by Jon M. Casey
Rohrer’s Quarry is the first concrete manufacturer in the U.S. to produce material using a CON-E-CO brand HRM-12 horizontal reversing mixer. Concluding what has been an eight month construction project that began in January 2008, Rohrer’s commissioned the facility at a ribbon cutting ceremony, Sept. 26, as more than 750 dignitaries, and members of the local community attended an open house at the new plant. While the horizontal mixer began making test batches in early July, the CON-E-CO Stationary Low Profile, Gravity Style, central mix concrete plant went into full production in mid-July. According to Justin Taylor, plant supervisor and dispatcher at the new facility, this replaces an existing dry batch plant that will remain operational as a second source of production when needed. Features of the enclosed plant design
The plant is enclosed in a steel-framed building that addresses fugitive dust and noise. It houses a high-tech, spacious batching control room and an office space. It also offers employee locker rooms, a driver’s lounge and a kitchen as well. 
Justin Taylor serves as dispatcher and plant supervisor of Rohrer’s concrete batch plant.
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On the production side, material is moved to the plant from six 12-foot x15-foot outdoor receiving hoppers via a 430-foot curved conveyor. Inside, it travels into six indoor compartments capable of holding 340 tons of aggregate. Three 200-ton cement silos keep the cement in constant supply and ready to use. Taking us on a tour to both the old and new facilities, Taylor said the new plant improves production in several ways. “This system gives us consistency, efficiency, and cleanliness that we were not able to achieve with the old system,” he said. “Our trucks are in and out of the new plant in 3 minutes while the average for the old plant was 8 to10. Now we can produce 200 yards per hour when we were doing well if we did 60 yards with the old plant.” Taylor said that with the new COMMANDbatch™ computer control system, manufactured by Command Alkon, each mix is formulated accurately every time. He also noted that with the material being stored indoors, and the monitoring system being able to measure the moisture content of the sand, there is no guesswork when it comes to getting the slump correct. Taylor added that with the BIN-MATE material handling system controller, by ATECH Industrial Electronics they are able to load one truck while the system is scaling the material for the next truck in line.
With the HRM-12 open for inspection, Justin Taylor explains how these four nozzles provide the necessary ingredients for a perfect batch of concrete.
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“All the driver has to do is pull in, get loaded and pull out,” he said. “A quick rinse of his truck, and he is ready to go. Three minutes, that’s all. The new mixer discharges the concrete into the trucks with very little in the way of splashing or mess. That saves the drivers a lot of time keeping their trucks clean. I’d say on average, each driver saves about an hour per day.”
Taylor said the HRM-12 features a cylindrical barrel that revolves on rubber tires. When a batch is complete, the HRM-12 reverses direction to discharge its concrete. Because of this simple, sturdy design, the HRM-12 has no hydraulic tilt mechanism with gears or pinions that will wear out. Taylor said that because the new plant automation is so precise and reliable, at the end of the day, there is very little in the way of plant cleanup.
“It takes me about 15 minutes per day to clean out the mixer,” he said. “I take an air chisel and a hammer into the mixer to remove any buildup. Then a spray with the pressure washer and the job is done.” Ed Oberholtzer, one of Rohrer’s 20 concrete truck drivers, agrees. He said that the trucks stay clean, making fill up quick and easy. “It doesn’t slow us up,” he said. “A quick rinse and we can head to the jobsite.” Improved quality
On the quality assurance side of things, QA supervisor Mark Coine said the new facility makes it a lot easier for his team as well. He said that with fewer problems to solve on the consumer side of production, they are able to accomplish more each day. In addition, they are able to do the work more confidently and with greater customer satisfaction.
“The mix designs are more consistent, which leads to a better quality product all around,” he said. “We are getting what we are looking for each time, because of the control that we have over the mixes.”
The three 200-ton storage bins located above the mixer are still shiny and new.
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Production continued during construction
According to Owen Blevins, vice president of Mid Atlantic Concrete Equipment, Mid Atlantic brought on Lancaster, PA-based Horst Construction as project manager. Horst designed and erected the plant’s enclosing building to protect area residents from noise and dust, and to shield the plant and personnel from the elements.
Bill Bendokus, an engineer for Horst Construction, said he thought this job went about as smoothly as a project could go. He said they met with few difficulties throughout the entire project, even with the blasting needed for site preparation. Because the plant was engineered 15-feet 4-inches off grade level, the blasting and the concrete pour for the foundation was an interesting yet challenging time during the project. He said that they only had to shut the plant down when electrical power considerations made it necessary. Most of those shutdowns were scheduled for weekends whenever possible.
“We built the new plant around the old one while it was in daily use,” said Bendokus, noting that trucks had to pass beneath the new construction to receive material from the old plant. With the foundation being three feet thick and filled with No. 12 rebar, the concrete pour presented unique challenges. “We made the concrete in the old plant, and filled a sufficient number of trucks with enough concrete to complete the pour,” said Bendokus. “We added stabilizers to the mixes so that they would last. Once we had the trucks filled, we shut down the old plant and completed the pour. We did all of that pour in off-hours. Amazingly, we did it in a half a day.” 
Wilbur Rohrer is delighted with the opening of the company’s new concrete plant.
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Fulfills a dream
Wilbur Rohrer, president and CEO of Rohrer’s Quarry said that the new plant had been in the planning stages for several years and was a vision of his former business partner, Chet L. Crouse. Crouse was Rohrer’s concrete division supervisor, until he lost his life in a motorcycle accident in 2005. Rohrer said that Crouse had worked to build Rohrer’s concrete business to the place where they could one day increase their capabilities with the addition of a new batch plant like this one.
“This plant has been in the planning stages for several years,” said Rohrer. “This plant is our commitment to the future in concrete production, and it is a memorial to Chet Crouse.” “This was my son Travis’s project,” continued Rohrer. “He took the dream that Chet had and made it come to fulfillment. It was a dream that we all shared, and Travis got it done.” |