How automation boosted efficiency for an Oklahoma producer

Tulsa Rock Quarry is boosting plant uptime and crushing efficiency in a big way.

The 360-acre limestone operation is one of six locations owned by Tulsa, Oklahoma-based Anchor Stone Co., which has long provided much-needed, high-quality construction aggregate to its region.

Recently, Tulsa Rock replaced an older impact crusher with a new automated cone crusher at its secondary crushing circuit, and the result is a major gain in daily production capacities at lower costs per ton.

“We needed to get away from impact crushing and reduce our maintenance costs and power consumption,” says Mike Neal, processing engineer at Anchor Stone.

Neal stresses that one of the biggest challenges with impactors is having to keep an eye on the primary, constantly monitoring the feed that’s being sent to the secondary circuit.

“An impactor can easily plug, causing hours of downtime and potential damage to crusher components,” he says. “Previously, we had to open the impactor up every night and inspect it.”

With the new cone, Neal says costly maintenance downtime is eliminated.

“Quite simply, once you put a pen to it – figuring out what operating costs were before and what they are now – it makes a lot of sense to upgrade to an automated cone,” Neal says. “We’ve lowered our operating costs while improving our plant uptime significantly.”

Anchor Stone installed a P500 Patriot cone crusher manufactured by Superior Industries. According to Neal, the cone was selected for its innovative design, heavy-duty construction, ease of maintenance and the versatility and simplicity of its automation system.

Superior’s product engineering and in-house automation teams worked closely with Anchor Stone on-site to ensure the crushing circuit performed to exact specifications while increasing efficiency and safety, as well as reducing wear costs and recirculating loads.

“The support from Superior is excellent,” Neal says. “They’re  always there for us, and that’s all you can ask for.”

Next-level cone design

With the latest cone designs, Neal feels Anchor Stone experiences the benefits of having a new cone crusher in its plant.

The operation had previously avoided cones. One reason why: older-style units did not offer tramp relief.

“In prior years, a piece of metal stuck within the cone demanded the dangerous task of cutting it out with a torch,” Neal says.

According to Mike Schultz, crushing product manager at Superior Industries, the design of the Patriot cone and its automation ensures day-to-day reliability, preventing the potential of costly machine damage.

The cone’s unique tramp relief system is designed with fewer accumulators for minimized maintenance, Schultz says. Most important, he points to the inclusion of a secondary pressure relief valve that ensures the crusher will open if a tramp event occurs.

“So even if an accumulator fails, the secondary relief valve will provide immediate pressure relief, allowing the crusher to open,” Schultz says.

Schultz adds that the inverted design of the tramp release cylinders means the hydraulic cylinder rod seal is not exposed during operation, greatly reducing the potential for contamination and failure.

In addition, Schultz says the cone’s automation package is a safety feature that acts as a warning system, alerting operators to conditions such as bowl float, excessive amperage or temperatures, and lubrication or low-flow oil issues.

Neal adds that another reason why Anchor Stone chose the Patriot cone is its weight and heavy-duty construction. Schultz says the unit is more robust than the typical cone.

“To make sure it will withstand the toughest applications, Superior’s engineers have beefed up the strength of the machine with a heavier-duty adjustment ring, base frame, eccentric and clamp ring,” Schultz says.

User-friendly automation

The Patriot cone is equipped with Vantage automation, which is designed and built in-house by Superior Industries.

Joey Doolittle, plant operator and electrician at Anchor Stone, describes the automation system as user-friendly.

“The touchscreen is very simple to operate, and we can train a new person on it very quickly,” he says.

As an electrician, Doolittle stresses that that one of the best features of the system is its sensor communication network that accesses a standard four-wire cable system from the cone crusher to all auxiliary systems.

“This streamlines setup, diagnostics and troubleshooting,” Doolittle says. “All the sensors wire back to a junction box on the cone, and we had to run one cable from that junction box to the PLC, which cut our wiring time and allows ease of maintenance over time. If there’s a problem with one of the sensors, we can open up that junction box and easily pinpoint it.”

Other systems are more complicated, Doolittle adds, and typically have dozens of separate conductor wires running from the PLC to each component.

“These small sensor wires don’t fair too well in the environment, making downtime common and troubleshooting quite difficult,” he says.

Big efficiency benefits

One of the biggest benefits of the crushing circuit is being able to make setting adjustments on the fly, Neal adds.

“This gives us greater flexibility when we have changes in material feed and allows us to easily tweak material processing within all circuits of the plant,” he says. “Prior to the new cone, it was challenging to make the same adjustments that we quickly make now with the push of a button.”

The auto-feed function, which automatically maintains optimum production levels, is another advantage.

“It takes the worries out of cone operation,” Neal says. “Regardless of changes in the feed, the system will always maintain the desired levels within the cone, and it’s going to maintain the desired amperage on the motor to make sure it’s operating at its highest efficiency.”

As a veteran processing engineer, Neal stresses that if you can maintain the desired level and the desired amperage, you’ll achieve the desired throughput.

“This cone runs all day, every day, in and out – and that’s a big benefit right there,” he says.

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Carol Wasson is a veteran freelance writer for the aggregate and construction equipment industries.