Eberspaecher North America believes its aftertreatment emissions system for on-highway trucks, soon to enter production, is "ideally suited" for off-highway vehicle applications.
"From an emissions standpoint, the system will be principally the same and will use a diesel oxidation catalyst and diesel particulate filter followed by urea-based selective catalytic reduction technologies. The only differences will be application related, like lower surface temperature requirements for the device, serviceability, and flexibility/modularity of design for the various off-road products," said Martin Romzek, Vice President of Advanced Engineering for Eberspaecher NA.
Various software tools will help Eberspaecher fine-tune its emissions system to meet the unique needs of off-highway vehicles. For instance, thermodynamic tools will help ensure low-temperature system surface temperature since certain off-highway vehicles come in close contact with weeds, grass, and other potential flame-igniting hazards.
"We can predict the thermal behavior of our emissions systems using a conjugate heat transfer calculation. That calculation—performed in our CFD tool—enables us to incorporate the heat source of the exhaust gas during regeneration along with the thermal conductivities of all internal components. By getting a complete picture of the thermal behavior—both internally and externally of the emissions unit—use of this analytical tool ensures that our design concept will adhere to very low surface temperature requirements prior to building any parts or doing any testing," said Romzek.
Because certain off-highway vehicles experience higher acceleration loads than passenger vehicles or heavy trucks, Eberspaecher engineers will rely on durability tools to predict the consequences. "FEA tools refined in our on-highway work will incorporate higher design targets to ensure that our concept designs are sufficient prior to any prototyping or testing," said Romzek. "From a CAD 3-D modeling standpoint, we see a high need for using 'parametric design.' By incorporating basic dimensions and criteria into a generic model, we can make very quick changes to facilitate the design and development of very flexible/modular concepts."
Eberspaecher begins producing its commercial on-highway vehicle exhaust aftertreatment systems this year. The company's 100,000-ft2 (9290-m2) Wixom, MI, canning plant houses the "equipment that produces the stainless steel converter shells using the latest roll forming and laser welding manufacturing technology," said Jack Pogorzelski, Director of Sales for Off-Highway Commercial Vehicle OEM Business at Eberspaecher NA.
The final production stage at the Wixom plant is the sizing process. "The pre-assembled converter is sized to achieve the optimum monolith retention force. What is unique about this process is the capability to individually size the shell to allow for the dimensional tolerance of each monolith and the tolerance in the density of each mat," said Pogorzelski, noting such high accuracy levels address durability requirements by ensuring monolith retention over the life of the vehicle.
Converter assemblies from the Wixom facility will be shipped to a 120,000-ft2 (11,150-m2) Brighton, MI, plant for final aftertreatment system assembly. "We will add production capacity, if necessary, to meet additional off-road market needs for final Tier 4 emissions regulations that start in 2013," said Pogorzelski.
Eberspaecher NA's production capacity for 2010 commercial on-highway truck systems is approximately 200,000 units a year. "Although we do not currently have off-highway contracts, we are working diligently with several potential clients. Most of the aftertreatment emissions systems for off-highway will enter production throughout 2013," said Romzek.