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Oh gush

PostPosted: Mon Mar 26, 2018 6:10 pm
by Onlyalittlebitdodge
I've assembled what I thought was a bit of a bastardised neutraliser, but what appears to be a geyser. I'm running a 50L boiler with a controlled 2400W element. Two 4" bubble plates go to 4"-2" reducer, 500mm of 2" packed section with a 2" x 300mm reflux condensor (I'm cleaning out some old heads and tails). If I try to run with the RC cooling, even at a very very low flow, my off take gushes. I removed half the packing and got the same result. If I turn off the RC water and control my flow using the element variac then everything works ok. My current hypothesis is a build up of product (and pressure?) below the RC...? Thoughts and/or questions? I've shutdown for the day with the aim to return to try and nut this out in the next day or two.
Cheers

Re: Oh gush

PostPosted: Mon Mar 26, 2018 6:17 pm
by The Stig
What % is your old heads/tails ?

Re: Oh gush

PostPosted: Mon Mar 26, 2018 6:25 pm
by Onlyalittlebitdodge
Approximately 28%

Re: Oh gush

PostPosted: Mon Mar 26, 2018 6:28 pm
by bluc
Flow increases when rc is used? :think: how is cooling water setup? So you have 2 4" plates feeding a 2" packed section and rc? Perhaps its flooding?
Not sure how high up a 4" sections sight glass, liquid would havd to be to flood a 2" packed section..

Re: Oh gush

PostPosted: Mon Mar 26, 2018 6:30 pm
by Onlyalittlebitdodge
Cooling water splits direct through the PC and through a valve into the RC. The outlet water for both go into a common hose. I'm wondering if the reduction from 4" to 2" before the packed section but after the bubble plates might have something to do with it

Re: Oh gush

PostPosted: Mon Mar 26, 2018 6:36 pm
by bluc
If straight off hose/tap pressure fluctuations can reek havoc with flow/abv.. but also 4" plates into 2" packed section I reakon could be an issue.. :-B I only have very limited experience with bubblers/ reflux stills....

Re: Oh gush

PostPosted: Mon Mar 26, 2018 6:47 pm
by Onlyalittlebitdodge
No town water so cooling is run off a pump - flow is steady. I tried slowly creeping down the flow to the RC and it went from approx 2 drips/sec to a geyser, no real inbetween stage. The bubble plates look to be ok, maybe the fluid level seems a little high but certainly not filling up. It is almost as though the packed section is filling up and then all fluid gets viciously ejected in a half litre burst

Re: Oh gush

PostPosted: Mon Mar 26, 2018 6:49 pm
by orcy
You sure it's not just just puking up the column. Or are the plates flooding and causing partial blockage which then surges through?

Re: Oh gush

PostPosted: Mon Mar 26, 2018 8:17 pm
by db1979
bluc wrote:but also 4" plates into 2" packed section I reakon could be an issue.

:text-+1:
Bubblers run faster than packed columns and 4" is 4 times faster than 2". So if you're running at the right speed for your 4" then your running way too fast for the 2". What do you normally run through this configuration? Is this an unusually high abv for it?

Re: Oh gush

PostPosted: Tue Mar 27, 2018 8:26 am
by Onlyalittlebitdodge
That makes sense to me then. This was the first run using this configuration. I've only recently started doing CFW and a nutri grain with malt extract variation which were run as a pot still without bubble plates. I had heads n tails left over and wanted to run them through for a neutral to keep up supplies until the VFW/NG are ready. Looks like I best get a 4" packed section and 4" RC, not the 2" ones I erroneously purchased. fml.
Cheers

Re: Oh gush

PostPosted: Sun Apr 08, 2018 6:16 pm
by Onlyalittlebitdodge
I spent some time doing some experimenting today. Turns out the issue come down to operator error and a lack of patience.

I was running the water through a t-piece which fed both the PC and the RC, and then the outlets of the PC & RC went again to a t-piece before returning to the tank. Trying to balance both flows created variables with not much tolerance for error, and temperature control was the other variable.
Using the t-piece was inconsistent as the water would naturally take the easiest path, essentially a non-linear flow resulted when trying to restrict only the RC flow while the PC flow was completely open. The 3m head back into the tank didn't help with the RC & PC outlet flows using the same hose also.
I was trying to balance flows and the element. I didn't have enough power going to my element to properly load the plates. Fluid would build up in the bubbletee and just sort of sit there with no observable bubbling going on. But the fluid was still building up. This had me looking for other issues rather than simple matter of not giving it enough grunt. With the plates loading in this way and vapour slowly heading up and out I was trying to reduce the cooling to the RC. When the RC was no longer doing its job because I had reduced the cooling flow and the plates seemingly doing not much but vapour still rising this then resulted in the gush.
With no way of testing pressures at my disposal I can only hypothesise that the vapour would build up until there was enough pressure and it all exited like last night's curry.
At the end of the day I learnt a few things, in particular the need to find the balance for your rig. And today I managed to run a neutral run with the 4" plates and 2" RC and packed section without having to swim out of the room

Re: Oh gush

PostPosted: Sun Apr 08, 2018 6:32 pm
by bluc
Cool did you just persevere with cooling water or did you change it? Mine is a bitter trickier to balance than my previous setup also which had different sources for cooling water. Pc blue drum rc town water.. :-B

Re: Oh gush

PostPosted: Mon Apr 09, 2018 9:37 am
by Onlyalittlebitdodge
I'm now running it in series, so into the PC and then the RC. It gets tricky when I slow the cooling flow to the lower limit for the pump and it cuts in and out

Re: Oh gush

PostPosted: Mon Apr 09, 2018 9:53 am
by Plumby
Try one of these, might help when you wind your pump down.
Screenshot_20180404-111136.png

You can wind the pump down and have additional flow adjustment.

Re: Oh gush

PostPosted: Mon Apr 09, 2018 9:58 am
by warramungas
Need a valve on your RC and your PC.
The rc controls flow through that condenser and the one on the PC puts a little restriction on that condenser so the water doesn't use the path of least resistance.
I use a 1/2" ball valve on my PC as adjustment doesn't need to be precise.

Re: Oh gush

PostPosted: Tue Apr 10, 2018 7:02 pm
by Onlyalittlebitdodge
:handgestures-thumbupleft:

Re: Oh gush

PostPosted: Sun Apr 22, 2018 10:49 pm
by Bushy
Valve on the pc turned down to a trickle and a valve on the rc running through one of these.
s-l300.jpg

Thousand fuckin posts

Re: Oh gush

PostPosted: Wed Apr 25, 2018 5:22 am
by Sam.
Bushy wrote:Thousand fuckin posts


Only taken ya almost 6 years.

We have had pelicans here rack that up in about 3 weeks before :laughing-rolling:

Re: Oh gush

PostPosted: Wed May 02, 2018 1:45 pm
by tipsy
Bushy wrote:Thousand fuckin posts


Congratulations Bushy! he says to get his post count up 8-}

Re: Oh gush

PostPosted: Mon May 07, 2018 9:20 am
by Onlyalittlebitdodge
Just a bit of an update... I continue to run the inlet through a t-piece which feeds both the RC and the PC, and then back to a t-piece and eventually into the water tank. I now have a valve on each inlet. Restricting the flow to the PC has resulted in it not overpowering the RC cooling water flow. Success.