small diesel engine cat con ??
small diesel engine cat con ??
(OP)
ok, here is the scoop
a single cylinder diesel test engine, driving a fixed
load of 8kwatts (generator) at a fixed speed of 1800rpm
the exhaust gas leaving the exhaust port is 640 degrees F
the exhaust is going into a prototype heat exchanger
i would like to insert a small catalytic converter between the exhaust port and the heat exchanger
can i use a cat made for a gas engine?
if not why not? if maybe how long will it last?
any input would be appreciated
what i am trying to determine is if i can do some cleaning of the exhaust stream and in doing so improve the quality of the exhaust stream heat.
the engine will also be used in a dual fuel mode, wherein it will be fueled ~90% with propane or natural gas.
if the gas cat will not work at all, where can i get a 1.75"
cat that will work on a diesel engine?
bob g
a single cylinder diesel test engine, driving a fixed
load of 8kwatts (generator) at a fixed speed of 1800rpm
the exhaust gas leaving the exhaust port is 640 degrees F
the exhaust is going into a prototype heat exchanger
i would like to insert a small catalytic converter between the exhaust port and the heat exchanger
can i use a cat made for a gas engine?
if not why not? if maybe how long will it last?
any input would be appreciated
what i am trying to determine is if i can do some cleaning of the exhaust stream and in doing so improve the quality of the exhaust stream heat.
the engine will also be used in a dual fuel mode, wherein it will be fueled ~90% with propane or natural gas.
if the gas cat will not work at all, where can i get a 1.75"
cat that will work on a diesel engine?
bob g





RE: small diesel engine cat con ??
The catalyst from a VW TDI diesel is the smallest diesel one that I know of.
RE: small diesel engine cat con ??
Mike Halloran
Pembroke Pines, FL, USA
RE: small diesel engine cat con ??
i am a bit concerned with particulate clogging as well, and am thinking of secondary injection to do a periodic burn off.
are the cats able to burn some soot?
or do i need a filter before the cat that can be periodically burned off?
thanks
bob g
www.microcogen.info
RE: small diesel engine cat con ??
ISZ
RE: small diesel engine cat con ??
- Steve
RE: small diesel engine cat con ??
You want an oxidation catalyst (25% soot reduction) or a catalyzed diesel particulate filter (95% or more reduction). You can talk to Miratech, DCL, CleanAIR Systems, Johnson Mathey, and countless other suppliers about getting one.
RE: small diesel engine cat con ??
Cheers
Greg Locock
SIG:Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips.
RE: small diesel engine cat con ??
- Steve
RE: small diesel engine cat con ??
RE: small diesel engine cat con ??
The catalyst on earlier VW TDI's was an oxidizing catalyst, which didn't do much, because engine-out HC and CO emissions from a properly-tuned direct-injection diesel are ordinarily already rather low. The new ones (2009+) have an extremely sophisticated system with an oxidizing catalyst and DPF in the same housing mounted as close to the engine as possible, since both of those function best when they are hot. There is a de-NOx catalyst a carefully selected distance down the pipe, since that device wants to operate in a lower temperature range. This is combined with an extremely complex engine control strategy because both the DPF and the de-NOx catalysts require periodic regeneration, which is done by making the engine operate differently, even under the same load conditions. Regenerating the DPF requires raising the exhaust temperature under lean operating conditions at intervals (imagine trying to set the soot on fire - it's not quite like that, but it's analogous - you need oxygen and heat) and regenerating the de-NOx catalyst requires running stoichiometric at intervals. The two regeneration intervals are not the same.
I'm not sure if the original poster wants to open that can of worms, or just use an oxidizing catalyst, which will be largely a cosmetic device if the engine is properly tuned.
RE: small diesel engine cat con ??
reading and now understand about enough to be dangerous
but hopefully enough to do what i am wanting to do.
because the engine runs at steady state, under full load
i can maintain temperatures without issue, and due to other control systems being designed and used on the engine adding a regeneration cycle is not much trouble.
as for adding fuel to burn off, that is probably the direction i will go because the burned fuel does not equate to loss, but rather the added heat will be recovered in the heat exchanger downstream anyway.
thanks
bob g
www.microcogen.info
RE: small diesel engine cat con ??
Fair call. I know very little. The one I've seen has some little cats near the header and some big ones under the floor. That is just about the full extent of my knowledge about diesel cats, all I really know is they get in the way of 'my' suspension and fuel tank.
Cheers
Greg Locock
SIG:Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips.