Improving cyclone efficiency for small particles

Test results of a new highly efficient add-on for cyclones are reported. The add-on has the same beneficial characteristics as cyclones (versatility, long-lasting, low construction and maintenance cost, simple design, little investment, little extra space, flexible operating conditions). The new device was tested in combination with Stairmand cyclones. Efficiencies without any additional filters reached 98% for a particle size distribution with an average of 1.6 mu m and >99% for particles >= 10 mu m. In the most effective mode of operation the dust enters the cyclone(s) and the depleted stream leaves for the add-on, a 'jet impingement chamber', which contains an air-blowing nozzle pipe pushing dust particles toward the wall creating clean gas in the center, which is released. The dust-enriched stream is recycled, i.e., added to the fresh feed for the cyclones. Experiments were performed under large-scale operating conditions and design methods applied to fully characterize the system's efficiency with all variables of operation including three dust particle size distributions covering the range from 0.3 to 200 mu m. (C) 2019 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.