Centrifuge photos for Knighty

[Julian]

God, I'm good ... it only took me about 10 mins to find them ... I even found an AutoCAD section

Let me know if they need explanation ...

















  Oh, this is a wmf file that appears not to open in the forum

Here's a copy converted to png, but it's not as clear, sorry!

[knighty]

ohhhhh

thats exactly what I need

are you interested in selling ?

I've been looking for somewhere to make me a bowl so I could build the rest around it - guess you know the ready to use ones are crazy money :-o


I said 2 litres/min in the other thread as a total guess... I'm going to have it mounted on the floor above my settling tank, so I can pump it up there and let it drain back down.... once it's filtered enough I can turn a couple of tamps so it drains to my storage tank instead

(thats the plan anyway)


and/or see how it comes out after 1 pass, if it's good enough might just pass it through once :-)

[Dickjotec]

I made one yonks ago from an aluminium saucepan in a cut off beer barrel. it worked OK but I didn't use it much so put it in an auction. Iirc the design was on the web on an American site.

[Julian]

ohhhhh

thats exactly what I need

are you interested in selling ?

I've been looking for somewhere to make me a bowl so I could build the rest around it - guess you know the ready to use ones are crazy money :-o


I said 2 litres/min in the other thread as a total guess... I'm going to have it mounted on the floor above my settling tank, so I can pump it up there and let it drain back down.... once it's filtered enough I can turn a couple of tamps so it drains to my storage tank instead

(thats the plan anyway)


and/or see how it comes out after 1 pass, if it's good enough might just pass it through once :-)

Not keen on selling as it was fabricated completely from sheet ali. using one of these new ali. soldering alloys and I'm a little concerned about it's strength.  If it disintegrates while running it could do considerable damage!

Casting a bowl shouldn't be too difficult.  Smashed up bell housings would make good material.

I only ever tried the centrifuge on WVO, not bio.  If I can build a "blast box" that will retain any shrapnel, i might try it on bio.

[oakwoodtv]

Would an aluminum pressure cooker be strong enough for the bowl.

[knighty]

I was worried I wouldn't be able to cast a bowl that was balanced enough... same for large pots / pressure cookers

I want to leave it running overnight (trying to set up for as little hands on time as possible) so it needs to be well balanced / reliable because if something goes wrong I won't be there to turn it off



there's only one local place I know with laths big enough to make a bowl, but they take forever to get anything done... last job they did for me was a 20min job... took them 18 months !
(and that's with me dropping in every few weeks to check up on it)

[Dickjotec]

Don't know if you could leave it running. The design I used had to have the crud removed as it sticks to the side of the 'fuge. It is semi solid so will not drain out. Once the rim is full then the cleaning stops. It depends how clean the liquid being 'fuged is I suppose.

[Julian]

Dick's right, but you can increase the capacity in three ways ...

Make the bowl deeper, make the bowl a bigger diameter or best option form an effectiveness point of view, if not fabrication, make the bowl taller.  A taller bowl will give a longer dwell time in the centrifuge as the liquid enters at the bottom and exits at the top.

I have seen centrifuges comprising horizontal cylinders which rely on a long transit time from one end to the other ... might be the way to go as the cylinder can be supported on bearings at both ends.

[Dickjotec]

Diameter is key though. The bigger the diameter the higher the G force for a given RPM. IIRC  a 200mm diameter at about 3000 RPM gives about 1000G. The higher the G the faster the particles go to the edge and the smaller the particles  that will be filtered out.

[Julian]

My rotor diameter was limited by what would fit on my lathe, so it ended up 180mm OD, but we were talking of ways to increase the crud capacity.

[Julian]

Would an aluminum pressure cooker be strong enough for the bowl.

As it's one piece, either drawn or spun, I'd have said it would be.  Don't forget though you need a partial lid to trap the oil/bio in the bowl.

[Dickjotec]

Sorry J it was intended for anyone who did not understand the principles.
The top for the pan, on mine, was machined from a piece of aluminium in a top hat form so it could be pressed in and held with set screws radially. I think it was about 1/2 inch thick.

[knighty]

I've emailed a few places about having a bowl made, I'll see what happens

once place I found making them casts the bowls and then I guess turns them down afterwards - I know a casting place so that might be an option ?

I've got a lathe, myford ml7, but it's a bit small for any big/heavy work :-)


hopefully the bowl will be able to hold more than enough crud for me.... if not I can always run it during the day and check on it every few hours to clean it out

[Julian]

Mine's an ML7 too, so you'd most likely be limited to 180mm OD.

[knighty]

http://www.wvodesigns.com/rpc-poboy-kit.html

~£200 delivered to uk is the best I can find so far

don't think I could have one made for much less than that... bug chunk of aluminium to start with then lots of machine time will probably add up quick !


they do a ready to use one for ~£600 delivered to uk... I don't want to spend that much but it is very tempting... at least I could get it up and running quick! (not much free time)