Tshwane-based technology and solutions provider Rand Technical Services (RTS) received an order from a local engineering company last month for an inertial spin filter to provide ventilation for the control room of a Mozambique-based mineral sands miner.
The inertial spin-filter unit, which will supply the control room with a high volume of clean air, is in the design phase and will be installed next month.
RTS MD Ian Fraser says the installation of the 40 000 Nm3/h spin filter will be completed by December.
RTS’s inertial spin filters, which have already been used by power stations, glass manufacturing plants, cement factories and steel mills, are well suited to mining applications where dust and harsh underground conditions require a robust, easy-to-maintain and energy efficient filter system.
The filters can be installed at a mine’s control room, a pump station, a transformer room, a workshop, underground offices or in mine shafts.
The self-cleaning inertial spin filter, which uses cyclone technology to remove up to 98% of 15 µm dust particles, is able to perform the role of the prefilter and the primary filter, says Fraser.
When employing only a standardised primary filter system, the filter media may clog too quickly.
The spin filter is activated when dust-laden air is blown through a module that consists of a series of small vortexes. The airflow is induced to spin by the fixed vanes at the front of the modules and a centrifugal force drives the dirt particles to the outside of the vortex, he explains.
The dirt-laden air is purged through the vents by a purge fan, where the dirt-laden air is kept in flight. From here, the dust-laden air is either dispersed or collected.
The spin filter removes most of the coarse dust and enough of the finer dust particles, reducing the need to install a secondary high-efficiency particle-arrestor filter, says Fraser.
"However, to remove dust particles of 5 µm or smaller in secondary filtration applications, the RTS spin filter significantly extends the life of the secondary installation, as conventional filter media are left with very low dust loadings, which, in turn, last longer."
The self-cleaning inertial spin filter also requires less maintenance than standard filters. When installed correctly, the units do not clog and do not require any filter media to be replaced, he notes.
Further, the filter units are energy efficient, as only an auxiliary purge fan, which directs the dust-laden air out of the air stream, requires power.
There is no limit to the throughput capacity of the filters, adds Fraser. The spin filters can be designed according to any specification.
"The largest-capacity filter designed by RTS, to date, has been 250 000 Nm3/h, which was used for a glass works application to provide clean dust-free air to the blowers for glass blowing," says Fraser.