DSS105: Safety Share - Failed Testing of High-Speed Abort Gates with Corey Gardiner

In today’s episode, Corey Gardiner, Manager of Asset Protection at Tolko Industries based out of Vernon, British Columbia, does a safety share on a failed testing of a high-speed abort gate. This share, which was submitted through the Wood Pellet Association of Canada and distributed by the BC Forest Safety Council, involves the testing of abort gates that didn’t work correctly under normal operating conditions.

The facilities involved were board plants equipped with dust collection devices and vessels. These systems were configured with spark detection equipment, which uses a water-based system to extinguish any sparks. If an event bypasses this safeguard, the second zone automatically operates a high speed abort gate that will eject burning material from the process prior to it hitting the bag house or the cyclone.

Two Tests, Same Problem

With two incidents covered in the safety share, Corey and his team were doing routine testing and a commissioning. They found that the gate wouldn’t close when the fans were in operation.

“There wasn’t enough pressure to actually drop the lip of the gate into the airstream to allow it to slam shut,” he says. “These happened a couple of weeks from each other and one of them was a brand new abort gate that was being tested for commissioning purposes. It was one of those problems you wouldn’t necessarily know unless you were testing with the fan in operation to determine if it was actually going to function or not.”

Upon investigation, they found that the force of the fan wouldn’t allow the gate to drop. When the system was tested with everything down, the gate would function normally, but when it was tested with the fan in operation, the velocity wouldn’t allow the lip to catch. After adjustments were made, retesting was done but the abort gates still wouldn’t operate properly.

“That’s when we had to start looking at other engineering solutions like getting some preloader helper springs,” Corey says. “It’ll normally have an adjustment, so you can adjust the spring tension. In this case, these things were maxed out and it still didn’t have enough force to overcome the force of the fan when there was no operation. So that’s when we had to take it to that next level and actually get these preloaded helper springs.”

A vendor was involved with the testing. When they realized that the device was not functioning properly, they confirmed that the actual gate function was fine, there was no material build-up to prevent the magnet from releasing, and that everything else was within spec. However, the lip wouldn’t drop into the airstream, so helper springs were added. The problem was later diagnosed as high negative static pressure within the ductwork when the fan was in operation.

Lessons Learned and Changes Made

Corey issued a hazard alert across the company, which called for all team members to test the abort gates at their facilities with a fan in operation to confirm that the problem wasn’t widespread. He also developed a corporate standard for the critical controls in dust collection systems, which outlined all inspection testing and maintenance procedures needed to meet NFPA and OEM requirements.

“I’ve got a third-party vendor that’s developing a companion training video on all these specifics just to make sure that all of our maintenance personnel are fully testing and inspecting these components as per (these) requirements,” he adds.

Conclusion

Corey recommends that all facility operators understand how their life safety devices operate as part of a system.

“There’s a bunch of interconnectivity,” he says. “So I feel it’s important for operators to understand how they’ll all interact and respond during a shutdown. A good example is an interlock to shut fans down or to leave them running. That should be thoroughly assessed to determine what the hazard is and which way to go, because there are two different routes you can go: to leave it either running or shut it off.

“Same as something like a rotary airlock: you’d want to ensure that if you’re having any sort of emergency shutdown, that rotary airlock stops as well. Sometimes in industry, they get viewed more as a material handling device versus an actual explosion choke. So that’s an important one to look at as well: how everything is interconnected and to do tests to see how they’ll respond when you hit an e-stop or have something go on.”

If you would like to discuss further, leave your thoughts in the comments section below. You can also reach Corey Gardiner directly:

Email: [email protected]

LinkedIn: https://www.linkedin.com/in/corey-gardiner-b649846b/

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