Equipment World Digital Magazine
Issue link: http://read.dmtmag.com/i/521868
EquipmentWorld.com | June 2015 87 particles. These, they say pose the greatest threat to lung health in that they can lodge deep inside lungs and stay there. And how do you get rid of ulta-fine soot particles? With the good old diesel particulate filter. The DPF made its first appear- ance in Tier 3, as a way to scrub out large soot particles. Most were large and required changes to the sheet metal and sight lines on the equipment. And they had to be purged (what the industry called "regenerated") every so often. That meant stopping the machine while a blast of fuel was injected into the exhaust raising temperatures in the DPF to burn off accumulated soot. DPFs also eventually filled up with unburned ash, which meant they had to be replaced or cleaned with a specialized machine. OEMs quickly set about to improve the situation. In smaller engines it was easy to meet the emissions standards without DPFs. This was done by tweaking EGR rates, injection and valve timing and using a diesel oxidation catalyst which also pulls soot out of the exhaust but neutralizes it much like a catalytic converter. Today you'll see a lot of OEMs making a point about having no-DPF engines. But when you get above 75 to 125 horsepower, engines make a lot more soot especially under the heavy loads big earthmoving machines encounter everyday. In most cases a DPF is necessary to bring these engines into compli- ance. For the future, if Stage V and Tier 5 go forward as anticipated, a DPF will likely be included on every diesel engine, large or small, stationary or mobile, by 2020. At Intermat there were five press events where engine OEMs show- cased their Stage V-ready engines. Most have tweaked their designs so at least the size of the DPF is minimized. Many are offering what they call "one can" solutions, meaning the DPF, DOC and SCR dosing hardware are all joined to- gether in one canister, rather than separate elements. But the DPFs that are on the shelves today will do the job just fine. They're capable of taking out the big soot particles as well as the ultra-fine stuff. No resizing or new filtration media will be re- quired and exhaust backpressures won't change. Now if we can only get the EPA to make a decision. Short Lead-times from North American Distribution Locations CONTACT YOUR LOCAL DEALER OR DISTRIBUTOR AT: 800-459-SEAT (7328) / WWW.CVGRP.COM ution Locations American Distr Material Handling Construction Agriculture Forestry Mining Crane Paving Untitled-7 1 5/27/15 9:46 AM