Open AccessMomentum, heat, and mass transfer analogy for vertical hydraulic transport of inert particles
Author(s) -
R Darko Jacimovski,
V Radmila Garic-Grulovic,
B Zeljko Grbavcic,
Mihal Djuris,
M Nevenka Boskovic-Vragolovic
Publication year - 2014
Publication title -
hemijska industrija
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.147
H-Index - 19
eISSN - 2217-7426
pISSN - 0367-598X
DOI - 10.2298/hemind130207025j
Subject(s) - reynolds number , turbulence , mechanics , mass transfer , heat transfer , momentum (technical analysis) , momentum transfer , hydraulic diameter , thermodynamics , heat transfer coefficient , flow (mathematics) , particle (ecology) , materials science , chemistry , physics , geology , optics , finance , scattering , economics , oceanography
Wall-to-bed momentum, heat and mass transfer in vertical liquid-solids flow, as well as in single phase flow, were studied. The aim of this investigation was to establish the analogy among those phenomena. Also, effect of particles concentration on momentum, heat and mass transfer was studied. The experiments in hydraulic transport were performed in a 25.4 mm I.D. cooper tube equipped with a steam jacket, using spherical glass particles of 1.94 mm in diameter and water as a transport fluid. The segment of the transport tube used for mass transfer measurements was inside coated with benzoic acid. In the hydraulic transport two characteristic flow regimes were observed: turbulent and parallel particle flow regime. The transition between two characteristic regimes (γ*=0), occurs at a critical voidage ε≈0.85. The vertical two-phase flow was considered as the pseudofluid, and modified mixture-wall friction coefficient (fw) and modified mixture Reynolds number (Rem) were introduced for explanation of this system. Experimental data show that the wall-to-bed momentum, heat and mass transfer coefficients, in vertical flow of pseudofluid, for the turbulent regime are significantly higher than in parallel regime. Wall-to-bed, mass and heat transfer coefficients in hydraulic transport of particles were much higher then in single-phase flow for lower Reynolds numbers (Re<15000), while for high Reynolds numbers (Re>15000), there was not significant difference. The experimental data for wall-to-bed momentum, heat and mass transfer in vertical flow of pseudofluid in parallel particle flow regime, show existing analogy among these three phenomena. [Projekat Ministarstva nauke Republike Srbije, br. 172022