Minimum fluidization velocity of particles with different size distributions at elevated pressures and temperatures

Dynamically structured fluidization: Oscillating the gas flow and other opportunities to intensify gas-solid fluidized bed operation

“…A clear expression of this are the known discrepancies between the many correlations to predict the minimum fluidization velocity of different powders [42]. Many works now focus on accounting for the effect of the particles' non-sphericity [43] and develop correlations suited to polydisperse systems [44,45], not only at ambient conditions, but also at high temperatures and pressures [46]. However, it is not always possible to control the specifications of raw materials, and the effect of changing particle properties is neither localized nor understood well enough to utilize them in general to impose a well-controlled, macroscopic flow pattern.…”

Data-Driven Prediction of Minimum Fluidization Velocity in Gas-Fluidized Beds Using Data Extracted by Text Mining

“…Considering that the operating temperature and pressure mainly affect the gas density and viscosity, in this work, the effects of temperature and pressure are implicitly reflected on the gas density and viscosity by the following formula: …”

“…This is, however, rather time-consuming and costly, especially considering the fact that real industrial fluidized beds always operate under elevated temperatures and pressures. Chemical engineers always fitted the measured U mf with the properties of particles and gases and established corresponding empirical correlations for convenience. ,− However, the accuracy and consistency of empirical correlations are impaired since most of these correlations were developed based on the data with limited experiments, which are only applicable for the situations with the same solid–fluid system under similar experimental conditions. ,,,, For example, Gupta et al investigated the suitability of 79 correlations for fine tailings materials and found that most correlations underestimate the values of U mf . Anantharaman et al also found that most correlations are highly empirical and system-specified, which hinders their applicability if tested on systems outside their scope .…”

“…5,8−10 However, the accuracy and consistency of empirical correlations are impaired since most of these correlations were developed based on the data with limited experiments, which are only applicable for the situations with the same solid−fluid system under similar experimental conditions. 5,8,9,11,12 For example, Gupta et al investigated the suitability of 79 correlations for fine tailings materials and found that most correlations underestimate the values of U mf . 13 Anantharaman et al also found that most correlations are highly empirical and system-specified, which hinders their applicability if tested on systems outside their scope.…”

Experimental study and modeling of oxy-char combustion in a pressurized fluidized bed combustor

“…The reactor can be heated to about 1273 K by the electric heaters, and its inner pressure can be controlled by adjusting the back-pressure valve. More details about the reactor can be found elsewhere [51]. Before each experiment, 0.5 kg silica sand was preloaded into the reactor with an unexpanded bed height of about 100 mm.…”