Detailed deposition characteristics around burner plane in an impinging entrained-flow coal gasifier

The droplets, coal particles and ash/slag particles generated in impinging flame, atomization and violent reaction at the burner plane lead to complex deposition characteristics in the impinging entrained-flow coal gasifier. To investigate the detailed deposition behaviors around burner plane, a new visualization system combined with high temperature endoscope and high speed camera was applied to capture the detailed process of deposition. With classification and statistical method, the CWS droplet and coal/ash/slag particle deposition behaviors as well as the detachment of adhered particles were discussed. The results show that the droplet deposition behaviors were divided into three types: deform and rebound without adherence, breakup and rebound without adherence and breakup with partial rebound and partial adherence. Over 50% of the droplets deform without any other behaviors. Only about 15% of the droplets adhere to the refractory wall. The particle deposition behaviors were divided into four types: rebound completely without breakup and adherence, adhere completely without breakup and rebound, breakup and rebound completely without adherence and breakup with partial rebound and partial adherence. The particles around the burner tend to rebound and the particles between the burners tend to adhere. Over 60% of the particles completely or partially adhere to the refractory wall and only a few particles break up. The detachment behaviors were divided into four types: detach completely, breakup and detach, detach after impact and multi-mode detach. Because of the low conversion degree of the particles around burner plane, the detach percentage of the adhered particles is relatively high and half of adhered particles detaches from the refractory wall completely. (C) 2019 Elsevier Ltd. All rights reserved.