Air cooled condenser

[Kegg_jam]

Man, you guys have been busy.

I was thinking a little scrubby in between 1&2 or 3 would divert some vapor into 1 and slow down the vapor a bit going to 4 and 5.

Maybe.

[shadylane]

Some of the flow from #1 will be from condensed liquid entering and passing through it because it's the lowest point. That being said I am impressed that you got it evened out as mush as you did. Wet flow manifold design is a tricky subject, and dry manifolds aren't anything to sneeze at either. That's why I would have just built a snake (flat worm) and said fuck it. Would have drove me mad.

Good point Brutal #1 had an equal output but it would drip then surge. Thought it was huffing, now I think it was from the liquid that condensed in the manifold draining into it.
Posting with KJ

[shadylane]

Man, you guys have been busy.

I was thinking a little scrubby in between 1&2 or 3 would divert some vapor into 1 and slow down the vapor a bit going to 4 and 5.

Maybe.

That might have worked also.
Thought about it but by then the end of the tapered manifold had already been brazed up.
Tried stuffing scrubbies in the end of the condensers but that didn't help.

[shadylane]

[quote="Brutal"]That's why I would have just built a snake (flat worm) quote]
Me thinks, finned tubing shaped like a worm with a fan blowing up through it would be the best aircooled design.
Never could find any curved finned tubing and didn't think it was possible to bend it without screwing up the fins.
Trane air conditioners use what I call hairy fins that could be bent but their too small in diameter for what we need.

[Kegg_jam]

Tried stuffing scrubbies in the end of the condensers but that didn't help.

I can see where that probably wouldn't have the desired effect. My thinking was that baffling the vapor in some way before it heads down to be condensed would have worked.

Your tapered copper tube looks sweet though!

[skow69]

Good work again. Did you measure the temp of the emerging liquid?

[shadylane]

At 240v 4500w the liquid output temp was at 190 to 200f after running for 30 minutes or so.
Air temp on the fan side of the condenser was 95F at the start.
Couldn't get a proper measurement of the air temp leaving the condenser
but it made the 10' x 12' still house unbearably hot real damn quick.
Ran the aircooled condenser for almost 2 hours and it was still knocking down all the vapor.

[shadylane]

Time to start another project.

[bitter]

I think that will work better. Another thing to think about is the dead space on the fan letting the air out. You need something to force the air to flow through the fins or you will not get optimal cooling.

B

[mason jar]

I'm likin' this one better Shady. I think it will probably be able to knock down
more power than the parallel version, though I guess that doesn't really matter
since your first one knocked down everything you threw at it. It will probably cool
down the product a bit more as well since it will be in contact with the pipes much
longer. It should be easier to build too. Wish I would have done mine like this.
It would have been smaller and cheaper.

[Brutal]

Time to start another project.

This is going to be the way forward. I predict 80-100 degree (f) distillate temp drops from the other design.

[shadylane]

It's all your fault mason jar, I wouldn't have started this if it weren't for you.
Well maybe I would have since I'm a glutton for punishment. But your convenient to blame.
This time I'll start with five of the 2' long finned tubes and use zip ties to hold them to the fan.
That will make it a lot easier to build and modify. I'd like to keep this build simple and cheap, so others can copy it.
Hopefully 3 of the finned tubes will be enough, but if not then 4 should work.
The fewer tubes used the better.
Posting with brutal

[mason jar]

It's all your fault mason jar, I wouldn't have started this if it weren't for you.

This time I'll start with five of the 2' long finned tubes and use zip ties to hold them to the fan.
That will make it a lot easier to build and modify. I'd like to keep this build simple and cheap,
so others can copy it. Hopefully 3 of the finned tubes will be enough, but if not then 4 should work.
The fewer tubes used the better.

I think 3 will work just fine. Heck, you might want to try just one to see how far you
could push it. It would be interesting to see how well just one section would work. No
soldering involved. If that's not good enough then add one or two more,
but I bet you won't need more than 3.

[shadylane]

That places the knockdown power at about 1kw per section. Good to know before placing an order.

That's some were in the ball park, 1 kw per section or 500w per foot for 3/4" finned tubing with a big fan blowing on it.

[skow69]

i know it complicates matters, but shrouding could have a big effect. Path of least resistance and all. Any air that doesn't go through the fins does you no good at all.

[shadylane]

The fan has 3 speeds, but I only ran it on high.
Next time I'll try running it on medium and low to see how much effect air flow has.
I'll also try not using a fan and see how much the finned tubes can knock down with convection currents only.

[Brutal]

I think "no good at all" is a little harsh. If air flows past both sides of the finned tubes with any velocity it will create a low pressure area on the downstream side of the finned tube. The low pressure area will help pull air through the fins. Certainly having air forced through would be more efficient use of the airflow though.

