Almost 100 Hrs, No Regen?

[sheepfarmer]

Soot builds up in 2 ways, low idle speed, and working it HARD where a lot of fuel is used to maintain RPM. If you are running at high RPM with little load, such as towing a ground driven rake, then you can go a very long time before a regen is needed. If you are tilling or hogging thick weeds and really working the engine where you can hear it burning more fuel, then you will have shorter regen cycles.

Not much different than road trucks on the Interstate. If towing a trailer, then a regen happens more frequently than if just tooling down the highway empty.

Idling soots up the DPF quickly, so avoid idle time as much as possible.

When running at optimum levels, high RPM with a lean mixture, there is less actual soot, and the DPF gets hot enough so soot doesn't accumulate, but as you dump more fuel in for working to keep the RPM up, then the exhaust coming out of the cylinder is heavily sooted and that sticks well because there is also more unburned fuel in there as well.

Also keep in mind that there is no DEF to help catalyze the exhaust, only the DPF to capture soot.

I am wondering about your observation that when you are really working the engine hard so as to make it burn more fuel that it creates more soot and more regens and more unburned fuel. I am thinking that this may be engine and tractor dependent. While it makes sense, the computer control of the common rail fuel supply is pretty good in my very limited experience with an L3560. I am guessing there is very little unburned fuel. You can watch the dpf per cent full graph as you work. It indeed goes up quickly as it warms up and if you let it idle. On mine if you work it hard the soot meter runs backwards as it burns off some soot. Under my version of light work it goes up slowly. Real data unfortunately might be hard to come by.

 

[ACDII]

When lugging the engine with hard use, like say hogging and hit a really thick patch that bogs the engine down is when the soot builds quickly with unburned fuel coating the DPF. Note there is a difference between unburned fuel and raw fuel. The unburned particles have lost their volatility and are basically just oil at that point.

Running at a high RPM at a steady working pace without any lugging is what you are referring to, and is the optimum performance mode to go the longest between regen cycles. The regen dumps raw fuel into the DPF to burn off the waste oil and soot.

When driving my. lets say light exhaust featured F350 down the interstate @ 70 MPH the fender above the pipe is clean. When I hook my 5th wheel up and do 70 with hard accelerations to get up to speed and taking hills, the fender turns black and I can see the exhaust coming out on a grade.

It's this type of work I refer to above. The engine controls can optimize fuel rates to provide just the right amount of fuel to reduce soot levels when working at a steady pace, its the lugging when more fuel is dumped in to increase the RPM back up that produces the most soot.