VM path is not working

[rad14701]

Late to the dance here but without making major modifications to the design I think the solution HookLine posted could be worthwhile... However, rather than have the restriction plate on the bottom, I'd be inclined to put it on the top of that horizontal rather than on the bottom...

[lampshade]

Lampshade..i stated there is no such thing a a vacuum in a open to atmosphere device (but that was on the other thread and got lost on this new one).
In a open to atmosphere device, as our still, we have at least ONE opening (potstill) and TWO (refluxstills are supposed to have a vent).

Thanks, Danespirit for your excellent descriptions of VM operation. However, I have one contrary view. You say that "there is no such thing as a vacuum in an open to atmosphere device."

Consider my still. Both the product and reflux condensers have two ports: a 1" vapor input port and a 1/4" liquid output port. You say that there is no condenser vacuum because the vents (1/4" liquid output ports) cause any vacuum to collapse due to atmospheric inrush. However, wouldn't the path of least resistance be the 1"vapor input port, for which the cross-sectional area is 16 times greater than the 1/4" liquid ouptut port?

[Danespirit]

Yes it would.
Vapor behaves (to a certain degree) as fluids, therefore we can use simple fluid dynamics to explain what might go on in there.
Nature is lazy, it doesn't waste more energy than necessary.Energy will be transformed into other forms so "waste" wouldn't be the suitable term.
So vapor will always "seek the easy way out"...BUT we have to have in mind that it meets resistance in it's path.
Like in an exhaust system it's not just the diameters of the manifold that matters, it's the combined resistance of the system that includes bends and mufflers.
Someone mentioned all the bends around your Liebig..those bends also contribute to that resistance.
Btw...Screw off that 1/4" pipe at the Liebig takeoff, it causes a choke!"
Would you have any mesh or similar in it? If..then pull it out.
You are dealing with two different systems feed by the same vaporfeed.
Liquid can run out of that curly takeoff on the LM side, BUT..on the VM side you are dealing with vapor. Vapor requires much more space than liquid.
On your LM side, the condenser doesn't create any vacuum when the vapor hits it. It simply collapses the vapor and by now liquid...it requires less space.
This process causes no vacuum, rather it creates a "void" around the condensing surface it meets.
The void however,will immediatly be filled by vapor coming from the column as "pressure" always levels out in connected containers (your vaporfeedpipe and condenserhousing). Remember: "for each 1 KW effective heatinput, 46 L of vapour is generated pr. minute."
That means roughly a vinebottle full of vapor pours in there every second...with ONLY 1 KW..!
Now it would be easy to see why no vacuum can exist in such system.
Before all this starts anyway..your system has to get rid of the noncondensable gasses prior to condensing. That means all air has to come out.
With a Liebig restricted by to many bends,mesh or narrow takeoff, this air will stand in the pipe, causing no output. Remember "The VM part is gravity feed"
Pull out any mesh, unscrew the 1/4" pipe...( get rid of the bends if still no output) and your Liebig will soon do what it's supposed to...collapsing vapor, creating a void to be filled by the vapor again.
Edit: See..you got a point with that CSA 1" to 1/4". Cause that is the ratio you have set up for the LM side compared to the VM side.

[still_stirrin]

...However, I have one contrary view. You say that "there is no such thing as a vacuum in an open to atmosphere device."....You say that there is no condenser vacuum because the vents (1/4" liquid output ports) cause any vacuum to collapse due to atmospheric inrush.

Air and hot vapors are both compressible fluids. For the system open to the ambient air, there cannot be a vacuum. There can be pressure differences, however. Because the fluid is compressible, as the fluid moves faster and faster the static pressure (gage differential pressure) decreases due to the conservation of mass....it's one of Newton's physical laws.

To test this principal, stick a straw into a glass of water and blow across the open end of the straw. The water will be drawn up into the straw (aspiration). Your exhaled air across the straw is moving faster than the stagnated ambient air and the static pressure in the moving air is lower than ambient. But if you stop blowing, the air once again returns to stagnant and the pressure equals the ambient.

Inside your closed piping network, ie - the still, the mass flow of vapor speeds and slows due to pipe size, equivalent pipe length, temperature, and static pressure. Piping bends can be related to piping equivalent length when calculating flow loss (pressure) due to friction, so pipe diameter reductions and multiple bends effectively make the network model as a long pipe.

