From components to controls, experts offer solutions to update the grandfathered batch plant for efficiency, RAP production, flexibility

Both batch and drum hot-mix asphalt (HMA) plants have their purposes in North America. Even the combination batch/drum plant, which you may have heard referred to as a dratch, has its advantages in certain markets. For those producers who have an older batch plant grandfathered into an area where disturbing the local regulatory authority could be a negative experience, making updates to run more efficiently or to run recycled content doesn’t have to be a frightening proposition.

While we will discuss upgrades that require alterations to your permit, there are actions you can take for efficiency that won’t require changes to your permit, such as performing routine maintenance and modernizing electrical components. Llew Williams, general manager, operations for Stansteel Hotmix Parts & Service, Louisville, Kentucky, spoke to this concept.

Consult Your Permit

“We would encourage owners to consult all applicable local, state and federal requirements before making modifications to their facilities,” Williams cautioned. “Every plant and jurisdiction is different. That said, many owners can realize meaningful improvements through maintenance, replacement of worn components, and operational optimization projects that improve reliability, consistency, and efficiency without significantly altering the fundamental operation of the plant.”

Some examples the Stansteel team listed include:

• Using the customers’ right to repair by replacing worn drag conveyor components, bucket elevator parts, flights, liners, bearings, bin level indicators, load cells, weighing systems, instrumentation, and other high-wear or serviceable items.
• Modernizing motor controls, VFDs and electrical components.
• Retrofitting individual plant components such as cold feed systems, AC pumping systems, silos or material handling equipment.
• Installing updated plant controls and data reporting capabilities.

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“In many cases, these types of projects can extend the useful life of a batch plant while improving uptime, mix consistency and operator visibility into production,” Williams continued.

Then there are some changes that require alerting your regulatory agency, and are likely to be met with immediate approval, such as improving air quality with a more efficient dust collection system or burner. T.J. Young, the proprietor of T2ASCO LLC, Overland Park, Kansas, shared that you should double-check what you want to change with the existing permit’s fine print.

“Generally, you should be very careful of making any changes in your plant involving your burner, your exhaust fan, your dust collector or your drier without checking your permit rules first; unless it is a direct replacement as to size, make and model, even when installing more efficient equipment. If you find your equipment is listed in specificity, it is wise to let the regulatory people know that you are making changes.

“This also includes changing fuels,” Young continued. “When making changes to equipment or fuel source that is more efficient from a dust collection or emission standpoint, changes are typically welcomed.”

Catherine Sutton-Choate, director of product compliance for Astec Industries, Chattanooga, also offered words of reassurance. You want to start with full transparency and a review of the existing permit, but you’re communicating the benefit for the community and environment.

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“As for replacing a burner, it is never okay to not tell the regulatory agency,” Sutton-Choate said. “You must keep them informed of any changes to the main source of emissions at a facility. However, this does not mean that the permit will be opened or revised in any way. As long as the burner has the same capacity as the one being replaced and the anticipated emissions are the same or less, the agency will merely document the change. This is more critical in some states than it is in others.

“As for changing fuels, it really depends on what fuels are included in the existing permit,” she continued. “If multiple fuels are listed, the plant can switch back and forth as needed. The only requirement is that they maintain the appropriate documentation per the permit. However, they cannot switch to a fuel that is not specifically listed in the permit without contacting the permitting agency to obtain approval first. I worked on several permit revisions years ago for customers to add the ability to combust recycled oils to their permit.”

Add RAP Systems

The addition of recycled material that Sutton-Choate references is a common theme for batch plant owners. Specifically, owners are often interested in adding the ability to run reclaimed asphalt pavement (RAP), which the original batch towers weren’t engineered to do. Jeff Meeker, CEO of Meeker Equipment Company, Belleville, Pennsylvania, and David Garrett, regional sales manager for Meeker, spoke of the history behind adding RAP systems to batch plants over the years and echoed Sutton-Choate’s optimism.

“Most batch plants were not designed to run RAP when built,” Garrett said.

The Meeker solution is the RAP Pak, which controls the flow of the RAP into the tower to minimize steam explosion. “We were delivering 15% RAP back when the systems were designed; now plants call for higher percentages and, depending on the customization, the system can do 40% in some towers,” Meeker said. “Each plant is different.”

The challenge of material temperature differentials is one the industry had to address when it came to introducing RAP to the batching system. We all recognize that RAP is prized not only because it’s a great recycling story, but also because it replaces a percentage of costly virgin materials. It contains residual asphalt binder. It also contains moisture. Both the binder and moisture contribute to blue smoke and steam concerns when added to the batch mixer, thus OEMs have assisted producers in finding custom solutions to introducing the material.

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For Ammann Group, Langenthal, Switzerland, this is answered in the manufacturer’s UniBatch tower. A spokesperson for the OEM provided: “RAP usage is now easier than ever.” With the Unibatch tower, producers add RAP to the mix design via Ammann’s RAC system. “This cold addition of RAP…can be integrated into any layout, easily allowing up to 30% RAP.” For higher percentages of RAP in the mix, the OEM can add its RAH50 drum to the Unibatch tower to preheat the RAP before introduction.

“It’s been an evolution,” Garrett concurred. “When we started using RAP the goal was often 10% and we would weigh it in the aggregate weigh hopper. In order to incorporate the higher percentages expected today, we use a stand-alone weigh hopper for the RAP and enter it directly into the mixer.”

