Coolant return flow, parallel or series

[Andrew_90]

Planning the return flow on my CCVM.

So there is the PC and the RC. I was thinking about plumbing the return from the RC into the PC return but I am scared that this may create some back pressure in the RC which has much less volume coming through it. It would just make my plumbing life easier if possible.

I have a sneaky suspicion that both return feeds must uncoupled and free to fall under gravity?

Also that one may wish to visually monitor the flow rates?

[Sporacle]

So I have plumbed my returns into the same line, my RC return line is plumbed in with a T with the single leg the return from the RC and this is orientated so that the return line water from the RC would have to flow uphill to get back to the PC if that makes sense, works for me

[still_stirrin]

You know…if you put the “flow control valves” on the discharge side of the condenser(s), then neither condenser will be affected by the other’s regulating flow (or “back pressure”). All the “pressure drop”, except for the discharge piping, will be through the flow contol valves. End of my fluid mechanics lesson.
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[stmaus]

The two condensors can just be plumbed in series, then you won't have that issue. PC out to RC in.

[still_stirrin]

The two condensors can just be plumbed in series, then you won't have that issue. PC out to RC in.

But this mandates that the flowrate through the PC is the flowrate through the RC. This may not be the best solution to heat management and reflux control, especially for a CCVM.
ss

[ShineonCrazyDiamond]

I don't know. I hook like that on my ccvm. Pc is just cold. You set it to the right rc flow. Ccvm is especially forgiving at rc temps. As long as it knocks down 100%, it's not fiddley.

My plated colum is the complete opposite. You'll never run right plumbed together. And you need needle accuracy to set the plates right with power.

[Stonecutter]

I use a series/parallel circuit. Split the lines just after the pump then reconnect after the valves.

:Edit: May not be exactly what you’re looking for but I got that gem of an idea from the search bar…

[LWTCS]

I don't know. I hook like that on my ccvm. Pc is just cold. You set it to the right rc flow. Ccvm is especially forgiving at rc temps. As long as it knocks down 100%, it's not fiddley.

My plated colum is the complete opposite. You'll never run right plumbed together. And you need needle accuracy to set the plates right with power.

Not an issue as long as the PC is unaffected by RC flow rates. This usually means that the PC should be somewhat "oversized ".

[LWTCS]

You know…if you put the “flow control valves” on the discharge side of the condenser(s), then neither condenser will be affected by the other’s regulating flow (or “back pressure”). All the “pressure drop”, except for the discharge piping, will be through the flow contol valves. End of my fluid mechanics lesson.
ss

Indeed.

[ShineonCrazyDiamond]

I don't know. I hook like that on my ccvm. Pc is just cold. You set it to the right rc flow. Ccvm is especially forgiving at rc temps. As long as it knocks down 100%, it's not fiddley.

My plated colum is the complete opposite. You'll never run right plumbed together. And you need needle accuracy to set the plates right with power.

Not an issue as long as the PC is unaffected by RC flow rates. This usually means that the PC should be somewhat "oversized ".

Guilty, I suppose, lol. It's one of yours, though

[LWTCS]

Yeah, otherwise if you reduce flow to the RC in order to collect , the distillate comes out way too hot.

Or, if you push enough flow to properly cool the distillate, the RC won't let any distillate pass over to the PC.

Having the big PC allows for a wider operating range for the RC and also provides the ability to send somewhat preheated water to the RC to avoid any premature hyper cooling.
That is to say if that's how you run the cooling circuitry.

[Lowie]

I run mine with water into the bottom of the PC then out the top (full noise) and into the RC (flow controlled) then out of the RC to waste. I also put a T with a shut off valve between the PC and the RC; this allows me to shut water off to the RC (open the T valve, close the RC flow control at the end of the run to collect tails down to 20%) whilst still allowing full flow through the PC. I've been running my still like this for years and removes the problem of extra hoses, no probs.

[Andrew_90]

Thanks.

@still_stirrin - I do want independent flows through the PC and RC for now and for the reasons you state. I understand that a series flow has worked for many, I am open and my view may change as I use the still more. The taps are already on the discharge side so even better still (pardon the pun).

@ShineonCrazy Diamond - I have little doubt that my RC will have sufficient effect when connected in series. I just get a little anal that's all. (I assume you are a huge Pink Floyd fan? I certainly am. (They will play Comfortably Numb at my memorial service)

As with many things there are a variety of ways to skin the cat. Will check out what will work for me.

[Demy]

I use the sitema in series, without separate valves (only the ball valve from which the water comes) so the exit of a PC goes incoming RC, I never had problems sincerely, I think everything depends on abbitudes and equipment. Of course it's just my experience, I don't ask myself limits and maybe one day I'll try separate lines ...

[kimbodious]

@Demy, I think that people who aren’t operating CCVM’s just can’t get their head around that it is simply just a matter of moving the RC coil up or down. It just isn’t helpful when people try to give advice on systems that they aren’t familiar with.

[Sporacle]

Yep 100% just move it up or down a fraction

[Setsumi]

I run my condensers in serial, but if I do them seperate i would keep the return seperate. The reason would be to be able to feel/monitor the reflux return's temprature and return stream size. This gives early warnings to cooling feed problems.

[LWTCS]

I run my condensers in serial, but if I do them seperate i would keep the return seperate. The reason would be to be able to feel/monitor the reflux return's temprature and return stream size. This gives early warnings to cooling feed problems.

Agree.

[Lowie]

@Demy, I think that people who aren’t operating CCVM’s just can’t get their head around that it is simply just a matter of moving the RC coil up or down. It just isn’t helpful when people try to give advice on systems that they aren’t familiar with.

LOL. Good point. I failed to read the ccvm part of the OP. My bad...

[Bushman]

One of the comments I hear on the forum is the difficulty controlling a CM still. I feel I have no problem dialing in as I have one hose in but separate valves to both the RC and PC. Also as mentioned having separate lines out for each makes it easier to analyze. Below is a picture of my setup. You have to zoom in to see my valve setup. Thus I have one line in and two lines out. Just a note my PC is an overkill and I throw only a trickle at it.

[Yummyrum]

Just a note my PC is an overkill and I throw only a trickle at it.

You don’t say … in which way

[Bushman]

Just a note my PC is an overkill and I throw only a trickle at it.

You don’t say … in which way

It’s about 40” long with four 1/2 inch tubes wound around like DNA to collect the product. After filling the outer tube it takes very little water to cool the vapor.
Zoom in on the product condenser as the outer shell is Borosilicate Glass so you can see the copper tubes.

[Yummyrum]

You a tease Bushy

[still_stirrin]

Aha!

A “shotgun worm”. Ingenious!
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[Bushman]

Aha!

A “shotgun worm”. Ingenious!
ss

I would love to take credit for the design but the original concept was Mash Rookies. He had 3 tubes twisting down, I thought 4 would be cool so he helped me make a jig and helped me with the process. Twisting the pipe was easy, connecting them together and fitting them all into a larger connector took a bit of maneuvering.