Effect of deflector angle and number on evaporation performance of desulfurization wastewater in a spray drying tower

Rotary spray drying technology with bypass flue is widely adopted to realize the zero-discharge of desul-furization wastewater in coal-fired power stations. Significantly, the deflector structure of the drying tower is an essential factor affecting the evaporation performance of desulfurization wastewater. This paper is aimed to study the effect of the angle and number of the deflectors on the evaporation perfor-mance in a drying tower of a 600 MW coal-fired station. Results show that the gas distributor divides the flue gas into internal and external parts, and the flue gas in the internal channel is the main factor affecting the evaporation performance. The deflector angles (especially for the internal deflector) have a remarkable impact on the evaporation behaviors, while the deflector numbers just have a minor effect on that. When the deflector number is 24 and the angles of internal and external deflectors are set at 0 degrees and 45 degrees, respectively, a better evaporation performance is obtained with the weighted average time of approximately 0.17 s and the complete evaporation distance of approximately 3.93 m. These optimal set-tings are adopted in the actual operation, and the industrial measured results show good performance is obtained.(c) 2022 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.