Effect of near-wall air curtain on the wall deposition of droplets in a semidry flue gas desulfurization reactor
- Tsinghua University, Beijing (China). Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Thermal Engineering
Various flue gas desulfurization (FGD) processes have been developed to reduce SO{sub 2} emissions from coal-fired power plants. The wall deposition of droplets is an important issue affecting the desulfurization efficiency and operating stability of semidry flue gas desulfurization (FGD) reactors. Various near-wall air velocities, near-wall air flow inlet heights, and spray characteristics were analyzed numerically to investigate their effect on the gas-liquid flow and droplet deposition characteristics. The analytical results show that the near-wall air curtain effectively reduces the wall deposition of droplets in the semidry FGD reactor. The droplet deposition ratio decreased rapidly with increasing near-wall air velocity due to the increased gas flow rates and the altered gas velocity distribution. The near-wall air flow inlet height had an optimum value due to the rapid decline of the near-wall air momentum along the reactor height. The optimum distance between the near-wall air inlet height and the droplet injection height was 1.2 times that of the droplet vertical movement distance before deposition based on the linear droplet movement. For commonly used spray characteristics in the semidry FGD process, i.e., droplet diameters of 50-150 {mu}m, spray angles of 10-70{sup o} and droplet initial velocities of 20-100 m/s, the droplet deposition ratio with the addition of the near-wall air curtain varied slightly with the droplet diameter and the spray angle but increased rapidly with the initial droplet velocity. Therefore, for the semidry FGD processes, the near-wall air curtain is an effective method to reduce the wall deposition of droplets for various droplet diameters and spray angles while the initial droplet velocity should be carefully controlled to reduce the wall deposition of droplets and improve the operating stability. 13 refs., 10 figs.
- OSTI ID:
- 20923839
- Journal Information:
- Environmental Science and Technology, Vol. 41, Issue 12; Other Information: youcf@tsinghua.edu.cn; ISSN 0013-936X
- Country of Publication:
- United States
- Language:
- English
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