Your LM side experiences a very short length and an increasing area (less restrictions) when compared to the VM branch. It is by far the "path of least resistance" so it will recieve its proportion of the vapor split at the tee. In fact, if you model the equivalent lengths of the two networks, the VM side is so much more restrictive, you won't see much, if any flow in that side. Sound familiar?

And the discussion of gravity being a motive force...well, that's true, but it's almost inconsequential. Gravity is a force which acts upon a mass....and there isn't much mass in the vapors, especially compared to water (or liquids). Sure, maybe a little more than the ambient air, but remember that the vapors are inside of the closed piping network, not in open air. You can't count on the vapors to be "pulled by gravity" through the piping network.

Bottomline, as I have said before...the LM and VM piping networks are not at all balanced in your design. Balance them and you will get a better split of the vapors at your column head.

While you may not agree with the physics, they are the laws of nature that we have to live with.
ss

[Danespirit]

Exactly Still stirrin...
I see my technical english still needs a update.
Excellent explanation, just one little thing :

There can be pressure differences, however. Because the fluid is compressible, as the fluid moves faster and faster the static pressure (gage differential pressure) decreases due to the conservation of mass....it's one of Newton's physical laws.

instead of fluid you meant gas, right..?

[still_stirrin]

Exactly Still stirrin...
I see my technical english still needs a update.
Excellent explanation, just one little thing :

There can be pressure differences, however. Because the fluid is compressible, as the fluid moves faster and faster the static pressure (gage differential pressure) decreases due to the conservation of mass....it's one of Newton's physical laws.

instead of fluid you meant gas, right..?

Believe it or not...a gas is a fluid too! It's just in the vapor state. The other state is...wait for it...liquid! And there is a 3rd state....solid! That's what ice (H20) is...solid water. Gaseous water is....steam!

So, fluid is the "correct term" to use.
ss

[Danespirit]

Yes i know that Still stirring..i wrote that in my last post, it's the reason why we can use fluid mechanics in the explanaition.
I just stumbled over the thing with compressible fluid. Fluids can't be compressed, gasses can.. (just my thinking again ).
Never mind it's not important, cause you did a excellent job with that explanation..
Yes... funny how water can have three different states within a 100 degrees Celsius.
Hopefully Lampshade has done some pipework and got the VM going..

[lampshade]

Hopefully Lampshade has done some pipework and got the VM going..

Yes, I did some preliminary experiments with cheap vodka in the boiler without any modifications -- yet -- to the sill pipework. I am able, sometimes, to get a nice pencil stream out of the VM path; other times, I only get a drop every 2 seconds.

I appreciate the explanations that you and still_stirrin have provided, as I never bought the commonly accepted "ethanol_is_heavier_than_air" explanation for VM operation -- I knew there was more to VM than that. On the other hand, accepting still-stirrin's description using fluid mechanics, I don't yet understand why plain water vapor does not enter the VM path. You, Danespirit, might have explained that in your description of the effects of water vs water-with-ethanol densities, but I missed that.

Given our new understanding of VM operation, it seems to me there is work to be done to increase our understanding of how to minimize reflux ratio (that is to say more vapor in the VM branch), an endeavor that should support higher ethanol yield (that is, shorter distillation times).

In my defense, I chose my still configuration to measure actual reflux ratio and to better understand VM operation. My "defective" still did support those objectives, albeit after a lot of frustration -- both to me, and to my distiller brethren. Now I need to figure out how to make a "useable" VM still. My next experiment is to insert scrubbies in the LM branch, as Hooklike recommends, in order to better balance the LM vs VM branches that supposedly is accomplished by inserting some resistance in the LM path.

[still_stirrin]

...measure actual reflux ratio...

The reflux ratio is the ratio of vapors condensed that travel back down the column to the vapors condensed and collected at the output.

If you could measure the MASS of the vapors coming out of the boiler and up the column...that would assist you in the measurement process, as the mass of the liquid condensing and falling back down the column is the difference between the mass rising and the MASS of the product (liquid) collected.

RR = (Mass up the column - Mass collected) / Mass collected

From this equation you can see that when the output is shut off, the RR is infinite as the denominator approaches zero. Also, when the collection equals the production from the boiler, the RR goes to zero (ala...pot still).

