CCVM Not All That & a Bag of Chips

[Bee]

At least not when run in reflux mode. It uses a crap load of water running the PC and the RC.
Is there a Reflux column design that uses less water and has an acceptable production rate in a 2" column?

[Salt Must Flow]

Have you tried carefully turning the water flow rate down on the reflux condenser in order to use the minimum amount of water? Some put a thermowell on the reflux condenser's output to view the temp and set the flow rate. I find that if the water starts to exit much hotter than 150F, vapor will begin escaping past the reflux condenser. I often set the flow to 135F. Some use a water flow meter which has a very precise needle valve to adjust their flow rate.

I use an oversized product condenser (shotgun condenser) when doing spirit runs so it barely requires a trickle of water to keep the product exiting around 60F.

[Yummyrum]

What kind of reflux coil and PC are you using ?
A double wound copper coil will be more efficient than a twisted Stainless steel corrugated Tubing and therefore will need way less water . But if you were going to make one of those , you may as well get a takeoff valve and convert it to VM .

As SMF said , the flow through the PC only needs to be a bare trickle . Ideally all it needs to do is condense the vapour . Obviously it will use heaps more if you need it to cool the distillate down to 20°C or what ever your Alcometer is calibrated at . But you really don’t need to care what the abv is as it will usually be a constant 95-96% anyway .

Thinking about it , I was going to say LM would use less water than a VM , since it doesn’t have a PC . But then I realised that they would actually use exactly the same .
The LM RC has to condense 100% of the vapour , some being taken off as product , the rest is reflux . Whereas the VM RC might only need to condense 95% of the vapour as reflux , the PC still hase to condense the 5% or so taken off as product .

So the bottom line is there is no design that uses less water . All you can do is use the most efficient condensers in any of them .

[shadylane]

Is there a Reflux column design that uses less water and has an acceptable production rate in a 2" column?

Off all the options a CM uses the least water but needs constant pressure and temp to run without drama.

[Yummyrum]

Is there a Reflux column design that uses less water and has an acceptable production rate in a 2" column?

Off all the options a CM uses the least water but needs constant pressure and temp to run without drama.

How do you figure that Shady ?
A defleg will condense everything that falls back as reflux and the PC will condense what vapour passes past it . Surely the overall cooling is the same as other still heads .

[shadylane]

A dephlemator is a partial reflux condenser that only needs to knock down a percentage of vapor. Therefor it's only using the amount of flow needed.
A reflux condenser must knock down all the vapor to avoid a dangerous leak out the vent, so it needs extra water flow for safety reasons.

[Saltbush Bill]

I think what shady is saying is true, but without testing i would say that the water amount difference would be minimal.

[Yummyrum]

A reflux condenser must knock down all the vapor to avoid a dangerous leak out the vent, so it needs extra water flow for safety reasons.

I’ll go with that Shady

You are probably right Salty . Not a lot in it .

[NZChris]

You have to remove the same amount of heat energy that you put in. Where you do it and how you do it makes no difference to the amount.

You can use free cooling tricks, e.g., leaving a door open on a windy day to help cool a still head.

[shadylane]

At least not when run in reflux mode. It uses a crap load of water running the PC and the RC.
Is there a Reflux column design that uses less water and has an acceptable production rate in a 2" column?

All types have similar cooling requirements, so it's a case of pick your preference.
As to using a "crap load of water" what are the dimensions of the RC and PC? What flow control valves are being used?
Big condensers are always good if you want to use less water.

[shadylane]

Is there a Reflux column design that uses less water and has an acceptable production rate in a 2" column?

Off all the options a CM uses the least water but needs constant pressure and temp to run without drama.

I'm going to argue with myself.
LM doesn't need a PC, so an LM would use the least cooling water since the liquid alcohol leaves the still hot.

[Bee]

I'm using a 1 1/2" diameter RC coil that has about 10" worth of coil in a 2" column. It's taking a lot of water and, even at full flow, I have to have it lowered a couple inches past the T going to the shotgun PC when taking off product. When stabilizing the column, it's same flow, just a couple inches lower (maybe 4" past the takeoff). The PC uses very little water in comparison. It's a very nicely made RC, no kinks, made by someone here.

[Yummyrum]

That condenser looks fit for purpose .
What power are you running ?

[Bee]

That condenser looks fit for purpose .
What power are you running ?