The McCrossan Process | “From the historical perspective, one of the first people to use RAP on a batch plant was C. S. McCrossan in Minnesota. This was a 10,000-pound Stansteel batch plant that was producing in a major metropolitan location. With the introduction of the milling machines and maintaining many roads in the area, they were accumulating RAP. Why not incorporate it? This system utilized a recycle bin feeding to a long belt conveyor that elevated the material up to the batch tower level, then the material was fed down the chute into the weigh hopper and utilized just like weighing up another material in the batching process.  They would weigh up the various materials from each hot bin and then weigh up the RAP, dump in the pugmill and mix it up. There was a lot of experimentation, but a tremendous amount of success.”—Llew Williams

Michael Petrie, the president of Motion Engineering, Caledonia, Wisconsin, shared how a customer in St. Michaels, Minnesota—Omann Brothers, Inc.—added recycle capability when upgrading a long-time batch plant to a combination facility. “Omann Brothers introduced RAP into their mix production by having a RAP collar on their aggregate dryer and running a two-conveyor system to be able to add RAP or RAS.”

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Sutton-Choate reminded readers of another vital component: “I have personally worked on batch plant scavenge systems, which are a necessity to run appreciable amounts of RAP through a tower based on most existing configurations.”

Whichever configuration turns out to be the most advantageous for your batch plant depends upon your specific plant. Mike Raasch, controls engineer at WEM Automation, Pewaukee, Wisconsin, stated, “The highest-priority upgrade will vary by plant.” He’s speaking not only in terms of adding RAP or changing a burner, but in terms of updating the controls for all of the above.

“A system with obsolete controls but accurate scales has different needs from a plant with a supportable PLC and unreliable weighing equipment,” Raasch continued. “The best starting point is a field assessment that identifies the systems creating the greatest production and support risk.”

To assist in receiving approval for a change in the batch plant’s operation, Garrett suggested telling the township or regulatory agency how the new feature is the best or newest available technology, how the new component offers improved heat efficiency, how the change is facilitating the use of recycle, and so on. Communication and full transparency are key, especially when our industry has new technology to improve aging infrastructure. Let’s discuss some more of those options.

Modernize the Older Batch

Williams shared that modernizing the older batch plant could be as simple as finding the right combination of replacement parts, controls upgrades, material handling improvements, combustion technology and engineering support to extend plant life and position owners for future production demands.

“Many batch plants operating today still have significant useful life remaining,” Williams said. “Owners are increasingly focused on strategic modernization rather than wholesale replacement. Whether the objective is improved reliability, higher production rates, increased RAP utilization, better automation or lower operating costs, customized upgrades often provide a highly attractive return on investment.”

The team at Ammann shared, “Plants built in the 1970s and ’80s are still standing across North America, but the tower—the screens, hot bins, weigh systems and control—is the part that’s fallen behind. Parts get harder to source. Uptime gets harder to guarantee. There’s no sound way of utilizing RAP. Every year, the gap to modern output and emissions standards gets wider. The UniBatch tower is built to drop onto that same footprint. It’s modular by design…[and] also built to interface cleanly with plant components from other manufacturers, so a full rebuild isn’t the only path to modern technology.”

For owners who seek the more complete makeover, the framework is already there. Mike Mauzy, sales manager for Reliable Asphalt Products Inc., Shelbyville, Kentucky, spoke of converting the batch plant to a combo batch/drum. He mentioned this option as a major upgrade that would likely require permitting, no matter what state or municipality you’re working in, “but the benefits far outweigh the headache of permitting.”

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For this type of upgrade, Mauzy suggested adding a mixing drum while keeping the batch tower so you can use the batching capabilities. Or you could remove the batch tower and use the existing elevator to feed an elevated mixing drum. “In either case, this major overhaul, which has been performed hundreds of times over the past 40 years, requires updated controls, screening equipment, belt scales, liquid metering upgrades, etc., to convert to drum mix plant capabilities,” Mauzy said. “Oftentimes, updated larger dryers, baghouses and increased silo capacity accompany these improvements. Utilizing existing equipment greatly reduces the investment over purchase of a new plant and likely reduces the permitting exposure while accomplishing some of the same benefits, like increased RAP usage, increased production, reduced emissions, etc.”

Petrie explained how Omann Brothers accomplished this task. Jim Omann had been a long-time batch plant owner, but within the last decade, had made upgrades to the existing batch plant that now allow the introduction of continuous mix production while switching between batch and continuous production as needed.

“It is absolutely possible to modernize an existing batch plant without replacing the entire plant,” Petrie said. “Rather than scrapping a functioning batch plant, owners can strategically upgrade controls, automation and production capabilities while extending the plant’s lifespan. Jim’s operation is a good example of converting a traditional batch plant to a flexible system capable of both continuous (drum) production and batch production, which has significantly reduced wear on the equipment while maintaining the ability to produce specialty mixes on demand. He upgraded his controls and automation first, allowing for expansion for future growth, then started upgrading equipment on the plant to avoid using the batch plant unless absolutely necessary for the specialty mix production, minimizing waste and wear on equipment.”

One of the areas batch plant owners might overlook when making an upgrade like this is the screen deck capacity. Petrie explained what Omann Brothers did.

“If looking to integrate an operation that involves switching from batch production to continuous mix, it is important to evaluate the screen deck,” Petrie said. “The screen deck often becomes the biggest production bottleneck. Smaller screen decks begin creating carryover once production exceeds their capacity. As an example, at Jim’s plant, their screen deck is limited to approximately 120 tons per hour; above that, carryover occurs. Also, efficiency drops and production suffers.

“Another thing to consider is bypassing the screen deck,” Petrie continued. “What Omann Brothers did is maintain their original screen deck, and extend their hot elevator to install a bypass that routes aggregate directly into the mixing drum. They then use a flap door/diverter to switch between continuous drum production and traditional batch production. This allows them tremendous flexibility. It reduces waste and significantly reduces wear parts, which are one of the costliest items for a manufacturer.”

Williams detailed this combination concept as the next “phase” in the history of accommodating RAP in batch plant production. Modifying the plant to have the best of both worlds allows the producer to keep the batch tower and the batch process for special mix designs and custom requirements while installing continuous drum mix capability that facilitates RAP introduction. Not every facility is a candidate for this combination.