The difficulty in "measuring the RR" is that it is extremely difficult to measure the mass flow off the boiler and up the column. You could use a flow meter to measure the volumetric flow and compensate it for temperature. But bear in mind that the composition is always changing, so the mass per unit time is variable even in a steady volume flow.

I'd suppose you could weigh your whole still, boiler and all, as the run progresses and calculate the mass reduction per unit time. But that would require a constant (steady state) of condenser water flow too so the still wouldn't increase or decrease in weight with water flow variation.

The flip side of the coin is that it is pretty easy to measure the mass of the product collected per unit time beause you could simply weigh it when collected.

So, since it is so difficult to "measure" reflux ratio, we typically "calculate" it based upon the ratios of the vapor paths. It is an approximation, but widely accepted as the RR.
ss

[DAD300]

still_stirrin, I agree and while I may want less than 1:1 reflux, I'm not sure why.

As you stated, while it isn't perfectly 1:1, approx minimum reflux ratio is achieved in the CCVM with the takeoff being the same size as the column dia.

The most perfect way to get minimum, controllable and less than 1:1 reflux, is the CM Dephlegamator, where the Dephl can be turned off completely and you have a pot still at no reflux. But the conventional Dephl also narrow the path to the takeoff. In a typical 4" column the Dephl may narrow the column area by as much as two thirds. Speeds vapor and needs better Product Condenser.

[still_stirrin]

...The most perfect way to get minimum, controllable and less than 1:1 reflux, is the CM Dephlegamator, where the Dephl can be turned off completely and you have a pot still at no reflux. But the conventional Dephl also narrow the path to the takeoff. In a typical 4" column the Dephl may narrow the column area by as much as two thirds. Speeds vapor and needs better Product Condenser.

Very good point Dad.

Because of the geometry of the dephlegamator in the column the up flow area is reduced. And as it does, vapor velocity increases (steady state mass flow, remember?) Note that due to the velocity increase through the dephleg tubes, the static pressure of the vapor drops. However, once it passes through the dephleg the vapor speed will once again slow and as it does, the static pressure rises. And because there is heat lost in the journey through the dephleg, as the vapor pressure rises, it exceeds the saturation pressure and the vapor will condense.

I see exactly this phenomena in my concentric LM head. It is a key to the exceptional knock down power of that reflux condenser.

Again, this mechanism is what keeps the minimum reflux at, or around 1:1. As a result, when the water is shut off to the dephleg, it won't fully run as a pot still because there will be some (albeit minimal) reflux occurring. Now, if the dephleg was built into a "bubble" where the up tubes flow area was equal to the column up flow area, you could truly realize a (less than) 1:1 RR, or even approaching zero.

Old CM designs with the cooling coils wrapped around the column didn't experience this (minimal) restriction to the RR due to static pressure changes to the vapor path. But, they weren't very efficient at heat transfer to fully knock down the vapor when a high RR was desired. Any flow restrictions in the vapor path will induce some reflux simply due to the velocity changes within the vapor path.

Interesting premise for those who run flutes, or CM with a dephleg reflux condenser.
ss

[lampshade]

...measure actual reflux ratio...

The reflux ratio is the ratio of vapors condensed that travel back down the column to the vapors condensed and collected at the output.

If you could measure the MASS of the vapors coming out of the boiler and up the column...that would assist you in the measurement process, as the mass of the liquid condensing and falling back down the column is the difference between the mass rising and the MASS of the product (liquid) collected.

RR = (Mass up the column - Mass collected) / Mass collected

My thought about measuring RR was to collect the VM (product) liquid and the LM (reflux) liquid, simultaneously for a given time, say 5 minutes. The LM takeoff valve must be fully open to collect all of the reflux that normally would be inserted into the column. Then RR is simply the amount of LM liquid collected vs the the amount of VM liquid collected.

I decided it was necessary to accurately measure RR since I didn't buy the commonly accepted theory of VM operation, that it is a gravity thing. However, now that I have a better and more realistic understanding of VM operation (fluid mechanics) -- thanks to still_stirrin and other contributors -- I now no longer feel obliged to measure RR. I will attempt to better utilize fluid mechanics in my next VM/LM combo still. I believe my current design would have worked if VM operation is solely a gravity thing -- but alas, it is a fluid mechanics thing and those laws must be obeyed for optimum VM operation.

[DAD300]

I like all the science...I really do. I just gave up trying to figure it out since nothing is new and I'm not going to set the world straight on "string theory."

