Continuous segregation of a binary mixture of heterogeneous （different density） solids is carried out in a gas-solid fluidized bed. We investigate how gas velocity, solids feed rate, flotsam feed composition, bottom...Continuous segregation of a binary mixture of heterogeneous （different density） solids is carried out in a gas-solid fluidized bed. We investigate how gas velocity, solids feed rate, flotsam feed composition, bottom discharge pipe diameter, and minimum fluidization velocity ratio of the flotsam to jetsam parti- cles influence the solids holdup, separation factor, and product quality （flotsam purity at the top outlet）. The results are interpreted in terms of solids holdup information. The results indicate that the separation factor decreases when the gas velocity, bottom discharge pipe diameter, flotsam feed composition, or the minimum fluidization velocity ratio increase, while the separation factor increases as the solids feed rate increases. The product quality decreases when the gas velocity, solids feed rate, or minimum fluidization velocity ratio increase, while the product quality increases as the bottom discharge pipe diameter or flot- sam feed composition increase. Correlations for predicting the separation factor and product quality are proposed using a logistic model for individual flotsam feed compositions, which satisfactorily compares with the present experimental data.展开更多
We propose a simple model of colloidal suspension,whereby individual particles change their diffusivity from high(hot)to low(cold),as the local concentration of their closest peers grows larger than a certain threshol...We propose a simple model of colloidal suspension,whereby individual particles change their diffusivity from high(hot)to low(cold),as the local concentration of their closest peers grows larger than a certain threshold.Such a non-reciprocal interactive mechanism is known in biology as quorum sensing.Upon tuning the parameters of the adopted quorum sensing protocol,the suspension is numerically shown to go through a variety of two-phase(hot and cold)configurations.This is an archetypal model with potential applications in robotics and social studies.展开更多
为了采用聚团-磁选的方式回收微细粒级硫化矿物,研究了油酸钠作用下,微细粒硫化矿物与磁铁矿之间的异相聚团机理。结果表明,静电力和疏水力是硫化矿物与磁铁矿颗粒间形成聚团的主要作用力。p H=4.0时,2种矿物动电位均小于20 m V,且油酸...为了采用聚团-磁选的方式回收微细粒级硫化矿物,研究了油酸钠作用下,微细粒硫化矿物与磁铁矿之间的异相聚团机理。结果表明,静电力和疏水力是硫化矿物与磁铁矿颗粒间形成聚团的主要作用力。p H=4.0时,2种矿物动电位均小于20 m V,且油酸钠在两种矿物颗粒表面吸附量最大,矿物颗粒间易发生异相聚团,人工混合矿聚团-磁选回收率达到最大,为87%;p H>7.0时,2种矿物动电位均大于60 m V,由于磁铁矿表面油酸钠吸附量大幅降低,疏水力减小,导致聚团效果变差,硫化矿回收率显著降低。展开更多
In work, it is constructed a discrete mathematical model of motion of a perfect fluid. The fluid is represented as an ensemble of identical so-called liquid particles, which are in the form of extended geometrical obj...In work, it is constructed a discrete mathematical model of motion of a perfect fluid. The fluid is represented as an ensemble of identical so-called liquid particles, which are in the form of extended geometrical objects: circles and spheres for two-dimensional and three-dimensional cases, respectively. The mechanism of interaction between the liquid particles on a binary level and on the level of the n-cluster is formulated. This mechanism has previously been found by the author as part of the mathematical modeling of turbulent fluid motion. In the turbulence model was derived and investigated the potential interaction of pairs of liquid particles, which contained a singularity of the branch point. Exactly, this is possible to build in this article discrete stochastic-deterministic model of an ideal fluid. The results of computational experiment to simulate various kinds of flows in two-dimensional and three-dimensional ensembles of liquid particles are presented. Modeling was carried out in the areas of quadratic or cubic form. On boundary of a region satisfies the condition of elastic reflection liquid particles. The flows with spontaneous separation of particles in a region, various kinds of eddy streams, with the quite unexpected statistical properties of an ensemble of particles characteristic for the Fermi-Pasta-Ulam effect were found. We build and study the flow in which the velocity of the particles is calibrated. It was possible using the appropriate flows of liquid particles of the ensemble to demonstrate the possibility to reproduce any prescribed image by manipulating the parameters of the interaction. Calculations of the flows were performed with using MATLAB software package according to the algorithms presented in this article.展开更多
The introduction of functionalized magnetizable particles and high-gradient magnetic separation represents a time and money saving alternative to conventional purification and separation unit operations in the biotech...The introduction of functionalized magnetizable particles and high-gradient magnetic separation represents a time and money saving alternative to conventional purification and separation unit operations in the biotechnical sector. This technique has some advantages especially for the recycling of immobilized enzymes. A new magnetic filter with sight glasses was constructed and produced to study the performance of high-gradient magnetic separation at varied parameters. By optical analysis the buildup of a clogging was identified as the major parameter which affected the separation performance. For the cleaning procedure, a two-phase flow of water with highly dispersed air bubbles was tested which led to a nearly complete cleaning of the filter chamber.展开更多