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“Each plant was individually evaluated and custom engineered to be able to operate still as a batch plant and as a continuous drum mixing type plant,” Williams said. “In this arrangement, all of the process had to be set up just like a drum plant with variable speed drives, belt scales, and scalping screens in the process and a comprehensive control system to alternate between running batch tower and the continuous drum mix process.”

Given the efficiencies of newer componentry, the producer may be pleasantly surprised by the environmental “wins” he can offer to his region. The burners of today have engineering advantages that air quality boards prefer to the burners of the 1970s. But not every region is looking for the same thing.

“Each state has its own permit regulations for the air operating permit for the plant,” Young said. “In fact, it is not always called an air operating permit. The state must follow federal guidelines, and can be more stringent than the guidelines, but not more lenient…You really have to know your local requirements.”

Mauzy spoke of this as it relates to the burner, specifically. “I would not carte blanche state that changing a burner requires a permit. That is likely the case. I believe in many cases, improved emissions, improved efficiency and reduced noise make the permitting process simpler. However, in some cases, as long as you are not increasing BTU or plant productivity, I am not certain that a new permit is required. In any event, converting to a newer, more efficient burner, especially if converting from an open air burner to a totally enclosed burner, should be seen as a major environmental improvement.”

It’s not just the addition of RAP capability or a more fuel-efficient burner that will delight the environmental boards. Also consider dynamic foaming technologies, which some OEMs call mechanical. Williams spelled out the exact reasons air quality authorities would look favorably upon this update to your facility: “By mechanically blending precisely metered water with liquid asphalt, the foaming process dramatically expands the asphalt binder and enhances coating of aggregates, RAP, RAS, and fines, creating a more homogeneous mix,” Williams said. “This improved blending allows producers to lower mix temperatures, reducing fuel consumption while helping cut blue smoke emissions and odors at the plant.”

A common theme from sources showed batch plant upgrades not only increasing efficiency, but doing so for the purpose of increasing production. Many upgrades and additional systems designed for the older batch plants are bringing those plants closer to the combination concept, and we’ll look more closely at that in part two.

No matter which upgrades you make, ensure all components and systems continue to operate cohesively. As hinted throughout this article, updating the electronics and controls is an important step for the batch plant owner, and that will be covered in depth in part two of this series in the October edition.

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Screen for Upgrades

If you plan to introduce continuous mix production at your batch plant facility to allow yourself flexibility between both, don’t forget to assess the screen deck. You may need to upgrade it to accommodate continuous mix production.

The screen deck often becomes the biggest production bottleneck. Smaller screen decks begin creating carryover once production exceeds their capacity. Consider this example from Omann Brothers. Their screen deck was limited to approximately 120 TPH. If capacity exceeded 120 TPH, carryover would occur, efficiency would drop and production would suffer.

If you can’t upgrade the screen deck, one solution is to bypass it. This is what Omann Brothers did. They maintained their original screen deck and extended the hot elevator to install a bypass that routes aggregate directly into the mixing drum. They then use a flap door/diverter to switch between continuous drum production and traditional batch production. This allows them flexibility while reducing waste and reducing wear.

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Modernize Your Batches

Sources offered a number of upgrades batch plant owners/operators can consider for bringing older facilities up to date.

For simple maintenance and one-to-one component replacement, owners have the right to repair and don’t have to alert regulatory authorities to their activities. But when it comes to upgrading or upscaling components, adding capacity, switching burner fuels or changing hours of operation, the proper governing bodies must be notified. Make sure you have a competent person assigned to assess the permit and assist in filing the proper paperwork. Then consider which of these upgrades can help you extend the life and efficiency of your older batch plant.

• Replace worn components and high-wear items such as drag conveyor and bucket elevator parts, bearings, bin level indicators, load cells, and the like.
• Update/recalibrate weigh scales.
• Modernize motor controls and electrical components.
• Add variable frequency drives.
• Retrofit individual components such as cold feed systems and AC pumping systems.
• Add a storage silo as well as material handling/transfer equipment.
• Install updated plant controls and data reporting capabilities.
• Upgrade to a modern, LoNOx or Ultra LoNOx burner.
• Upgrade your exhaust fan and add a VFD.
• Update your dust collector.
• Upgrade your dryer/dryer flighting
• Incorporate modern drum control systems to optimize drying efficiency.
• Assess your screen deck’s capacity and consider bypass options.
• Consider adding warm-mix asphalt technologies, including dynamic foaming systems.
• Consider an external RAP or another RAP system to facilitate recycle.
• Update obsolete relay logic or an unsupported PLC architecture.
• Install blue smoke scavenging systems around the loadout area.
• What would you add to this list? Share online!

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Upgrade for RAP

BEFORE: This belt conveyor was feeding 5% RAP directly to the weigh hopper.

AFTER: Upgrading with a custom rotary mixer allows more than 40% RAP.

Both photos courtesy of Stansteel Hotmix Parts & Service

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Ask the Experts

The experts who took the time to contribute to this article ascribe to The Asphalt Pro theory that all boats rise with a rising tide. They have years of experience to share and can be reached:

Kiel Stead at Ammann Group NA | (407) 634-7703, Kiel.Stead@ammann.com

Catherine Sutton-Choate at Astec Industries | (423) 618-9545, csutton@astecindustries.com

Jeff Meeker at Meeker Equipment | (215) 828-2651, jmeeker@meekerequipment.com

David Garrett at Meeker Equipment | (888) 333-0323, davidgarrett@meekerequipment.com

Michael Petrie at Motion Engineering | (414) 510-6097, mike@motionengineering.net

Mike Mauzy at Reliable Asphalt Products | (502) 529-9043, M.Mauzy@ReliableAsphalt.com

Llew Williams at Stansteel Hotmix Parts & Service | (502) 860-2997, lwilliams@stansteel.com

T.J. Young at T2ASCO LLC | (913)-634-4967, tjyoung2@att.net

Mike Raasch at WEM Automation | mraasch@wemautomation.com

Duininck celebrates 100 years with newly commissioned portable counterflow plant in Texas

In 2024, Duininck commissioned a new 350-ton-per-hour (TPH) portable counterflow asphalt plant in Texas—their first of its kind. For most contractors, a new plant build is about efficiency, mobility, or production capacity. For Duininck, it was all of that—and a return to a partnership grounded in trust, flexibility, and shared values built over more than 30 years.

