cm concoction

[googe]

Hey all, having a go at building a cm, my brain hurts from thinking but I think ive got things sorted finally. Its not the usual way there done, but hey, if I don't try I wont know. Its 2' all the way.

[Mud Mechanik]

Not sure I'm following your concept...it looks like the flange on your cold finger is blocking vapor traffic

[googe]

The finger is the vapor path , it's flattened 1" to create more cooling surface . That's the idea anyway.

[Mud Mechanik]

You would rather try and force vapor through a 1" column than use the 2" in your picture ?:shock:

[googe]

Think I should explain better it's the reflux condenser your looking at, not the column, I know you'll probably say it's to big but I have this stuff sittin around gathering dust and want to try different things so here we are. hope the pic helps, the product condenser will be on the right of it flowing through 2" all the way.

[rad14701]

The finger is the vapor path , it's flattened 1" to create more cooling surface . That's the idea anyway.

Nope... Cooling surface is the same... However, any vapor or water traveling through that flattened tube will have vastly increased vapor/liquid speed, vastly reducing efficiency... That's my take on it...

[googe]

I thought vapor knockdown was about surface area?. From what I've read, vapor will only be knocked down around 3mm from the cooling surface?. I thought that a tube flattened would have alot more cooling surface than a regular tube. it's like if you got a 1' tube and put it in a 2' jacket it wouldn't knock down much, but if you put the same amount of 1/2' tube calculated at the same volume of the 1' in a shot gun style condenser it would knock down alot?. Eg; more surface area is cooled.

[Mud Mechanik]

I think what Rad is saying is that a piece of 1 inch pipe is one inch....no matter if you flatten it a little or not, it is still 1 inch.

[Prairiepiss]

The surface area would be the actual walls of the pipe. And how much surface area they have. So a 1" pipe will have the same wall surface area if its flattened out or not.

[Mud Mechanik]

The surface area would be the actual walls of the pipe. And how much surface area they have. So a 1" pipe will have the same wall surface area if its flattened out or not.

Thats what I was trying to say....thanks PP, I'm not that good with putting my thoughts into words.

[googe]

Why do radiators use flat tubes?.

[Mud Mechanik]

because to get the same amount of round tubes in a radiator, it would be 4 feet tall.

[googe]

I'll just agree to disagree.

[myles]

Can I see if I have this right? You put a 1" vapour path inside a 2" jacket filled with water. Then to minimise the vapour distance to a cold surface, you slightly flattened the tube. If that is correct what we are looking at is a big single core shotgun condenser that is being used as your reflux condenser. You will have vapour and reflux condensate traveling in opposite directions inside that central core.

Assuming that is correct you are not really maximising the potential of that 2" water jacket.

[googe]

Thank God someone gets it, thanks myles, well said. Im not saying im right, im just trying to explain what im doing. I keep getting negative feed back with no explanation why it's negative. I've never tried what I'm attempting and Haven't read anything about it that I could find. IM just trying new things. Would you mind explaining why the 2' jacket isn't being maximized?.

[myles]

Yes that is no trouble at all. You have a lot of water volume inside that jacket that never gets close to copper. Now the typical way to deal with this is to put in a larger number of 1/2" tubes. This is a good size because it has a fairly small distance between cold surfaces. You don't want to cram in too many because it stops the water circulating effectively, although you can use baffles.

The total surface area of for example 3 x 1/2" tubes, is a lot more than the surface area of a single tube with the same cross sectional area as 3x CSA of a 1/2" tube.

And of course the more volume occupied by vapour also reduces the weight. I do have to say though that this vapour tube style condenser is not the "ideal" configuration for a reflux condenser. It still works off course, but there are more compact options available.

[thecroweater]

Yep googe I see what ya want to achieve, to make the "condensing more efficient . Thing is as I see it yes you are increasing the vapour contact with a cooling surface no worries but on the down side more of your cooling water is doing nothing towards condensing and you are increasing your vapour speed so in reality you haven't really achieved any increased efficiency . think about your radiator analogy more, . by flattening your vapour path you have increased ya condensing contact surface but also ya vapour speed plus now you have a larger void in the water jacket . Now you could fit another 1 or 2 flattened pipes in there and this should work with the efficiency of a radiator , you need to use the same thinking as ya did with that davies condenser (more cooling surface and no increase to vapour speed eg: vapour constriction)

[googe]

Thanks Myles and crow, cleared it up very Nicely . that's already in the pipeline crow, 3 1' flattened pipes in a 2 or 2.5' jacket for a stripper, will knock down tons I reackon. I've built this thing now so might as we'll try it. Thanks for the feedback.

[rad14701]

Let's not confuse liquid with vapor... Vapor will collapse without being in direct contact with the copper... All you need to do is reduce the ambient temperature and dew point within the condenser to the point where the vapor collapses and doesn't re-vaporize... That's the non-overly-technical version...

[googe]

Just curious as to why you said that rad?. was I confusing liquid with vapor?

[rad14701]

Just curious as to why you said that rad?. was I confusing liquid with vapor?

I was referring to the flatteneing of the tubes issue... Liquid won't cool as fast in an open tube as it will in a flattened tube, but this is not the case with vapor... Vapor collapses (condenses against the walls)... I did mention dew point... Heat travels to cold, not vice versa... As vapor collapses it will continue to collapse even as the vapor density diminishes... Because of this theoretical phenomenon there is no real benefit in flattening a vapor tube... Does that help resolve any remaining confusion...???

[googe]

Yes it does thanks. I have other questions but I'll leave it there, don't know how all you lot know all.this stuff, your certainly switched on. Gets very frustrAting when IM to thick to understand things right.