For airflow efficiency blocking off the area between the tubes, and adding a molded shroud would make the most difference. Something like this:

[shadylane]

Didn't get anything done today on the aircooled condenser.
Needed to go to town for 3/4" copper elbows for the build, but my grandson showed up early in the morning wanting to earn some money to buy the latest version of his favorite video game. Instead of going to town for parts, I bought 8400 pounds of chat from the local gravel pit and paid him to unload it from the trailer with a shovel.

[shadylane]

Brutal, your picture of a fan shroud got me to thinking. All the radiators used on cars have the fan on the sucking side.
Even the ones that use an electric fan. There must be a reason for this.

[Hound Dog]

Brutal, your picture of a fan shroud got me to thinking. All the radiators used on cars have the fan on the sucking side.
Even the ones that use an electric fan. There must be a reason for this.

Could just be because the fan would actually block the airflow at highway speeds if it was in front of the radiator.

[shadylane]

Ready for a test run. None of the joints are soldered, just have tape wrapped around them for now.

[MichiganCornhusker]

Wondered how you were going to do the angle fittings, I see what you did there, clever.
I like it.

[shadylane]

I think the tubing could be annealed, soldered and then bent. Haven't tried that but It might work
It would be simpler than cutting a slice out and brazing it back together.
Just finished a test run with water. The condenser knocked down 4500w at 11:50 minutes per liter.
The output temp was 70.6c - 159.2F and the boiler pressure was 1.9 inches of water.
Tomorrow I might start taking sections off the condenser until it blows steam, then turn the power down until it starts condensing again. That way I can find out the max knock down power per foot of condenser.

[Hound Dog]

I was wondering if you could make the connections with soft tube. Flare out the ends with a swagging punch to fit over the ends of your pipe, then bent in a "U".

Many ways to skin that squirrel though.

[mason jar]

Just finished a test run with water. The condenser knocked down 4500w
at 11:50 minutes per liter. The output temp was 70.6c - 159.2F

Shady, forgive me for geeking out a little here, but you were knocking down:

kW = (evaporation heat of water) x (water weight in kg) / (collection time in seconds)
   = 2260 * [1kg / (11.83*60)]
   = 3.18 kW

So your heater was putting out 4.5kW and making about 3.2Kw of steam. That's pretty darn good.
My burners aren't nearly that efficient. I guess that's the advantage of the electric heating element
being INSIDE the boiler. Most of the heat is transferred directly to the liquid instead of being wasted
by radiating out into the room.

and the boiler pressure was 1.9 inches of water.

What do you mean by boiler pressure? I thought our stills were open to the atmosphere
so there should be no pressure. Sorry if I'm missing something here.

Tomorrow I might start taking sections off the condenser until it blows steam, then turn the power
down until it starts condensing again. That way I can find out the max knock down power per foot
of condenser.

I bet two or three sections will still knock down all your steam. Anyway, no matter how
you look at it, the fact that something so simple can knock down all that steam is pretty
amazing.

[Hellnoh2o]

what a nice build Im impressed, My MIDI-STILL designed for water holds about a gallon and a half and it has 3/8 stainless coiled finned tubing with 5 turns at 6" diameters with a small fan blowing up through the coils. even before I modified the still with a controller, I would run that thing hard on a stripping run and never saw any vapor and could maintain a steady stream.

[Sambo_Jones]

There will always be a small amount of pressure, has to be a difference for anything even steam to move. Take atmospheric pressure at sea level 75'F at 50% RH you have about 14.69 psi of air pushing downwards, for vapor to move up it needs to have some force to push it upwards even a few feet, hence the 1.9 in WC. And 1.9 in WC is a minute amount of pressure, given under the afore mentioned standard condition it takes just over 28 in WC to make 1 psi. This pressure comes from the volumetric expansion rate of the fluid changing from liquid to vapor.

[WooTeck]

that is some beutifull work there shady.

[mason jar]

There will always be a small amount of pressure, has to be a difference for anything even steam to move. Take atmospheric pressure at sea level 75'F at 50% RH you have about 14.69 psi of air pushing downwards, for vapor to move up it needs to have some force to push it upwards even a few feet, hence the 1.9 in WC. And 1.9 in WC is a minute amount of pressure, given under the afore mentioned standard condition it takes just over 28 in WC to make 1 psi. This pressure comes from the volumetric expansion rate of the fluid changing from liquid to vapor.

OK, that makes sense. I guess I was thinking that 1.9 inches of water was more pressure. If I would
have bothered to look it up, I would have found that 1.9 inches of water is less than 0.07 PSI. So a
SMALL amount of pressure will be there just to force the steam through the outlet. Got it.

[shadylane]

Wondered how you were going to do the angle fittings, I see what you did there, clever.
I like it.

Here's another way that works at any angle.