Help needed running my reflux still

[OzKev]

Why does this design of the reflux not use slanted plates like a boka? What is the difference in theory? I can see the take off section is full size as apposed to the boka reduced section after the plate. Which is better/why?

[cap73n]

So I ran it last night, and you were right Mech; condenser was too close to takeoff :angry-banghead: easy fix though because I did actually leave roughly 50mm headroom between the top coil of the condenser and the cap plate :handgestures-thumbupleft:

[Zak Griffin]

Because it's a VM, not an LM reflux...

You control the takeoff by adjusting the gate valve, which allows vapour to reach the PC.

Have a read of Different types of still, Brendan has explained it all there.

[C2H6O]

OzKev with this style of still you control the amount of vapor you take and how much is returned down the column (Vapor management). This is normally controlled with a gate valve off a tee in the column. The take off here is bigger because you want enough steam to be able to pass through. This design needs a product condenser.

With a boka (Liquid management) You control how much liquid you take off (pooled on slant plates) the take off here is small as you only want a little trickle. Here you don't need a product condenser as its already in liquid form (It does help to have one if you want to cool the product though.

Your Still is coming together nicely Cap. Hopefully next time everything is 100%. Were you able to knock down all the vapor?

Cheers

[OzKev]

Because it's a VM, not an LM reflux...

You control the takeoff by adjusting the gate valve, which allows vapour to reach the PC.

Have a read of Different types of still, Brendan has explained it all there.

OzKev with this style of still you control the amount of vapor you take and how much is returned down the column (Vapor management). This is normally controlled with a gate valve off a tee in the column. The take off here is bigger because you want enough steam to be able to pass through. This design needs a product condenser.

With a boka (Liquid management) You control how much liquid you take off (pooled on slant plates) the take off here is small as you only want a little trickle. Here you don't need a product condenser as its already in liquid form (It does help to have one if you want to cool the product though.

Your Still is coming together nicely Cap. Hopefully next time everything is 100%. Were you able to knock down all the vapor?

Cheers

As soon as I read your replies I though how silly the question was. I should have picked up on that factor up front. Anyway, thanks for the responses and I'll let this get back to discussing Cap's setup. :handgestures-thumbupleft:

[cap73n]

Were you able to knock down all the vapor?

Yeah knocked down the vapour easily, even when I was mucking around with the power and had it up at 2000w. Just no matter how hard I tried, I couldn't adjust the coolant right so that I was collecting more then a few drops whilst not simultaneously wasting ethanol vapour out the top: it was either not enough coolant flow thus losing vapour out the top, or it was too much coolant flow thus cooling the vapour at the takeoff.

[TheMechwarrior]

You shouldn't be touching the cooling water flow at all.
At 2.4kW I was getting a couple of litres an hour output so you should be seeing about 1.5L/h.

Issues you can have:
1. Your product condenser being too close to your VM offtake ==> raise it
2. You've raised it but now vapour is escaping the top ==> your water flow is insufficient ==> get a bigger pump or your condenser is too small ==> make a bigger coil (min 100mm 1/4" double helix)

Try connecting the cooling in this manner:

Cooling water supply to the outlet of the PC
Cooling water outlet from the PC goes to the inlet of your RC
Cooling water return supply from your RC

Let me know how you go with those ideas.

Cheers,

Mech.

[cap73n]

So I raised my reflux condenser so that the bottom is a good 100mm from the take off point. and have been running it this evening. Its working but I'm only getting like 350ml an hour at about 95%. Ive got the gate valve wide opened and am running at 2000watts.

If I turn the water to my reflux condenser down steam comes out the top and it doesn't seem to change the collection rate anyway.

I bunged a few screws wrapped in teflon tape in the holes at the top of my column (note: i have the gate valve wide open) to stop any escaping vapours and then turned the water to the reflux condenser down and am now collecting about 1.5litres an hour.

What do you think mech?

[C2H6O]

Blocking the venting to the atmosphere is a dangerious practice, it only takes a small mistake on your behalf or maybe even a gate valve fail and you are in a lot of trouble.. It is best to find a better solution to the problem. My guess would be the size of your gate valve, it's 1/2" isn't it. I use 1" that's said I don't have it open much.. Sure others will help you out with a solution.

[cap73n]

Yeah fair call. I might as well call it a night anyway

[C2H6O]

By the sounds of it you have the know how to make modifications mate, sure you'll have it running awesome in no time. :handgestures-thumbupleft:

[TheMechwarrior]

:text-+1: don't block the vent valves

Remember this is a VM still...don't adjust the cooling water flow, you want it running at maximum.
Try raising your reflux condenser higher mate, at 2400W I had mine about 180mm away from the VM offtake, possible a wee bit higher.
Have a look at my picture again and you'll see.
Sounds like you are almost there.

As for your gate valve, worry about that after you've raised the RC.
Raise it as high as you can until vapour starts to escape, do this slowly, counting the number of coils inside v outside. Once you find the limit drop it back in with a couple of coils to spare.
You will now be running your VM as hard as it can go at that power setting.
Your output rate and quality is now controlled via your gate valve, in fact you should be able to set the gate valve to give you 95% and you won't need to touch anything from the time you start taking product until the time product will simply stop coming out. :handgestures-thumbupleft:

Cheers,

Mech.

[cap73n]

Yeh I think you might be right about the valve. I also have a step down to 3/8inch and back up to 1/2inch directly before the valve. I think I read somewhere that a step down was needed after the takeoff. But maybe Im wrong.

[Jed]

I am new at building but is brass a no no unless pickled etc. I went stainless tap with ptfe guts.
I like the idea of two elements for water vinegar cleaning and fast warmup and then turn one off for run.

[TheMechwarrior]

I am new at building but is brass a no no unless pickled etc. I went stainless tap with ptfe guts.
I like the idea of two elements for water vinegar cleaning and fast warmup and then turn one off for run.

Yes, replace brass with stainless and yes with the elements.