Search

This study is focused on reducing the pressure drop, conveying velocity, and power consumption in a horizontal gas–solid flow. Four types of lattice models, which are fixed in the particle inlet, are proposed to easily generate the oscillation of the wake flow to easily convey the gas–solid two-phase flow. A horizontal pipeline with an inner diameter of 80 mm and length of approximately 5 m was used. Polyethylene particles with an average diameter of 2.3 mm and density of 978 kg/m3 were employed as conveying solid materials. The experimental ranges of the average gas velocity and solid mass flow rate were 10–16 m/s and 0.10–0.47 kg/s, respectively. Compared to the nonlattice gas–solid flow, reductions in the total pressure drop, conveying gas velocity, power consumption, and additional pressure loss were achieved in the range of lower gas velocity when using the lattice model. The highest reduction rates of the minimum conveying velocity and additional pressure drop were approximately 5.12% and 15.2%, respectively. In the acceleration region, the particle concentration in the flows with the lattice model was larger than that in the nonlattice flow near the upper part of the pipe and lower than those in the nonlattice flows in the lower part of the pipe. The time-mean axial particle velocity and particle fluctuating velocity in all lattice model flows were higher than those in the nonlattice flow, according to particle image velocimetry measurements, particularly in the upper part of the pipe. [Display omitted] • The lattice models were applied to gas-solid two-phase flow. • Pressure drop, minimum velocity, and particle velocity were measured. • The pressure drop and minimum velocity are reduced by using lattice model. • High particle velocity and fluctuating velocity were observed in the upper part of pipe. [ABSTRACT FROM AUTHOR]

In the pneumatic conveying process, the particles move to the bend under the influence of inertia to form a particle rope, which will cause a serious collision between the pipe wall and the particles. In order to reduce energy consumption, three sizes of dune models were designed according to the bend structure and blockage ratio. The system pressure drops, particle flow pattern, particle velocity distribution, and pulsation velocity intensity are studied in this research, and the wavelet multi-resolution analysis is used to perform the particle velocity. The findings indicate that the dune model effectively reduces the ideal conveying gas velocity and pressure drop, and the maximum reduction rate of ideal conveying gas velocity is 10.26%. The dispersion of particles is fully in the vertical pipe in the condition of dune model and the axial velocity is larger than the condition of no model. Moreover, the large-scale low-frequency motion dominates the movement of particles in the pipe, while the appearance of small-scale high-frequency motion breaks the pattern of low-frequency motion. [Display omitted] • Dune model is installed in a 90° bend to reduce energy consumption and wear. • Increasing tail size of dune model facilitates particle dispersion in vertical tube. • The maximum reduction rates of optimal conveying gas velocity is 10.26%. • Large-scale low-frequency motion dominates the movement of particles in tube. [ABSTRACT FROM AUTHOR]