While not cleaning your baghouse filter is bad, cleaning your filters too much isn’t a very good idea either. If you don’t clean your filters enough, dust will build up on them faster and they will plug up faster; however, cleaning them too much can cause issues too.
Filters are cleaned by blowing compressed air into the filter. If the filter is a bag (in a baghouse) then the filter has a metal cage for support. The compressed air expands the bag slightly moving it away from the cage. This dislodges the top layer of dust on the filters allowing that dust to fall into the hopper below. If the filters are cartridges, the support is an integral plastic housing. The compress air still expands the filters, dislodging the top layer of dust.
Every time the filter is expanded it is wearing out. Over time, a hole can develop and expand enough to let dirty air through the filter. Or the filter can get caught up on the cage and rip, thereby bypassing the filter.
The best way to minimize this issue is to only clean when required. Manual or adjustable timers can be used, but without constant monitoring, they will either clean too often or not enough. A clean on demand controller is best for a baghouse. It uses a differential pressure transmitter to monitor the pressure drop across the filters. When the pressure drop is high enough, it will initiate cleaning until the pressure drop is lowered below a certain level. Depending on the model of controller you have, you can also monitor the unit for broken bags and inoperative air valves. The other benefit is that by cleaning only when required, you are saving on compressed air usage.
The main drawback of clean on demand controllers is when the bags are plugging up, you begin cleaning more often. And if you are not properly monitoring the situation, they will begin continuously cleaning. This happens when the bags are plugged up and no matter how much cleaning the pressure drop will not fall below the shut off pressure.
So when picking out your dust collector controller, remember that you don’t want to clean your bags too much, but you don’t want to under clean them too.
Enjoy this video from The Dust Efficiency Clinic at Aerodyne:
Five Signs Your Dust Collection System Needs Maintenance