The construction business has been booming in Kansas City since 2005. Area media reports that the city's downtown district is experiencing the most dramatic transformation in its history, with more than $3 billion of new construction and renovation. Multifamily construction permits have seen a rise as high as 72 percent. And, more than 600 new construction sector jobs were created in 2006. Consequently, the region's demand for high-quality aggregate is nothing short of explosive.
Shawnee Rock Company saw the upsurge coming late in 2004. "We knew we needed to get a new plant to be able to take advantage of this very strong market," said Jim Murray, director of operations for Shawnee Rock Company, a producer with three quarry locations on the west side of Kansas City. "Initially, our biggest concern was the immediate availability of a new impact crusher, and its delivery and setup in time to meet our demand. Timing was a big issue."
In April 2005, the operation was up and running with a new Telsmith PA6060 primary impact crusher, a customized addition to a KPI/JCI Fast Pack portable plant and a modification that is ideally suited to its application, material characteristics and production goals. "Typically, the Fast Pack plant has always had a jaw crusher as a primary," Murray noted. "However, we did not want a jaw due to the softer limestone that we crush. We're impactor people, and Telsmith offers a beefier Andreas-style model as a primary. It does a much better job of crushing the ledges that we have here in our quarries. We haven't had any problems getting our muck-pile feed through this unit."
The impactor has delivered no less than a 30-percent increase in production capacity, and the plant is delivering an average of 600 tons per hour, he said.
Murray said the Telsmith Andreas-style impactor is the most productive and cost-effective choice for his application. A hydraulic adjustment feature allows more control over product size, power consumption and blow bar wear. The 46-inch by 60-inch feed opening takes in large feed and the PA6060 incorporates a massive solid-type rotor combining higher inertia crushing and reliability. According to Telsmith engineers, this results in longevity and lower operating costs.
The new impactor is also the optimal choice for the region's limestone. "The low abrasiveness and the material's softer characteristics make this impactor style a good match as a primary," Murray said. Also, Telsmith said, in some stone, impact crushing improves the competency of the final product by allowing the stone to fracture on the weakest bonds or seams.
Aside from overall productivity, Murray stressed that the biggest benefit of the Telsmith impactor is the ease of adjusting the aprons. "It takes all of about five minutes to make the adjustments. It only requires the push of one button."
Telsmith has engineered the PA6060 with push-button control of all functions, including frame open and close, feed plate raise and lower, and upper and lower apron adjustment. Hydraulic adjustment cylinders are equipped with position sensors so once the apron set point is established, the apron will return to that setting automatically after relief.
"We shoot our rock down to a feed size of 36 inches to 40 inches," Murray said. "We have a BTI hydraulic breaker on the plant, so if we have a big boulder coming at us, we can pop it once or twice." The unit is also designed to easily handle any bridging problems, he says, referring to the impactor's tilting mono-block feed plate, which is hydraulically controlled to allow the operator to safely clear any bridging.
While some operations experience higher wear parts and maintenance costs with impactors, Murray said that is not the case at any of his sites. "Again, our material is fairly soft, so we don't see an excessive amount of wear."
Telsmith engineers designed the PA6060 with features aimed at boosting service life and ease of maintenance beyond typical industry standards. For example, the unit is built with oversized 220-millimeter, wide-series bearings and a large rotor shaft. Each blow bar is designed for three rotations, allowing up to four wear surfaces. Heavy-duty mono-block aprons are interchangeable and reversible to maximize utilization. Additionally, only two shapes of frame liners are used. Via interchangeable wear parts, the PA6060 reduces wear part inventory needs, simplifying maintenance and reducing operating costs. Ease of maintenance is provided by inspection doors located on both sides of the machine and a frame that opens hydraulically to allow for safe and quick access to the blow bars and liners.
Murray said the flexibility of the plant allows them to produce a variety of different products. "Everything we make is KDOT-approved material such as an AB3, and clean 3/4-inch, 1/2-inch and 3/8-inch product." The only time they have a dust product is when they are making clean stone, he said, explaining that any dust that comes off the high frequency screen is normally added back into the AB3 material.
Although the operation has moved the plant only once in the last two years, Murray said having portability is important. "We have four other portable plants, and having mobility is important in taking on whatever the market may hold for us in the future."
Combining solid crushing equipment and high portability, Shawnee Rock Company can meet market demand by moving the plant to where added capacity is needed, at the time it is needed. Being able to react quickly to customer requirements improves their competitive edge.