soot filter regeneration: passive or active?

I'm looking into soot filters and would like to know if the heavy duty trucks sees a lot of active regeneration or is not happening that often. I have seen the video from Volvo Trucks website and seems that active regenerations hardly should occur for long haul trucks. Do you notice you have an active regeneration going on?

Thanks Truckers for your response.

 

It depends a great deal on application. Heavy hauls tend to be mostly passive. Light loads in cooler climates tend to have more frequent active regeneration going on although most regens still occur in route running down the highway versus having to pull over and do a forced regen manually. At Mid America Truck show last week, most of the discussion I heard was that no engine mfg. has been perfect so far and there is a lot of updates to current products in the field today. Adding in the problem of drivers mis-fueling the new engines with high sulfur fuel is not helping things either.

 

Ok, this is a complex question that is going to require a complex answer due to the different types of driving being done. From what I have been told during a regen the best rpm to be at to help accelerate the regen process is around 1200-1400 rpm. This will slow the air flow down enough to create a large amount of heat. Now this is if you are pulling a load. I delivered a truck from Columbus Indiana to, well let’s just say Washington state. During that trip I only had two regens. Once because I idled the truck overnight and the other from use. This was an isx and the truck was bobtailing. Now at work we have trucks running with full loads that are doing regens every 8 hours. Granted this does not represent the large population of Cummins engines out there. Now on another truck it was doing 2 regens per 11 hours of driving. It all depends on the rpm at which you drive. So to answer your first question for long haul truck an active regen should not be an everyday occurrence unless you idle a lot or sit in traffic a lot. To answer your second question, on Cummins engines you should not be able to notice that the regen is happening. You have four stages at which your engine will handle this. The first two recognize that the filter is getting full and start adjusting you engine to fix this. These are minor things that you will never notice such as egr valve closing. Number three will start to limit your engines abilities to meet emissions. This is your engine shutting off all emission equipment to handle the “fault” because at this point your check engine light should be on. Still no limiting on your engines power. The fourth step limits your engines power and speed. It becomes a dog, no power at all. This forces you to try and find a shop to fix it. Step five really is not a step, this is why I did not list it, it will force you to shut your engine down, if you do not it will do everything to try and make you shut down. Buzzer and alarms going off everywhere including a stop engine light. I have been to this point before a couple of times, it is not pleasant. If you keep going you risk cracking the filter. This will give you your power back. Now you will have to replace this $3,500 filter though. It will also let black smoke or soot out, you will be able to see it. Now let me tell you this, it is a lot harder to break these filters than everyone wants you to believe. I spent 30 minutes with one hitting it with a pry bar and sledgehammer to get the filter out of the housing. Back to the topic though, if you do a lot of stop and go then you will have more regens. If you do not get up to a minimum of 1200 rpm it will not do a regen. It will wait until you get up to 1200 rpm. If you have any more question please ask.