Hardrives, Inc. produces more than 1.4 million tons (1.27 million tonnes) of asphalt per year and credits its Dillman UnidrumTM plant for being quiet and efficient.

When thinking about an asphalt plant, friendly, neighbor, and quiet are not the words to come to mind, but Hardrives, Inc. has changed the connotation of the phrase. In a quiet little neighborhood in Minnesota, residents have no idea that a UniDrum™ plant from Dillman, a division of Astec, Inc., is producing asphalt mere miles away.

Location, Location

Hardrives, Inc. in Rogers, Minnesota, isn’t just some small company. From its humble beginning in 1963, with asphalt paving as its primary business, the company celebrated its 50th anniversary in 2013 and continues to grow. There are more than 300 employees who work in its four operating divisions at its offices in Minneapolis and St. Cloud. A Dillman 500 TPH (453 MTPH) UniDrum plant has been the most recent addition to the company’s fleet in November 2014. Hardrives bought the portable Dillman plant, but made it a stationary plant in Rosemount, Minnesota. This location is perfect since Hardrives uses virgin aggregate from the University of Minnesota in its mix. The university owns 2,500 acres (1011 hectares) with more than a 40-year supply of aggregates.

Hardrives, Inc. is concerned with being environmentally friendly as well. The monitoring and maintenance of the plant is the key to ensuring that the facility has low emissions and operates with minimal environmental impact. They use 20 percent RAP (reclaimed asphalt pavement) in most of their mixes, but use up to 40 percent RAP in residential projects.

Steven Hall, CEO and president of Hardrives, Inc., said: “We produce and lay down more than 1.4 million tons (1.27 million tonnes) per year. We work on around 200 projects a year in Minnesota and parts of the Dakotas.” This is a lot of asphalt and a big area for the plants to be working in. They have seven plants, but the most efficient and favorite is the Dillman Unidrum plant. Hall believes the most beneficial aspect of the plant is its control house, drum, and burner. He finds the drum and burner to be exceptionally quiet and that neighbors can’t hear when it’s running. He finds that it’s noticeably quieter than any of his other plants.


The Unidrum Delivers

Dillman has many years of experience building heavy-duty equipment for the asphalt pavement industry. The Dillman unified drum is a high-quality counterflow design that is offered in both portable and stationary arrangements.

The Dillman UniDrum has an extra-long drum that allows it to produce quality hot mix at a high production rate with a high percentage of recycle. The long drum length maximizes mixing and drying times to reduce fuel consumption and provide superior mixing. It eliminates the time-consuming procedure of trunnion alignment and ensures proper equipment operation. The key is its unique pivot pin system, which allows the contractor to easily dial in the dryer in a matter of minutes without the need of any specialized equipment. The single point trunnion adjustment allows for a significant reduction of excess trunnion wear, premature deterioration of hardened tire surfaces, broken trunnion shafts, bearing failures, and thrust roller assembly damage.

The UniDrum has a heavy-duty support structure. The supports are produced by certified welders using heavy, structural I-beams. The I-beams are a high safety value and they provide rigidity and stability to the entire drum unit, which minimizes maintenance.

Warm Mix System

There’s also an optional warm mix system that saves energy and eliminates smoke and emissions without compromising the mix quality. The system uses water to produce a foam asphalt that is odorless, smokeless, and longer lasting. Injecting water causes the liquid asphalt to foam and expand in volume without the addition of costly additives. The foaming action helps the liquid asphalt coat the aggregate at a lower temperature. With the additions the Astec warm mix system, the plant saves energy and eliminates smoke and emissions without compromising mix quality. Hall said that it has exceeded environmental permits and regulations. The UniDrum allows them to run the state DOT-approved 20 percent RAP/RAS (reclaimed asphalt pavement/recycled asphalt shingles).

Service You Can Trust

When asked why he chose the Dillman UniDrum plant, Hall said, “The responsiveness and knowledge of employees at Dillman and Astec. The expertise and the knowledge of the individuals we’ve worked with are exceptional. We had other prices of competing firms, but we felt that Astec’s knowledge and service are what lead us to them. Astec employees are the best and know what they are talking about. Many of them have been with the company for years, so when the issue is described, they know what is causing the problem and how to fix it.”

Hardrives, Inc. looks forward to sending operators to the Astec Advanced Customer Schools in the future. Hall wants to ensure his equipment is running as efficiently as possible, so he goes with Astec. It has paid off since his UniDrum plant is producing more tons than initially expected. The UniDrum plant is designed for 500 TPH (454 MTPH) and Hall has been producing 525 TPH (476 MTPH). This has been a pleasant surprise and is cost-effective in the long run.

Astec personnel pride themselves on their attention to their customers’ needs. Their plants, parts, and customer service is the best in the business. People usually don’t consider customer service as a big part of the package, although it’s the difference that makes Astec the company to go with in the long run.

“After a year of operation, it went very smooth and any minor details have been worked out. We’ve bought a lot of equipment before and we usually have a year to figure it out, but the bugs were limited and any problems we had were small. When we had a problem, Astec was there immediately to help. That was great. I wouldn’t hesitate to buy another Astec product.”

  • The Dillman Unified Drum has a high-quality counterflow design to produce hot-mix asphalt with a high percentage of recycle.

  • Three 300-ton (272 tonne) silos hold the mix for use as needed.

  • Four Heatec 30,000 gal (113,562 l) vertical liquid asphalt storage tanks with catwalks between the tanks.

  • A 100,000 CFM Four Mod Reverse Pulse Baghouse with  triple 10 ft x 15 ft (3.05 m x 4.57 m) recycle feed bins (2 RAP, 1 RAS) seen on the left.

  • A 10 ft x 16 ft (3.05 m x 4.87 m) 12-compartment cold feed system enables Hardrives ample flexibility to make a variety of different asphalt mix types.