I measure quantity and ABV. Then I hope for quality and making better.

[lampshade]

The observation that the VM head does not collect tails is consistent with the gravity theory for VM operation. The commonly accepted thought used to be that the VM head stops collecting tails because tails, unlike ethanol, are lighter than air.

Can this tails observation be reconciled with fluid mechanics?

[DAD300]

I think so...if you apply enough power and as the abv drops you are carrying over enough "other" components to make it heavier.

[skow69]

The thing is you're trying to fit a natural process into one tidy little box and the world is more complex than that. The gravity model does work. The heavier ethanol TENDS to go down while the lighter water TENDS to go up. But there are more factors at work. The vapor split will tend to favor the larger port but it will never match the calculation by circular mill area because of the multitude of other factors, many of which we don't recognize at all. The point is don't ignore the effect of gravity on your next build or it will be just as disappointing as this one.

[skow69]

Because of the geometry of the dephlegamator in the column the up flow area is reduced....
...
Any flow restrictions in the vapor path will induce some reflux simply due to the velocity changes within the vapor path.

Interesting premise for those who run flutes, or CM with a dephleg reflux condenser.
ss

Automotive air conditioners depend on this phenomenon. They call it an expansion valve. Net effect: It makes stuff colder.

[lampshade]

The thing is you're trying to fit a natural process into one tidy little box and the world is more complex than that. The gravity model does work. The heavier ethanol TENDS to go down while the lighter water TENDS to go up. But there are more factors at work. The vapor split will tend to favor the larger port but it will never match the calculation by circular mill area because of the multitude of other factors, many of which we don't recognize at all. The point is don't ignore the effect of gravity on your next build or it will be just as disappointing as this one.

What I don't understand is how ethanol vapor can be pushed into the vertical reflux condenser, yet needs gravity to fall into the downward product condenser.

Bottom line: It seems to me that RR cannot be derived from geometry (relative cross-sectional areas) alone, and that in order to know RR it must be measured.

[Tokoroa_Shiner]

The thing is you're trying to fit a natural process into one tidy little box and the world is more complex than that. The gravity model does work. The heavier ethanol TENDS to go down while the lighter water TENDS to go up. But there are more factors at work. The vapor split will tend to favor the larger port but it will never match the calculation by circular mill area because of the multitude of other factors, many of which we don't recognize at all. The point is don't ignore the effect of gravity on your next build or it will be just as disappointing as this one.

What I don't understand is how ethanol vapor can be pushed into the vertical reflux condenser, yet needs gravity to fall into the downward product condenser.

Pressure and path of least resistance.

The pressure in the boiler ( yes there is pressure, just very low, which is why all stills need to be vented) pushes the alcohol vapour up. It will keep going up until it reaches condenser, or, until it finds a hole in the side of the column( VM take off/ path of least resistance) closing the take off valve causes more resistance. Thus causing more vapour to bypass the take off and be condensed by the RC, falling back into column to be refluxed.

[Danespirit]

The thing is you're trying to fit a natural process into one tidy little box and the world is more complex than that. The gravity model does work. The heavier ethanol TENDS to go down while the lighter water TENDS to go up. But there are more factors at work. The vapor split will tend to favor the larger port but it will never match the calculation by circular mill area because of the multitude of other factors, many of which we don't recognize at all. The point is don't ignore the effect of gravity on your next build or it will be just as disappointing as this one.

What I don't understand is how ethanol vapor can be pushed into the vertical reflux condenser, yet needs gravity to fall into the downward product condenser.

Pressure and path of least resistance.

The pressure in the boiler ( yes there is pressure, just very low, which is why all stills need to be vented) pushes the alcohol vapour up. It will keep going up until it reaches condenser, or, until it finds a hole in the side of the column( VM take off/ path of least resistance) closing the take off valve causes more resistance. Thus causing more vapour to bypass the take off and be condensed by the RC, falling back into column to be refluxed.

Good points there Skow and Tokoroa..!

And exactly the reason why we keep "preaching" the ventilation of a column is mandatory NOT optional.
Though we deal with very low pressures here, if we deny the gasses this option a serious condition occurs that quickly get out of hand..!
Pressure rises dramatically and by then we are not standing near to a still, but a bomb waiting to go off.

