Monitoring of the fluidized bed particle drying process by temperature and pressure drop measurements

Abstract Detailed understanding the particle mixing and segregation dynamic is essential in successfully designing and reasonably operating multicomponent fluidized bed. In this work, a novel fluorescent tracer technique combining image processing method has been used to investigate the mixing and segregation behavior in a binary fluidized bed with wide size distributions. The particle number percentage in each layer for different gas velocities is obtained by an image processing method. Fluidization, mixing and segregation behavior has been discussed in terms of bed pressure drop, gas velocity and mixing index. Different types of binary particle systems, including the jetsam and the flotsam-rich system, are analyzed and compared. The mixing indexes at different minimum fluidization velocities are also analyzed and compared with other work. The results show that the theoretical minimum fluidization velocity calculated from the bed pressure drop cannot represent the whole fluidization for a wide size distribution binary particle system. The effect of a wide size distribution is an inflection point in the mixing index curve. There is also a dead region in the bottom of the bed that consists of particles with large size and a low degree of sphericity. The particles in the dead region are extraordinarily difficult to fluidize and should be considered in the design of fluidized beds in industrial applications.

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Effects of ripening stage and steaming time on quality attributes of fat free banana snack obtained from drying process including fluidized bed puffing

Journal of Food Science and Technology ◽

10.1007/s13197-015-2051-5 ◽

2015 ◽

Vol 53 (2) ◽

pp. 946-955 ◽

Cited By ~ 5

Author(s):

Somkiat Prachayawarakorn ◽

Chonlada Raikham ◽

Somchart Soponronnarit

Keyword(s):

Fluidized Bed ◽

Quality Attributes ◽

Ripening Stage ◽

Drying Process

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The Pressure Drop at Critical Fluidization of Large Particles in Vibrated Fluidization Bed

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.550-553.2763 ◽

2012 ◽

Vol 550-553 ◽

pp. 2763-2766

Author(s):

Xue Jun Zhu ◽

Jun Deng

Keyword(s):

Pressure Drop ◽

Fluidized Bed ◽

Large Particle ◽

Particle Diameter ◽

Future Design ◽

Vibration Strength ◽

Bed Height ◽

Large Particles ◽

Vibrated Fluidized Bed ◽

Critical Fluidization

The pressure drop at critical fluidization for two-dimensional vibrated fluidized bed(240 mm×80 mm) was studied, with large particle glass beads of average diameters dp of 1.8mm, 2.5mm and 3.2mm.The effect of the vibration strength, the static bed height and the particle diameter on the pressure drop was analyzed. The results of the study show that the pressure drop decreases with the increase of the vibration strength. It plays an even more prominent part with decreases of the static bed height and the particle diameter. The empirical correlation equations to predict the pressure drop was established, and the results of the prediction was compared with the experimental data, the error is in range of ±10%. The results can provide references for future design and research on the vibrated fluidized bed.

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Experimental Study of Drying Process of COLZA Seeds in Fluidized Bed Dryer by Statistical Methods

Advances in Chemical Engineering and Science ◽

10.4236/aces.2012.21016 ◽

2012 ◽

Vol 02 (01) ◽

pp. 129-135

Author(s):

Jamshid. Khorshidi ◽

Hassan. Davari

Keyword(s):

Experimental Study ◽

Fluidized Bed ◽

Statistical Methods ◽

Drying Process ◽

Fluidized Bed Dryer

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Sustaining low pressure drop and homogeneous flow by adopting a fluidized bed biofilter treating gaseous toluene

Chemosphere ◽

10.1016/j.chemosphere.2021.132951 ◽

2021 ◽

pp. 132951

Author(s):

Lichao Lu ◽

Dong Dong ◽

Marvin Yeung ◽

Zhuqiu Sun ◽

Jinying Xi

Keyword(s):

Pressure Drop ◽

Fluidized Bed ◽

Low Pressure ◽

Homogeneous Flow ◽

Gaseous Toluene

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Hydrodynamics of Pulse-Stabilized Fluidization at Incipient Fluidization

10.1115/imece1999-1220 ◽

1999 ◽

Author(s):

Subhadeep Gan ◽

Donald E. Beasley

Keyword(s):

Pressure Drop ◽

Secondary Flow ◽

Fluidized Bed ◽

Flow Rate ◽

Test Section ◽

Video Recording ◽

Small Displacement ◽

Pulsation Frequency ◽

Primary Flow ◽

Oscillatory Component

Abstract A laboratory scale experimental facility which models a Pulsed Atmospheric Fluidized Bed Combustor (PAFBC) has been developed; this facility is designed to examine the effect of an opposing secondary flow having an oscillatory component on a bubbling fluidized bed. The secondary flow is oriented in a vertical direction. The secondary flow is introduced into the bubbling bed through a tailpipe that extends through the bed and ends just above the porous polyethylene distributor. A pulsed flow simulator that employs a small displacement of a relatively large piston with variable drive radius and speed provides the oscillatory component of the secondary flow. The fluidized bed test section has a cross-sectional flow area of 30.5 by 30.5 cm with a height of 53 cm. Heat exchanger surfaces are modeled by two symmetric horizontal cylinders housed in the test section. The following test parameters are controlled: the primary flow rate, the mean secondary flow rate, the pulsation frequency and the amplitude of the secondary flow. Pressure taps are located just above the distributor and in the freeboard region to measure overall bed pressure drop. The facility is operated with a range of particles from 345 μm to 715 μm and a range of superficial fluidization velocities corresponding to the bubble flow regime. Fluidization curves were generated for traditional fluidization, using the primary flow through the porous distributor, with both primary and a steady secondary flow, and with primary and a pulsed secondary flow. Significant departures from the linear Darcy flow curves in the fixed bed region were observed, and attributed to significant local fluidization. Time resolved measurements of the overall bed pressure drop clearly indicate phase-locking behavior of the overall bed pressure drop with imposed frequency. Bubbles formed in pulse-stabilized fluidization are significantly smaller than in traditional fluidization, as observed through video recording of the present bed.

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