Boreskov Institute of Catalysis of the Siberian Branch of Russian ...

OP-III-16Numbers of curves are according to samples on Figure 1. It is shown the pressure dropfunction ΔР/L has a square-law dependence on superficial velocity W, ΔР/L=А·W+B·W 2 . Atused experiment conditions it is significance that flow regime into porous walls is a Fickdiffusion or a transition region between Fick and Knudsen diffusion [5]. This fact confirms anaccuracy to use momentum transport equation by Darcy’s law for porous media.Velocity fields were calculated on inlet part of monolith in various flow regimes withboth porous and impermeable monolith walls. On Figure 3 the example of velocitydistribution in porous wall was shown by colours according colour scale in the figure centerand equal sise vectors. As a result of this simulations there are two main features at least.Firstly comparatively intensive flow is in frontal part of monolith increasing flux of reactiongases into catalyst wall. In case of exothermic catalytic reactions it can made for catalystoverheating. Secondly a comparison of velocity fields for porous and impermeable monolithshow a important differences. For example vortex placed on inlet edges of monolith channelshave various intensity. There was changed a heat and mass transfer processes in inlet part ofmonolith.Fig. 3. Flow distribution in frontal part of monolith with porous walls. Velocity was shown by colours accordingcolour scale in the figure center and equal sise vectors.References1. R. Schwiedernoch, S. Tischer, C. Correa, O. Deutschmann. Chem. Eng. Sci. 58 (2003) 633 – 642.2. N. Gupta, V. Balakotaiah. Chem. Eng. Sci. 56 (2001) 4771–4786.3. S. Hardt, W. Ehrfeld, V. Hessel, K.M. Vanden Bussche. Chem. Eng. Comm.190 (2003) 540-559.4. S.T. Kolaczkowski. Catalysis Today. 83 (2003) 85–95.5. М. Девиен. Течение и теплообмен разреженных газов. Изд. иностр. литературы. М. 1962.122