Processing using cavitation

[photoman290]

http://repositorium.sdum.uminho.pt/bitstream/1822/3674/1/SSChE2005-176p%5B1%5D.pdf

seems to work for me. takes me to a pdf of the system.

[greasemonkey]

HTTP Status 404 - /bitstream/1822/3674/1/SSChE2005-176p[1].pdf

type Status report

message /bitstream/1822/3674/1/SSChE2005-176p[1].pdf

description The requested resource (/bitstream/1822/3674/1/SSChE2005-176p[1].pdf) is not available.

Apache Tomcat/7.0.25

[Julian]

http://repositorium.sdum.uminho.pt/bitstream/1822/3674/1/SSChE2005-176p%5B1%5D.pdf

seems to work for me. takes me to a pdf of the system.

Interested in seeing that, but like GM, the link doesn't work for me either.

How big is the pdf?

[Head Womble]

I used to suffer cavitation in my 110lpm pump, this was when I was running 22mm pipework and only during demeth when the temp was over 75°,
in this case the cavitation is the meths flashing to vapour due to the low pressure at the pump inlet.

It seems there are a few different forms of cavitation, high or low pressure.

[greasemonkey]

Log out and click the link. Worked for me. Weird.

[photoman290]

the trick to getting the  ASM and the oil to mix properly within a OFR (oscillatory flow reactor) is getting  the speed of the plunger right.  i am thinking windscreen wiper motor. the Cambridge uni one used a cam  on the end of the plunger and adjusted the stroke. the pinched tube idea would make it possible to experiment with the method without spending a lot of money. will try it with the plastic tube and hose clips first.
 you don't need a large plunger so something like a small pneumatic cylinder might work. some thing like the rig in the video at the start of the thread but  just change the middle bit with the pump should work.

[Julian]

This?




Certainly easy to knock up!  Blurb with this diagram states the baffles need sharp edges (presumably to create turbulence), so I'm not sure squashing tubes would work.

You seem to be describing a metering pump for the ASM injection.  The fuel emulsification system I worked on used one to dose the water and catalyst mixture.  But it would need to be set in respect of the oil flow through the OFR (unless you under dose and assume several passes.  A possible drawback would be glycerin accumulation between the baffles unless it was mounted vertically.

[Julian]

Three meetering pumps here ... http://www.ebay.co.uk/itm/ELECTRONIC-METERING-PUMP-/190927943875?pt=LH_DefaultDomain_3&hash=item2c743138c3#ht_95wt_1134





Or what about a speed controlled peristeltic pump?

[photoman290]

yes that is the basic system. the squashed tube idea is supposed to work just as well.,and is even easier to knock up. i was thinking you could mix the oil and catalyst together in a container cold or  below 65 degrees, and introduce it to the OFR though the plunger then heat it as it is pumped around the system. think that was how they did it at uni,but it was a long time ago and i wasnt taking notes. of course in the modern age you would just film it with your phone. for the plunger i was thinking a  toilet cytem diaphragm may work. have to test it in some bio first of course, although it will only be in contact with the oil and meth rather than finished bio.

thge reason i thought it would be worth rearecting this idea was the rig in the cavitaion video is ideal for experimenting. could try both methods and see if which one works best.

[photoman290]

if the link i  posted doesn't work. try putting n reis ofr into google. comes up as 2nd entry on google. or did a minute ago.

[mon]

Would something like an ultrasonic cleaner work.

100W transducers and driver circuit for ~£70

http://www.ebay.co.uk/itm/100W-ULTRASOUND-GENERATOR-and-40KHz-Ultrasonic-transducer-Cleaner-/221289920476?pt=LH_DefaultDomain_0&hash=item3385e837dc

Maybe attach directly to the reactor and or pipework, although I'm not sure what longterm effect this would have on Copper, maybe stick in onto steel/stainless steel pipe work?

[Julian]

Would something like an ultrasonic cleaner work.

100W transducers and driver circuit for ~£70

http://www.ebay.co.uk/itm/100W-ULTRASOUND-GENERATOR-and-40KHz-Ultrasonic-transducer-Cleaner-/221289920476?pt=LH_DefaultDomain_0&hash=item3385e837dc

Maybe attach directly to the reactor and or pipework, although I'm not sure what longterm effect this would have on Copper, maybe stick in onto steel/stainless steel pipe work?

Ultrasonic cleaning baths work by creating cavitation and there are some commercial setups use ultrasonics, bit they are much more powerful.  Every so often I snipe a load of ultrasonic cleaning baths, but they all go for far more than I'm willing to pay.

What you link to may well do the same as a cleaning bath ... I think it's about the same power ... might be worth a shot if someone is willing to fork out.

[Jamesrl]

This?




Certainly easy to knock up!  Blurb with this diagram states the baffles need sharp edges (presumably to create turbulence), so I'm not sure squashing tubes would work.

I built a version similar to that but swagged copper tube and had 3 running in parallel, compared to a 2 stage educator it was close to useless.

[therecklessengineer]

I've started wondering if what I know as an ejector, where a jet fires across a void before entering the throat, might not be a better design ... all the serious commercial devices are made that way.

I use an ejector on my plant which I made on the lathe at work. It works brilliantly well and in my experience better than a venturi - but then I've never been able to make a venturi perform as others claim.

[Jamesrl]

My best performing venturi was an ejector, work that one out.