Analysis of a pulsed corona circuit

A fast risetime pulsed corona reactor has been developed to investigate the treatment of polluted gaseous effluents. The pulsed high-voltage circuit used to drive the coaxial reactor tube consists of a controllable constant current power supply, a storage capacitance, a self-breaking spark gap, and fast current/voltage diagnostics. The circuit design is coaxial from the storage capacitor (a length of 50 /spl Omega/ cable) to the reactor tube (a coaxial wire-tube geometry) to minimize the circuit inductance. Using a high-pressure hydrogen spark gap, the apparatus achieved a risetime of approximately 2 ns. The length of the applied pulse was altered by using different lengths of storage capacitor cable. A minimum pulse width was achieved by using a matching 50 /spl Omega/ load placed before the reactor tube, which produced a square pulse with a width of 10 ns at the input to the reactor tube. The driving circuit and corona load were simulated using a simple time-varying resistance to represent the corona discharge. The resulting waveforms are compared with those obtained experimentally. The simulation results were also used to verify the integrity of the fast-pulse measurements. Finally, experimentally obtained results are presented on the effect of the corona pulse width on the efficiency of NO decomposition in nitrogen.