Easy coil condenser

[lampshade]

I wanted my first coil to be easy to make. My idea:

• a single coil (not a double helix)
• the coil is made from 1/4" OD tubing (not 3/8")
• wrapped around a 1" mandrel (instead of the common 1/2" mandrel)
• a 1/2" coldfinger

In addition to being easier to wind (hopefully), this condenser should, compared to other designs, more evenly spread the vapor over the cooling surfaces.

Does anyone have any thoughts about whether this condenser,

• is indeed easier to wind
• is 8" long able to knock down 2000 watts?

EDIT: I also thought I would wrap wire around the coldfinger, for turbulence.

[YHB]

Yes it is easier to wind and yes it will knock down 2kW

The only problem with this arrangement is the connection from the bottom of the coil to the cold finger.

Have a look at this post where there is an alternative method with no connection between the two elements and has greater cooling power due the two separate sources of coolant.

http://homedistiller.org/forum/viewtopi ... 4#p6948378

[lampshade]

has greater cooling power due the two separate sources of coolant.

Hi YHB, last time we talked, it was about your power controller. I really enjoyed your referenced thread. How's your girl working for you?

Could you explain the above quote? I don't see how two separate sources of coolant has greater cooling power.

[RumRunR]

Look at the second set of pics, there you'll see separate coolants. Really nice job he did bending that weaving coil

[lampshade]

Look at the second set of pics, there you'll see separate coolants. Really nice job he did bending that weaving coil

So let me paraphrase, to insure I understand correctly. With two sources of cooling, two different cooling settings are supported: Low cooling (1 source) and Hi cooling (2 sources). However, two sources do not provide any more cooling than it both coils were run off of one cooling source. What is provided is a low cooling feature.

[lampshade]

One advantage of my coil configuration is the open space between the outer wall and the coil (0.25"). I intend to insert this coil into a Thor's hammer (horizontal orientation). The reflux (condensed liquid) runs down the side of the outer wall and this space insures than no additional cooling is imparted by the coil to the reflux, which could adversely affect the column equilibrium.

[YHB]

has greater cooling power due the two separate sources of coolant.

Hi YHB, last time we talked, it was about your power controller. I really enjoyed your referenced thread. How's your girl working for you?

Could you explain the above quote? I don't see how two separate sources of coolant has greater cooling power.

It is possible to connect the coil and the cold finger;

1) in series - as per your proposal, so that the coolant passes through the coil first then the same coolant which will now warm / hot pass through the cold finger and not be as effective as if it was cold water.

2) In parallel - as per my proposed alternative, here cold water enters both the coil and the cold finger at the same time thus increasing the amount of colling availanle. This option will use more will use more cold water but increase the cooling capacity. I use this for configuration for stripping and it deals very easily with the full heating capacity of my my boiler.

One advantage of my coil configuration is the open space between the outer wall and the coil (0.25"). I intend to insert this coil into a Thor's hammer (horizontal orientation). The reflux (condensed liquid) runs down the side of the outer wall and this space insures than no additional cooling is imparted by the coil to the reflux, which could adversely affect the column equilibrium.

On the alternative method there is still free space, the coil is formed round a 22mm tube making the outside diameter circa 40mm. 22mm + (2 x 8mm) = 38.

The suggestion is based on my experience of trying to connect the coil to the cold finger which I founds somewhat troublesome.

[redmud]

I built my 8" condenser with a 1 1/2" mandrel outside diameter of my coils is 2" then I ran an 8" x 3/4" coldfinger up the middle in my 2" boka on a 4 gallon pot I run on the small burner of my stove. It does about a quart every hour and a half without loosing steam out of the vent.

The bend at the bottom is tough since I went into the side of the 3/4 inch Cold finger I had to make the hole oval shaped and give the1/4" pipe a sharp bend to center the finger.

[myles]

The very first coil I made (that actually worked after I scrapped a few) is still in use and is currently in a horizontal configuration inside my own column. I wound the coils independently and then joined them with small equal T's



It is not exactly pretty but it still works fine. Central feed down the centre then up both coils in parallel.

1 option for the coldfinger is to put on and end cap and then drill it. This gives you a double thickness of copper for the solder joint onto the coil. Like this one.



That is a 22 mm cold finger with 2 of 6 mm coils and it will just fit into a 54 mm shell.

