阻尼式脉动气流分选装置分选机理的基础研究

对于传统气流分选装置，物料的沉降末速是决定不同组分有效分选的主要因素．因颗粒的沉降末速与颗粒的密度、粒度和形状有关，故影响传统气流分选装置有效分选的因素较多．阻尼式脉动气流分选装置是一种新型的气流分选机．在传统的气流分选机中加入阻尼块，将在分选装置中形成气流的加速、减速区域，所产生的脉动气流可实现物料在分选装置内按密度有效分离．实验选用两种粒度相近、密度不同的示踪颗粒作为被分选组分，实验研究表明，与传统气流分选相比，阻尼式脉动气流分选可获得更高的分选效率和更宽范围的操作条件。

Separating Mechanism of Passive Pulsing Air Classifier

For the traditional air classifier, the difference of terminal velocity of particles is one of the main factors to achieve effective separation. Because the terminal velocity in turn is dependent on the particle's size, shape and density etc, it is difficult to achieve an ideal separation result. To improve the separation efficiency of particles, a new type of air classifier, the passive pulsing air classifier, was introduced. In the pulsing air classifier, expansions and contractions of the throats impose a distance-varying airflow which alternately accelerates and decelerates the particles. A density-dominant separation was achieved because of the pulsing airflow. In order to evaluate the separation effect of different air classifiers, two species of the tracing particles which have similar particle size and different density were adopted. The results of the laboratory experiments indicate that the pulsing classifiers achieve more effective results of separation and get a wider range of operating velocities of the airflow than the traditional ones.