In this post, Jeremy Vaughn, Senior Parts Manager at ProcessBarron’s precipitator parts warehouse, outlines the information needed to create a checklist and schedule for routine electrostatic precipitator inspections conducted by plant staff.
More than a thousand electrostatic precipitators (ESPs) were built in the decades following the Clean Air Act of 1970. This equipment is aging, but there are steps you can take to prolong the life of your ESP. Annual inspections by ESP experts can identify major problems and prevent failures inside the unit. They also help your mill create a multi-year plan for proactive maintenance that can reduce long-term costs and improve reliability.
Mill personnel also play an essential role in monitoring day-to-day performance and catching potential problems at the first sign of trouble. In this post, I will help you create an inspection schedule and checklist that enables your team to identify and resolve problems before they cause a critical failure.
Inspect the Exterior of Your Unit
Start by inspecting the exterior of your ESP. You can tell a lot about how the precipitator operates by performing a visual inspection to look for any changes or signs that air and dust are escaping.
Walk Down the Rapper Deck
Performing daily or weekly walk-downs of the rapper deck is one of the most important things you can do to keep your electrostatic precipitator operating at a desirable level. First, put your rappers in “walk-down mode” to enable sequential firing. Then audibly verify that each is firing, marking them as they cycle through the program.
If you identify rappers that are not firing, check the programming or contact an ESP maintenance specialist at 800-226-3267 to investigate further.
Inspect the Penthouse Purge Air System
Inspect any fans, filters, and heating elements that provide warm purge air to your unit. Verify that all fans are running, filters are clean, and heating elements are operating at proper temperatures.
Check the Transformer Rectifier
The transformer rectifiers (TR) energize the interior frames of the unit. Check the readings and verify your TRs are operating at their full capability.
Sample the TR’s Insulating Oil
TRs use silicone fluid or mineral oil to insulate electrical components and keep the TR operating temperatures stable
Most mills don’t test this oil very often, and carbon can build up. This can cause an explosion that could destroy your TR. You could save approximately $20,000 to $45,000 it may cost to replace the TR by taking a sample for lab analysis. This is a straightforward way to anticipate problems in advance, but it’s a step that most plants miss.
Document Everything
Documentation is essential. Developing a plan for documentation performs 2 functions. First, it establishes your baseline so you can immediately spot changes in ESP performance that may indicate operational issues. Second, a good plan for documentation enables communications between teams. This prevents situations such as when an electrician is testing the oil, but he’s not talking to the maintenance planner who’s developing the maintenance schedule. This could create a planned outage that is then less efficient than it could be because of communication breakdowns. All of this can be avoided with a good documentation and communication plan.
When to Call the Experts
Some troubleshooting can be done over the phone, but we have an emergency repair team available 24/7/365 that will expeditiously come to you to keep your ESP up and running. Here are some red flags that indicate it’s time to involve an ESP maintenance expert.
Unexpected Readings on the TR
Take action when you see unexpected readings on your transformer rectifier controls. The TR is similar to a rev limiter in your vehicle. It goes full speed ahead and then backs off when it senses a spark or arc within the unit. So, if you see the TR sparking heavily, there’s probably something in the unit causing an issue. Keeping an eye on the control readouts is very important.
High Amp Draw on Drag Conveyor Motors
The drag system has many moving pieces, and observing the loads needed to convey the particulate can be helpful in assessing the conveyor system’s health. Drag bushings can wear out, or excessive build-up of damp or hard particulate can put extra strain on the drive motors. Either way, an ESP expert can help you develop the best plan for resolving the issue.
Problems in the Unit
Our team can assist with troubleshooting over the phone, and if that doesn’t solve the problem, we can put boots on the ground to see what’s happening. Depending on the issues you are experiencing, we look for options to keep your unit operational until more thorough repairs can be scheduled during your planned outage. If repairs in the unit can’t wait until your planned outage, a mini outage will take at least 2 to 4 days because of the time required to cool the precipitator down so that it can be repaired safely and then put it back into operation after repairs are completed.
Keeping Your ESP Operating Efficiently
Unplanned downtime can cost millions, so we recommend collaboration between plant staff conducting daily/weekly/monthly inspections and annual inspections by an ESP expert. This provides the information you need to develop a multi-year plan to make the most of your budget by strategically addressing maintenance and repairs during planned outages. Call us to see how we can help your plant enable smart, clean, and efficient production.