文摘Continuous segregation of a binary mixture of heterogeneous （different density） solids is carried out in a gas-solid fluidized bed. We investigate how gas velocity, solids feed rate, flotsam feed composition, bottom discharge pipe diameter, and minimum fluidization velocity ratio of the flotsam to jetsam parti- cles influence the solids holdup, separation factor, and product quality （flotsam purity at the top outlet）. The results are interpreted in terms of solids holdup information. The results indicate that the separation factor decreases when the gas velocity, bottom discharge pipe diameter, flotsam feed composition, or the minimum fluidization velocity ratio increase, while the separation factor increases as the solids feed rate increases. The product quality decreases when the gas velocity, solids feed rate, or minimum fluidization velocity ratio increase, while the product quality increases as the bottom discharge pipe diameter or flot- sam feed composition increase. Correlations for predicting the separation factor and product quality are proposed using a logistic model for individual flotsam feed compositions, which satisfactorily compares with the present experimental data.
基金supported by the National Natural Science Foundation of China(12375037 and 11935010)
文摘We propose a simple model of colloidal suspension,whereby individual particles change their diffusivity from high(hot)to low(cold),as the local concentration of their closest peers grows larger than a certain threshold.Such a non-reciprocal interactive mechanism is known in biology as quorum sensing.Upon tuning the parameters of the adopted quorum sensing protocol,the suspension is numerically shown to go through a variety of two-phase(hot and cold)configurations.This is an archetypal model with potential applications in robotics and social studies.
文摘为了采用聚团-磁选的方式回收微细粒级硫化矿物,研究了油酸钠作用下,微细粒硫化矿物与磁铁矿之间的异相聚团机理。结果表明,静电力和疏水力是硫化矿物与磁铁矿颗粒间形成聚团的主要作用力。p H=4.0时,2种矿物动电位均小于20 m V,且油酸钠在两种矿物颗粒表面吸附量最大,矿物颗粒间易发生异相聚团,人工混合矿聚团-磁选回收率达到最大,为87%;p H>7.0时,2种矿物动电位均大于60 m V,由于磁铁矿表面油酸钠吸附量大幅降低,疏水力减小,导致聚团效果变差,硫化矿回收率显著降低。
文摘In work, it is constructed a discrete mathematical model of motion of a perfect fluid. The fluid is represented as an ensemble of identical so-called liquid particles, which are in the form of extended geometrical objects: circles and spheres for two-dimensional and three-dimensional cases, respectively. The mechanism of interaction between the liquid particles on a binary level and on the level of the n-cluster is formulated. This mechanism has previously been found by the author as part of the mathematical modeling of turbulent fluid motion. In the turbulence model was derived and investigated the potential interaction of pairs of liquid particles, which contained a singularity of the branch point. Exactly, this is possible to build in this article discrete stochastic-deterministic model of an ideal fluid. The results of computational experiment to simulate various kinds of flows in two-dimensional and three-dimensional ensembles of liquid particles are presented. Modeling was carried out in the areas of quadratic or cubic form. On boundary of a region satisfies the condition of elastic reflection liquid particles. The flows with spontaneous separation of particles in a region, various kinds of eddy streams, with the quite unexpected statistical properties of an ensemble of particles characteristic for the Fermi-Pasta-Ulam effect were found. We build and study the flow in which the velocity of the particles is calibrated. It was possible using the appropriate flows of liquid particles of the ensemble to demonstrate the possibility to reproduce any prescribed image by manipulating the parameters of the interaction. Calculations of the flows were performed with using MATLAB software package according to the algorithms presented in this article.
文摘The introduction of functionalized magnetizable particles and high-gradient magnetic separation represents a time and money saving alternative to conventional purification and separation unit operations in the biotechnical sector. This technique has some advantages especially for the recycling of immobilized enzymes. A new magnetic filter with sight glasses was constructed and produced to study the performance of high-gradient magnetic separation at varied parameters. By optical analysis the buildup of a clogging was identified as the major parameter which affected the separation performance. For the cleaning procedure, a two-phase flow of water with highly dispersed air bubbles was tested which led to a nearly complete cleaning of the filter chamber.