Editor’s Note: Duininck was founded in 1926 when three entrepreneurial brothers started a road construction business in Prinsburg, Minnesota. In keeping with AsphaltPro’s anniversary celebrations this year, we wish the Duininck team a Happy Centennial!

History of an Industry Relationship

The relationship between Duininck and CWMF traces back to the early 1990s, when a problematic baghouse order from another vendor brought together Harris Duininck, second generation owner, and Loren Mick, founder of CWMF. Loren stepped in to help resolve the issue, and sparked a working relationship built on service, accountability, and mutual respect.

Travis Mick, vice president at CWMF, remembers those early days clearly. “Harris and my dad were like oil and water at first—very different personalities—but somehow it worked. They ended up building a real friendship grounded in respect, even if they didn’t always agree.”

Even after Loren’s passing, the personal connection remained. “Harris stayed in touch and shared stories about the two of them working together,” Travis added. “That kind of legacy says a lot, not just about companies, but about people.”

Duininck’s Texas roots go back to 1985, when challenging business conditions in Minnesota prompted expansion south.

Chris Duininck, president of Duininck Minnesota, has watched that trust carry forward. “What started between Harris and Loren evolved naturally as both companies grew,” Chris said. “As we matured, the partnership carried through to our teams at every level.”

In 1999, Duininck commissioned CWMF to build a complete asphalt plant from the ground up, which was an experience that set the tone for future collaboration.

Growing Across State Lines

Duininck’s Texas roots go back to 1985, when challenging business conditions in Minnesota prompted expansion south. Fifty families relocated from Prinsburg, Minnesota, helping launch the Texas division, while Harris Duininck remained in Minnesota guiding diversification and growth at home.

Timeline Snapshot

1985: Duininck launched its Texas division and 50 families relocated from Prinsburg, Minnesota

2024: The new portable counterflow plant was commissioned in Texas

Today, Duininck operates asphalt plants in both regions, shifting crews as seasons change and investing in equipment that supports large-scale, geographically dispersed projects. For Texas, flexibility was critical, and Duininck selected a 350-TPH portable counterflow plant to support its Texas operations in the early 2020s. It was commissioned in 2024. (See sidebar for details.)

“With a market defined by long haul distances and decentralized projects, mobility matters,” Chris explained. “A portable plant allows us to bring production closer to major highway and municipal work, reducing transport time, fuel use, and cost—without compromising quality.”

The 350-TPH counterflow system delivers the output required for major infrastructure projects while maintaining tight temperature control and efficient fuel use, which are key factors in Texas’ high-heat paving environment.

“Our experience led us to partner with CWMF to build a plant suited to our needs,” Chris added. “The last complete plant we purchased was more than 20 years ago, and the timing was right to deploy additional resources in the market.”

After three decades, the partnership operates without complexity.

“A lot of our deals have been done on a handshake,” Chris said. “It all comes down to trust—trusting each other to get the job done and meet commitments.”

From CWMF’s perspective, that familiarity leads to better solutions. “When you know a customer this well, you understand what matters most to them,” Travis said. “That allows us to recommend equipment and configurations that truly support how they work.”

Both companies point to people as the foundation of quality work.

“Our employees take pride in their workmanship and in representing the company well,” Chris said. “There’s real satisfaction in supporting a family business and recommending them across the industry with confidence.”

“That connection matters,” Travis added. “People work harder for people they trust, and that’s been true at every level of this partnership.”

CWMF, now a legacy brand within Astec, reinforces the long-term strength of customer relationships like Duininck’s, providing scale and stability behind the products and values that have earned trust over decades.

More than 30 years in, the Duininck–CWMF relationship isn’t just about equipment. It’s about consistency, accountability, and building for the long haul, one plant at a time.

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Why Duininck Chose a Portable Counterflow Plant for Texas Operations

Plant Type: 350 TPH Portable Counterflow Asphalt Plant

Location: Texas

Built By: CWMF

Commissioned: 2024

Duininck selected a 350-TPH portable asphalt plant to support Texas operations defined by long haul distances and decentralized job sites. Mobility allows production to move closer to large highway and municipal projects, reducing transport time, fuel consumption, and overall cost while maintaining consistent mix quality.

Counterflow technology was the preferred choice due to its ability to meet both performance and environmental expectations. By moving aggregates opposite the exhaust stream, the system is designed to maximize heat transfer, improve fuel efficiency, deliver tight temperature control, and reduce emissions, which management saw as critical advantages in high-temperature paving environments.

The system supports Duininck’s production target of 350 TPH, aligning with the scale of heavy civil and municipal work common across Texas. Its ability to integrate high volumes of recycled asphalt pavement (RAP) also supports sustainability goals while lowering material costs.

Mix Design: Minnesota vs. Texas

Minnesota

• Focus on freeze-thaw durability
• Softer binders (PG58-34)
• Higher recycled content
• Rounded glacial aggregates
• Emphasis on crack resistance and long-life pavement

Texas

• Built for extreme heat and heavy truck traffic
• Stiffer binders (PG70-28/PG76-28)
• Angular limestone and granite aggregates
• Dense-graded structures for rut resistance

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Shared Direction, Sustainability

Both regions are expanding balanced mix design (BMD) programs, blending volumetric targets with performance-based testing to meet durability expectations across climates.

Duininck’s operational and sustainability strategy centers on smart material management—locating plants near job sites, sourcing aggregates locally, and reclaiming and recycling asphalt whenever possible. Recent projects, such as reprocessing materials at Willmar High School, have demonstrated both environmental benefits and meaningful cost savings.

