For engineering applications of water dilution controlling system,the fluid dynamics of a mixed flow was studied with computational fluid dynamics(CFD) simulations and self-designed experimental set-up.In order to exa...For engineering applications of water dilution controlling system,the fluid dynamics of a mixed flow was studied with computational fluid dynamics(CFD) simulations and self-designed experimental set-up.In order to examine the predictability of CFD model for the headbox in industrial scale,two pulp suspensions before mixing were treated as homogeneous flows separately.Standard k-ε turbulence models with the mass diffusion in turbulent flows-species transport approach were applied in the simulations.A numerical simulation of this headbox model was analyzed with semi-implicit method for pressure linked equations scheme with pressure–velocity coupling.Results show that the model can predict hydrodynamic characteristics of headbox with injecting dilution water in a central diffusion tube,and the distribution of water content at the outlet of the slice lip is ideally normal at different speeds.展开更多
Fines represent a significant volume of biobased wood material and filler,which is of significant importance to sheet quality.New imaging technology reveals the true nature of the behavior of fines in the retention pr...Fines represent a significant volume of biobased wood material and filler,which is of significant importance to sheet quality.New imaging technology reveals the true nature of the behavior of fines in the retention process.This study illustrates new chemical mixing systems,novel and efficient flash mixing methods,and active measurement and automation systems pertaining to efficient management of fines in the stock flow prior to headbox in paper,board,and tissue production,which can reduce additive,fresh water,energy consumption,and the carbon footprint of production to improve sustainability and provide novel opportunities for fines and filler management.展开更多
基金Supported by the Science&Technology Plan Projects of Guangzhou City(15020079,Study on Quality Intelligent Control of Modern Paper Machine and Energy-saving Technology with Equipment)Guangdong Provincial Science&Technology Plan Projects(2015B020241001,Research and Application of Biomass Pretreatment and Ethanol Production Technology)
文摘For engineering applications of water dilution controlling system,the fluid dynamics of a mixed flow was studied with computational fluid dynamics(CFD) simulations and self-designed experimental set-up.In order to examine the predictability of CFD model for the headbox in industrial scale,two pulp suspensions before mixing were treated as homogeneous flows separately.Standard k-ε turbulence models with the mass diffusion in turbulent flows-species transport approach were applied in the simulations.A numerical simulation of this headbox model was analyzed with semi-implicit method for pressure linked equations scheme with pressure–velocity coupling.Results show that the model can predict hydrodynamic characteristics of headbox with injecting dilution water in a central diffusion tube,and the distribution of water content at the outlet of the slice lip is ideally normal at different speeds.
文摘Fines represent a significant volume of biobased wood material and filler,which is of significant importance to sheet quality.New imaging technology reveals the true nature of the behavior of fines in the retention process.This study illustrates new chemical mixing systems,novel and efficient flash mixing methods,and active measurement and automation systems pertaining to efficient management of fines in the stock flow prior to headbox in paper,board,and tissue production,which can reduce additive,fresh water,energy consumption,and the carbon footprint of production to improve sustainability and provide novel opportunities for fines and filler management.
