Vibration of gas-solid fluidized beds is often used to enable fluidization cohesive particles; however, it has also been shown reduce the minimum velocity (Umf). Here, we show via experiments that vibration can both Umf and bubbling (Umb) in Geldart Group B D particles. We observe reduced more than Umb, thereby creating a densely packed, bubble-free state when superficial gas between Umb. Umb d...

The influences of the superficial velocity and particle diameter on gas–solid flow characterizations in a rolling circulation fluidized bed (RCFB) are clarified by using electrical capacitance tomography method. Gas–solid include time-space averaged volume fraction ᾱz′, time transition cross-sectional average 〈α〉t, radial profile 〈α〉r/R. Two kinds particles selected case that is 0.22 mm set to ...

The transition from stratified to intermittent air-water two-phase flow was investigated experimentally, by visualization and pressure drop signals analyses, in a 30 mm ID pipe. flow’s onset found be mainly dependent on the liquid superficial velocity pipe diameter. Plug flow, Less Aerated Slug (LAS) or Highly (HAS) flows could obtained gas grounds. available models, compared experiments, not p...

The influence of granulometric properties of the material and of the operational conditions on the drying kinetics of nonhygroscopic material was studied. Four fraction sizes of dolomite were chosen and dried in four dryers by different heating methods. Dolomite was dried in a microwave dryer under different microwave heating powers. During convective drying the effects of temperature and super...

Fluid velocity has the potential to cause severe erosion damage to oil & gas production infrastructure. In order to avoid or alleviate damage due to erosion, the American Petroleum Institute Recommended Practice (API RP) 14E recommends a threshold fluid velocity for production tubing and pipelines. However, field and laboratory data have proven that the applied empirical constants, known as C-f...

Circulating Fluidised Beds (CFBs) are widely applied in the process industry, for mostly gas-solid and gas-catalytic reactions. The riser is the key component of the CFB being the process reactor. The important design parameters are the operating gas velocity (U) and the solids concentration flux (G). The CFB operation starts at moderate to high superficial gas velocities. Its voidage exceeds ~...

This paper presents the numerical investigation of the effects of the general bed characteristics such as superficial gas velocities, bed temperature, bed heights and particle size, on the direct synthesis in a 3D fluidized bed reactor. A 3D model for the gas flow, heat transfer, and mass transfer was coupled to the direct synthesis reaction mechanism verified in the literature. The model was v...