Building, fitting and testing an acoustic agglomerator to reduce or eliminate dust loading from the machine house on draglines

[摘要] Acoustic agglomeration of airborne particles has been known for the last 75 years when it was first observed that small particles tend to "stick" together in the presence of an intense acoustic field, thereby forming larger particles. The concept, as applied to the treatment of an exhaust stream carrying dust particulate, is illustrated in the performance graphs showing the efficiency of removal of dust particulates using a both an experimental cyclone and a commercially available Dynavane cyclone. This is without impeding the flow (backpressure) of air through a dragline air handling unit; a strong sound field can be applied to stimulate rapid agglomeration of smaller particles into larger ones. The larger particles can then be more effectively removed by standard particle capture methods, such as cyclones and electrostatic precipitators.The object of the C18029 project and the extension project is to increase the size/mass of the2.5 micron dust particulates by four to seven times to increase the efficiency of a standard Dynavane inertial separator at reducing all respirable dust to lower than the recommended .15mg Metre3. Ultrasonic agglomeration of itself does not affect the dust particulate mass but conditions the dust particulates for efficient removal by other means.The purpose of acoustic agglomeration is to increase the size of respirable dust particles to a size range that can be extracted from air intake flows by other means such as microcyclones or filters.The main findings from the computer modelling, laboratory testing and prototype operation on a Dynavane show acoustic agglomeration technology reduces DPM mass by up to 80%compared to untreated air flows and the technology operates efficiently when fitted to a working Dynavane. It produces very little backpressure on air intake fans and is able to operate over a wide range of operating dust loads.The outcome for the coal mining industry is a dramatically improved understanding of the behaviour of respirable dust particulates and the efficient removal of much smaller dust particulates than is achieved with standard micro filtration methods. The outcome of this will be a greatly improved acoustic respirable dust agglomerator and commercial ultrasonic agglomerator/Dynavane inertial setarator dust extraction method for draglines used on coal mines.

[发布日期] 2013-06-01 [发布机构] ACARP

[学科分类] 地球科学(综合)