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

In this article, simulation runs were conducted to predict the drying evolution of sand in conical spouted beds with a nonporous draft tube using the Eulerian−Eulerian approach. The simulation results were validated against experimental data reported in the literature, and good agreement was achieved. In addition, the effects of various operating and design parameters, such as superficial gas velocity, inlet air temperature, the draft tube's length and diameter, and the solid phase's initial moisture content on the sand drying, were carefully investigated. It was found that the operating temperature and superficial gas velocity are the most essential parameters for improving the drying process and reducing the drying time of the sand particles. In addition, the choice of drag model, restitution coefficient, and specularity coefficient were found to have no significant influence on the drying time of the solid phase. Moreover, increasing the particles' diameter and initial moisture content leads to longer drying times, whereas increasing the conical bed angle prolongs the drying time for the solid particles. On the other hand, increasing the nozzle diameter and entrance length decreases the drying time of the solid phase. Furthermore, reducing the diameter and length of the draft tube also decreased the drying time.

Section: T H Imentioning

confidence: 99%

Comprehensive CFD-TFM Simulation of Drying in Spouted Beds with Draft Tubes

Naghdi,

Arabi,

Molaei Dehkordi

2024

“…A spouted bed is a device with stable gas–solid circulation flow pattern, and its applications include mixing, heating/cooling, drying, , coating, and chemical reactions, and the related industries are the chemical and electrochemical, metallurgy, food and agricultural, pharmaceutical, as well as energy and nuclear sectors. Gishler applied spouted bed technology in drying process industry for the first time and reported significantly improved efficiency.…”

Section: Introductionmentioning

confidence: 99%

Experimental and Numerical Study of Cross-Domain Hydrodynamics in an Integrated Pneumatic-Spouted Bed

Jiao

Wang

Mei

et al. 2023

As an essential resource, the drying, upgrading, and efficient utilization of lignite are of great significance to the development of the low-carbon economy. In this work, a novel drying system, combining a pneumatic and spouted bed, is designed to achieve lignite deeply dewatering. The system is investigated experimentally and numerical simulated to characterize the hydrodynamics of particles moving across the domain, such as pressure drop, fountain height, and pressure fluctuation. The results show that there is a critical gas velocity that changes the flow pattern of the bed when the static bed is higher than 50 mm. When the gas velocity increases to the critical value, the spouting state becomes unstable and the corresponding pressure drop will undergo a secondary mutation. This work provides a deeper understanding of the flow structure and particle motion in the novel drying system under various industrial operating conditions.

“…It was pointed out that poor hydrodynamics could be induced by porous plates during the drying process. Duan et al 6 evaluated swirl flow effects on the particle drying process in a spouted fluidized bed. It was found that the integral swirling blade nozzle could accelerate the moisture diffusion and enhance the drying rate, which was sensitive to the bed load.…”

Section: Introductionmentioning

confidence: 99%

Estimation of the Fluidization Behavior of Nonspherical Wet Particles with Liquid Transfer

Wang

2022

Many industrial processes involve wet-particle systems. Particle shape influences the liquid transfer and interaction between particles in wet-particle systems. In this work, a spouted fluidized-bed system with nonspherical wet particles is investigated, where the liquid transfer model is implemented in the CFD-DEM framework to consider the redistribution of liquid content after the collision of nonspherical wet particles. The behaviors of spherical and nonspherical wet particles in a spouted fluidized bed are compared. The results demonstrate that nonspherical wet particles can strengthen the liquid bridge force and particle agglomeration in contrast to spherical wet particles. The liquid transfer results in a clear discrepancy of liquid content on the particle surface. The multiple contacts with neighboring particles inside the agglomeration reduce the liquid content on the particle surface, which is enhanced under a higher aspect ratio.