Improvement of the classification performance of a rectangular jet virtual impactor

Kuniaki Gotoh, Hiroaki Masuda

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)


The effect of flow characteristics on the performance of a virtual impactor with a rectangular jet has been studied experimentally. Flow visualization revealed a three-dimensional flow structure and flow instability on the classification performance, classification experiments were carried out using the virtual impactor with an improved collection nozzle which was designed to avoid the adverse pressure gradient. The newly designed collection nozzle improved the classification performance in the high inertia region, which is larger than a cut point of the virtual impactor. However, the separation efficiency is still lower than that predicted by the theory based on the two-dimensional flow. Since the flow visualization revealed that the flow in the classification zone was partially disturbed by the new collection nozzle, the entrance part of the impactor was newly designed to introduce 2 additional clean airflows. These clean airflows prevented flow disturbance and attained the theoretical classification performance in the high inertia region.

Original languageEnglish
Pages (from-to)221-232
Number of pages12
JournalAerosol Science and Technology
Issue number3
Publication statusPublished - 2000
Externally publishedYes

ASJC Scopus subject areas

  • Environmental Chemistry
  • Materials Science(all)
  • Pollution


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