Propane.

[shadylane]

That condenser looks fit for purpose .
What power are you running ?

Propane.

Propane can supply a lot of power so it's going to take a shit load of water to knock down the vapor.
That and with an open flame, you don't want any vapor out the vent.

[Bee]

It doesn't seem to matter how low I turn down the flame.

[Salt Must Flow]

It doesn't seem to matter how low I turn down the flame.

This is an example where electric is ideal, but I think I recall you saying you can't do electricity for some reason. Electric is measurable, repeatable and more safe (in my opinion). Electric allows you to run at 0%-100% input with 1% increments. With gas/flame, you just have to figure out your burner, need to able to turn it down enough, ESPECIALLY with a 2" reflux column because the power input is relatively low.

What burner are you using?

In the past, I did a little testing with water flow rates through 1/4” OD tubing using my home water pressure:
It took 1 min 5 seconds to accumulate 1 gallon through 10’ of 1/4" OD tubing.
It took 1 min 24 seconds to accumulate 1 gallon through 20’ of 1/4" OD tubing.

So based on those flow rates I realized that if I require a higher flow rate, the 1/4” OD tubing is the bottleneck. I would need larger diameter tubing to get a higher flow rate.

Considering you are using a 2” reflux column, you should not require a higher flow rate than what’s listed above. That leads me to believe that your power input is just too high. You need to turn the gas burner down or get a smaller burner that can be turned down enough.

[shadylane]

How is the reflux and product condenser plumbed?

[Salt Must Flow]

shadylane asked, "How is the reflux and product condenser plumbed"? That is a very good question. For those following this thread, there's some insight in this previous thread by Bee where Shadylane pointed out how he intended to plumb his condensers would allow the least rout of resistance to flow through the product condenser therefore starving the reflux condenser of water. shadylane also posted a diagram of how he recommended plumbing both the reflux condenser and the product condenser. Bee never responded.

Now we're on another one of Bee's threads trying to play catch-up as well as trying to troubleshoot without any pertinent information.

Bee ... your problems would be easily solved by clearly showing us what you are working with. Photos are worth 1,000 words. Let us see what your still looks like, how it is currently plumbed, what hoses are being used, etc...

[Fletching]

If the coil is 1 1/2” in diameter and the column is 2”, are you using any copper mesh to fill in the gap between the RC and Column walls? I noticed that mine got much more efficient at knocking down vapor when weaving copper mesh in with my coil, making it a tight fit against the column walls.

[Bee]

shadylane asked, "How is the reflux and product condenser plumbed"? That is a very good question. For those following this thread, there's some insight in this previous thread by Bee where Shadylane pointed out how he intended to plumb his condensers would allow the least rout of resistance to flow through the product condenser therefore starving the reflux condenser of water. shadylane also posted a diagram of how he recommended plumbing both the reflux condenser and the product condenser. Bee never responded.

Luckily I'm using semi-transparent lines water lines so I can see what is where. I have a valves that controls flow to each condenser (see the other thread). I'm tightening down the PC valve so that it gets almost nothing and opening the RC valve until I see the RC supply line fill up and the RC takeoff line shows drainage. I'm pushing enough pressure from the main water that I can control the RC flow rate by opening/closing the RC valve.

[Yummyrum]

I’ve always just run the PC and RC in series on my VM still . Even when I throttle the flow so the RC is working at maximum efficiency , there is more than enough coolant through the PC to cool the distillate down to measuring temp .

[shadylane]

At least not when run in reflux mode. It uses a crap load of water running the PC and the RC.

How much water is a "crap load"

[Roo]

How much water is a "crap load"

It is equivalent to a metric "shit load"

[Bee]

At least not when run in reflux mode. It uses a crap load of water running the PC and the RC.

How much water is a "crap load"

Judging by the Mk1 eyeball flow meter, it looks like there's about 5x more water coming out the end of the drain hose. In pot mode, it's just a beyond a trickle to a flow. In reflux, it's about full hose diameter flow.

[Bee]

I’ve always just run the PC and RC in series on my VM still . Even when I throttle the flow so the RC is working at maximum efficiency , there is more than enough coolant through the PC to cool the distillate down to measuring temp .

That ought to cut down on water use. I'll give that a try along with Fletching's suggestion to put a little copper wool on the RC.

Thanks guys! Merry Christmas!