Editor’s Note: The Focus on Performance series from AsphaltPro Magazine allows OEMs and service providers in the industry to highlight asphalt professionals who have improved efficiencies and the bottom line through best practices and performance. This month’s installment, featuring a producer in the Northeast, dives specifically into efficiencies gained through a burner retrofit.

When a Maryland producer was looking to upgrade their dated burner system to improve reliability and energy efficiency, Detroit Stoker Company, Monroe, Michigan, responded with a HADES burner and HBC burner control system.

The customer operates a 400 tph, dual drum plant, which includes a counterflow dryer and separate mixing drum. The burner replaced a dated 100 MBtu/hr sealed in burner, which had proven to be difficult to service and maintain. Detroit Stoker with partner, Meeker Equipment Company LLC, Belleville, Pennsylvania, provided a new HADES-100 (100MBtu/hr) dual fuel burner capable of firing natural gas (primary fuel source) with No. 2 and/or recycled fuel oil backup fuel.

The original burner system included:

1. Direct drive fan with 1,800 rpm 100-Hp motor.
2. Single control actuator with linkages driving a fan outlet damper (airflow control) and fuel control valve(s) for gas and fuel oil.

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The new burner system features include:

1. A direct drive, 1,800-rpm fan; however, due to the energy efficient design of the burner, only a 60-Hp motor was required to achieve the same burner rated capacity. In addition, a variable frequency drive (VFD) is now used for precise combustion air flow control via the HBC panel.
2. Independent (gas and fuel oil) direct coupled fuel actuators controlled by the HBC panel.
3. More compact footprint/package as a result of smaller combustion air fan and reduction in ancillary dampers/drives/linkages. This improved design results in higher reliability and maintainability.

These features offer numerous advantages, such as precise combustion air/fuel ratio control across the entire burner input range (low to high fire). This means maximum fuel efficiency can be achieved regardless of plant production rate.

Additional benefits include enhanced safety as the HBC panel is continuously monitoring both air and fuel demand versus feedback and “cross-limiting” the air/fuel ratio such that the burner cannot go rich. In a linkage-based system, when the linkage slips or fails, the burner can literally be firing at any ratio, and the writer has seen burners firing in extremely rich and potentially explosive conditions as a result.

VFD savings are well documented. The motor horsepower is proportional to the speed cubed, resulting in significant energy savings by adjusting the motor’s speed to match the required load, instead of running at full speed constantly. A small speed reduction results in large energy savings. VFDs also improve efficiency with a better power factor and can extend motor life by reducing startup current.

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Final tuned CO emissions were well under 200 ppm corrected to 7% O2 dry across multiple firing rates. Burner tuning is not only much more precise but far easier to accomplish with the use of fully characterizable air/fuel tuning curves in a burner control panel like the HBC. Tuning is accomplished with the simple change of combustion air VFD speed and/or the fuel valve(s) position electronically with the push of a button. This is of course accomplished while monitoring emissions, burner and overall plant performance.

This burner retrofit provides the producer with a future-proof, energy-efficient combustion system designed for decades of reliable operation. By replacing an outdated, maintenance-intensive burner with the HADES-100 and HBC control platform, the plant now benefits from significantly reduced electrical energy consumption, precise and repeatable air/fuel ratio control, lower emissions, and a streamlined mechanical design with fewer wear components.

The VFD, independent fuel actuators, and modern cross-limiting combustion logic all contribute to sustained fuel savings, extended equipment life, and enhanced operational safety. Together, these improvements ensure that the plant will continue to operate at peak efficiency with lower operating costs and reduced environmental impact—delivering long-term sustainability for both production and energy management.

HMA plant start-up tips for the 2026 season

To keep the hot-mix asphalt (HMA) plant in top operating condition, it’s important not to rush or skip start-up steps. Here’s a quick guide to supplement the longer pre-check article found in the January issue and to walk your team through getting your asphalt plant running properly for a profitable summer.

First and foremost, think safety. It’s easy to get complacent after a long hiatus. Refresh yourself and your team on safety procedures before getting back to work.

Take the time for a thorough inspection. Visually inspect the components, looking for worn cables, broken water lines, damaged refractory tubes, and loose or missing shields. Work your way through the plant, checking for anything that’s worn, damaged, loose or missing after it’s been sitting idle during the winter:

• Start with the drive belts, looking for frayed spots and cracks, as well as checking the tension and alignment. Ensure it matches the owner’s manual.
• Then move to the sheaves, checking for cracks, chips or broken edges.
• Also look over the conveyor belts to ensure there’s no stretching, cuts or excessive wear. Also check that the drive pulley’s lagging is intact.

Change the oils. If you didn’t change oil in all of the gearboxes when shutting down at the end of 2025’s season, do that now. Pay attention to any signs of water or metal shavings, which indicate damage. Also replace the air compressor crankcase oil and any airline oils.

Keep all the parts moving with some testing. When moving parts don’t do what they should, the whole operation will suffer:

• Test the venturi gates, watching that they close completely.
• Check the spray nozzles and, if they’re clogged or broken, clean or replace them.
• Run through all of the gates, as well, ensuring correct operation for the silo gates, cold feed bin gates, gob hopper gates and drag conveyor bypass gates.
• Test the limit switch paddles and then move on to the controls, making sure the indicators and switches all operate properly.

Also check the alignment of the plant frame. If necessary, level it to ensure the least amount of trunnion wear.

Finally, know when to call a professional for assistance. Have a qualified service tech come in to tune the burner. This is something you want to do at least once, if not twice a year, as routine maintenance.

Mike Devine is the president of ADM FAYAT Group. For more information, please visit https://www.admasphaltplants.com/ex-series/

Get your winter plant upgrades and spring pre-check list to increase 2026’s production success

January is the right time of year for most North American asphalt producers to handle updates and upgrades at the hot-mix asphalt (HMA) plant. Maintenance activities that were too cumbersome to schedule during the height of construction season when a shutdown would mean a costly delay to production can be executed now.

