Experiment to Study the Upward Flow of Water Through a Bed of Coarse Ballotini
Abstract
The characteristics associated with water and air flowing vertically upwards was investigated through a bed of coarse ballotini (glass beads with a nominal diameter of 485 microns).Different flow rates for water and air is applied to determine the pressure drop and differentiate between the fixed bed and the fluidized bed characteristics. Also the measured onset of fluidization was compared with the predicted one. From this experiment it was obtained thatthe pressure drop increase as increasing the fluid (water or air) rates until it reach constant value. In addition, the bed height is constant as flow rate increased in fixed bed and it is increased as the flow rate increased when fluidization occurred. Furthermore, it was found that the air fluid requires higher flow rate than water in order to fluidize the bed.
1
Nomenclature
Symbols Dp ε ρa μ ρs ρw A Φs L D V ∆P Description particle size (mm) porosity density of air (Kg/m3) viscosity (N.s/m2) density of particle (Kg/m3) density of water (Kg/m3) bed cross-section area (m2) sphericity bed height (m) diameter (m) velocity (m/s) pressure drop (mm H2O)
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Table of contents
Abstract Nomenclature Contents List of Figures List of Tables 1. Introduction 2. Experimental Set-up 2.1 2.2 Apparatus Procedure
1 2 3 4 4 5-6 6-7 6 7 8-12 13 13 14
3. Results and Discussion 4. Conclusion 5. Reference Appendices
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List of figures
Figure1 : fixed and fluidized bed apparatus Figure2: Flow rate versus Pressure drop for experimental data Figure3: Pressure drop versus Flow rate for experimental and theoretical data. Figure4: Bed pressure drop (mm H2O) versus flow rate (L/min) obtained from the experimental data. Figure5: Bed pressure drop (mm H2O) vs. flow rate for the experimental and the theoretical value Figure6:Various steps in the air fluidization.
List of tables
Table1: Experimental and Theoretical data for water passing through a bed with glass beds. Table 2: Results and data obtained
The characteristics associated with water and air flowing vertically upwards was investigated through a bed of coarse ballotini (glass beads with a nominal diameter of 485 microns).Different flow rates for water and air is applied to determine the pressure drop and differentiate between the fixed bed and the fluidized bed characteristics. Also the measured onset of fluidization was compared with the predicted one. From this experiment it was obtained thatthe pressure drop increase as increasing the fluid (water or air) rates until it reach constant value. In addition, the bed height is constant as flow rate increased in fixed bed and it is increased as the flow rate increased when fluidization occurred. Furthermore, it was found that the air fluid requires higher flow rate than water in order to fluidize the bed.
1
Nomenclature
Symbols Dp ε ρa μ ρs ρw A Φs L D V ∆P Description particle size (mm) porosity density of air (Kg/m3) viscosity (N.s/m2) density of particle (Kg/m3) density of water (Kg/m3) bed cross-section area (m2) sphericity bed height (m) diameter (m) velocity (m/s) pressure drop (mm H2O)
2
Table of contents
Abstract Nomenclature Contents List of Figures List of Tables 1. Introduction 2. Experimental Set-up 2.1 2.2 Apparatus Procedure
1 2 3 4 4 5-6 6-7 6 7 8-12 13 13 14
3. Results and Discussion 4. Conclusion 5. Reference Appendices
3
List of figures
Figure1 : fixed and fluidized bed apparatus Figure2: Flow rate versus Pressure drop for experimental data Figure3: Pressure drop versus Flow rate for experimental and theoretical data. Figure4: Bed pressure drop (mm H2O) versus flow rate (L/min) obtained from the experimental data. Figure5: Bed pressure drop (mm H2O) vs. flow rate for the experimental and the theoretical value Figure6:Various steps in the air fluidization.
List of tables
Table1: Experimental and Theoretical data for water passing through a bed with glass beds. Table 2: Results and data obtained
References: Calculations: Water Dp ε ρa μ ρs A Φs 4.85E-04 m 0.425 1.00 Kg/m3 1.84E-05 N.s/ m2 2.24E+03 Kg/m3 0.0019635 m2 1 Table of constants used For fixed bed: A= (π) × D2 = (π) × (485E-6)2 = 0.00196 m2 V= flow rate/ A = (0.1/( 60 ×1000)) /0.00196 = 0.00085m/s ∆P =(ρs + ρf)×(1-ε) ×L ∆P = (2.24E+03 + 1.186 ) × (1- 0.425) × (308/1000) = 274.6mmH2O