Baghouse Maintenance - Focus Where it Counts
Many maintenance and engineering teams assume that baghouse dust collectors require substantial amounts of maintenance in order to function properly. Since many plants maintain legacy systems they often “settle” for letting the unit run poorly as they feel its not worth it to invest the time and resources to optimize an older collector. That's a common but dangerous assumption as most industrial dust collectors, even older ones, require only minimal investment in key parts and operational practices in order to bring them up to acceptable condition. In contrast, failure to maintain these systems often results in excessive downtime and lost productivity - plus the well understood potential for costly health/safety and environmental violations.
Rather than just lecture about maintenance, though, let’s consider 3 of the most overlooked maintenance tasks for baghouses and how they can make a real difference with only minimal resources.
- Accurate DP Readings
- Functional Pulse Jet System
- Replace Bags When Blinded
#1 - Keep Differential Pressure Readings Accurate
Differential pressure has been called the principal metric for baghouse operation. It's a core metric that maintenance and operation teams should consider before making any decision. For this reason, accurate differential pressure readings are crucial. Maintenance technicians need to carry out the small, but vital PM task of blowing out the airlines that run to the differential pressure sensors monthly, or even weekly, in order to keep the DP readings accurate. This is because dust will regularly buildup on these air taps inside the unit negatively affecting the DP readings or even damaging the sensor itself. If at any point the DP readings become suspect (e.g. abnormally low DP below 1”) then techs can take additional steps to troubleshoot differential pressure readings in order to return them to accuracy.
#2 - Keep Pulse Jet System in Good Condition
The heart of every fabric dust collector is its cleaning system. For pulse jet baghouses, this system allows for high air to cloth ratios and highly efficient operation. But it comes at a price. The pulse jet cleaning system has several key components that must be carefully maintained in order to achieve these benefits. Be sure to keep each pulse valve in good working order to ensure efficient cleaning, as well as maintaining a supply of clean, dry compressed air. This requires occasional replacement of the internal diaphragms within each pulse valve as well as treatment of the compressed air to remove moisture, oil and dirt.
#3 - Replace Bags As Entire Set When Blinded
Many facilities only replace individual bags when they actually fail and develop a leak (i.e. failure from damage to the bag, or manufacturing defect). Some feel this is more cost-effective than replacing entire sets of filters. However, the only “putting out fires” approach results in much higher costs overall, as it leads to constant downtime, higher emissions and even more premature failure of nearby bags which become worn by escaping dust. A good strategy is to manage entire sets of filters and change them when appropriate. Of course, occasional early failures of individual bags are unavoidable. But spot changing more than 5%-10% of the total bags requires the entire set to be changed or else drastically increased failure rates will be seen.
An even better strategy is to predict and preempt failure. The sensitivity of triboelectric detectors allows early warning of gradually deteriorating performance - often well in advance of the failure. Instruments installed strategically can help to identify the imminent failure down to the compartment - or even the row. (This also facilitates rapid leak location in case of a failure.) Doing so allows for a brief scheduled downtime to identify the potential leaker and change it before it ruptures and results in damage to nearby bags.
Plants should carefully monitor the failure rates of individual bags, operating differential pressure as well as emissions to determine when filters have become blinded or reached their maximum usable service life. Auburn's TRIBO series of detectors, for example, enable this sort of predictive monitoring.
While this strategy may involve more upfront costs in replacement filters, in the long run it is guaranteed to result in less production loss through increased reliability and lower overall emissions and lower operating costs.
Would you like to learn more about how compartment level particulate monitoring can streamline baghouse maintenance? Request a free 30 minute consult and one of Auburn's technical engineers would be happy to speak with you!