Volume 79, Number 1, July 2007
Article Number 14001
Number of page(s) 5
Section Electromagnetism, Optics, Acoustics, Heat Transfer, Classical Mechanics, and Fluid Dynamics
Published online 06 June 2007
EPL, 79 (2007) 14001
DOI: 10.1209/0295-5075/79/14001

Flow and jamming of granular mixtures through obstacles

F. Chevoir1, F. Gaulard1 and N. Roussel2

1  LMSGC, Institut Navier - 2 allée Kepler, 77 420 Champs sur Marne, France
2  Laboratoire Central des Ponts et Chaussées - 58 Boulevard Lefebvre, 75015 Paris, France

received 25 October 2006; accepted in final form 15 May 2007; published July 2007
published online 6 June 2007

Due to the formation of arches, granular materials may jam when flowing through obstacles, as in the case of hoppers. As a way to quantify this process, we study experimentally the flow of binary granular mixtures through sieves, as a function of two parameters: the proportion of large grains and the ratio of large grains to sieve hole size. We distinguish three regimes: steady flows, jamming, and progressive clogging. In the case of steady flows, we measure the dependencies of the flow rate on the two parameters and observe a generalization of the law known for mono-disperse grains flowing through a single aperture. Moreover we measure how the critical size of the holes leading to jamming depends on the proportion of large grains. In the case of progressive clogging, we measure the slowing down of the flow rate and identify two mechanisms associated to the trapping of the large grains in the holes of the sieves and then to the formation of a filtration cake.

45.70.Mg - Granular flow: mixing, segregation and stratification.
81.05.Rm - Porous materials; granular materials.

© Europhysics Letters Association 2007