A properly designed electrostatic precipitator (ESP) and a Fiber Bed Filter Mist Collector System will both provide 0% opacity initially. However, on an ESP, the contact surfaces collect the particulate material and the efficiency gradually diminishes until the ESP requires cleaning.
There are three areas that set the Fiber Bed Filter technology apart from ESP filter systems:
Performance:
A properly designed ESP and a Fiberbed Filter System will both provide 0% opacity initially. As the contact surfaces collect the particulate material, the efficiency gradually diminishes until the ESP requires cleaning.
While the start point efficiency is at or near 99%+, almost immediately, by the nature of the ESP’s design, the surface gets dirty and the efficiency begins to fall off until it reaches a point where the visible emissions are above the limit. This requires cleaning of the ESP so that the surfaces are able to remove a higher level of particles and return near to its original performance. The cleaning process is never able to return the surfaces to their original state, so after several cleanings, the electrostatic precipitator system requires a major overhaul to meet visible emission requirements.
Fiberbed Mist Collector System. Pacific Continental Textile, Compton, CA. One (1) of nine (9) ESP’s replaced
Fiberbed Filters maintain a constant removal efficiency throughout the filter life. As the filters get ‘saturated ‘ with particulate, the only thing that changes is that the pressure drop increases requiring more energy to move the process exhaust through the filters. The opacity control remains at or near Zero throughout the filter life of 1-2 years depending on the process. The new China regulations (DB/33-962) for opacity are so stringent that thousands of ESP filter systems are now being replaced or will be replaced over the next two years with Fiberbed Filters.
Maintenance:
As mentioned above, the ESP needs frequent maintenance to remain in compliance. The extent of this maintenance depends on the products being produced, the production input, and the type of ESP filtration (Dry vs. Wet). A dry ESP adds a second layer of maintenance. The cooling section is normally an air-to-water or air-to-air heat exchanger. In either case, the emissions common to the textile industry coat the cooling surfaces reducing the cooling effectiveness and thereby increasing the inlet temperature which negatively impacts the performance of the ESP. One ESP may require a day to a week of downtime just to clean the cooling system, and perhaps another day for the ESP itself. The wet ESP uses water/direct contact for cooling. The water eliminates the maintenance of the heat exchanger, however the water is directly in the electroplate zone. This, over time, can cause serious operational problems.
The Air Clear Fiberbed Filter Mist Collector requires a major maintenance effort (two days of maintenance to remove and replace the fiberbed filters) once every 1-2 years. Weekly maintenance amounts to the removal of collected oils and routine maintenance on bearings etc., all of which can be done during operation. Weekly maintenance amounts to removal of collected oils once a week and routine maintenance on bearings etc., all of which can be done during operation. The Air Clear Fiberbed System is a highly automated PLC controlled system designed for optimum performance with the lowest amount of manpower attention. The result is increased operating time and a shift from maintenance personnel to production personnel due to increased availability for production.
Fire Risk:
Both the ESP and Fiberbed filters have a potential inherent fire risk. Due to the introduction of the high voltage, the potential for short circuits causing a fire is very great in an ESP filter system. The Fiberbed has a first stage water scrubbing section that makes transfer of fire to the Fiberbeds themselves nearly impossible. Fires in ESPs occur with such frequency that insurance carriers are beginning to refuse insurance on processes using ESPs or demanding that ESPs destroyed in a fire be replaced with an alternative technology. In addition to the cyclonic quench section, Air Clear Fiberbed units incorporate a complete fire piping section integral to the unit, inlet and outlet fire detectors, flow switch interlocks to ensure water supply and cooling, a fan ‘shutdown’ interlock, a pump ‘on’ interlock, and complete interface to the plant’s fire alarm system. Air Clear has replaced 9 ESPs in the textile mills in the South Coast Air Quality Management District (LA) with our Fiberbed Filter Mist Collector Systems. We have also replaced ESP filtration in other locations in the USA, China, and Korea.