The 5/8" minus material was sorted by a Cedarapids- ElJay 7'x20' triple deck sizing screen. Final product from the finishing stage includes 3/8" chip, 5/8" chip and 3/8" minus.

Plant Upgrade Increases Efficiency

When Meridian and Cedarapids first looked at the plant's flow diagram, the assumption was the site was not producing high enough levels due to a bottleneck in the tertiary finishing stage.

"Upon closer examination, both the manufacturer and customer decided the solution to eliminating the site's bottleneck was to rethink the secondary crushing stage instead of the tertiary circuit," commented Mark Krause, Director of Product Management for Cedarapids.

"After consulting closely with the customer, Cedarapids determined that replacing the secondary Rollercone Classic with a new Cedarapids/ElJay Rollercone MVP™ 450 Rollercone would be the solution to increasing plant efficiency," stated Krause.

Both Meridian and Cedarapids agreed it was more economical to replace the secondary than the two cones and screen in the tertiary circuit.

Economical Solution

The secondary cone's foundation was used for the MVP450, reducing installation time and cost. The MVP was simply dropped into the circuit on the existing foundation.

Easily handling the large feed material from the 4248 jaw primary, the MVP450 gave Meridian significantly greater crushing efficiency at the secondary stage, thereby increasing the plant's ability to produce final product as required by customers.

Brad Ward, Northwest Regional Assistant Manager for Meridian stated, "With any arrangement other than using the Rollercone MVP, we would have had to double our investment to achieve the same results. The MVP450 gives us more finished product on the first pass. With the old layout we could only yield around 200 tph, but with the MVP450 we're at 350-375 tph of 5/8" minus finished product."

Another cost saving advantage to the Rollercone MVP is the new cone's automatic closed side setting (CSS) adjustment capability. The MVP offers on the fly adjustment.

Ward commented, "Before the installation, if we wanted to change the CSS to produce a different product, we had to shut the plant down. Now, with auto-adjust, we run the MVP choke fed, make the setting change on the fly and have zero lost production time."

Ongoing Support

Even after the MVP450's initial installation, Meridian continued to work with Cedarapids and Balzer Pacific Equipment, Cedarapids' dealer for the Pacific Northwest, fine tuning the operation.

According to Ward, "Balzer Pacific and Cedarapids have been excellent with applications support and fine tuning our operation. Concerns were addressed immediately."

With continued support from both manufacturer and local dealer, a modified liner for the MVP450 was designed and installed that further increased the unit's output by 25 percent.

The modified cone liner gave the MVP a reduction ratio of 10:1 compared to the 6:1 ratio of the previous Rollercone Classic. This has significantly saved on liner wear costs of the two tertiary cone crushers and helped increase plant uptime by reducing maintenance.

Meridian's Granite Falls Quarry Operation is an excellent example of how the application of new technology, along with looking at an application problem in a different way, was the most effective final solution. The MVP450 proved to be the economical and simple means of improving the plant's efficiency and output capabilities at the same time.