High-efficiency, maintenance-free cyclone technology replaces conventional dust and exhaust filters

Current industrial filtration methods often require costly maintenance, and filter membrane replacement on an ongoing basis. However, Tshwane-based Rand Technical Services (RTS) offers robust, highly-effective inertial spin filter technology for industrial dust and exhaust separation, which is virtually maintenance-free. This is according to Ian Fraser, Chairman of RTS.

Cyclone technology
Says Fraser:  “Spin Filter units are a high-efficiency application of cyclone technology. Air to be separated is blown through a module that consists of a series of small vortexes. The air flow is induced to spin by fixed vanes at the entry to the vortexes, and centrifugal force then drives the dirt particles to the outside of the vortex.”

The dirt-laden air is purged through an annular port at the end of the vortex tube. A purge fan is used to keep the dirt-laden waste air in flight, from where it is either dispersed or collected as required. Clean air then exits to process. “Ninety-eight percent of particles 15 microns and larger are removed by this simple process,” he observes. 

“In some industries this is particularly useful for materials reclamation, as the environment is protected and, at the same time, valuable fines are recovered that would otherwise be lost into the atmosphere,” Fraser explains.

Constant resistance, consistent performance
Unlike conventional filter membranes, which clog due to pressure build-up after a period of use, the pressure drop across the spin filter module never increases. The units are self-cleaning, and do not block when correctly installed - thereby offering consistent performance with constant resistance. They are highly energy-efficient too, as the pressure drop though the Spin Filter is constant and does not increase as dust is removed.

“Not only is pressure constant for the life of the unit, but the unit itself has an exceptionally long working life. We have installations still going strong that are 23 years old. The sturdy, high density polypropylene construction of the blocks is highly resistant to erosion.  Spin filters are proving to be very effective in mining applications with heavy dust loads.  This technology is finding wide application in Coal, Gold, Diamond and other mining environments and is also meeting arduous dust removal challenges in underground applications.  We have built up a population of spin filters in mining and industry that includes MCC rooms, control rooms, transformer rooms, machinery spaces and  workshops, to name but a few.  This technology has also proven effective for the cooling of variable speed drive installations,” notes Fraser.

Unlimited capacity
According to Fraser, the spin filters are constructed in modules that can be built up into large panels, sized to match required air flow and so offering an unlimited capacity on engineered systems. The smallest available unit, containing one Inertial spin filter  module, handles from 1200 to 2500 Nm3 per hour with ease, and upper range capacity is only determined by the application, and the available space.

Delivering a rapid return-on-investment, the spin filter system has an excellent track record in industries such as power stations, glass plants, cement factories, steel mills and, as above, coal gold and platinum mines.

Spin Filters provide sufficient filtration for most environmental applications, such as transformer rooms and control rooms, without the addition of secondary filters. In  applications requiring secondary filters to remove finer particles, such as in air compressor intakes, the spin filters substantially extend the life of the secondary filters. Conventional filter membranes are left with very low dust loadings and so last far longer. There is also a beneficial ripple effect on cost-saving throughout the plant. Downtime from both planned and unplanned shutdowns is greatly reduced - less damaging friction from dust particles means far less equipment wear and tear, or failure.”      

Protects switchgear and electrical systems
A substantial reduction in switchgear and other electrical system breakdown is achieved once spin filters are installed. Even when planned maintenance for other equipment is delayed or overlooked, the units deliver consistent, maintenance-free performance to keep electrical systems functioning reliably.

Environmental benefits
Fraser goes on to state:  “The benefits of the spin filter system are almost endless. Return-on- investment is rapid; due to a substantially smaller spend on filtration maintenance and replacement – not to mention the ongoing reduction in equipment breakdown and support costs. Environmental benefits are also considerable, due to the reduction in undesirable emissions.”

‘Unsung Hero’ of Industry
“Filtration is one of industry’s ‘unsung heroes’. Without it, many processes would literally grind to a halt, and pollution and unhealthy working conditions would be greatly increased. Inertial spin filters have succeeded on their own proven merits, even during depressed economic conditions. They keep on saving time, labour and money long after they have paid for themselves.

While nothing succeeds like success, the Inertial spin filter also demonstrates that ‘nothing succeeds like proven, effective simplicity’,” concludes Fraser.