot current I. If the spot velocity increases with the spot current stronger than ʋ ∞ I1/2 then the E-diagram reveals the existence of an upper limit lu for the spot current. This result can be used to explain qualitatively the experimentally observed phenomena of "spot multiplicity" and “spot extinction”.Quantitative conclusions are obstructed by the lack of knowledge about the velocity dependence on the spot current, ʋ(I). Experimental and theoretical studies to provide a better understanding of the physical background and the analytical laws describing the motion of the cathode spots are urgently needed.

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