What is going on in a column is really a complicated process of many factors playing together.
One of those is Bernoullis law that seriously is a fact when we have restrictions and should be part of the equation.
In any kind of a still we are dealing with vapors.
The liquid part is let alone here to simplify the model.
Vaporspeed can be calculated on basis of the inputpower and the column diameter. A little bridge to the understanding is : For every 1 Kw put into the boiler we generate just short of 46 L steam every minute (in this case a mix of water,ethanol and a few other compounds).
Let's take a common 2" VM as a example: Cross sectional areal (CSA) is : A=Pi x r*2
Now we can calculate the volume using the CSA and the length of the column: V= Pi X r*2 X l
Ideal flowrate 0,30 to 0,45 m/s that would be 12 to 18 inch per second.
12 inch per second require 0,824 Kw of input power for 18 inch per second it would be 1,235 Kw.
Before someone jumps out of the seat, because he is putting 2 or 2,4 Kw in his column without problems, it should be said we have not yet had the thermal loss into the equation. A uninsulated column can easily loose several hundred watts on this account (heating costs will just rise).
Every still is loosing heat due to the temperature difference from the inside to ambient temperature. That's one of the reasons to insulate, another is not to disturb equilibrium due to sudden temperature fluctuations.
Now this equation holds for an empty column without restrictions, when we add packing to it...it's a whole new ballgame!
Powerinput will increase vaporspeeds further, causing the refluxrate to increase.
The distillers running flutes would happen to experience a problem called "entrainment". That happens when a plate is excessive loaded and splashes up under the upper plate, causing it to loose efficiency.
In a column we call this "flooding" , we now have a state were the column can't handle the powerinput. We have a aquatic environment, more than we wanted.
Bernoullis law applies here: A restriction in the vaporpath, will cause the vaporspeed to increase at the restriction".
We can now understand WHY it is very important to have the vaporspeeds in mind ,when designing a still.
The powerinput can easily be moderated when running the still.
The diameter of the vaporpath can only be modified downwards, so it has to be dimensioned correct in the building phase.

Edit: Lampshade...did you have the time to modify your still and do a run..?
After all it's your rig we want to "cure" from "lame output disease"

[skow69]

What I don't understand is how ethanol vapor can be pushed into the vertical reflux condenser, yet needs gravity to fall into the downward product condenser

I'm not sure I understand your dilemma. Ethanol can be pushed into the product condenser without gravity. When the opportunity to fall is presented, gravity just gives a bit of an edge to the ethanol. Think of a mixture of oil and water. The heavier water will always sink to the bottom.

In your particular case I think that effect is pretty small compared to the difference in port sizes. I assume that thermometer has 1/2" NPT threads so the bushing takes up a lot of room in a 1" pipe. In fact, if that is the case, just moving it to the other side of the tee could make a world of difference.

Bottom line: It seems to me that RR cannot be derived from geometry (relative cross-sectional areas) alone, and that in order to know RR it must be measured.

I agree.

EDIT: However, we know what factors effect it, so you don't need to measure it to do everything possible to minimize it.

[lampshade]

Edit: Lampshade...did you have the time to modify your still and do a run..?
After all it's your rig we want to "cure" from "lame output disease"

Yes I did insert scrubbies at the location that Hooklike recommended (in the RC path). Sometimes I could get a pencil-sized stream out of the PC, but I was not able to get that except on a few occasions. I have concluded that my still head is unsalvageable and will replace it with a conventional VM head. One idea I did ponder was to replace the PC condenser with a condenser that is identical to the RC (which is a cross-flow condenser), to balance the RC and PC paths, but I don't want to run the risk and incur the cost of another failure.

I want to thank everyone for their patience with me. I was just too clever (cute) by half and I apologize for wasting your time.

If only I had read http://homedistiller.org/forum/viewtopi ... 4&start=60

[Danespirit]

Edit: Lampshade...did you have the time to modify your still and do a run..?
After all it's your rig we want to "cure" from "lame output disease"

Yes I did insert scrubbies at the location that Hooklike recommended (in the RC path). Sometimes I could get a pencil-sized stream out of the PC, but I was not able to get that except on a few occasions. I have concluded that my still head is unsalvageable and will replace it with a conventional VM head. One idea I did ponder was to replace the PC condenser with a condenser that is identical to the RC (which is a cross-flow condenser), to balance the RC and PC paths, but I don't want to run the risk and incur the cost of another failure.

