Effect of operating conditions and particle properties on performance of vertical air-lift

Abstract

The effect of the fluidization air flow rate and the transport air velocity on the solids mass flow rate and the pressure drop along the transport pipe was investigated in a vertical air-lift. The use of two different materials, glass (150 µm) and zirconium oxide (260 µm) particles (Geldart's B class), enabled to estimate the effect of particle properties on the air-lift performance. Different levels of the solids mass flow rate were obtained by varying the fluidization air flow rate while keeping the transport air velocity constant. The solids loading ratio varied between 2 and 16 for both types of particles. The pressure drop was nonlinearly related to the solids mass flow rate at most of the transport air velocities tested. State diagrams presenting the relationship between the transport air velocity, the solids mass flow rate, and the pipeline pressure drop were constructed to characterize the flow pattern and to compare the behavior of the glass and zirconium oxide particles. Owing to the larger size and higher density, the zirconium oxide particles displayed higher pressure drop values than the glass beads and the minimum pressure drop shifted towards higher transport air velocities. The velocity at the transition between dilute and dense phase conveying was approximately in the range of 7 to 10 m/s for glass beads and 10 to 12 m/s for zirconium oxide, at the solids mass flow rates tested. The flow patterns could be also effectively characterized from the analysis of the pressure drop fluctuations at different transport air velocities.

The performance of airlift pump for the solid particles lifting during the transportation of gas-liquid-solid three-phase flow: A comprehensive research review

“…Some researchers proposed the model based on the balance of momentum by Kato et al., 5 Mahrous, 46 Yoon et al., 47 and Ma, 37 based on empirical correlation by Kawashima, 48 based on the power balance by Dedegil, 49 based on the multi-fluid model by Tomiyama et al., 50 and Hatta et al. 36 Other researchers, 51 such as Tomiyama et al., 51 Yoshinaga and Sato, 8 Hatta et al., 36 Hatta et al., 52 Liang and Peng, 53 Pougatch and Salcudean, 6 Cazarez et al., 54 Chladek et al., 34 and Hu et al. 4 conducted experimentally and analytically three-phase flow in vertical pipes.…”

Conveying Characteristics of Pulverized Coal in a Top‐Discharge Blow Tank System

“…Thus, investigation on the conveying characteristics of a top-discharge blow tank will be favorable to industrial applications. Chladek et al [27] investigated a vertical air-lift which was similar to the top-discharge blow tank. Ratnayake et al [11] formulated a model to predict the entry pressure loss in a top-discharge blow tank, and the predicted values agreed well with the experimental data.…”

Effect of Operating Conditions and Powder Properties on Pneumatic Conveying Characteristics of a Top Discharge Blow Tank

“…Most research is focused on the discharge characteristics of bottom discharge blow tanks [13][14][15][16][17][18]. A few publications [19][20][21] on vertical pneumatic conveyers with a fluidized-bed solids feeder or vertical air-lift which was similar with top discharge blow tank in structure indicated that the solid mass flow was affected by the fluidizing and transporting gas flow rates, height of fluidized bed, riser diameter, and riser length. The characteristics in terms of gas-solids two-phase flow structures and the apparent behavior of particles and fluidparticle interactions are closely linked to operating conditions, particle properties, and blow tank configurations.…”