Design of a nozzle structure for uniform distribution of active substances in plasma jet honeycomb array configuration

Array plasma jet structure is often used to increase the treatment area but repulsive forces between the jet units lead to the fact that the active substances often do not cover the entire area. In this study, an array structure composed of seven unit pipes is used, and each pipe is equipped with a honeycomb nozzle to form a honeycomb array device. Each honeycomb nozzle contains a center channel surrounded by six adjacent channels, forming a regular hexagonal geometry. By adjusting the direction of the honeycomb nozzle structure, the nonuniformity of the active substance distribution between the jet units is compensated, and the uniform distribution in the treatment area of the array device is realized. The results show that when the inclination angle of the honeycomb nozzle is 12°, the jet distribution obtained is the most uniform. Compared with traditional array devices (without honeycomb nozzles), the addition of the nozzle structure makes the distribution of downstream active substances more concentrated and uniform. The honeycomb array device achieves the best results at a gas flow rate of 5 slm and a treatment distance of 5 mm, with a maximum sterilization area of 1039 mm2, and 100% sterilization can be achieved by treating Escherichia coli (E. coli) for 6 min. Compared with traditional array devices, the sterilization efficiency of E. coli has been increased by nearly 25% in the treatment time of 4 min.