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Power Play


Central Stone Powers Portable Rock Crushing Plant With Onsite Energy Generation.

By Mark S. Kuhar

Central Stone Co. operates quarries in Illinois and Missouri, producing aggregate products from a number of separate operations. Aggregate produced by Central Stone is used to build homes, roads and a wide variety of public and private construction projects in its market area.

The quarries are largely in rural or remote areas where utility power is not always available, so Central Stone generates the power it needs to run the rock-crushing plant on-site using a diesel generator set. When one of the company’s rock crushing plants was recently upgraded and required more power, the company turned to MTU Onsite Energy for a complete remote power solution.

“We have a 1.5 MW prime-rated MTU Onsite Energy generator set that powers the portable rock-crushing plant for about ten and a half hours every day,” said Dell Moss, quarry superintendent for Central Stone. “The plant has two Raptor XL400 cone crushers, a Cedarapids jaw crusher and various conveyors and material-handling equipment. We have also installed a 50 kW MTU Onsite Energy auxiliary generator set that, in colder weather, is used to power heaters in the water jacket of the main generator and also keep the oil warm in the crushers.”

Tough Work
A quarry environment provides a host of challenges for engines and generator sets such as dust, moisture, huge loads, extreme temperatures and long hours. Equipment that wants to prove itself in this situation must be strong, tough and persevering.

The Series 4000 has experience operating day in and day out, under extreme conditions and in hard continuous operation, according to the company.

The prime-rated 1.5 MW generator set is powered by a 12v Series 4000 MTU diesel engine, known for its reliability, low fuel consumption and high load-factor capabilities.

The keys to the superior load acceptance and transient response are the engine’s Advanced Diesel Engine Control (ADEC) system and additional cylinder displacement per kW of output.

ADEC systems have been developed and produced by MTU specifically for use with the very latest high-performance diesel engine technology – designed not only for full control of the Common Rail technology in the Series 4000, but above all for the management of frequent extreme loads and sudden load changes, which can be overcome effortlessly and smoothly using this system.

With approximately 20 percent greater cylinder displacement than some generator drive engines, the MTU Series 4000 has significantly more reserve horsepower and torque. This design philosophy also reduces internal stresses on pistons, crankshaft, bearings and other moving parts and increases durability.

Durability was an important factor in Central Stone’s application due to the number of hours the generator set needs to run every workday.

“The ADEC not only helps the engine respond quickly to changing loads,” said Michael Ware, sales engineer for Interstate Power Products, the local MTU Onsite Energy distributor, “but it maintains the combustion at peak efficiency for low emissions, low fuel consumption and high power output.”

In selecting the generator set for this prime-power application, Central Stone worked carefully with Ware, who made sure that the generator set met all of Central Stone’s specifications.

“We were able to meet their expectations on price and availability, but of prime importance to them was the fact that the generator set could produce the required amount of power, day in and day out,” Ware said. “As with all MTU Onsite Energy products, the generator set was factory tested to make sure that it met all rated output and performance criteria.”

On the Move
Central Stone’s portable plants are set up in a quarry and are operated until a sufficient stockpile of aggregate is accumulated, according to Moss. Then, the entire plant is moved to a different quarry to crush and stockpile material there.

“We will probably move this plant to four different quarries over time,” says Moss.

“We may stay in one place from six months to a year at a time and then move to another quarry, which can be up to 85 miles away.”

When it needs to be moved, the 1.5 MW generator set will be placed on a flatbed trailer and moved to a new site, according to James Papenhausen, director of safety, purchasing and maintenance for Central Stone.

“The generator is sitting on the ground for the time being, but we will eventually permanently install it on a drop-bed trailer for more convenient transportation.”

Both Moss and Papenhausen say that the MTU Onsite Energy generator set has been working flawlessly for the upgraded portable rock crushing plant, ensuring that the aggregate stockpiling operations will keep up with customer demand.