Equipment World Digital Magazine
Issue link: http://read.dmtmag.com/i/885126
T he day you take delivery of a new machine is one of excite- ment and celebration. But this year, and in the future, the thrill of new iron should be tempered with a thorough plan to manage the new exhaust emissions systems that come with your Tier 4 Final equipment. Exhaust emissions from diesel en- gines have been cut by more than 95 percent in the last decade. To get diesel exhaust this clean, Tier 4 Final engines above 74 horsepower use a technology called selective catalytic reduction (SCR) and need regular refills of a product you'll be dealing with a lot – diesel exhaust fluid (DEF). In an SCR system DEF is sprayed into the exhaust stream before it enters a catalytic chamber. In the catalytic chamber the DEF converts to ammonia and changes the NOx in the exhaust (a harmful pollutant and source of smog) into harmless water and nitrogen. SCR technology is an ingenious EquipmentWorld.com | October 2017 49 engines | by Tom Jackson | TJackson@randallreilly.com MANAGING TIER 4 FINAL EMISSIONS SYSTEMS New engines above 74 horsepower come with sophisticated exhaust aftertreatment technology that demands preparation and protocols.