粉尘预荷电与荷高压导电多孔陶瓷管耦合的除尘新技术研究

Research on new dust elimination technique combined with dust pre-charge and conductive porous ceramic tubes loaded with high voltage

研究了粉尘预荷电与荷高压导电多孔陶瓷管耦合的除尘新技术。该技术首先通过设置直流负电晕(-20kV)的预荷电器对粉尘进行荷电,再使含尘气体穿过荷载高压负电(-5 000V)的导电多孔陶瓷管的管壁而进行过滤除尘。结果表明,该技术降低了导电多孔陶瓷管除尘过程的气体压降。在相同除尘时间(60min)内比较,该技术的粉饼压降(787Pa)仅为无荷电条件下粉饼压降(4 300Pa)的0.183倍;在相同粉饼质量(1 000g)的情况下比较,该技术的粉饼压降仅为无荷电条件下40 min粉饼压降(2 747Pa)的0.286倍。这很可能是因为粉尘荷电导致的颗粒间斥力使粉饼更加疏松,而且导电多孔陶瓷管荷载与粉尘相同的电荷,两者结合松散,减小了过滤过程中的气体压降。该技术有望显著降低工业多孔陶瓷管除尘过程的气体压降,并延长其再生周期。

A new dust elimination technique combined with dust pre-charge and conductive porous ceramic tubes loaded with high voltage was investigated. During the operation of this technique,the dust was firstly pre-charged by pre-charge appliance with DC negative corona （-20 kV）, and then the gas containing dust was forced to penetrated the wall of conductive porous ceramic tubes loaded with DC negative high voltage （-5 000 V） to undergo dust elimination. It was revealed by the results that, this new technique obviously decreased the gas pressure drop of the conductive porous ceramic tubes during the de-dust process. With the new technique, the dust-cake pressure drop （787 Pa） was only 0.183 times to that without pre-charge （4 300 Pa） in the same conditions during the same operation time （60 rain）. The dust-cake pressure drop under the new technique was only 0.286 times to that without pre-charge at the 40th minute （2 747 Pa） in the same conditions under the same dust layer mass （1 000 g）. The results were high possibly caused by the fact that the electrostatic repulsion force between the dust particles gave rise to loosely compacted dust layer,furthermore,the electrostatic repulsion between the conductive porous ceramic tubes and the pre-charged dust particles brought about very loose attachment between them,and the gas pressure drop during filtration was decreased. This new technique was expected to obviously reduce the gas pressure drop of porous ceramic tube in industrial de-dust operation, and prolong its regeneration period.