A crossed-flow pulsed corona reactor

The chemical radicals created during an atmospheric-pressure partial discharge have been shown to be beneficial in the abatement of a variety of gaseous pollutants. These pollutants range from the nitrides of oxygen present in diesel engine exhaust to fluorinated and chlorinated compounds entrained in semiconductor process tool effluent. Despite promising technical advances in the electrical and chemical efficiencies available from this nonthermal technique, achieving the treatment volumes and rates required in practical applications may require large, parallel combinations of existing reactor designs. The pulsed corona reactor (PCR) is one device that is routinely used to create the requisite nonthermal plasma environment. Although simple, this geometry is problematic in accommodating higher treatment rates since the pollutant flow is introduced axially and complex manifolds will be required to direct the flow through numerous parallel reaction chambers. Furthermore, difficulty is anticipated in maintaining the axial alignment of the high voltage inner conductor in the long tubes over time. To solve this problem, the current work describes an alternative reactor geometry, referred to as the crossed-flow PCR (X-PCR), where the pollutant stream is introduced perpendicular to the wire-cylinder reaction chamber through the use of a perforated outer cylinder. The X-PCR has been implemented as part of a plasma-assisted catalysis investigation underway at the Institute for heavy-duty diesel exhaust aftertreatment. The performance of the reactor in a raw diesel exhaust environment will be discussed along with the NO/sub x/ removal efficiencies obtained when used in conjunction with a unique lean-NO/sub x/ catalyst.