Bag-In/Bag-Out (BIBO) HEGA-HEPA Filtration

Bag-in/Bag-out (BIBO) Filter Systems are specialty side-access filter housings that permit the removal of the used air filters into a disposal bag. These heavy-duty disposal bags are mounted on collars underneath the filter access doors. When it’s time for filter change-out, the filter access doors are removed, exposing these seam-welded bags that are secured onto the door collars. An elaborate procedure is followed to remove the used filters and then replace the filters, all completed without exposing the contaminants within the filter housing, when it is done properly. The housings themselves are constructed of Type 304SS or 316SS, to ASME N509 Nuclear Standard. The standard describes the construction, welding procedures and materials allowed on these specialty housings.

BIBO filter systems, by their nature, are used on critical applications where exposure to the dust, fumes or gases could be harmful (or possibly fatal) to service technicians. For that reason, these housings usually employ extremely high efficiency filters, such as HEPA (High-Efficiency Particulate Air), ULPA (Ultra-Low Penetration Air) or HEGA (High-Efficiency Gas-Phase Air) filter elements. Most BIBO filter systems are designed as multi-stage systems: Prefilter Stage(s), followed by HEPA/ULPA stage(s) and possibly HEGA filters (if there is a gaseous compound or radio-isotopes potentially in the gas-stream).

The BIBO system filter selections are dependent on the contaminants present and their concentration. Regardless of the contaminants, all filters are changed through the specialty bags, and all high-efficiency filters are sealed into the housing with heavy-duty clamping-mechanisms, to ensure there are no contaminants bypassing the filters. Often, these housings are provided with test apparatus to allow for the challenge of the various high-efficiency filters in the housing, all completed without any exposure to potential contaminants within the air stream. It is also very common to see bubble-tight dampers installed on the opposed flanges of the housing to permit isolation of the filter housing/module when filter change-out is completed.

There are many applications for Bag-in/Bag-out (BIBO) filter systems, including, but not limited to:

• HVAC Systems in Nuclear Power Generating Stations
• Fume Hoods and Extraction Fans removing toxic fumes (Heavy metals, etc.)
• Pharmaceutical applications such as Cytotoxic drugs, high-potency or active ingredient manufacturing & packaging, etc.
• Hospital Air Isolation Rooms (AIR’s), and other negative pressure procedural suites such as Brachytherapy, Endoscopy are performed, but the air cannot be exhausted without possible re-entrainment.
• Cyclotrons require specialty BIBO filter systems with HEGA filters