McLanahan Ships Second Largest Rotary Wet Screen to Repeat Oil Sands Customer
McLanahan has shipped its second largest Rotary Wet Screen to an oil sands customer in Canada.
For this project, McLanahan replaced the structural components of the Rotary Wet Screen, providing two drum ends – a feed end and a discharge end – and a screen section made up of eight separate screen panels.
The screen section is made up of eight separate panels.
The inside diameter of the Rotary Wet Screen is 16 feet, and the screening section measures 48 feet long. Just the structural portion, without the liners, lifters and plows, weighs nearly 250 tons.
Once fully assembled on-site, the Rotary Screen will measure approximately 70 feet long and weigh close to 400 tons.
Approximately 9,000 pounds of weld wire was used to fabricate the Rotary Wet Screen.
“My favorite part of this project is the sheer size of this machine,” said Tyler Piper, Assistant Director of Engineering for Dry Processing at McLanahan. “When it’s on the computer, you don’t quite get a grasp of how big it actually is, and then when you see it out on the shop floor, it’s quite impressive.”
The drum end as seen through the screening section.
Not only is it the second largest Rotary Screen, it is also the second largest machine McLanahan has ever built. The largest was a 16x60 Rotary Wet Screen for the same customer in 2012.
How Rotary Screens work
Rotary Wet Screens break down and separate a wide range of materials. This particular screen will process oils sands, a mixture of bitumen, sand and water, but rotary equipment can process everything from aggregates and limestone to phosphates and iron ore.
“You name it, we can process it,” said Piper.
Driven by a gear and pinion that spins the entire unit, the Rotary Screen lifts and drops the material until it is small enough to fall through the screen openings. The reject material discharges out the end of the drum.
“The benefits of Rotary Wet Screen are twofold,” Piper said. “One, they are able to break down the material into a pumpable product that goes on for further processing, and two, they’re able to separate any of the bad material and put that into the reject pile.”
Rotary Screens in oil sands
This Rotary Wet Screen was designed to process a nominal 6,000 tons per hour of oil sands and can handle surges up to 8,000 tph. Using a combination of hot process water and the drum’s rotation, the screen breaks down and separates the bitumen from the sands for further processing, which involves heating the bitumen, removing excess carbon and condensing the vapor.
The final product is synthetic crude oil, which can be further refined into gasoline, jet fuels and other petroleum-based products.
Continuous improvement benefits the customer
McLanahan is continuously improving its equipment, and customer feedback plays a large role in those design changes.
“When we’re designing a machine, we’re always looking at ways to improve the design. A lot of those improvements come from customer feedback,” Piper shared. “We always try to implement what’s feasible, and when we’re able to do that, we’re providing our customers with a better product and making our future products better.”
Because Rotary Screens can be so massive, McLanahan had to build a furnace (shown partially assembled on the right) in its shop to heat-treat the drums.
Product improvements with this project included changes in weld design to help protect the cylinder and changes in the mating flanges to help the cylinder go together more efficiently.
Piper said, “We’ll take things we learn from this project, what we’ve learned from the customer, and try to implement that across all lines or rotary equipment.”
Ultimately, continuous improvement ensures McLanahan customers get the best product with the most reliability and maximum availability.
After-sales service and support
Further ensuring product reliability and availability, McLanahan provides after-sales service and support for the life of its machines.
Sections of the Rotary Wet Screen are welded together.
“We’re always only one phone call away to help our customers,” Piper said.
Demonstrating the size of the Rotary Wet Screen, part of the team that worked on it stands in front of the assembled screening sections.