If you just wish to use a single coil and coldfinger joining them is easy. Just put a female to female reducer on the end of your coldfinger. If you don't wish to bend a tight 180 degree bend the alternative is to use 90 degree street (male to female) elbows. This gives you a nice compact bend as they telescope inside each other.

coldfinger.png (353 Bytes) Viewed 5749 times

You can also file down both ends of the 90 degree elbows to make the bend more compact if you wish. Off course if you fill your tube with salt then you can wind a much tighter bend than the recommended minimum bend radius. My inner coil is actually a 6 mm tube wound onto a 15 mm mandrel.
(EDIT: 15 mm DIAMETER mandrel - recommended minimum bend RADIUS is 15 mm)

Getting the salt out of such a tight coil takes time. Just connect it up to a water supply and leave it alone. EVENTUALLY the water will work its way through - might take a day.

[maheel]

imo the join from the coil to the coldfinger is a PITA.... i hate making them

i reckon a double wound coil is so much easier to make

for 2" column i use a keg spear for the inner mandrel and 3 bits of paper for the outer mandrel

[lampshade]

If you just wish to use a single coil and coldfinger joining them is easy. Just put a female to female reducer on the end of your coldfinger. If you don't wish to bend a tight 180 degree bend the alternative is to use 90 degree street (male to female) elbows. This gives you a nice compact bend as they telescope inside each other.

Does anybody know if 1/4" OD (6mm) fittings are available. Where to get them?

[redmud]

I did see some at Lowe's in Oregon not sure if all of them stock their shelves the same.

[lampshade]

This is my idea for connecting the coil to the cold finger:

• The coil end is not bent. Instead, the end of the coil lies on the edge of the coil.
• A 1/2" street elbow is soldered to the cold finger.
• The male end of the elbow is capped.
• A 1/4" hole is drilled into the side of the elbow, near the end of the cap.
• The end of the coil is soldered into the elbow side.

[lampshade]

Or, instead of using an elbow"

• connect a tee to the coldfinger,
• cap both ends,
• and extend the tee length to just under 2".

The tee will then wedge into the 2" outer shell, thereby providing a structure to position the cold finger in the middle of the shell.

[YHB]

This will give you 6 solderered joints to make within 1.1/2" - a bit tricky, be careful.

[lampshade]

This will give you 6 solderered joints to make within 1.1/2" - a bit tricky, be careful.

Good point, YHB. Thanks for your advice and interest.

[lampshade]

I finally built the easy coil condenser. It is 8" long and knocks down 2000 watts of ethanol vapor. Winding the 1/4" (OD) coil, filled with salt, around a 1" mandrel was very easy, due to the larger than normal mandrel diameter. The hardest part was bending the tails to align with the holes in the 2" cap. (Unfortunately, I mangled the coil windings somewhat during this alignment. ) I cut the cap to shorten it to get a better view for inserting the tails.

Easy coil condenser side view

For extra gripping power, I inserted the 1/4" (OD) tails through a 1" length of 1/4" (ID) tube. I drilled two holes in the cap, just wide enough for the 1/4" (OD) tails to slide through. The 1/4" (ID) sleeves were, therefore, wide enough to completely cover the cap holes and provide a good grip for soldering. The sleeves also provide additional mechanical strength and rigidity, since outside of the cap, the tails are subjected to stress when connecting the water hoses.

I am using a cross-flow condenser and thus left a gap in the middle of the coil for the vapor to enter into the coil. I also ran a copper wire around the 1/2" coldfinger for increased turbulence. (I don't know if this really has any effect on the condenser knock-down efficiency: It just seemed like a good idea at the time and was ... wait for it ... "easy". )

Detail showing winding inserted into capped street elbow

Inserting the winding into the coldfinger was also easy (some folks report this is difficult). Looking at the coil end picture, you can see that I attached a 1/2" street elbow to the end of the coldfinger. The street elbow was then capped with a 1/2" cap in which a hole was drilled into the side to accept the end of the winding. I did not have to bend the end of the winding into any fancy, and thus difficult, gyrations in order for it to easily insert into the capped street elbow. NOTE: I abandoned the connection scheme that I described in earlier posts, per YHB's advice.

Re-reading the above posts, I see that Myles suggested using a street elbow with a regular elbow. Sorry, Myles, for the belated acknowledgement. However, my scheme is a little different and does not use the regular elbow.

[lampshade]

I introduced the dark discoloration in the above pictures when I soaked the condenser in vinegar. Does anyone know how I can remove this discoloration? Buffing is obviously out of the question.

