Flosep

Flosep, a section of the national Nuclear Manufacturing Centre (NNMC) of Necsa, with more than 20 years experience in air filtration, is a leader with their patented self-cleaning filters. Flosep's team of highly skilled and innovative personnel offers a total air filtration solution service to industry. Through a network of agents and distributors worldwide; the international experience and trends are studied and made available to the air filtration industry. Flosep has two groups, namely gas cleaning filtration and DryKeep® transformer oil drying system:

Gas cleaning filtration system

Filter operation:

A constant pressure gradient in the filter causes dust-laden air to flow over a vortex generator towards the outlet tube. This dust-laden air is then spun at a high velocity resulting in dust particles being thrown to the wall of the tube by the centrifugal force. At this point, the dust particles are through their own momentum ejected by scavenge air (bleed air) through a scavenge opening, while the clean air flows through the tube outlet.

Locomotive Air Filtration

Flosep is a leader in dust control and flow analysis and has developed a range of self cleaning hi-flow filters specifically designed for locomotives.

The biggest single success factor in the South African air filtration industry was in motive traction power (locomotive engines) which has contributed to make the rail system more efficient and economical. The superior-technology which is built into locomotives requires efficient protection from the harsh environment in which they operate. Flosep's self-cleaning locomotive filters remove potentially harmful particles from ventilation air used for the cooling of electrical equipment and provide clean air for the cooling of traction motors and the pressurization of associated switchgear.

Mining Air Filtration Equipment

Filtration is done of pressurised air for: draglines, electric shovels and haul trucks. Pre-filtration is done of intake air for: internal combustion engines, compressors and gas turbines. Dust suppression and / or collection is done on drills, crushers and conveyor transfer points.

Ventilation Air Filtration

Primary air filters are used on ventilation systems which incorporate secondary filters. Filtration of pressurization air for: substations, control rooms, MCC rooms, winder houses and compressor rooms.

Industrial Air Filtration

Pre-filtration to reduce dust loads on secondary or final filters. (Such as bag houses and ESP's) is used for:

• Product recovery
• Fan protection

ISOKINETIC Sampling and Testing

Flosep uses a mobile iso-kinetic sampling laboratory, which consist of a computerized dual point flow control unit and data accumulation system.

Measurements are done in real time using combination probes for normal and high temperature measurement. High humidity measurements are done with heated combination probes. Measurements are done in accordance with BS Code 893 for iso-kinetic sampling and BS Code 3405 for pitot tube traverses. Particle size analysis of sampled dust is performed with Flosep's Malvern Master Sizer.

DryKeep® TRANSFORMER OIL DRYING SYSTEM

Background

Several factors shape the life expectancy of a transformer. One such a factor is the moisture content within a transformer which has a significant detrimental impact on the ageing of a transformer. It is for this reason that the reduction of moisture or prevention of moisture increase in the transformer is important for transformer maintenance. Unlike the existing techniques, which removes water after it has accumulated in the transformer; the DryKeep® system performs this function in a ongoing and pro-active basis which effectively slows down the aging process.

The main advantage of the DryKeep® unit lies within continuous moisture management, as opposed to the very rapid traditional drying methods. By implication, the DryKeep® unit

has a less dramatic impact on the transformer, as it can safely purify the oil while the transformer is still on load.

The system comprises one, two or three (depending on the model) completely passive cartridges which are sized to match the transformer, from 1 MVA to the largest of units. Each cartridge contains a high technology absorbent material designed to remove

dissolved water from the oil that passes through the cartridge. As moisture migrates from insulation to the oil, it is gently removed by the DryKeep® system. The system is unique in that, unlike similar drying techniques, the moisture that is under normal operating temperatures .

Application

• New Transformers

After manufacture the total moisture content in new transformers is less than 0.5%. The DryKeep® will maintain this moisture content and eliminate moisture build-up.

• Repaired Transformers

After a major overhaul in a workshop environment with vapour-phase treatment, the moisture content of the repaired transformer is similar to that of a new transformer (less than 0.5%).

• In-Service transformers having moisture content up to 2%.

Transformers, irrespective of age, can be fitted with DryKeep® to reduce the moisture in the transformer and eliminate moisture build-up.

• In-service transformers having moisture content exceeding 2%.

          Installation of the DryKeep® is also recommended. It will however be necessary to replace the
          saturated cartridge more frequently due to the high moisture content being absorbed out of the
          transformer. This process should be continued until the moisture content is reduced to a
          sufficiently low level and less frequent replacement of the cartridge is required. Thereafter the
          DryKeep® will eliminate moisture build-up. It will however be necessary to re-clamp the windings
          of the transformer due to the shrinkage of the outside insulation that has developed during the
          moisture management process, unless the moisture removal is strictly controlled to prevent
          shrinkage from occurring.

• Storage tanks containing transformer oil with very little moisture content.

          The DryKeep® can be installed on the basis that it maintains the moisture content and eliminates
         moisture build-up.

• Storage tanks containing transformer oil with very high moisture contents.

Application is the same as for in-service transformer having moisture content exceeding 2%. Installation of the DryKeep® is recommended.

For more information contact Flosep: