Save Time, Money on Slats
BY A.J. Ronyak
Let’s say the ground man walked around the plant this morning and came back with a bad report on the slat conveyor. He can tell if you start up with it “as is” this spring, it’ll run heavy to the right or left or whathaveyou. There’s an easy, time-efficient way to maintain the slat conveyor to keep it running longer than the original equipment manufacturer’s (OEM) suggested life, and taking care of it during the off-season is the first step. Let’s look at the basics.
Take Care of the Routine
First, pay close attention to the parts that typically show the most wear. Watch the head and tail bearings. Watch the head and tail sprocket. Watch the chain, the floor and the slats. It’s wise to have replacement parts for these items in stock. In the event that you get into construction season with the slat running heavy to one side and you determine you have a worn bearing, you can replace it in 15 or 20 minutes at the end of the day if you have the part in stock. Otherwise, you’ll be running inefficiently and causing damage to other components of the conveyor while you wait for the bearing to come in.
Also watch the conveyor for running heavy to one side. Let’s say your ground man discovers the chain is running heavy to the side but the sprockets are perfectly aligned. That tells you the discharge chute is causing the problem. It’s causing the mix to hit and slide the conveyor incorrectly. To solve this problem, you can realign the chute with the conveyor, or you can put in a diversion chute to force the mix to hit dead center. Adjust the flow of the asphalt by welding in a heavy impact, AR plate in the chute.
In addition to daily walk-arounds, open up the slat once a month and look at the components. Watch where the sprocket makes contact with the chain. Excessive cupping here can do more wear to a chain. By repairing these items as needed, you save components from harming other components. Also at this once-a-month inspection, check on the head and tail shafts. Take a good look at the chain. Everybody sells chain, but I always bought my chain through Dillman Equipment. I recommend always keeping a rex chain and sprocket components on hand for this monthly checkup, as well as other maintenance checks.
Make a Four-Year Plan
At some point, you have to do full-blown restoration to the slat conveyor system. It’s obvious when it’s time to replace it, and that’s when you want to bring in a steel specialist and have him manufacture a floor—or more—with a harder steel. He’ll take a floor sample with the bolt pattern and come back with a new floor. While this sounds expensive at first, you’ll get an additional 285,000 to 500,000 tons per year out of the improved components. It’s worth spending a few extra dollars up front to keep from repeating the larger maintenance project next year.
First, I’ve replaced floors with the slat upright and it’s not easy. But you have to figure out if you have room to get the assembly out of there and on the ground. Once you’re done with it, hire a crane to lift it back in place. But while it’s down, make sure you make good use of the opportunity to replace and improve parts.
If we’re going to take down a 500 ton per hour slat, I’ll improve parts, hardface the slats before I put it back up. With hardfacing, you have material running on a secondary surface and you extend the slat conveyor’s life a couple years. You have to spend a little extra money to get the longevity, but I’d sure rather replace my slat conveyor once every four years instead of every two years.
For the hardfacing, I’ll have a metal specialty company copy all the slats and the floor and any hard plating. For projects where I’ve done this before, these surfaces ended up lasting more than a third longer than the OEM’s prediction. Usually you’ve got a heated floor, so you’ll purchase the heat strips from the OEM regardless of how you hardface the other components. If you can deal locally, you save on shipping. These floors come in all different sizes, but you can literally have everything built with harder steel and get a couple hundred thousand extra tons of life from it.
A.J. Ronyak is the proprietor for Asphalt Solutions, Cape Coral, Florida. He offers consulting services in addition to his asphalt additive. For more information, contact him at (623) 853-2273 or email@example.com.