Prep your plant for spring successfully

Spring is nearly upon us.

In colder climates, the snow is hopefully melting, temperatures are slowly rising and the sun is maybe making more frequent appearances. For those who shut operations down, all of this means it’s time to ramp plants back up for the long production season ahead.

Allen Snavely knows this seasonal ritual full well. As Kemper Equipment’s senior field service specialist, Snavely regularly participates in the installation of crushers, screens and conveyors. But whether a plant is going online for the first time or the last, Snavely suggests producers approach all start-ups as brand-new installations.

To Snavely, this means checking a variety of things.

“If you’re adding equipment, check the electrical,” he says. “Check rotations, verify your interlocking system and make sure if a belt shuts off everything behind it shuts down.”

The list of items producers should check before starting production is numerous and, depending on who you ask, certain checks rank as higher priorities than others. The best way to ensure everything is vetted before a seasonal start-up, then, is to come up with an effective plan.

“A successful spring start-up begins with good planning,” says Dale Mclean, regional product line manager of crushers at FLSmidth. “If you have good planning and procedures in place – and a maintenance team that is well trained and understands each procedure thoroughly – that will help with the overall positive results of a spring start-up.”

Still, even the most thoughtful plans require time to execute.

“We’ll go in three weeks ahead of time and scour the entire plant,” says Jim Levy, vice president and general manager of crushing and service operations at Mellott Company. “If you need parts, it gives you the time to order them. I’ve seen start-ups supposed to start so many times on March 1. Before you know it, you’ve spent a couple of days addressing this and that, and March 1 becomes March 15.”

Preparing a plant for a start-up is not necessarily a one-person job, either.

“I would say you would have six to eight guys walking around the plant checking on things,” Snavely says.

Considerations

The freeze and thaw effect can impact a plant in a number of ways. With this in mind, Levy will automatically look for frozen material that has the potential to thaw and cause damage – including material hung up in bins and underneath screen decks.

“Look at any area where material could accumulate and thaw,” Levy says. “That could lead to stalled belts.”

The freeze and thaw can also affect how level a plant is heading into spring – particularly a portable one.

“As snow melts, you may lose some level on your crushers just based upon settling on the cribbing,” Levy says. “It’s always good to check the tightness of cribbing blocks.”

Additionally, the freeze and thaw can change the environment around a plant. Inspect roads and highwalls to ensure employees aren’t put in danger.

“If you have some breakback on the top of your highwall, water gets down in there and freezes and thaws,” Levy says. “You’ll see sloughing in the spring, with huge chunks of material sloughing off the highwall. It just shears right off.

Levy also advises checking that berms are at the proper distance at the base of the highwall.

Crushing

Of course, no spring start-up can be successful without a detailed inspection of the processing plant. This includes all crushers.

“The big thing for crushers is fluids and viscosity,” says Mark Oviatt, president of Kimball Equipment.

Levy agrees, noting that condensation in crusher oils can become an issue from a plant sitting over the winter.

“It’s a good idea to change the oil when starting in the spring so there’s no water or condensation built up,” he says. “Make sure you have the proper oil in. You’ll want to check your manufacturer’s recommendations for the temperatures you’re going to be experiencing to avoid any premature failures related to oils and lubrications.”

Checking electrical connections tied to crushers is another item on Levy’s list of things to do.

“The pothead on your electric motors can draw condensation through the winter,” Levy says. “Once ice gets in there, it acts as a conductor. We’ve seen where we lost electric motors.”

Condensation can become extra worrisome with track-mounted plants.

“After [a track plant] sat over the winter, we went to start the machine,” Levy says. “Ice and water had actually gotten into one of the plug connectors in the unit itself. It instantly started tracking the moment we went to turn on the machine. That was something no one ever gave a thought to. We turned the key, and it started going.”

Other start-up issues can surface with electrical systems, too.

“A lot of crushers have their own enclosed electrical panel that may not be inside an enclosed MCC (motor control center) building,” Levy says. “That could even contribute to the loosening of the electrical connections in there. Maybe your wires are expanding or contracting a bit. That loosens the connection. You can obviously blow the motor up and have intermittent shutdowns.”

Screening

Checking screens is another worthwhile step to take ahead of start-up.

“We have a couple of customers who check the screen decks when they shut down during the winter,” Oviatt says. “They’re always subject to cracking – the beams and cross braces and main decks that hold the screen cloth. You really need to put a guy in there with a flashlight.”

Conveying

Producers must also pay close attention to conveyors. According to Oviatt, conveyor downtime is the No. 1 reason plants are forced to shut down. Most downtime, he says, is attributed to components such as idlers, pulleys and bearings.

“In the spring that’s probably the place you would check first and be the most thorough with because there are lots of moving parts,” Oviatt says.

Jeff Poe, field engineering manager at PPI, illustrates what can happen when idlers freeze.

“If they freeze, the belt will just slide across them,” Poe says. “If it’s not addressed, you can wear a hole in the idler. Then, you get a sharp edge and it can shut your belt [down] if it’s not addressed in a reasonable amount of time. Depending on the type of material – say hard rock – you can have a hole worn in that idler in three to four days.”

Belt tracking issues can also emerge.

“In extreme cases, if you have idlers seize up or freeze up, you may not have enough horsepower to start the conveyor,” Poe says. “I’ve seen customers shut down a conveyor [after] an extended period of time passed. When they went to start it up, temperatures were still cold and freezing, and they didn’t have enough horsepower to start up.”

Takeaways

The list of spring start-up issues that can surface goes on, from guarding and greasing to cleanliness around the plant. So it’s imperative that producers develop a plan and carve out ample time to ensure a safe, efficient start to their production season.

“The last thing you want to have is a crusher or any piece of equipment go down when you’re mid-production,” Mclean says. “This is called an unplanned maintenance, which does nothing but cost money to a producer.”