This work aims to provide a relationship of how the key operational variables of frother type and impeller speed affect the size of bubble （D32）. The study was performed using pilot-scale equipment （0.8 m^3） that ...This work aims to provide a relationship of how the key operational variables of frother type and impeller speed affect the size of bubble （D32）. The study was performed using pilot-scale equipment （0.8 m^3） that is up to two orders of magnitude larger than equipment used for studies performed to date by others, and incorporated the key process variables of frother type and impeller speed. The results show that each frother family exhibits a unique CCC95-HLB relationship dependent on n （number of C-atoms in alkyl group） and m （number of propylene oxide group）. Empirical models were developed to predict CCC95 from HLB associated with other two parameters a and ft. The impeller speed-bubble size tests show that D32 is unaffected by increased impeller tip speed across the range of 4.6 to 9.2 m/s （representing the industrial operating range）, although D32 starts to increase below 4.6 m/s. The finding is valid for both coalescing and non-coalescing conditions. The results suggest that the bubble size and bubble size distribution （BSD） being created do not change with increasing impeller speed in the quiescent zone of the flotation.展开更多
Gasification efficiency is an important factor that determines the actual technical operation as well as the economic viability of using a gasifier system for energy production. In this study, the impact of the physic...Gasification efficiency is an important factor that determines the actual technical operation as well as the economic viability of using a gasifier system for energy production. In this study, the impact of the physical properties of torrefied bagasse and the influence of gasifier design and operating variables were investigated in a computer simulated downdraft gasification system. Results obtained from the study indicated an interrelationship between feedstock characteristics, especially with regard to feed size, design variables such as throat angle and throat diameter as well as gasifier operating conditions such as temperature of input air and feed input. These variables influenced the efficiency of the gasification process of sugarcane bagasse because of increased enhancement of combustion zone reactions, which liberated huge amount of heat that led to a rise in the temperature of the gasification process. This condition also created increased tar cracking within the gasification system, contributing to reduction in the overall yield of tar.展开更多
Both intake volumetric flow and through-screen velocity （the velocity of water as it passes through the screen） are important variables affecting fish impingement at industrial water intake structures including thos...Both intake volumetric flow and through-screen velocity （the velocity of water as it passes through the screen） are important variables affecting fish impingement at industrial water intake structures including those at power plants. However, there are limited data available on quantitative assessments of impingement following changes in power plant operation such as reduced volumetric flow and intake velocity. Impingement studies were conducted at Bay Shore Power Plant in 2005-2006 （baseline） and again in 2013-2014 following fish protection mitigation which included reduced intake volumetric flows （from 33.5 m^3·s^-1 to 9.1 cm·s^-1）, a reduced through-screen velocity （from approximately 79.2 cm·s^-1 to 11.6 cm·s^-1）, modified traveling screens and installation of a fish-return system to gently and quickly remove any fish that were impinged back into the waterbody. A comparison of baseline and post-mitigation results suggested that with this mitigation in place, impingement reductions can exceed 90% for robust dominant fish species in the area.展开更多
基金Project supported by the Collaborative Research and Development Program of NSERC(Natural Sciences and Engineering Research Council of Canada) with Industrial Sponsorship from Vale,Teck Cominco,Xstrata Process Support,Agnico-Eagle,Shell Canada,Barrick Gold,COREM,SGS Lakefield Research and Flottec
文摘This work aims to provide a relationship of how the key operational variables of frother type and impeller speed affect the size of bubble （D32）. The study was performed using pilot-scale equipment （0.8 m^3） that is up to two orders of magnitude larger than equipment used for studies performed to date by others, and incorporated the key process variables of frother type and impeller speed. The results show that each frother family exhibits a unique CCC95-HLB relationship dependent on n （number of C-atoms in alkyl group） and m （number of propylene oxide group）. Empirical models were developed to predict CCC95 from HLB associated with other two parameters a and ft. The impeller speed-bubble size tests show that D32 is unaffected by increased impeller tip speed across the range of 4.6 to 9.2 m/s （representing the industrial operating range）, although D32 starts to increase below 4.6 m/s. The finding is valid for both coalescing and non-coalescing conditions. The results suggest that the bubble size and bubble size distribution （BSD） being created do not change with increasing impeller speed in the quiescent zone of the flotation.
文摘Gasification efficiency is an important factor that determines the actual technical operation as well as the economic viability of using a gasifier system for energy production. In this study, the impact of the physical properties of torrefied bagasse and the influence of gasifier design and operating variables were investigated in a computer simulated downdraft gasification system. Results obtained from the study indicated an interrelationship between feedstock characteristics, especially with regard to feed size, design variables such as throat angle and throat diameter as well as gasifier operating conditions such as temperature of input air and feed input. These variables influenced the efficiency of the gasification process of sugarcane bagasse because of increased enhancement of combustion zone reactions, which liberated huge amount of heat that led to a rise in the temperature of the gasification process. This condition also created increased tar cracking within the gasification system, contributing to reduction in the overall yield of tar.
文摘Both intake volumetric flow and through-screen velocity （the velocity of water as it passes through the screen） are important variables affecting fish impingement at industrial water intake structures including those at power plants. However, there are limited data available on quantitative assessments of impingement following changes in power plant operation such as reduced volumetric flow and intake velocity. Impingement studies were conducted at Bay Shore Power Plant in 2005-2006 （baseline） and again in 2013-2014 following fish protection mitigation which included reduced intake volumetric flows （from 33.5 m^3·s^-1 to 9.1 cm·s^-1）, a reduced through-screen velocity （from approximately 79.2 cm·s^-1 to 11.6 cm·s^-1）, modified traveling screens and installation of a fish-return system to gently and quickly remove any fish that were impinged back into the waterbody. A comparison of baseline and post-mitigation results suggested that with this mitigation in place, impingement reductions can exceed 90% for robust dominant fish species in the area.
