Drying of pasty and granular materials in mechanically and conventional spouted beds

Sousa, Robson Costa de; Ferreira, María do Carmo; Altzibar, Haritz; Freire, Fábio Bentes; Freire, José Teixeira

doi:10.1016/j.partic.2018.01.006

Cited by 32 publications

(17 citation statements)

References 18 publications

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“…A large temperature difference between the flaxseed surface and the evaporation front makes the release of moisture much easier. Therefore, higher temperatures of the inlet air resulted in shorter drying times . For instance, the drying process took 30 min when operating at a temperature of 80 °C in association with IR‐assisted heating (Table ).…”

Section: Resultsmentioning

confidence: 99%

Effect of infrared‐assisted spouted bed drying of flaxseed on the quality characteristics of its oil extracted by different methods

et al. 2019

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BACKGROUND: Infrared (IR)-assisted spouted bed drying (SBD) has emerged as a potential alternative to the traditional hot air drying for heat sensitive components. The aim of this study was to investigate effect of IR-assisted SBD and application of cold press (CP), solvent extraction (SE) and ultrasound assisted extraction (UAE) on the quality of flaxseed oil. SBD and IR-assisted SBD were performed at air temperatures of 40, 60, 80 ∘ C and their effects on the drying rate, fatty acids composition and oil peroxide and acid values were evaluated. Quality of oil extracted from the dried flaxseeds by CP, SE and UAE methods was then evaluated.RESULTS: Increasing air temperature in the presence of IR increased the drying rate. The peroxide values (PVs) of IR-SBD samples were higher than those of SBD at the same temperature. IR treatment did not notably change the composition of fatty acids in flaxseed oil, except in linoleic acid content. UAE gave higher extraction yield than CP and SE methods. UAE yielded an oil with higher percentage of saturated fatty acids, whereas the percentage of omega-3 and omega-6 fatty acids was higher in the CP method. The oil extracted by CP exhibited lower levels of PV (0.516 meq O 2 /kg oil) and acid value (1.36%), as compared to oils extracted by SE and UAE methods. CONCLUSION: Both UAE and conventional methods did not significantly influence the composition of fatty acids in the extracted oils. Nonetheless, the CP method yielded an oil with a high percentage of omega-3 and omega-6 fatty acids. Oil extractionCold press extraction A mechanical screw press (Barad Eng. Group, D50 Model, Isfahan, Iran) was employed to press out the flaxseeds in one go, thereby grinding the seeds.

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Section: Resultsmentioning

confidence: 99%

Effect of infrared‐assisted spouted bed drying of flaxseed on the quality characteristics of its oil extracted by different methods

et al. 2019

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“…Glass, alumina, and polyethylene beads (Geldart D particles) were used in this study. Such particles have been often used in several studies , and are considered as inert solids suitable for most applications . The particle properties and the different experimental conditions employed in both the conventional and the mechanical configurations are presented in Table .…”

Section: Methodsmentioning

confidence: 99%

“…However, in the mechanical spouted bed initially developed, the air is injected into the bed tangentially through a “whirling ring”. , In this sense, our research group has dedicated efforts to propose a modified mechanical spouted bed with a perpendicular supply of air through the inlet orifice. , This feature allows operating the experimental unit as either a mechanical or a conventional spouted bed, leading to versatile and viable equipment for different types of processes and operations. In a previous study performed by Sousa et al, the modified mechanical spouted bed has presented lower performance than the conventional spouted bed when handling pastes of complex composition, i.e., skimmed milk. Thus, different stirrers have been studied for the experimental unit proposed, as the stirrers proposed by Reyes and Vidal .…”

Section: Introductionmentioning

confidence: 99%

Fluid Dynamic Analysis of a Modified Mechanical Stirring Spouted Bed: Effect of Particle Properties and Stirring Rotation

AzevedoBarros

Brito

Freire

et al. 2020

Ind. Eng. Chem. Res.

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The purpose of this study is to perform the fluid dynamic analysis of a modified mechanical stirring spouted bed, which has been proposed as a promising alternative to the conventional spouted bed. Thus, a comparison is also performed between the dynamic behaviors of such equipment. The addition of the stirrer to the spouted bed enhanced the movement of particles in the bed. The mechanical stirring spouted bed presented better performance than the conventional configuration at stirrer rotations above 90 rpm. Small particles were less susceptible to the effect of stirrer rotation than large particles, demanding a higher rotation to provide a lower minimum air flow rate. The proposed model provided good predictions in terms of maximum pressure drop and minimum air velocity in the modified mechanical stirring spouted bed. The findings of this study contribute to the development of versatile and promising equipment for different processes and operations, providing the key parameters for an appropriate design.

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“…The disadvantages of the traditional spouted bed include weak radial disturbance of the gas-particle phase and low contact efficiency caused by the high-density accumulation of particles in the annulus zone. Subsequent studies optimized the material processing efficiency of the spouted bed by modifying its structure, resulting in the multi-jet spouted bed, spout-fluidized bed, , spouted bed with a draft tube, − internal circulation spouted bed, mechanical spouted bed, and slot-rectangular spouted bed . Although the abovementioned transformations have optimized the performance of the spouted bed, the complexity of these new structures limits their scope of applications.…”

Section: Introductionmentioning

confidence: 99%

Experimental Investigation of the Swirl Flow Enhancement Effect on the Particle Drying Process in a Novel Spouted Bed

Duan

Zhao

et al. 2021

Ind. Eng. Chem. Res.

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The swirl flow effect was introduced in the spouting bed to change the velocity and volume distribution of the gas phase in different directions, strengthen the radial disturbance, increase the contact area, and optimize the mass transfer, heat transfer, and transmission efficiency of the two-phase flow in the spouted bed. The drying efficiencies of a conventional spouted bed and a spouted bed with an integral swirling blade nozzle (ISBN) under various particle diameters, filling weights, and drying temperatures were experimentally studied. It was found that under the same conditions, the drying activation energy of the ISBN increased, the drying time was shortened, the drying rate increased, the moisture diffusion in the bed accelerated, and the unit energy consumption decreased. When T = 70 °C, d = 1.5 mm, and m = 66 g, the ISBN drying efficiency was the highest.

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Drying of pasty and granular materials in mechanically and conventional spouted beds

Cited by 32 publications

References 18 publications

Effect of infrared‐assisted spouted bed drying of flaxseed on the quality characteristics of its oil extracted by different methods

Effect of infrared‐assisted spouted bed drying of flaxseed on the quality characteristics of its oil extracted by different methods

Fluid Dynamic Analysis of a Modified Mechanical Stirring Spouted Bed: Effect of Particle Properties and Stirring Rotation

Experimental Investigation of the Swirl Flow Enhancement Effect on the Particle Drying Process in a Novel Spouted Bed

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