WIP- Air cooled, vapour speed controlled build

[benja]

Well, had a productive day today. Morning spent building the new controller, and arvo brazing the column.
Controller is based around an SSR, with dual temp sensors to automate heat/run cycle, and shut it down if the column gets to 90deg+. Dual temp thermometer hasn't arrived from HK yet, but will be mounted on the left of the controller box. There are 3 run modes- boost (both elements 2400W, but only until column reaches 60deg), controlled 600W element and controlled 1800W element. Still a lot of wiring to do yet, but that will have to wait until the weekend.
The column has 12 cross pipes, each 1/2" in diameter brazed in with 45% silver rods, and on the flanged end of them will be mounted 50mm fans. Calculations show this should be able to knock out somewhere around 600-800W from memory (did them a few years ago!), looking forward to trying it out. Bottom flange is for a tri-clover fitting. Outlet is via a needle valve- just wondering if PTFE tape is OK for the thread seal, or if i should seek out something better. Suggestions welcome.
Whole thing needs a darn good buff, i know this will only have a small effect on performance, but it looks much better for a maiden voyage.
Lots of wiring to be done yet, all in silicone cable for anything that goes near the boiler or column. Should have a test run on the weekend.
Will update when something exiciting happens!

Cheers

Benja

[astronomical]

pretty cool lookin

[heartcut]

I like it! PTFE tape is fine. Looking forward to hearing how she runs. Might try a scrubby in the top of the condensor if it doesn't get all the vapor.

[Samohon]

Looking good benja...

[jake_leg]

Nice looking control box.

Would it help to have fins inside the cooling pipes to allow more surface area in contact with the flowing air? Perhaps insert extruded aluminium tube of the right diameter held in place by thermal grease.

This kind of idea:

[benja]

Nice looking control box.

Would it help to have fins inside the cooling pipes to allow more surface area in contact with the flowing air? Perhaps insert extruded aluminium tube of the right diameter held in place by thermal grease.

This kind of idea:

Thanks for your comments.
jake_leg I dont think there is any benefit to this, i need a fast heat transfer, which won't occur with a bigger thermal mass. Besides, the x flow pipes are only 1/2" OD!

[jake_leg]

Did you read the link that you get by clicking the picture? It's the same concept as running a spiral wire inside the coolant side of a Liebig. It makes for a longer twistier coolant path and more contact with the heat exchanger surface. You could do it with a spiral wire actually. It's probably more beneficial where you have fat pipes and/or viscous coolant though.

The reason I mention it is that your cooling capacity is not that huge and you need some excess capability. Anything you don't knock down will come out of the top.

[benja]

Yep, like you said, better in big pipes, and with viscous fluids, which I have neither of.
Cooling capacity is no issue either, I have 0-100% control via a SSR for both a 600W or 1800W element, so all I need to do is balance the vapour speed to the cooling capacity of the head.
Got all the wiring finished today, really suprised it worked first time! Will see if I can get it all together and give it a run next weekend, to see how efficient the head actually is.

[jake_leg]

I guess you'll be fine. But it does seem to me that your take off rate will be limited by cooling capacity.

[benja]

Finally finished the wiring of the controller over the weekend. Everything worked perfectly, first time. Actually, that's not quite true, I left the neutral off the 2 relays, so nothing happend first time. Once that was fixed, it worked perfectly. Start/stop, 4 heating modes (auto 1800W, 2400W, controlled 600W and controlled 1800W), indication lights, dual temp probes, temperature dependant switching from heat up to run, auto cooling start plus safety shutdown if temp>90deg!
Just need to mount the 4 temp sensors (2x for automation, and 2x for indication) and get the outlet pipework sorted and it should be ready for a wet test this weekend.

Cheers

Benja

[Lynx_Gen]

that things pretty cool! I'd like to see of vid of that thing all togther and running...

I give up on the ole coil condensor in the head. I wont be playing around with trying to make one of those ever again, so Im looking for ideas on which way to go... I do have a very interesting idea to try, kinda styleish, and should knock out anything I'll ever through at it!