Cyclonic particulate filters

[Stuart]

I'm contemplating building a small device like this to see if it actually works on my exhaust. Apparently Dyson, the vacuum cleaner guy, made one but the authorities didn't like the fact that everyone would have these little bags of toxic waste to dispose of. Much better we should all breath it in they said
http://en.wikipedia.org/wiki/Cyclonic_separation

[sbrumby]

Apparently the merc sprinter has a particle catcher so it complies with the latest regs, and it also passes on test. But here is the catch, every so often a valve opens and dumps to atmosphere. So if you are following a sprinter and you see a puff of smoke you will know what it is.

[Stuart]

I might have to look out for one of them up the breakers Are you sure it's cyclonic in style and not a mesh Part of the reason for experimenting is that I want to be able to reuse. Maybe a good compromise would be to have a water chamber attached which, when heated by the exhaust, squrts the resulting steam at the collected particles That would allow them to drip out and down and keep them from re-entering the air. It might also keep the business end of the device clean.

I'm messing with a copper cylinder rescued from a skip at the moment. It has a detachable bottom end complete with hole and centre tube. I shall lose the tube but use it's base as the point of the accelorator cone. I'm holing that I can silver solder parts of it and that it will not melt with the exhaust heat

[forhire]

I have thought about this myself. I wonder how small you could make one and still get results?

Here's a good read on the topic:
http://www.academicjournals.org/jpge/PD ... %20al..pdf

From the conclusion of the above document:
"A simple cyclonic separator reduces PM from diesel
exhaust about 34-61% without deteriorating other
emissions and fuel consumption. Average cyclonic
efficiency increased with the increase in speeds and
loads. Average cyclonic efficiency increased from 37% at
650 rpm to 59% at 1200 rpm."

[andrewaust]

Interesting reading guy's, might have to look further into it myself.


A

[Stuart]

I've been sidetracked away from this as I am building a fake silencer to replace the left side one. It will be good storage device and stop ppl asking where the pipe has gone
I got for 4" pipe from the breakers but had to cut it long ways as silensor is wider. Made main bracket today from durillium ( I think that's right) and its strong and light. The fun bit will be finding a suitable lock & inserting the key into the hole to open it

[andrewaust]

Sounds like a nifty idea Stuart, good thinking !!


A

[Stuart]

It was Sönkes idea but I digress!

I got hold of an ally oil filter which I may cut down and try to form into the cone that will go inside the assy. Kind'a wondering whether it will melt It's not a priority at the moment but watch this space

[Stuart]

Looks like you can buy them If you have deep pockets

http://www.alibaba.com/product-gs/47192 ... image.html

[macspud]

Here's a link to an article on the Dyson exhaust particulate filter.
http://books.google.co.uk/books?id=BTUB ... er&f=false

[Stuart]

Cheers for that Great find! Just this week I gave a cone shaped bit of card to a metal worker friend of mine to shape. Hopefully he will use stainless. Making a cone out of metal is a bit beyond me just now. I will post details as & when they come but I can't pressurise my man as its a favour he's doing me.

[Stuart]

I now have my cone and am continuing the build Might have to get silver soldering soon...

Ok, coming together. I have a stainless heat-shield within the main body and now need to fix a lid on somehow. Then I need to afix the verticle 'out' pipe and a capture canister to the bottom. Blunting drills on the stainless earlier

[Stuart]

Strapped the device onto the bike the other day and the exhaust gases seem to be passing through it ok. I'll need to make a container to fix on the bottom yet though to collect the soot/particles.
In soldering up the downpipe my one concern was that I'd fix it too low near the point of the internal cone and thus restrict the flow of gases. By my reckoning its about 1.5" up from that point giving the gases 5.5 to 6" on cone to accelerate up in before shooting up the middle and out.
I'll have to run this under load and for a time before I see substantive results. It will be a while before I can figure a container though.