Five original equipment manufacturers (OEMs) and plant service providers took time prior to seasonal shutdown to offer their top tips for making the most of your winter schedule. Starting with ideas for upgrading to enhance your 2026 production, these gentlemen offer non-branded advice you could implement before season startup. They also dive into the top maintenance issues you should be watching out for in today’s asphalt mix production climate.

“A plant dry run not only verifies equipment’s operational capacity but gives a team a baseline for typical plant noises and vibrations they can expect during operation. This gives the team a head start on keying in on new noises or smells that may indicate looming issues.”—Ted Hope

The 2026 Pre-Checklist for Your Plant

Check and Control the Burner

More than one source wanted to remind asphalt professionals of the burner at the heart of your HMA plant. Terry Elbert of Commercial Asphalt Plant Services, Minneapolis, Minnesota, suggested inspecting and performing maintenance on the burners prior to spring startup.

“Both the hot oil heater burner and rotary dryer burner have fans that suck in dust throughout the year,” Elbert said. “This dust can collect in and on areas such as impellers, dampers, pressure switches and lines, pilot valves, ignitors, and scanners. Buildup of debris on dampers can affect air-fuel ratios, resulting in inefficiency. Buildup on impellers can cause balance issues, resulting in premature bearing failure. Buildup of debris in pressure switch lines, ignitors and pilot valves/plumbing can result in the dreaded misfire. Just a little cleaning in these areas can save you a lot of trouble later.

“It is also a good idea to test burner safeties at this time,” he continued. He cautioned that some burners in the field might have safety switches that have failed or weren’t wired or adjusted properly.

Make Plans for Plant Maintenance this Winter

But don’t stop there. “While you’re at it, have your combustion gases analyzed. This will tell you if you are burning efficiently throughout the firing range. Sometimes small air-fuel adjustments can result in big savings.”

Ron Heap, the president of Tarmac International, Inc., Kansas City, Missouri, spoke of investing in burner control technology for remote monitoring and troubleshooting. He started with a financial scenario.

“Let’s say mid-year, a burner goes down and the plant cannot make repairs and bring the dryer back online,” Heap theorized. “It will cost $2,000 to get a burner tech to the site and $2,000 for him to return home. If there is one day of work, that brings the cost to $6,000. Add to that the lost revenue from being down. My suggestion is to invest in a burner control that allows the operator to see the instrument limit stream that caused the failure and allow a serviceman to get online and see the burner, negative pressure at the burner faceplate, and the ID fan function. 90% of the onsite service calls can now be via a phone call and an internet connection to the burner control.”

Iván Fernández Hevia, international sales director of Intrame, Valladolid, Spain, also highlighted the importance of investing in various controls, stating this will depend heavily on the specific plant being evaluated.

“Generally speaking, for an older plant, I would suggest upgrading the controls and automation systems, including a full set of sensors,” Fernández Hevia shared. “This allows operators to monitor and control every parameter, generate comprehensive reports, and ultimately reduce operating costs while detecting potential failures in advance.”

Does it snow on your plant? “For customers in cold regions with snow during the winter such as Greenland, Switzerland, United States and Poland, we usually recommend covering all the motors, allowing ventilation,” Intrame’s Fernández Hevia shared. “When snow slowly melts, moisture can get inside and damage the motors, so this helps prevent that.”

How Lubrication Strategies Cut Costs at the Plant

Analyze the Parts

“Each year it is required that a NFPA® (National Fire Protection Association) test be performed on the burner and the fuel train,” Heap said. “This can check the double block valves for leaks, which can reduce the risk of an explosion if both stay open when they should be closed. The review will also point out other instruments that have failed. Finally, the burner can be tuned for lower CO which saves money on fuel and reduces emissions of CO to the atmosphere.”

Michael Petrie, the president of Motion Engineering, Caledonia, Wisconsin, also addressed analyzing the burner’s efficiency prior to season startup.

“I recommend firing up the burner, lighting it, and cycling it up and down while making some test mix if possible,” Petrie shared. “Be sure to use an analyzer during this process as it is the only way to confirm proper fuel efficiency and reliable burner performance. Running test mix helps confirm that every component is ready for a smooth, productive asphalt season.”

Winter Asphalt Plant Greasing: What to Know and Avoid

The team at Astec Industries, Chattanooga, Tennessee, agreed with the importance of using an analyzer to double-check burner and fuel efficiency. They also recommended the use of another type of analyzer all over the plant. Ted Hope, the director of service at Astec, suggested plant personnel perform a thermographic electrical inspection.

“A thermographic electrical inspection helps reveal electrical issues with the equipment such as: Loose connections, which can be from installation, overtime due to vibrations, or even thermal cycling; undersized components; and failing or damaged breakers and starters. These catches early in the season can help avoid costly downtime and last-minute repairs. A thermographic electrical inspection can be done with just the equipment running but will reveal the best results under a load.

“The start of a season would be a great time to do an inspection,” Hope continued. “These inspections can help operators across all regions and plant sizes find and repair issues before they create downtime. It is always less costly to do the repairs on your schedule than the equipment’s.”

Get Clean Production Next Season

The inspection isn’t something your plant personnel will necessarily do on their own. Hope explained: “A thermographic electrical inspection requires an infrared thermal camera (major brands being FLIR or Fluke), but the inspection is almost always sold as a service. The reason for this is due to certifications and training the inspector must have to provide an adequate report and results. There are many providers across the world that provide this service.”

Along with investing in a thermographic electrical inspection, plant personnel should consider investing in an inline flow meter on the main gas line to track fuel consumption.

Petrie suggested this technology “provides precise tracking of fuel consumption, which is critical for optimizing plant efficiency. As the industry moves toward transparency and accountability of a plant’s carbon footprint, accurate tracking will likely at some point no longer be optional. This technology is one way to start collecting meaningful data to understand how your asphalt plant is performing to benchmark energy use. I think that in time, regulatory agencies will require documentation of fuel consumption per ton of asphalt produced. Adopting this technology early would allow for a strategic advantage.”

Get Strategic

Elbert suggested another technology that can add a strategic advantage as we head into 2026.

“As far as adding a new technology, my first choice as an operator would be license plate identification for trucks coming onto the scale,” Elbert said. “Information for that truck can be saved and auto populated on the scale ticket. This may not make sense for a smaller operation that utilizes the same small group of trucks but, for a larger operation selling multiple mix types to multiple customers, this can free up unnecessary CB chatter, reduce ticket errors and save data entry time. Any technology that allows your operator more time to focus on the plant will pay dividends.”

It will also pay dividends to run some strategic tests during the off season when performing maintenance doesn’t require an interruption in production.

“Run a rotational test on veiling,” Heap suggested. “Here you would run a plug of material into the drying section and watch the veil as it moves through the drying zone. Misadjusted drying flights can be easily seen, and a movie taken with a phone. Doing [such testing] improves safety and reduces dollars spent.”

Mix-and-Match Asphalt Plants

“Complete a dry run before starting up,” Astec’s team suggested.  “A trial run of the equipment can give the team on site time to test all the motors, belts and rotating steel—all before it is used to make asphalt. A plant dry run not only verifies equipment’s operational capacity but gives a team a baseline for typical plant noises and vibrations they can expect during operation. This gives the team a head start on keying in on new noises or smells that may indicate looming issues.”

Petrie recommended getting the tank farm hot and circulating liquid asphalt cement (AC) throughout the system.

“Circulation of the hot oil system is paramount to ensure that the meter pump is functioning properly and that there is proper flow without restriction in the system,” Petrie said. “It is important to check that valves and pumps are working properly and there are no blockages throughout the system. If this is not checked, it could lead to a multitude of problems including changing out valves and pumps, replacing or cleaning strainers, flow problems, and leaks.”

“This technology is one way to start collecting meaningful data to understand how your asphalt plant is performing to benchmark energy use.”—Michael Petrie

Back to Basics

Along with the guidance offered here, don’t forget the foundational concepts of good plant operation. If your plant has been running for a few years, the winter downtime is the right time to get back to basics with maintenance and inspection.

“I would encourage them to inspect the entire plant for buildup,” Elbert said. “Inspect the baghouse for buildup. Baghouses tend to condensate more at the end of the season as temperatures drop; this can lead to ‘mudding’ on the baghouse walls or on the auger grates if you have them. You will want to clean this so it doesn’t continue to build.

“Inspect the ductwork between the dryer and baghouse,” he continued. “Oftentimes, dust can settle out and build up in the bottom of the ductwork. This causes higher velocity and premature wear. Clean or chisel the recycle scoops and the drum mixing area. Check the silos. Buildup on the cones will not go away when you put hot mix on top of it; it will only continue to grow. Start the season out free of buildup throughout your plant.”

Top Plant Fixes to Plan for Winter Downtime

Hope also spoke of general housekeeping. “A clean and organized plant site greatly enhances the chance of catching issues before they turn into lost production time,” he shared. “Clean equipment can show leaks potentially long before the seal or bearing completely fails. This gives the plant personnel time to get the item replaced before its inevitable failure. This extends well beyond mechanical as a clean electrical cabinet or panel is not only safer but prevents potential issues caused by dust and greatly decreases troubleshooting time if an issue arises.”

By using this winter’s downtime to install meaningful upgrades and prepare your pre-startup checklist, you’re strategically planning for a prosperous 2026 and guarding against unpleasant surprises in the spring. At the end of the winter day, the guidance and ideas mentioned above are the top tips to help enhance your bottom line.

Resources for More Information

The original equipment manufacturers (OEMs) and service providers who responded to questions for this article took time to share their expertise with the readers of AsphaltPro and provided excellent information. To address additional questions you might have, reach out to them, or your specific OEM, directly.

Astec Industries

Ted Hope

thope@astecindustries.com

Office (423) 827-1591

Commercial Asphalt Plant Services

Terry Elbert

Terry@caplantservices.com

Office (763) 910-0051

Intrame

Iván Fernández Hevia

ivan.fernandez@intrame.com

Office (954) 865-9627

Motion Engineering

Michael Petrie

Mike@motionengineering.net

Office (414) 510-6097

Tarmac International

Ron Heap

Rheap@tarmacinc.com

Office (816) 220-0700

Editor’s Note: The Focus on Performance series from AsphaltPro Magazine allows OEMs and service providers to highlight professionals in the industry who have improved efficiencies and the bottom line through best practices and performance. This month’s installment features a case study with electric heat from Intrame.

This article explores the transition from traditional oil heating to electric heating systems for asphalt storage. With increasing focus on emissions reduction, energy efficiency and sustainability, electric heating offers operational and environmental advantages. Through technical analysis and real-world data, we evaluate the energy demands of maintaining asphalt temperature and compare the economic and environmental implications of both heating methods.

Of course, the data and figures presented in this article are intended to provide a general overview and to stimulate reflection on the potential benefits of transitioning to electric heating. They are based on typical conditions, and on theoretical calculations. However, actual values may vary significantly depending on many factors such as equipment design, meteorological conditions, electrical grid capacity, energy prices, fuels compositions, etc.

Asphalt plants are continuously evolving to reduce environmental impacts and increase efficiency. Some key development areas include:

• Reduction of pollutant emissions
• Increased use of recycled materials in asphalt mixes
• Lower productions and storage temperatures
• Improving production energy efficiency per ton of hot-mix asphalt

Increasing efficiency by reducing the energy required to produce each ton of hot mix offers the two main benefits of lower operational costs and reduced pollutant emissions and carbon footprint. This results in greener, more environmentally friendly and sustainable asphalt plants.

