When you calculate the life expectancy of filters, there are multiple environmental factors that play a role into the final answer. In some instances, filter bags end up failing prematurely. In this article, we discuss the top 3 reasons filters fail too soon and how to avoid them.
When calculating the life expectancy of your filters, there are multiple environmental factors that come in to play. Filters can last anywhere from a few weeks up to 5 years or more, but it really varies. The top factors that can influence filter life are:
- Volume of dust loading
- Air to cloth ratio
- Filter fit and installation
- Dust characteristics
But what if your filter bags fail sooner than expected? Here are a few reasons they may be failing prematurely.
- Dust Characteristics
- Poor Fit & Installation
- Undersized Dust Collector
Standard dust collection systems are designed for dry dust environments. If you have over 20 percent of moisture or oils in your process (e.g., working with fertilizers or concrete) you may need to consider a different type of filtration system. If you continue to operate with uncontrolled moisture, the physical properties of your dust may change due to the increase in water content. Certain types of dust can then become sticky or heavy which would cause your dust cake to build quickly, affect the ability of dust to fall off during cleaning and thereby creating a scenario where your filter bags fail prematurely. An excess of moisture can also cause excessive dust build-up in your duct work, rotary valve, and inside the dust collector’s walls. Common industries that deal with moisture are:
Industries with Moisture
When considering how abrasive your dust can be, consider the hardness of the material being filtered along with the shape. If material is abrasive, a filter bag media with the ability to resist the additional wear and tear is generally recommended. Different types of filter media more resistant to abrasive dust are:
Filter Bag Media Used with Abrasive Dust
- Aramid (Nomex)
The velocity of your airflow can also make your dust more abrasive. Highly abrasive dust may require your housing to be fabricated in stainless steel, titanium or other costly materials that are able to withstand long term wear.
Filter Bag Fit & Installation
Filter Bag Fit
To help give your filter bags better life expectancy, make certain to have the proper bag to cage fit. Filter bags with the correct flex allows the precise amount of momentum to happen when the filters hit the cage. Filter bags with insufficient flex are too rigid and can prevent dust build-up from properly falling off during the cleaning process. The general recommendation is to have between 1/4″ to no more than 3/8″ pinch on your filter bag on each side of the cage. Filter bag media with sensitive bag to cage fit are:
Sensitive Bag to Cage Fit
If you have filter bags with the following medias, also consider oversizing your filters due shrinkage that can occur in temperatures above 450 Degrees F.
Sensitive to Shrinkage
Filter Bag Installation
Proper installation of filter bags allows for optimal dust handling and cleaning efficiency. When it comes to filter bag installation, common errors to watch out for are:
- Top Load –The groove between the double beaded snap band should be set into the cell plate. For a video tutorial on the proper way to install this type of filter bag, visit this guide here.
- Bottom Load – Raw top bags should be folded over the cage with enough material to allow for proper and tight clamp placement.
Undersized Dust Collector for CFM
A couple of the biggest problems we see people run into with an inappropriately sized dust collector are:
- Consistently clogged filters
- Reduced filter life
- Higher maintenance costs
To avoid the dangers of an undersized dust collector, consider both CFM and Air to Cloth Ratio. For example, if you have an air to cloth ratio that is too high, the dust you are trying to collect embeds into the filters too fast for your system to efficiently pulse. You end up with rapid build-up of dust, which ends up clogging your filters and making your dust collector work even harder than it should be.
Prevention is the best method for avoiding filter bags failing prematurely and total dust management. Achieving longer filter bag life means the design of your dust collection system should be correct for your specific application from the very beginning.
At U.S. Air Filtration our specialists are available to help with the design of your dust collection system. Or if your filter bags fail continuously, we can help guide you to the right solutions. For assistance now, contact us at 888-221-0312 or email [email protected].