I suspect this discoloration is something that leaches out of the solder joints and I fear that it impaires the copper-to-vapor cooling efficiency.

[lampshade]

The 1/4" (ID) sleeves are conveniently sized for a 1/4" (OD) tube. The same would be true for 3/8". If one were interested in making sleeves for other diameter tubes, a section of the same diameter could be cut lengthwise.

Checkout http://homedistiller.org/forum/viewtopi ... =2&t=21258 for an alternative method for strengthening butt joints.

[wv_cooker]

Maybe try some citric acid instead of vinegar. Citric acid usually does a good job.

[DAD300]

SS Gas Flex Pipe...

I have never ruined one, not even the first! Plastic hose and a hose clamp fit the ends perfectly.

[lampshade]

My hat off to you, DAD. That design of yours sure is easy. And it don't need no stinkin' cap. Might I suggest calling it the "damn easy coil condenser."

[DAD300]

If capable of knocking down all vapor, no coil should need a cap.

I get these SS Gas lines very cheaply and have never kinked one. I have even coiled one, and straitened them out to change the length of end pieces.

After having used this for years, the SS Scrubbie at the top is more to keep bugs out!

They make great product condensers also!

Put a 1/2" x 60" SS Flex Line inside a keg spear for a product condenser that will handle 4,500 watts. 1/2" hose pressed over the ends and hose clamped.

[lampshade]

If capable of knocking down all vapor, no coil should need a cap.

True, but the cap isn't only used to contain the vapor. Typically the cap is used for other things, like captivate the condenser at the top of the column (so the condenser doesn't move up and down) and provide a rigid support structure for the cooling tubes.

Having said that, the only difficulty I had when fabricating the easy coil condenser was attaching the cap. That is a topic for future … wait for it … easy exploration.

[rager]

so this ?


http://www.amazon.com/Spectre-Performan ... e+gas+line" onclick="window.open(this.href);return false;" rel="nofollow

[Hound Dog]

so this ?


http://www.amazon.com/Spectre-Performan ... e+gas+line" onclick="window.open(this.href);return false;" rel="nofollow

Heck no! That is a stainless braid over a rubber hose! You want a line for natural gas not gasoline... Go to Plumbingsupply.com and check out Gas Flex Connectors. You will see what he means. It is section of corrugated stainless pipe. They have precut sections with fittings on the ends. Heck, Home Depot probably has some but if they are Brasscraft brand they are powdercoated yellow and you don't want that either. If you go generic with hose clamps like DAD did you can buy the brand name Gastite or Armaflex but you will probably have to buy a large section.

[rager]

so this ?


http://www.amazon.com/Spectre-Performan ... e+gas+line" onclick="window.open(this.href);return false;" rel="nofollow

Heck no! That is a stainless braid over a rubber hose! You want a line for natural gas not gasoline... Go to Plumbingsupply.com and check out Gas Flex Connectors. You will see what he means. It is section of corrugated stainless pipe. They have precut sections with fittings on the ends. Heck, Home Depot probably has some but if they are Brasscraft brand they are powdercoated yellow and you don't want that either. If you go generic with hose clamps like DAD did you can buy the brand name Gastite or Armaflex but you will probably have to buy a large section.

that's what I was wondering . I read that I was a ss over rubber but i was just asking. trust i know about rule number 8. ill keep looking that's why i asked
ill continue to do my research. thanks for the heads up hdog.

[Hound Dog]

Good deal! Glad to see you are on top of it. I really like DAD's idea with the corrugated stainless gas line. I will have to try it on a build soon.

[rager]

Good deal! Glad to see you are on top of it. I really like DAD's idea with the corrugated stainless gas line. I will have to try it on a build soon.

trust me as do i. that's why i asked. ill check out those site you posted. seems like a really good idea if it works out

[DAD300]

More like this...http://www.ebay.com/itm/DORMONT-20-3132 ... 1c378ff9fe" onclick="window.open(this.href);return false;" rel="nofollow

I have bought the yellow painted stuff and burnt the coating off...but better to look for the uncoated. Some ACE hardware and the HVAC stores sell it by the foot. I've gotten the uncoated 1/2" o.d. x 60" for as little as $3usd each. And I paid $12usd for a 5/8" o.d. x 48" piece.

The 1/2" o.d. can be coiled to fit in a 2" pipe easily or a twisted loop of the larger works.