Study On Jet Ionizer And Its Characteristics

The research of efficient pollution abatement and environmental control technology has become much more important nowadays because of environment pollution, especially the problem of haze and fog, which is getting worse with the development of social economy. As one kind of flue gas purification device with high practicality and efficiency, WESP (Wet electrostatic precipitator) has tremendous potential in pollution abatement, however, its high costs has restricted its application. In this paper, a new type of WESP called Ion Injection WESP has been investigated to combine the advantages of WESP and traditional precipitator.This paper focuses on testing Jet ionizer and its characteristics. In research of two kinds of ionizers with more than 7kV of applied voltage and 70L/min of gas flow rate, ion current has become 14μA at most and ion density is about 2.7×1010/cm3 at distance of 30mm and 1.37×1011/cm3 around the nozzle for needle-ring-type, while ion current and density for needle-type ionizer has been 22μA,4.38R1010/cm3 and 2.13×1011/cm3 at most, respectively. For both two kinds, ion current and density outside will be increased with higher magnitude of applied voltage. Gas flow rate has little influence on ion current, but has negative effect on ion density. Fitting analysis shows that ion current and density will be exponential decay with further measurement distance, and ion current could be divided into two parts:intrinsic ion current and additional current. As for needle-ring-type ionizer, Creepage phenomenon could get significantly restricted with giant grounding resistance and when the resistance increase from 100MΩ to 400MΩ, the efficiency of ion injection turn to 30.2% from 14.4%. Diameter of the grounded ring is a negative factor to ion current and density. Moreover, due to the influence of leakage current, needle-type ionizer is considered better than needle-ring-type in ion current and energy density.Jet ionizer experiment in WESP has been done and shows:the flow rate in ionizer is beneficial to the safety of high voltage insulation and to the output of ion generated; as magnitude of applied voltage increase, the collected ion current could be 36μA at most with one working ionizer and 123μA at most with three. In general, the collected ion current with three ionizer is about 3 to 4 times larger than with one. Above all, it demonstrated that the designed ionizer and the system have great effect in ion generation and chargeability.