Self-cleaning effect and secondary swirling clean gas for suppressing particle deposition on vortex finder of gas cyclones

In order to suppressing the particle deposition on vortex finder, a series of gas cyclones with the secondary swirling clean gas were developed inspired by the gas purge effect. Effects of the width and extension length of the flow channel as well as the secondary inlet velocity and running time on the particle deposition pattern, the deposited particle mass and the cyclones’ performance were experimentally investigated, respectively. The results show that the ultrafine particles (Stokes number Stk < 0.0358) are mainly loose deposited on the walls under the secondary gas. Compare to the conventional cyclone with single tangential inlet, the total deposited particle mass of the improved cyclone has a maximum reduction more than 60%, and the collecting efficiency is increased up to 97.5% under the basically same pressure drop. The corresponding no-deposition area is increased by about 13%, and remains constant in spite of extending the running time. Moreover, an interesting phenomenon named “self-cleaning effect” of the vortex finder was captured for the gas cyclones, and mechanism of the secondary clean gas on the particle deposition is preliminarily analyzed. The results can deepen the understanding of the particle deposition on the vortex finder and guide the design of the anti-coking gas cyclones.