Three More Challenges in Baghouse Maintenance
Challenge #1: Training Issues
Kevin said that in this opinion, the biggest challenge in baghouse maintenance is training issues and overall knowledge loss in the industry. Facilities will have personnel who have been maintaining the same baghouse system for 10 or 15 years, and once those people retire, they are either not replaced or they don’t have time to thoroughly train their replacements.
“What we’re seeing is a lot of knowledge about how this system is supposed to operate getting lost,” he said. “That’s not the fault of anyone in particular. But the baghouse system and the dust collection system in general are usually not the priority. The production equipment is always the priority for maintenance people because that’s where they make their money. That’s where the company makes their money.”
When experienced employees retire or leave, companies will often outsource their baghouse maintenance needs to companies that excel at general maintenance but have little knowledge about dust collection equipment.
He used an analogy learned from baghouse specialist and Airdusco colleague Chris Falleur. “The baghouse is the lungs of a dust collection system. If your lungs are clogged up, you’re not breathing. If the filters are clogged, the system isn’t breathing.”
Kevin presented an example of a pneumatic conveying system that was transferring to a filter receiver, which is basically a bag house. The customer was having problems with the line clogging close to the inlet point where an airlock was dropping into the system. They took it apart a dozen times, cleaned it out, and were convinced that their airlock was feeding too much.
When the Airdusco team examined the filter receiver, they discovered that at some point, someone had left the door open on the unit. The filters had gotten wet and become completely clogged, so there was nowhere for the air to go.
“They weren’t thinking about the way that system operated,” Kevin said. “Their training had fallen down in (that area), so they were looking in the wrong place to find a solution. We were able to help them with that.”
He recommended that once a year or at least every two years, facilities bring in an outside company to work with their maintenance people for a week. These hands-on sessions, which are essentially technical briefings, will keep company personnel up to date on how the system works and how to spot issues before they become major problems.
Kevin also recommended that facility owners regularly do baseline assessments of their baghouse systems to compare current operation to original parameters. “If you know what your starting point is and know what the original design was, you can get it back to that point and then maintain it better.”
Challenge #2: Production Takes Priority
With production receiving the most attention, other operations are often neglected until major problems arise, such as the baghouse bags being completely plugged or a bearing going out on a fan.
Kevin recommended that at least once a day, someone pay close attention to baghouse operation. For example, if they look at the differential pressure gauge and see that nearly every day, it’s running and around one and a half inches and then starts easing up towards two inches, they will know that their bags are becoming impinged and need to be changed.
“They don’t have to wait until they’re in the middle of production and all of a sudden, the bags have gone from four and a half inches to 10 inches because they’re completely impinged and they have to shut down production.”
Challenge #3: Cheap Replacement Parts
For Kevin, the third biggest challenge associated with baghouse maintenance was opting for cheap replacement parts.
In most cases, a specific bag material or design is required for a given system. It may be more expensive than a common 16-oz polyester bag, but managers are either unaware of what the original design called for or prefer to buy strictly on price. As a result, they install the wrong filter or part, a decision that can easily cost them more money.
He recalled a case that colleague Chris Falleur at Airdusco had to deal with. One company had three large filters with over 1200 bags in each of them. These bags had to be changed quarterly because the material being processed was hot, abrasive, and involved noxious gases, and the ultimate cost was about a quarter of a million dollars per bag change for the three filters, which added up to one million dollars a year.
“Chris was experimenting with other bags. He finally found one that was much more expensive than the bags they were originally using, but (it) would actually work, do the right job, have the proper filtration. And they went from changing quarterly to changing every five years. So even though the bag was much more expensive, he basically saved them five million dollars over that same time period in bag changes.”
“It can take some time, some money and some effort to maintain a dust collection system,” Kevin said. “But that time, money and effort is well spent because it’s far more expensive and dangerous to neglect it when you’re dealing with combustible dust. You want to make sure that your main mitigation, which is normally your dust collection system, is operating to the best of its ability.”