对比研究了藻菌混合包埋（MI）和藻菌分层包埋SI1（藻外菌内）、SI2（藻内菌外）固定化藻菌对养殖废水中氮、磷的去除效果,以及光照、温度对3种处理脱氮去磷的影响。试验结果表明,在设计条件下处理72 h MI与SI2对氮的去除率分别为91.20%...对比研究了藻菌混合包埋（MI）和藻菌分层包埋SI1（藻外菌内）、SI2（藻内菌外）固定化藻菌对养殖废水中氮、磷的去除效果,以及光照、温度对3种处理脱氮去磷的影响。试验结果表明,在设计条件下处理72 h MI与SI2对氮的去除率分别为91.20%和90.77%,显著高于SI1。MI与SI1的去磷效果显著强于SI2,处理72 h后2者对磷的去除率分别为90.31%和84.78%,SI2仅为32.09%。当[光]照度〈6 000 lx时,SI2氮去除率在88%以上,显著高于MI与SI1;[光]照度〉6 000 lx时,SI2与MI对氮的去除率均高于89%,显著高于SI1。MI与SI1对磷的去除率在85%以上,显著高于SI2。MI、SI1、SI2去除氮、磷的最佳温度为20-30℃。展开更多
A new first degree solids mixing rate is proposed to evaluate the mixing of solids in small scale Iluidized beds. Particle mixing experiments were carried out in a 2D fluidized bed with a cross-section of 0.02 m ×...A new first degree solids mixing rate is proposed to evaluate the mixing of solids in small scale Iluidized beds. Particle mixing experiments were carried out in a 2D fluidized bed with a cross-section of 0.02 m × 0.2 m and a height of Im. white and black particles with average diameters of 850 and 450 μm were used in our experiments. Image processing was used to measure the concentration of the tracers at different times. The effects of four representative operating parameters （superficial gas velocity, ratio of tracer particles to bed particles, tracer particle position, and particle size） on mixing are discussed with reference to the mixing index. We found that the Lacey index depends on the concentration of the tracers, The position of the tracers affects the initial mixing rate but not the final degree of mixing. However, the new mixing rate equation does not depend on the initial configuration of the particles because this situation is considered to be the initial condition. Using the data obtained in this work and that found in literature, an empirical correlation is proposed to evaluate the mixing rate constant as a function of dimensionless numbers （Archimedes, Reynolds, and Froude） in small scale fluidized beds. This correlation allows for an estimation of the mixing rate under different operating conditions and for the detection of the end point and/or the time of mixing.展开更多
The spatial distribution of concentration and velocity of a gas jet impinging with abump is studied in this paper. The conception of mean dispersion rate of concentrationis employed to describe the mixing process of g...The spatial distribution of concentration and velocity of a gas jet impinging with abump is studied in this paper. The conception of mean dispersion rate of concentrationis employed to describe the mixing process of gas jet in the near wall. The result showsthat the radial non-dimensional distribution of concentration and velocity of the second jetare normal, the axial nonudimensional distribution of concentration is exponential and theaxial non-dimensional distribution of velocity is lineal. The mixing rate of the jet gas in thenear wall is enhanced because of the existence of the bump. Base on these results, a new"space-wall-space" mixing conception for small or medium D.I. diesel engine is proposed.展开更多
文摘A new first degree solids mixing rate is proposed to evaluate the mixing of solids in small scale Iluidized beds. Particle mixing experiments were carried out in a 2D fluidized bed with a cross-section of 0.02 m × 0.2 m and a height of Im. white and black particles with average diameters of 850 and 450 μm were used in our experiments. Image processing was used to measure the concentration of the tracers at different times. The effects of four representative operating parameters （superficial gas velocity, ratio of tracer particles to bed particles, tracer particle position, and particle size） on mixing are discussed with reference to the mixing index. We found that the Lacey index depends on the concentration of the tracers, The position of the tracers affects the initial mixing rate but not the final degree of mixing. However, the new mixing rate equation does not depend on the initial configuration of the particles because this situation is considered to be the initial condition. Using the data obtained in this work and that found in literature, an empirical correlation is proposed to evaluate the mixing rate constant as a function of dimensionless numbers （Archimedes, Reynolds, and Froude） in small scale fluidized beds. This correlation allows for an estimation of the mixing rate under different operating conditions and for the detection of the end point and/or the time of mixing.
文摘The spatial distribution of concentration and velocity of a gas jet impinging with abump is studied in this paper. The conception of mean dispersion rate of concentrationis employed to describe the mixing process of gas jet in the near wall. The result showsthat the radial non-dimensional distribution of concentration and velocity of the second jetare normal, the axial nonudimensional distribution of concentration is exponential and theaxial non-dimensional distribution of velocity is lineal. The mixing rate of the jet gas in thenear wall is enhanced because of the existence of the bump. Base on these results, a new"space-wall-space" mixing conception for small or medium D.I. diesel engine is proposed.
