They are high efficiency filters composed of a series of pockets through which the air to be treated passes. These pockets are made in glass microfibers media supported on the air outlet side by a nonwoven covering, and are properly clamped to a support frame. Strong seams 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).
APPLICATIONS
They are used in air treatment units and ventilation plants either as final filters or as pre-filters to absolute filters in order to make their life longer.
FEATURES
Four different type are available: VH45, VH65, VH85 and VH95. The following table shows the filtration class according to EN 779:2012 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 | |||
| VH45 | VH65 | VH85 | VH95 | |||
| 592 x 592 x 535 | 10 | 3400 | 70 Pa | 80 Pa | 100 Pa | 130 Pa |
| 592 x 592 x 635 | 4000 | |||||
| 592 x 592 x 735 | 4500 | |||||
| 592 x 592 x 915 | 5000 | |||||
| filtration class according to EN 779:2012 | M5 | M6 | F7 | F8 | ||
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 250÷300 Pa.