Testing a new screening system amid intense market pressures

Editor’s Note: This is the second part of a story that began in last month’s issue of Pit & Quarry about sand-and-gravel producer Nels Ostero Ltd. in Taylor, British Columbia, Canada. The first installment discussed Nels Ostero’s need to beef up screening efficiency and the first stages of working with W.S. Tyler to implement its Pro-Deck approach to screen media optimization.

Nels Ostero, an aggregate operation near Taylor, British Columbia, Canada, had a problem. Development of the oil and natural gas fields of the Peace River Region in northeastern British Columbia was moving quickly, and demand for aggregates was skyrocketing.

While that sounds like an opportunity – and it was – Nels Ostero was unable to capitalize because it was burning through screens too quickly.

The company’s crews had to change out screen media – on the feed end of the washing screens in particular – up to four or five times per year per machine. It was taking too much time, and time was money. Add in lost revenue due to customers going to other suppliers to get aggregates more quickly, and Nils Ostero, the operation’s manager, knew he needed to act.

The approach to Pro-Deck
Markus Kopper, Haver & Tyler’s general manager at the company’s British Columbia service center, visited Nels Ostero in August 2013 to inspect the site’s vibrating machines and put W.S. Tyler’s Pro-Deck approach to work. The company’s approach revolves around finding an ideal combination of media on a screen deck to maximize its efficiency.

Ostero told Kopper that he especially hoped to curb the maintenance required on his two washing screens. Dubbed the “East” and “West” screens, they demanded the most maintenance of any equipment on site, cost over $15,000 per screen to change out, and soaked up two 11-hour shifts for several employees. Plus, the entire plant needed to shut down during the repair. At a rate of $17 to $26 per metric ton of saleable drainage gravel and concrete sand, the lost production was alarming.

After a full inspection of each vibrating machine, the W.S. Tyler expert and his team completed a Pro-Deck efficiency report and offered recommendations for screen media changes. Although Ostero originally intended to implement the manufacturer’s recommendations only on the East screen so he could compare the wear on the two screens, he opted to install the recommended media on both right away.

Ostero swapped out the majority of the screen media on the washing screens with Ty-Max at the feed end, followed by Ty-Wire and then Cobra Vibe at the discharge end.

Ty-Max consists of specially formulated polyurethane developed for optimum wear resistance to minimize change-outs and maximize productivity – exactly what Nels Ostero needed. Because this meant reducing the open area to get a larger impact surface, Kopper recommended screen media on the remainder of the deck that would balance open area to successfully complete the sizing of materials.

Ty-Wire, a blend of polyurethane and wire cloth, provides better wear life than wire cloth while allowing for more open area. Cobra Vibe self-cleaning screens provide maximum open area while preventing blinding or pegging.

Putting it to the test
The Nels Ostero operation started its season with the Pro-Deck system in mid-April. In just a few months, Nilson Ostero is already delighted with the modifications and relieved the operation is better able to keep up with constantly growing demand.

He reports downtime for screen change-outs has been cut in half. Since the screens are specifically designed for the portion of the vibrating screen deck on which they are placed, they last longer. For example, the placement of Ty-Max at the feed end is ideal because it’s designed for areas with high impact. Nilson Ostero predicts the Ty-Max will last a couple of seasons.

Although the specialized screens cost more upfront than the system the company had been using previously, Ostero says the payback makes the decision a no-brainer.

“We’ve found it’s worth the cost,” he says. “These screens allow more plant uptime, so they pay for themselves in just the first few months of operation. And the longevity is phenomenal. We’ve already sliced our downtime and maintenance in half.”

Ostero says even after several months of operation, the screens are still holding strong. He projects that, with the Pro-Deck system in place, they will reach at least twice the life of the previous system. As an added, unexpected bonus, Nels Ostero has decreased its water consumption on the screens due to the switch to Cobra Vibe, which is the most flexible screen media on the market. This self-cleaning design reduces blinding and pegging and ensures the screen stays clean, which, in Ostero’s case, reduced the water needed to clean material from its washing units.

On top of the screen longevity and boost in efficiency, Ostero has been thrilled to see his biggest fear – loss in production – dissolve with the fines. While Ty-Max reduced open area on the feed end, the Cobra Vibe provided more open area at the discharge end. This blended solution gave Ostero the optimal combination of open area, durability and productivity. So as it’s turned out, Ostero says, his greatest fear going in has actually been the most impressive improvement.

“Usually, when switching to a more durable screen, the open area decreases and production is lost,” he says. “But the Ty-Max is holding strong at the feed end, which has reduced change-outs and actually helps us maximize productivity.”

Ostero says Kopper’s performance improvement predictions have been right on.

Take note
Ostero swapped out the majority of the screen media on the washing screens with Ty-Max at the feed end, followed by Ty-Wire and then Cobra Vibe at the discharge end.

Laura Stoneburner is a writer and public relations specialist at Ironclad Marketing, Fargo, N.D.