Particle rotation plays an important role in gas-solid flows. This paper presents an experimental investigation on the spatial distribution of average rotation speed for glass beads in the upper dilute zone of a cold ...Particle rotation plays an important role in gas-solid flows. This paper presents an experimental investigation on the spatial distribution of average rotation speed for glass beads in the upper dilute zone of a cold circulating fluidized bed(CFB) riser. It is shown that in the horizontal direction,the average rotation speed in the near-wall area is larger than that in the center area,while in the vertical direction,it decreases as the height increases. The reason resulting in this distribution is analyzed by considering several factors including particle size,particle shape,particle number density,particle collision behavior,and the surrounding flow field,etc. The effects of CFB operation conditions on the spatial distribution of average rotation speed are also studied. The results show that the increasing superficial gas velocity increases the average rotation speed of particles in the near wall area but takes nearly no effect on that in the center area. The external solids mass flux,however,takes the opposite effect. It is found that the average rotation speeds of particles in both areas are increased as the total amount of bed material increases.展开更多
One of the most important properties of the torrefied pellets, along with high calorific value, is their hydrophobicity. Inability to absorb moisture and self-destruct under its influence determine possibility of usin...One of the most important properties of the torrefied pellets, along with high calorific value, is their hydrophobicity. Inability to absorb moisture and self-destruct under its influence determine possibility of using of pellets in the pyrolysis reactor. For the technology of two-stage thermal processing of biomass, developed at the Joint Institute for High Temperatures, the amount of synthesis gas which can be obtained from one kilogram of torrefied pellets is also important. A construction of the pilot torrefaction reactor powered by flue gas is shown. The results of experimental investigations of hydrophobicity of torrefied pellets produced by the reactor and quantity of synthesis gas which can be obtained by two-stage thermal processing of the pellets are presented. It is shown that torrefaction allows simplifying the process of conversion of pellets into synthesis gas without significant reduction in the volume of the gas.展开更多
This study was conducted to investigate the effects of fresh fermented soybean meal（FSM） on the growth performance of nursery piglets, nitrogen excretion in feces, and the concentrations of ammonia（NH3） and partic...This study was conducted to investigate the effects of fresh fermented soybean meal（FSM） on the growth performance of nursery piglets, nitrogen excretion in feces, and the concentrations of ammonia（NH3） and particulate matter（PM） in the piggery. A total of 472 nursery piglets（Landrace×Yorkshire,（16.3±0.36） kg body weight） were randomly allocated into two treatments with 236 pigs in each treatment. The pigs were fed the basal diet without fresh FSM（control） or diet containing 10%（100 g/kg） fresh FSM（FSM group）, and the crude protein content of the two groups was consistent. The feeding trial lasted for 28 d. The results showed that the pigs fed fresh FSM had increased（P〈0.05） average daily gain（ADG） compared with the control. There was no significant difference（P〈0.05） in feed to gain ratio（F：G） between the two groups. During the whole experiment, the concentration of NH3 in the piggery decreased（P〈0.05） by 19.0%, and the concentrations of PM（PM（10） and PM（2.5）） in the piggery decreased（P〈0.05） by 19.9% and 11.6%, respectively, in the FSM group, compared with the control. The ammonia nitrogen and nitrite content in feces increased（P〈0.05） by 32.9% and 28.4%, respectively, in the FSM group. The fecal p H declined（P〈0.05） significantly in the FSM group compared with the control. At the end of experiment, total protein（TP） concentration was increased（P〈0.05） significantly and blood urea nitrogen（BUN） concentration was decreased（P〈0.05） for pigs fed the diet with fresh FSM. The results indicated that dietary fresh FSM not only improved the growth performance of nursery piglets, but also reduced the NH3 concentration in the piggery due to nitrogen conversion, and decreased the concentrations of PM（10） and PM（2.5） in the piggery.展开更多
基金the National Key Technologies Supporting Program of China during the 11th Five-Year Plan Period (No. 2006BAA03B01)the China Postdoctoral Science Foundation(No. 20070421165)
文摘Particle rotation plays an important role in gas-solid flows. This paper presents an experimental investigation on the spatial distribution of average rotation speed for glass beads in the upper dilute zone of a cold circulating fluidized bed(CFB) riser. It is shown that in the horizontal direction,the average rotation speed in the near-wall area is larger than that in the center area,while in the vertical direction,it decreases as the height increases. The reason resulting in this distribution is analyzed by considering several factors including particle size,particle shape,particle number density,particle collision behavior,and the surrounding flow field,etc. The effects of CFB operation conditions on the spatial distribution of average rotation speed are also studied. The results show that the increasing superficial gas velocity increases the average rotation speed of particles in the near wall area but takes nearly no effect on that in the center area. The external solids mass flux,however,takes the opposite effect. It is found that the average rotation speeds of particles in both areas are increased as the total amount of bed material increases.
文摘One of the most important properties of the torrefied pellets, along with high calorific value, is their hydrophobicity. Inability to absorb moisture and self-destruct under its influence determine possibility of using of pellets in the pyrolysis reactor. For the technology of two-stage thermal processing of biomass, developed at the Joint Institute for High Temperatures, the amount of synthesis gas which can be obtained from one kilogram of torrefied pellets is also important. A construction of the pilot torrefaction reactor powered by flue gas is shown. The results of experimental investigations of hydrophobicity of torrefied pellets produced by the reactor and quantity of synthesis gas which can be obtained by two-stage thermal processing of the pellets are presented. It is shown that torrefaction allows simplifying the process of conversion of pellets into synthesis gas without significant reduction in the volume of the gas.
基金Project supported by the Key Agricultural Projects of Ningbo Science and Technology Bureau of Zhejiang Province(No.2013C11008),China
文摘This study was conducted to investigate the effects of fresh fermented soybean meal（FSM） on the growth performance of nursery piglets, nitrogen excretion in feces, and the concentrations of ammonia（NH3） and particulate matter（PM） in the piggery. A total of 472 nursery piglets（Landrace×Yorkshire,（16.3±0.36） kg body weight） were randomly allocated into two treatments with 236 pigs in each treatment. The pigs were fed the basal diet without fresh FSM（control） or diet containing 10%（100 g/kg） fresh FSM（FSM group）, and the crude protein content of the two groups was consistent. The feeding trial lasted for 28 d. The results showed that the pigs fed fresh FSM had increased（P〈0.05） average daily gain（ADG） compared with the control. There was no significant difference（P〈0.05） in feed to gain ratio（F：G） between the two groups. During the whole experiment, the concentration of NH3 in the piggery decreased（P〈0.05） by 19.0%, and the concentrations of PM（PM（10） and PM（2.5）） in the piggery decreased（P〈0.05） by 19.9% and 11.6%, respectively, in the FSM group, compared with the control. The ammonia nitrogen and nitrite content in feces increased（P〈0.05） by 32.9% and 28.4%, respectively, in the FSM group. The fecal p H declined（P〈0.05） significantly in the FSM group compared with the control. At the end of experiment, total protein（TP） concentration was increased（P〈0.05） significantly and blood urea nitrogen（BUN） concentration was decreased（P〈0.05） for pigs fed the diet with fresh FSM. The results indicated that dietary fresh FSM not only improved the growth performance of nursery piglets, but also reduced the NH3 concentration in the piggery due to nitrogen conversion, and decreased the concentrations of PM（10） and PM（2.5） in the piggery.