One approach to achieve these goals is to use electrical heating instead of oil heating. Throughout this article, we will explore how electric heating can be one of the answers to reducing both costs and emissions.

Electrify Asphalt Plant Heat Efficiency

A Case Study

This study is complex due to the numerous variables affecting the results. Some of these variables are the type and size of tanks, type and thickness of the thermal insulation, type and thickness of the tank cover/skin, filling level, medium ambient temperatures, average winds and storage temperature, among others.

As an initial approach to the energy required to maintain the temperature of liquid asphalt cement (AC) inside a tank, over a 24-hour period, we will use some heat transfer calculations, applied to a standard Intrame electrically heated tank, under the following conditions:

• Storage temperature of the liquid AC: 320ºF (160ºC)
• Tank capacity: 16,000 gallons (60m3)
• Tank filling level: 75% = 12,000 gallons (45m3)
• Liquid AC density: 60 lbs/ft3 (960kg/m3)
• Specific heat of the liquid AC: 0.501 BTU/Lb·ºF / 2.098 kJ/kg·ºK
• Average wind speed: 10 ft/s (6.82 MPH)
• Ambient Temperature: 50ºF

Meeker Spotlights Electric Heater & UL‑142 Tanks at World of Asphalt

Insulation:

• Material: mineral wool
• Thermic conductivity at 320ºF: 0.061W/(m·K)
• Thickness: 8 inches

External cover/skin:

• Material: aluminum
• Surface emissivity coefficient: 0.05
• Thickness: 1.2 mm

The theoretical energy required to maintain 12,000 gallons of liquid AC, at 320ºF, inside the tank, over 24 hours, under these conditions, using convection, conduction and radiation calculations, is approximately 200 kWh, which equals 16.7 Wh/gallon/day.

We have also remotely monitored the temperature drop of several tanks, when disconnecting the heating over a 24-hour period, at different times of the year, with different inside and outside temperatures and winds.

Process Heating Company Designs Lo-Density® Hot Oil for Auto Control, Even Temp

The first intuitive conclusions are:

• The fuller the tank, the slower temperature drop it has. An almost empty tank can lose temperature at a rate more than double that of a full tank.
• The hotter the AC is in the tanks, the faster it loses temperature.

After some field data analysis, we found an average temperature decrease in summer, from 11ºF to 14ºF per day, and from 14ºF to 18ºF per day in winter, when heating is disconnected at 320ºF.

With this information, we can calculate the energy required to maintain the temperature of the AC inside a tank, for a 24-hour period. This will be done using the most common tank size in Europe, which is 16,000 gallons (60m3), filled to ¾ capacity (12,000 gallons):

Assuming a total heating efficiency of 80% for the hot oil system, and 90% for the electric heating, the approximate energy output required for keeping the temperature in the tank at 320ºF is:

Hot oil system: 264 kWh = 22 Wh/gal

Electric system: 234 kWh = 19.5 Wh/gal

Please note that the figures above refer to 8-inch mineral wool insulated tanks. Electrically heated tanks are insulated with a minimum of 8 inches or even 12 inches of mineral wool, reducing thermal losses considerably.

According to EPA’s 2020 grid emission factors, CO₂ emissions of U.S. power generation grid are 0.818 lbs/kWh. Therefore, maintaining 12,000 gallons of liquid AC, at 320ºF for 24 hours using electric heating, will require an energy of 234 kWh, and will generate approximately 0.096 tons of CO₂/day.

Referencing the cost of the electrical energy according to the U.S. Energy Information Administration (EIA), the average cost in 2024 was $0.0844/kWh. Utilizing this cost factor, the cost of the electrical energy needed to maintain the temperature of the AC inside the tank at 320ºF is:

Depending on the geographical location and solar radiation availability, this cost may be further reduced by partially powering the electric heating system through photovoltaic energy, which also contributes to lowering overall emissions.

We have also collected field data from different plants, operating under diverse weather conditions, various tank specifications and AC types.

Based on this information, the average No.2 diesel oil consumption required to maintain the AC at target storage temperature is approximately 0.003 gallons of diesel per gallon of AC per day. Assuming an average fuel cost of $2.50 per gallon, this results in a daily heating cost of $0.0075 per gallon of AC, significantly higher than $0.0017 per gallon per day associated with electric heating.

In terms of emissions, maintaining the temperature of 12,000 gallons of AC using a hot oil heater would require burning: 0.003 x 12,000 = 36 gallons/day, which will emit 0.41 tons of CO₂/day, further reinforcing the environmental benefits of electric heating solutions.

In addition to the figures above, burning fuel to heat oil has other associated costs and disadvantages that should be considered, such as oil changes and scheduled emissions testing. In some countries, a 24-hour custodian is required to ensure safe operation of hot oil systems. This norm is gaining ground in more and more countries as the emphasis on safety and lowering insurance costs becomes more predominant worldwide. In these cases, an auto-shutdown feature is required. An assigned custodian must go to the heater and inspect to be sure everything is operating properly, then press a reset button before the allotted time in order to keep the system running.

Hot oil heaters are reliable and essential for multiple applications, and they have served the industry for decades. However, with growing emphasis on sustainability and cost control, electric heating is gaining ground. In countries like France, Spain, the United Kingdom and Poland, nearly 100% of all new asphalt plants are equipped with electric heating.

Electric heating of AC storage tanks represents a forward-looking solution for the asphalt production industry. It offers a compelling combination of economic savings, operational simplicity and environmental responsibility. As energy prices and emissions regulations continue to evolve, the adoption of electric heating systems will likely become the new standard across global markets.

Iván Fernández Hevia is the international director at Intrame, managing operations across nearly 50 countries. He brings deep expertise in navigating the technical and regulatory specifications of diverse markets.