Condensor possibly wound to tight

crackher · Post by **crackher** » Fri Mar 31, 2006 1:00 pm

Anyone have any thoughts on possibly winding the condensor coils to tight. I tried (my theory at least) to get as many linear ft of 1/4 copper into my condensor as possible. as a result I have a coil where there are no air gaps inbetween the coils.. I ran it last weekend, and was able to climb a ladder to look down into the condensor. the vapour was coming up and thenslowing down hanging around in the cavity of the condensor and the condensing on the coils. do you think it would work more efficiently if there were gaps?

the ethanol tastes great though. I ran it for 7 hrs at 3/4 to full open reflux and pulled a steady 4-7drips a sec

level Joe · Post by **level Joe** » Fri Mar 31, 2006 1:36 pm

"no air gaps inbetween the coils"

Gaps all around each winding? = good
No gaps between the winding above and below? = bad
No gaps between the inner and outer coil and the shell wall? = worst

If its that you have no gaps between the winding above and below, you should be able to carefully pull it apart, if your condenser shell can handle a longer coil.

"do you think it would work more efficiently if there were gaps? "

It would work better...

because if the vapor has to "push" through it may go through so fast, it might not fully condense. If the coils are opened up the vapor will "mingle" through slowly losing more of its energy/heat. Usually more copper is better but you shouldn't need your water valve on much more than a crack to knock down the vapor.

But...

If it works good and your purity/% is what you think it should be, why fix what aint broke?

Swag · Post by **Swag** » Fri Mar 31, 2006 2:00 pm

Air gaps will give you a little more surface area on the coil which is a good thing. However, you probably have plenty of surface area already.
If the condenser is doing the job and condensing all the vapor, what's the problem? Don't fix it if it aint broke.

OldStormy · Post by **OldStormy** » Fri Mar 31, 2006 2:30 pm

Hi All,
After winding my coil (double helix) I carefully opened it a little using a flat bladed screwdriver. Overall it increased the length of the condenser by about 30%. I believe the vapour needs a fairly open pathway to circulate fully around the condenser to gain maximum effect.
Cheers,
OldStormy

Post by **Grayson_Stewart** » Fri Mar 31, 2006 3:39 pm

My double helix is wound pretty tight. I think it would work even better if it was spread apart a little to allow vapor to weave through the coils, but the top half of the condensor can be held by hand so I don't need to worry with it.

If the heat input is't over powering the column or condensor then of course its not an issue that need to be addressed but its always a good topic for a discussion.

TEC · Post by **TEC** » Fri Mar 31, 2006 4:12 pm

I made a coil for my still. Used salt to keep it from flattening out, worked great until I tried to remove the salt. After messing with it for a day and a half. I made a condenser out of 4 11.5" pieces of 1/4"id tubing and 8 90's. It fits loosely into a 2"x 12" head so I stuffed a unrolled copper scrubber folded in half into the center and pulled some out through the tubes so it was even.

I only need to run a very small trickle of water through it to keep up with 1350 watts of power. Of course I had left the coil with the salt soaking in water and it dissolved out on it's own by the next day.

Just goes to show that necessity is the mother of invention and you don't need 20' of tubing if you space it out evenly and use packing to transfer the heat/cooling.

furball · Post by **furball** » Fri Mar 31, 2006 5:35 pm

I was wondering if any one had made their coil loose enough to allow a few wraps of structured packing around the out side prior to slipping into there condensor tube, then inserting a center section of structured packing down the middle of their coil. This would greatly increase the surface area and should knock down a lot of the vapor in a relative short distance. This is one of the things that I was going to incorporate into mine when I get the time to build it.

Furball

Post by **Grayson_Stewart** » Fri Mar 31, 2006 6:01 pm

My condensor has enough room for 3 or 4 wraps of structured mesh around the condensor. I've done it a couple of times, but usually don't because I have to carefully "screw" the wrapped condensor into the shell to prevent the mesh from bunching up. Not something I want to spend time doing standing on a step ladder for all the neighbors to see.

TEC · Post by **TEC** » Fri Mar 31, 2006 6:31 pm

I was wondering if any one had made their coil loose enough to allow a few wraps of structured packing around the out side prior to slipping into there condensor tube, then inserting a center section of structured packing down the middle of their coil.

furball,

I thought that was what I said, except instead of using a coil, I have 4 straight tubes running up and down linked in series with 90 degree elbows. I'm sure that if it was not for the packing, it would not condense the vapor worth a damn.

I thought my post made sense, but maybe it was the alcohol talking

furball · Post by **furball** » Fri Mar 31, 2006 8:08 pm

After the second read, your right! Night shift is killing my comprehension, Do'h.
Sorry for the confusion.

Furball

crackher · Post by **crackher** » Mon Apr 03, 2006 12:25 pm

every one makes a good points. I noticed on the weekend that I can run a tonne more heat than normal. I still can hold the column temp steady (she jumps to 78C though, but steady for hours) if I increase the cooling waater speed, lower the cooling water temperature, and increase the reflux ratio. but in the end I could not cool fast enough if I tried to add even more heat. (btw I am using an external propane heat source). My cooling tower is 3" cooper ~18" long and filled with a coil that is the same length of 1/4 copper tube that was wound around a 2" pipe (tightly i.e. there are no gaps between each coil top and coil bottom). I want to open up the coil, and lengthen the condensor to the point where I can increase my temperature to increase my vapour speed, but still condens everthing. Does this sound plausible??

TEC · Post by **TEC** » Mon Apr 03, 2006 12:38 pm

crackher,

You don't say if you have any packing around and inside of your coil. If you don't try adding some and you will see a large increase in cooling.

crackher · Post by **crackher** » Tue Apr 04, 2006 4:15 am

TEC you,re saying that I should place packing (i.e. scrubbers) around my cooling coil inside the condensor unit? Will that not make the still more difficult to clean. and what is the principle reason for the packing (cooling through conduction?) Sounds interesting though. The only thing I can see it doing is slowing the vapor speed down long enough to hang around and condens?

TEC · Post by **TEC** » Tue Apr 04, 2006 6:12 am

crackher,

Around the coil and inside of the coil.

Think increased surface area and turbulence of the vapor stream.

crackher · Post by **crackher** » Tue Apr 04, 2006 9:54 am

TEC,

I giver a try why not nothing else could happen right, it could only get better or worse...lol

Captin Moron · Post by **Captin Moron** » Sun Apr 09, 2006 9:05 am

I wondered the same thing myself. I had to really force my coil into the condenser, which means its snug against the wall. It works, but im useing a faster water flow than I had anticipated. I dont recycle my water either (yet the town doesnt bill me for increased consumption either) so its more of a enviroment/ waste consious thing

maybe I will rewind a new coil so the vapour can surround the coil instead of going just inside it.

Will it make a difference? Im not really sure. It depends on how you think about it.