I want to thank everyone for their patience with me. I was just too clever (cute) by half and I apologize for wasting your time.

If only I had read http://homedistiller.org/forum/viewtopi ... 4&start=60

Hey Lampshade..don't give up yet, a lost battle doesn't mean loosing the war.

Look on it from a different angle: "It's not a problem..it's a task to complete".
And you can complete this task, without throwing the whole stillhead into the trash.
Ahhh...you are not wasting our time (though i can't speak for others). I have enjoyed helping you along, alabeit we havent reached the goal yet, but we will!
But you were wasting our time, if you quit now...hmmm.. so back in the sadle cowboy..we are going to ride!
This is my idea of what this forum is about, to help eachother with any trouble that may occur along the road..
So let's not give in to a damned still...it ain't a water seperator for Deuterium, just a still that has to be modified a bit.
Let's aim for the target and get this bullseye,ok?

So..you put in the scrubbies like Hook recommended and this gave you output.
That means you created a more balanced environment for the two paths, and succeeded partly. (good so far)
Now have you tried removing the small 1/4" tube at the takeoff (end of Liebig)..? You should do it if not.
Could it be the waterfeed at the bottom of your Liebig is blocking the takeoff tube partly, causing further restriction..?
Try removing the whole Liebig and check if there is any output through the VM valve.
Be CAREFULL hot vapors will come out, so gloves and LOTS of ventilation! (outside would be good)
Turn the still off immediatly after checking this and let it cool down. You are running electric, so it should be safe if you are carefull.
This is NOT recommended for distillers running on gas or open flame..
If you got steamoutput, you Liebig is the troublemaker. (which i think it is).
Solution : Get rid of all those bends on the Liebig and provide a straight vaporpath downwards to it.

Now, safe the time and money for a new crossflowcondenser, get this rig up running.

[Brutal]

I don't see the point in starting completely over. Your idea to make the PC the same size as the RC is the way to go, and if you tossed it out and started over I think that's about where you would end up next time anyway. Also making a different PC is never a waste. Make it removable and use it on another still or three!

Finish it out bubba!

[lampshade]

OK, if I modify the existing stillhead, I need to replace the product condenser with one that presents less resistance. A shotgun comes to mind, but I don't have the skills to fabricate one. Instead, I was thinking of a condenser that is modeled on the easier to build reflux condenser and DAD300's gas flex pipe coil (diagram attached, which is easier viewed when clicked on). I have given this the working title of "inverted dimroth condenser."

What are your thoughts?

[HookLine]

Yes I did insert scrubbies at the location that Hooklike recommended (in the RC path). Sometimes I could get a pencil-sized stream out of the PC, but I was not able to get that except on a few occasions.

How long are you waiting after you open the product arm valve before you call it? Because in my experience it can take some time for product to start coming out of a VM after you open the valve. It is not instant like with an LM, especially at the start of a run when you are bleeding heads off real slow.

There is a remote possibility you have too much resistance from the product condenser, as you suggested. Though I think that is unlikely.

One other possibility is that you are losing vapour up the reflux return line, which is quite large (1/2" I am guessing). That can be fixed by adding a vapour lock in that line (if you don't have one already inside the column).

Apart from the expansion chamber on the reflux arm, and possibly the reflux return line, both of which can be fixed, I can't see anything wrong with your design That basic design has been tested many times and works fine. Certainly would not be ditching the whole head yet.

[Brutal]

You could build it as a mirror of the reflux side. The reflux side seems a but large to me. Maybe consolidate some components to make it dead even on both sides?

[lampshade]

C'mon... the silence is deafening. I can't believe nobody has a comment about the proposed modification (inverted dimroth condenser) to my stillhead.

I may wear a lampshade over my head, but that doesn't mean I can't hear you.

[Danespirit]

You idea is ok, friend...modyfying your Liebig would be easier, though..

[lampshade]

You idea is ok, friend...modyfying your Liebig would be easier, though..

Thanks, Danespirit,

I don't understand your comment. You say I should modify my Liebig. Just how should I modify my Liebig?

My Liebig is in the the VM path. Many have commented in this thread that my PC condenser presents too much resistance. So I am proposing to replace the existing Liebig with a wider "inverted Dimorth condenser," which I think will present less resistance in the VM path than does the current Liebig.

BTW, my great-grandparents came to the USA from Denmark.