Modeling of Prebreakdown VI Characteristics of a Wire-Plate Electrostatic Precipitator Operating Under Combined Dc-pulse Energization

With the advent of pulse energization in electrostatic precipitators, the need for developing a model to simulate the physical processes in the prebreakdown region, at which the precipitator normally operates, is also increasing. The development of such a model helps in predicting the VI characteristics of a precipitator, which will be important to diagnose the electrical problems associated with the precipitator during its operation. The paper reports the details of a proposed model to predict the VI characteristics of a wire-plate precipitator operating under the influeuce of repetitive pulses superposed on a dc bias. The model begins with the calculation of space charge density near the HV electrode during the pulse-on period and then proceeds with the drift of space charges in the pulse-off period aided by the dc bias. The pulse duration was ~250 ns. The pulse repetition rate was 50 Hz. The predicted results were validated against the experimental results conducted on a laboratory model of a wire-plate precipitator. The studies were conducted for dust free conditions

Injection of N-Radicals into Diesel Engine Exhaust Treated by Plasma for Improved NOxNO_x Removal: A Feasibility Study

Reported in this paper is a feasibility study on the injection of plasma induced N radicals for the abatement of NO and $NO_x$ present in the actual diesel exhaust. The radical laden diesel exhaust was further treated by discharge plasma in a dielectric barrier discharge reactor. N radicals were produced in a separate plasma reactor filled with $BaTi0_3$ pellets and were then injected into the treatment zone. There was a significant improvement in the efficiency when the radicals were injected compared to that when there was no radical injection. The efficiency of $NO_x$, removal at 0 load with plasma alone was 14% whereas with the injection of N radicals it went up to 38%. The results of the experiments conducted at different loads are discussed

Voltage-Current Characteristics of Plate Type Precipitator Geometry Under Combined DC/Pulse Energizations

An attempt has been made to study the voltage-current characteristics of a wire-plate precipitator geometry under clean air conditions. Helical wires have been used as corona electrodes. The studies were conducted with DC and DC superposed on nanosecond pulse respectively. The repetitive pulses with a rise time of the order of nanoseconds were generated from a MARX type impulse voltage generator. A comparative study of effect of pulse repetition rate, pulse width and effect of DC bias has been made on the voltage-current characteristics. The obtained results were discussed and compared with previous investigations