In-situ study on flow and rotation behaviors of coal particles near the burner plane in an impinging entrained-flow gasifier

The flow behaviors of the coal particles during coal gasification in the entrained-flow gasifier are closely related to the stable operation of the gasifier, while it is difficult to observe the particles during the operation of the gasifier due to the influence of high-temperature environment and complex atmosphere. In this study, based on a bench-scale opposed multi-burner (OMB) coal-water slurry (CWS) entrained-flow gasifier and an advanced visualization system composed of a high-temperature endoscope and a high-speed camera, the flow and rotation behaviors of the coal particles near the burner plane are investigated. The region near the burner plane is divided into jet zone and impinging core. The particle trajectories in the two zones are tracked. The particle velocity distribution and velocity fluctuation index are calculated. The particle rotation and flame oscillation behaviors are quantified. The results show that the proportion of total particle trajectories in the impinging core is higher than that of the jet zone. The velocity of the particles is mostly distributed in the range of 0-4 m/s. The particle fluctuation index in the impinging core is greater than that in the jet zone, indicating that the impinging flow is more unstable in comparison with the jet flow. The particle rotation angular velocity fluctuates within a certain range, while the fluctuation range of flame oscillation angular velocity is extremely great and can be easily disturbed by the flow field. For a single particle undergoing volatile oxidation, flame oscillation and particle rotation are isotropic. The flow field near the burner plane is reconstructed based on particle flow behaviors. The reconstruction results can be applied to verify the simulation of flow field.