A model describing the absorption process of SO2 into limestone slurry with a spray scrubber is presented. Both the physical performance of the spray liquid in the scrubber and the involved chemical reactions are anal...A model describing the absorption process of SO2 into limestone slurry with a spray scrubber is presented. Both the physical performance of the spray liquid in the scrubber and the involved chemical reactions are analyzed in the model. A con- tinuous concentration change of H+ was solved by iterative coupling using Matlab, and it was found that there was a remarkable influence on the concentration of the other elements in the process of SO2 absorption. The calculations show that the enhancement factor exponentially grows with an increasing value of pH and logarithmically decays with an increasing value of the driving force. To verify the accuracy of the model, experiments were also carried out, and the results suggest that the model, after combining the physical performance of the spray and the enhancement factor, can more precisely describe SO2 absorption in a spray scrubber. Furthermore, a commercial computational fluid dynamics (CFD) tool is used to perform several simulations which describe and clarify the effects of variables on SO2 absorption. The results of numerical simulation can provide a basis for further design and optimization of the scrubber.展开更多
The steady and dynamic rheological behaviors of precipitated calcium carbonate (PCC) suspension in polyethylene glycol (PEG) were investigated on a TA AR2000ex rheometer. Under steady shear consistency index K and flo...The steady and dynamic rheological behaviors of precipitated calcium carbonate (PCC) suspension in polyethylene glycol (PEG) were investigated on a TA AR2000ex rheometer. Under steady shear consistency index K and flow exponent N of suspensions with different volume fractions were determined. The shear-thinning and the discontinuous shear-thickening behavior were observed at different constant frequencies from 10 to 100 rad/s. The relationship between the complex viscosity and the constant frequency were determined. As the volume fraction increases,flow exponent N shows a rapid increase,and it increases dramatically when the discontinuous shear-thickening takes place,while consistency index K decreases. Dynamic oscillatory shear experiments were conducted at constant strain amplitude and constant frequency,respectively. For the frequency sweep,the system shows viscous property in entire range of the frequency investigated,and the complex viscosity shows discontinuous jump at a critical frequency of 10 rad/s. For the strain sweep,on the other hand,at low strain the elastic modulus is strongly dependent on the strain,and the viscous modulus is independent of the strain. But at the critical strain point both of the moduli show an abrupt jump and the system transits from elastic to viscous at a strain of 0.1.展开更多
The present work deals with the removal of Ni（II） ion using activated charcoal prepared from the dry leaves of bitter orange tree （Citrus aurantium）. The effects of its concentration, adsorbent dosage, particle si...The present work deals with the removal of Ni（II） ion using activated charcoal prepared from the dry leaves of bitter orange tree （Citrus aurantium）. The effects of its concentration, adsorbent dosage, particle size, pH and temperature on removal of Ni（II） ion have been studied. The removal of Ni（II） ion is higher at lower concentration and gradually decreases as the concentration increases. The pH of 5 was the most suitable. The removal of Ni（II） ion increases with the increases in the adsorbent dosage. The effect of particle size reveals that the percentage removal of Ni（II） ion decreases with increase in particle size of adsorbent. The effect of temperature shows that as temperature increases, the percentage removal of Ni（II） ion decreases and this is due to the interaction forces weakening at high temperature. Thermodynamic parameters from the effect of temperature were calculated.展开更多
基金Project supported by the National Key Technologies Supporting Program of China during the 11th Five-Year Plan Period (No.2006BAA01B04)the New Century Excellent Talent in University(No. NCET-06-0513), China
文摘A model describing the absorption process of SO2 into limestone slurry with a spray scrubber is presented. Both the physical performance of the spray liquid in the scrubber and the involved chemical reactions are analyzed in the model. A con- tinuous concentration change of H+ was solved by iterative coupling using Matlab, and it was found that there was a remarkable influence on the concentration of the other elements in the process of SO2 absorption. The calculations show that the enhancement factor exponentially grows with an increasing value of pH and logarithmically decays with an increasing value of the driving force. To verify the accuracy of the model, experiments were also carried out, and the results suggest that the model, after combining the physical performance of the spray and the enhancement factor, can more precisely describe SO2 absorption in a spray scrubber. Furthermore, a commercial computational fluid dynamics (CFD) tool is used to perform several simulations which describe and clarify the effects of variables on SO2 absorption. The results of numerical simulation can provide a basis for further design and optimization of the scrubber.
基金Projects (50774096, 50606017) supported by the National Natural Science Foundation of China
文摘The steady and dynamic rheological behaviors of precipitated calcium carbonate (PCC) suspension in polyethylene glycol (PEG) were investigated on a TA AR2000ex rheometer. Under steady shear consistency index K and flow exponent N of suspensions with different volume fractions were determined. The shear-thinning and the discontinuous shear-thickening behavior were observed at different constant frequencies from 10 to 100 rad/s. The relationship between the complex viscosity and the constant frequency were determined. As the volume fraction increases,flow exponent N shows a rapid increase,and it increases dramatically when the discontinuous shear-thickening takes place,while consistency index K decreases. Dynamic oscillatory shear experiments were conducted at constant strain amplitude and constant frequency,respectively. For the frequency sweep,the system shows viscous property in entire range of the frequency investigated,and the complex viscosity shows discontinuous jump at a critical frequency of 10 rad/s. For the strain sweep,on the other hand,at low strain the elastic modulus is strongly dependent on the strain,and the viscous modulus is independent of the strain. But at the critical strain point both of the moduli show an abrupt jump and the system transits from elastic to viscous at a strain of 0.1.
文摘The present work deals with the removal of Ni（II） ion using activated charcoal prepared from the dry leaves of bitter orange tree （Citrus aurantium）. The effects of its concentration, adsorbent dosage, particle size, pH and temperature on removal of Ni（II） ion have been studied. The removal of Ni（II） ion is higher at lower concentration and gradually decreases as the concentration increases. The pH of 5 was the most suitable. The removal of Ni（II） ion increases with the increases in the adsorbent dosage. The effect of particle size reveals that the percentage removal of Ni（II） ion decreases with increase in particle size of adsorbent. The effect of temperature shows that as temperature increases, the percentage removal of Ni（II） ion decreases and this is due to the interaction forces weakening at high temperature. Thermodynamic parameters from the effect of temperature were calculated.
