Kokosing Materials Inc.’s plant in Wooster, OH, produces hot mix asphalt for what Brian Pearce, assistant vice president of operations, terms “a very competitive market.” Through 2018 the Wooster location relied on a batch plant to serve the market, but the plant – the oldest in the company – was struggling to produce the volume and kind of mix the market demanded.
“Everything on that plant was the oldest of all the plants at KMI,” says Pearce, who has been with KMI for 33 years.
KMI made updates to the plant, but ultimately a major change was required.
“To be competitive over the last three years KMI made some upgrades to it, but the family realized that the plant was getting so old that they either had to do something significant or not have a plant in that market,” Pearce says. “The family decided to upgrade the plant so we could be competitive in that market. They were looking at the long haul like they always do.”
Floyd Cheek, Astec sales rep, says KMI decided to switch to a Double Barrel drum plant, which required a retrofit of the control system. KMI opted for installation of Astec’s powerful and user-friendly PMIII control system, which combines top-of-the-line industrial hardware with a Windows operating platform to create plant controls that are efficient, easy to operate, and exceedingly accurate.
How the PMIII Makes an Impact
Designed as a complete solution for HMA facility control, the PMIII eliminates traditional consoles and allows monitoring and control of all plant functions from an industrial-grade PC.
“The PMIII has been available for six years and we’ve made upgrades to it each year,” Cheek says. “It’s our primary control system and our best-selling one. It’s very user friendly, very self-explanatory. We’ve got it so that just like a cell phone you can look at the screen and know what to do.”
The PMIII package includes an industrial personal computer, console, junction box and an Uninterruptible Power Supply (UPS) maintains power on the computer after loss of electrical power to enable orderly shutdown of the system. Among other cutting-edge technology (see sidebars below), the PMIII features baghouse controls that control pressure drop by automatically adjusting pulse cycle depending on monitored pressure drop, and an alarm system that provides text messaging and logging of all system errors and an audible alert for key system errors.
Even more convenient, PMIII is compatible with DASH, Astec’s data acquisition system, which makes available real-time plant data to anyone with the app. “By using the app you can tell from the field what’s going on at the plant,” Cheek says. “It’s valuable for laydown guys trying to keep track of material coming to the jobsite. It’s also great for those owners who want to track production at the plant and get all the nitty gritty little facts of what’s going on in real time at the plant.”
40 Years of Success at KMI
Started in 1980, Kokosing Materials Inc. is a subsidiary of Kokosing Construction, a third-generation, family-owned company. Kokosing Construction was started in 1950 and today has 3000 employees, runs 10 paving crews, and operates five limestone, sand and gravel plants that serve KMI.
KMI operates 16 stationary hot mix asphalt plants and one portable plant. All plants are in Ohio, and in 2019 they produced a combined total of 2.8 million tons of HMA for the Columbus/Toledo/Cleveland areas. KMI sells mix to municipalities, townships and private contractors. Pearce says the customer mix varies depending on the market each plant serves, but overall 60% of KMI’s mix is sold internally to Kokosing Construction for use by its paving crews and 40% is sold to private customers.
KMI also operates two asphalt terminals, one on the Ohio River, to which they barge liquid asphalt, and the other in Mansfield which is certified to produce polymer-modified asphalt binder. The company employs 120 people between the lab, the mechanics and the people who operate the plants. The Wooster plant that received the PMIII retrofit sells 80% of its mix to Kokosing Construction crews and 20% to private buyers.
KMI has received seven Quality Paving Awards from Flexible Pavement of Ohio and two Quality in Construction Awards from the national Asphalt Pavement Association.
KMI Sees the PMIII in Action
Cheek says he has been talking with KMI about the PMIII for some time.
“KMI has always used our blending control system and over the years I’ve told them maybe they should look at using our entire system,” says Cheek, who has worked with Kokosing for more than 30 years and with Astec for 44 years. “When the decision to change from the batch to the drum plant came about it was a good time for them to look into it.”
Astec used the company jet to fly KMI representatives to a Florida plant so they could view the PMIII system in operation.
“I knew that once they saw the PMIII in real-time operation they would buy one,” Cheek says. “I think they were pretty impressed with the way it operated.”
A Winter Retrofit
Pearce says KMI originally purchased the late-1960’s 2-ton Barber-Greene batch plant in 2003. In 2005 KMI upgraded the plant’s rotary mixer to give the plant some recycling capability. “When purchased it had zero recycling capability,” Pearce says. “With that upgrade the Wooster plant could produce 225 tph with up to 30% recycled material in the mix.”
But to be successful in the Wooster market, KMI needed to produce more mix and needed to be able to include more RAP in its mix.
So in the winter of 2018-2019 KMI bought a used Double Barrel drum, and while the plant was offline for the winter completed the PMIII controls retrofit and had the plant up and producing mix by April 15 when KMI typically starts its season. In addition to switching to a drum plant, KMI refurbished an Astec baghouse, installed a Variable Frequency Drive on the baghouse exhaust fan, installed an inertial separator, and installed a new aggregate inline conveyor.
KMI also decided to rewire the entire plant along with the upgrade. Programable Logic Control (PLC) panels were placed in a climate-controlled room directly beneath the control room, and all switches were changed out.
“We had a very good serviceman from Astec who stayed with us three weeks to set everything up and calibrate it for a very smooth transition,” Pearce says. “We used our own in-house electricians to install the controls; we have pretty sharp guys.
“We really modernized the plant. We went from buttons and control panels all over the place to having nothing now. We went from prehistoric to the 21st century,” Pearce says. “The plant now runs with two computer screens and a mouse in the control room. Everything is controlled by a computer.”
Pearce says that operator John Thorne, plant manager, went from running the oldest controls in the company to the newest. “He picked it right up. It was a very smooth transition.”
More PMIIIs in KMI’s Future
Pearce says switching to the Double Barrel drum plant controlled by the PMIII increased production to 300 tph and the plant can now accommodate up to 40% RAP “to make us more competitive.”
“Installation of the PMIII control system has enabled our plant to produce more mix and to incorporate more RAP in the mix we produce. We’ll run 110,000 tons through that plant this year and 80,000 tons of that will be for the Ohio DOT,” Pearce says.
“We’re very pleased with the controls and the way the plant reacted. With the PMIII we see more consistency in the quality of the mix, and it gives us better control over the mix design. By enabling our operator to control everything from two screens and a mouse we have a much more efficient operation and it’s much easier to run.”
Pearce says that for 2019 the Wooster plant is the only KMI plant that relies on the PMIII system. “We like the controls so well that we’re installing two more of them in the winter of 2019-2020,” he says.