They are high efficiency filters composed of a series of pockets through which the air to be treated passes. These pockets are made in synthetic media and are properly clamped to a support frame, available also in plastic material. Strong seams or edge weldings ensure the good seal of pockets. The property of these filters is the high filtering surface (proportional to the depth of the bags and their number).
The version with the support frame made of plastic, besides ensuring a perfect seal between the filter media and frame, facilitates the disposal of filters after their use (incinerable).
APPLICATIONS
They are used either as final filters or as pre filters to absolute filters for air treatment units and ventilation plants. These filters are particularly well suited for application (like food processing and pharmaceutical production) where use of fiberglass media may be restricted.
FEATURES
Synthetic media offers lower resistance than fiberglass at the same air flow rate. The following table shows the filtration class according to EN 779:2012 Standards for the available types and the nominal capacities with the pertaining initial resistance for some standard sizes.
| Front dimensions and depth | Number of pockets | capacity [m3/h] | initial pressure drop | |||
| SH65 | SH85 | SH95 | SH99 | |||
| 592 x 592 x 535 | 8 | 3000 | 90 Pa | 110 Pa | 140 Pa | 160 Pa |
| 592 x 592 x 635 | 3600 | |||||
| 592 x 592 x 735 | 3800 | |||||
| 592 x 592 x 915 | 4250 | |||||
| filtration class according to EN 779 | M6 | F7 | F8 | F9 | ||
Capacities comprised between the 75% and the 125% of the mentioned ones are allowed for a good working of filters. Approximately it is possible to consider, inside this range, a linear correspondence between resistance and capacity. The limit working temperature is of 90°C approx.
Filters with different number of pockets, different frontal and/or depth dimensions are available.
INSTALLATION & SERVICE
It is advisable to foresee a pre-filtration stage before these filters. The LOM-BAG filters can be installed into proper holding frames having frontal access and usually designed to fit any possible pre-filters. It is advisable to replace these filters once having reached a resistance of 300÷350 Pa.