A DEF JAM FOR OFF-HIGHWAY?

摘要

As SCR moves into more off-road applications at Tier 4 final, contamination becoming a major concern. In some ways, diesel exhaust fluid (DEF) is a simple product. Just a mixture of 32.5% urea, the rest deionized water. That's it. But even simple things have a way of going awry when the human element is added to the mix. Now, as more Tier 4 final engines incorporating selective catalytic reduction (SCR) aftertreatment systems that use DEF to reduce emissions are being used in off-road applications, there's growing concern among many in the industry that operators and maintenance staff don't know how to handle the sensitive fluid. The biggest risks to DEF in off-road applications come from the dust and dirt common on most worksites as well as from contamination from other fluids - even water - because of improper storage or misuse. And that lack of knowledge can come with a steep price: contaminated DEF will eventually shut down a machine and can force expensive repairs.