The development of an efficient technology for removing fine particles in flue gas is essential as the haze is becoming more and more serious.To improve agglomeration effectiveness of fine particles,a dual zone electr...The development of an efficient technology for removing fine particles in flue gas is essential as the haze is becoming more and more serious.To improve agglomeration effectiveness of fine particles,a dual zone electric agglomeration device consisting of a charging chamber and an agglomeration chamber with bipolar barb electrodes was developed.The bipolar barb electric agglomerator with a polar distance of 200 mm demonstrates good agglomeration effectiveness for particles with a size less than 8.0μm under applied AC electric field.An optimal condition for achieving better agglomeration effectiveness was found to be as follows：flue gas flow velocity of3.00 m/s,particle concentration of 2.00 g/m^3,output voltage of 35 kV and length of the barb of16 ram.In addition,4.0-6.0μm particles haste the best effectiveness with the variation of particle volume occupancy of-3.2.展开更多
Purification of oil droplets is crucial for enhancing air quality in machining plants.However,the small particle size and high purification resistance of oil droplets present challenges.Electricity agglomeration pretr...Purification of oil droplets is crucial for enhancing air quality in machining plants.However,the small particle size and high purification resistance of oil droplets present challenges.Electricity agglomeration pretreatment technology,which leverages strong inter-particle forces,improves the purification efficiency of small particles without increasing the resistance of purification equipment,showing significant application potential.This study numerically investigates the effectiveness of electricity agglomeration influenced by physical parameters(surface tension,droplet diameter)and collision parameters(collision velocity,collision angle)of oil droplets.Results indicate that surface tension and collision velocity are critical factors.When surface tension exceeds 20 mN/m,oil droplets are more likely to agglomerate upon collision.Additionally,increasing collision velocity leads to progressive destabilization of oil droplets.The critical velocities for agglomeration-separation and separation-fragmentation are identified as 8 m/s and 16 m/s,respectively.A Weber number(We)–collision angle map was constructed to represent the collision behaviors of oil droplets,revealing that at We<14.4,oil droplets agglomerate effectively after collision at any angle.This value is twice that of water droplets,indicating that oil droplets are more prone to agglomeration upon collision.These findings provide valuable insights for optimizing parameters in electrical agglomeration processes.展开更多
The charge quantity of small particulates such as PM2.5 plays a key role in the collection efficiency of an electrostatic precipitator（ESP）. Under a single electrostatic voltage, it is difficult to charge and absorb...The charge quantity of small particulates such as PM2.5 plays a key role in the collection efficiency of an electrostatic precipitator（ESP）. Under a single electrostatic voltage, it is difficult to charge and absorb small particulates. A new method of superimposing an alternative voltage on the electrostatic voltage is provided in this paper. Characteristics of small particulates are analyzed under alternative and electrostatic voltages. It is demonstrated that an alternative voltage can significantly improve the collection efficiency in three aspects： preventing anti-corona, increasing the charge quantity of small particulates, and increasing the median particulate size by electric agglomeration. In addition, practical usage with the superposition of alternative voltage is provided, and the results are in agreement with the theoretical analysis.展开更多
基金supported by the Key Technology R&D Program of Hebei,China(No.13211207D)
文摘The development of an efficient technology for removing fine particles in flue gas is essential as the haze is becoming more and more serious.To improve agglomeration effectiveness of fine particles,a dual zone electric agglomeration device consisting of a charging chamber and an agglomeration chamber with bipolar barb electrodes was developed.The bipolar barb electric agglomerator with a polar distance of 200 mm demonstrates good agglomeration effectiveness for particles with a size less than 8.0μm under applied AC electric field.An optimal condition for achieving better agglomeration effectiveness was found to be as follows：flue gas flow velocity of3.00 m/s,particle concentration of 2.00 g/m^3,output voltage of 35 kV and length of the barb of16 ram.In addition,4.0-6.0μm particles haste the best effectiveness with the variation of particle volume occupancy of-3.2.
基金sponsored by the Natural Science Basic Research Program of Shaanxi(No.2024JC-YBMS-421)the National Natural Science Foundation of China(52378110).
文摘Purification of oil droplets is crucial for enhancing air quality in machining plants.However,the small particle size and high purification resistance of oil droplets present challenges.Electricity agglomeration pretreatment technology,which leverages strong inter-particle forces,improves the purification efficiency of small particles without increasing the resistance of purification equipment,showing significant application potential.This study numerically investigates the effectiveness of electricity agglomeration influenced by physical parameters(surface tension,droplet diameter)and collision parameters(collision velocity,collision angle)of oil droplets.Results indicate that surface tension and collision velocity are critical factors.When surface tension exceeds 20 mN/m,oil droplets are more likely to agglomerate upon collision.Additionally,increasing collision velocity leads to progressive destabilization of oil droplets.The critical velocities for agglomeration-separation and separation-fragmentation are identified as 8 m/s and 16 m/s,respectively.A Weber number(We)–collision angle map was constructed to represent the collision behaviors of oil droplets,revealing that at We<14.4,oil droplets agglomerate effectively after collision at any angle.This value is twice that of water droplets,indicating that oil droplets are more prone to agglomeration upon collision.These findings provide valuable insights for optimizing parameters in electrical agglomeration processes.
基金Project supported by the National High Technology Research and Development Program of China(Grant No.2004AA52930)the Fundamental Research Funds for the Central Universities(Grant No.2014JBM109)
文摘The charge quantity of small particulates such as PM2.5 plays a key role in the collection efficiency of an electrostatic precipitator（ESP）. Under a single electrostatic voltage, it is difficult to charge and absorb small particulates. A new method of superimposing an alternative voltage on the electrostatic voltage is provided in this paper. Characteristics of small particulates are analyzed under alternative and electrostatic voltages. It is demonstrated that an alternative voltage can significantly improve the collection efficiency in three aspects： preventing anti-corona, increasing the charge quantity of small particulates, and increasing the median particulate size by electric agglomeration. In addition, practical usage with the superposition of alternative voltage is provided, and the results are in agreement with the theoretical analysis.
