科研之友
微信
新浪微博
Facebook
分享链接
摘要
In this paper, a randomly packed granular filtration model was built to investigate the mechanism of particle deposition on the granular surface, including the deposition positions, the backfiow of particles and the relation with Stokes number. The deposition positions of particles of different size on the granular surface were exhibited, and the results showed that the diameters of particles deposited on the leeward side of the granule are smaller than 5 mu m. The deposition area is larger and more uniform for smaller particle deposited on the windward side of the granule and it leads to a higher pressure drop. Besides, the concentrations of particles smaller than 5 mu m linearly decrease with the height of the model between 50 mm-78 mm, and for the cases of lager than 15 mu m, they dramatically drop between 50 mm-63 mm and the decline rate gradually reduces to zero with respect to 78 mm. Other cases of particle diameters between 5 mu m-15 mu m are between the above two situations. The Stokes number based on the inlet gas velocity versus the grade collection efficiency and the Stokes number based on the normal impaction velocity of particles versus the particle diameter are concluded to evaluate the filtration performance and the sticking probability of particles and they are expressed with two equations.
