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Re: Bitsa the bubbla build

PostPosted: Thu Aug 09, 2018 3:29 pm
by Doubleuj
23mm sounds better 8-}

Re: Bitsa the bubbla build

PostPosted: Fri Aug 10, 2018 7:59 pm
by mattyb
A little bit of progress today. Got the guts of the RC done and almost finished my first plate. What's the consensus on how long the down comer should be under the cap?? I have 25mm above and will put a 1" cap on the bottom but not sure how long to make the tube. Oh and only went through 3 bits doing the perf plate holes :handgestures-thumbdown:

Pics to follow

Re: Bitsa the bubbla build

PostPosted: Fri Aug 10, 2018 9:49 pm
by mattyb
went a bit hard with the disc on the copper so aint no copper porn but it should do!
rc.jpg


rc.jpg

Re: Bitsa the bubbla build

PostPosted: Fri Aug 10, 2018 10:07 pm
by dans.brew
mattyb wrote:went a bit hard with the disc on the copper so aint no copper porn but it should do!

Good work matt!
Never mind copper porn, as long as its not a sprinkler when done mate :laughing-rolling:
Did you have it sitting in the 4" pipe when you stuck it together?

Re: Bitsa the bubbla build

PostPosted: Fri Aug 10, 2018 10:26 pm
by mattyb
dans.brew wrote:
mattyb wrote:went a bit hard with the disc on the copper so aint no copper porn but it should do!

Good work matt!
Never mind copper porn, as long as its not a sprinkler when done mate :laughing-rolling:
Did you have it sitting in the 4" pipe when you stuck it together?


Nah I didn't but it still slides in nicely.

My problem is I don't have patience so always rush everything lol. Not the best hobby for that. The one thing I have learned is you need patience in this game !!!!

Re: Bitsa the bubbla build

PostPosted: Fri Aug 10, 2018 10:39 pm
by dans.brew
All good then!
When ya catch the build bug its hard to not just dive in without thinking ahead a bit.
This site is full of builds and not too many of them wouldn't of encountered a hickup or two (definately mine)... so if you take pleanty of time to research its possible to save a bit of heartache.
Once your RC is done... you've got one of the more fiddly parts done i think.

Re: Bitsa the bubbla build

PostPosted: Sat Aug 11, 2018 8:36 am
by db1979
Looking good :handgestures-thumbupleft: half way on the RC, the RC is a big confidence booster. Don't forget to drill the water inlet and outlet holes before adding the internals.

There's been discussion on and off about downcomer lengths, cup sizes and fluid depths. Some say the cup needs to be deeper than the fluid bath, I disagree, you just need a vapour lock.

Have a look at the photo below of 5 stars early downcomers:
IMG_1591.JPG

These downcomers allow the cup to sit just above the fluid bath below, the idea being that the fluid coming out of the downcomer only has a short distance to fall and ends up in the bath far away from the next downcomer. Mine aren't like this though, they are very short, just below the plate (about 5 mm clearance) and they work fine. The fluid leaving the downcomer doesn't end up near the next downcomer.

The current 5 star downcomers have the cup positioned a short distance below the plate, as shown below:

DSC_0228.JPG


Some builders even have the cup as part of the plate below and the downcomer tube simply sits in it when assembled. This means a loss of active plate area though.

So a short answer is: it's up to you how long you want your downcomer to be. I don't think it makes much difference.

Re: Bitsa the bubbla build

PostPosted: Sat Aug 11, 2018 8:20 pm
by bluc
Hmmmm just got downcommwrs from 5 star as in thursday...dont look like that...

Re: Bitsa the bubbla build

PostPosted: Sat Aug 11, 2018 8:34 pm
by db1979
Maybe they've got a new version, point is though that it really doesn't matter how long your downcomer tube is, and the downcomer cup doesn't need to be deeper than the fluid bath depth.

Re: Bitsa the bubbla build

PostPosted: Sat Aug 11, 2018 9:27 pm
by mattyb
thanks guys. I think I will make it short but with a big cap as I am making the cap so can't see the harm. Will try do some more reading on it but have a 2 & 3 year old that have decided sleep is something not required anymore !!

Soldered in the RC top plate today............. Think I may re do the whole thing.........not good. should have just made it out of solder! too embarrassed to show pics, will review it in the morning

Re: Bitsa the bubbla build

PostPosted: Sat Aug 11, 2018 9:32 pm
by mattyb
bluc wrote:Hmmmm just got downcommwrs from 5 star as in thursday...dont look like that...


Any chance of a pic Bluc?

Re: Bitsa the bubbla build

PostPosted: Sun Aug 12, 2018 1:14 am
by Dig Brinker
Latest design is a bubble cup under the plate as a downcomer as far as I know. That’s it. No extension. Five above, one below. All the same. Was on the 5 star website for couple years as complete 4” plate. That’s how I bought mine.

Edit: this works for bubble caps, not totally sure about perf plates.

Re: Bitsa the bubbla build

PostPosted: Sun Aug 12, 2018 11:22 am
by bluc
Resized_20180812_112222_2276.jpeg


Resized_20180812_112240_4233.jpeg

Re: Bitsa the bubbla build

PostPosted: Sun Aug 12, 2018 3:32 pm
by warramungas
bluc wrote:
Resized_20180812_112222_2276.jpeg


Resized_20180812_112240_4233.jpeg


I'd have thought those holes at the bottom of the downcomers there would be more worn out through years of use on your plates bluc. :))

Re: Bitsa the bubbla build

PostPosted: Sun Aug 12, 2018 6:18 pm
by mattyb
bluc wrote:
Resized_20180812_112222_2276.jpeg


Resized_20180812_112240_4233.jpeg


Awesome thanks. A picture is worth a thousand words!

Re: Bitsa the bubbla build

PostPosted: Sun Aug 12, 2018 7:20 pm
by bluc
warramungas wrote:
bluc wrote:
Resized_20180812_112222_2276.jpeg


Resized_20180812_112240_4233.jpeg


I'd have thought those holes at the bottom of the downcomers there would be more worn out through years of use on your plates bluc. :))

But I just bought them... :laughing-rolling:

Re: Bitsa the bubbla build

PostPosted: Sun Aug 12, 2018 11:08 pm
by RC Al
The job of the downcomer is to let sufficient liquid volume down while stopping vapor going up, I haven't done the legwork fully on these, but it would seem to me that any length lower than the plate is just interfering with the action of the bubble matrix*

The slots in the cup ensures that the liquid forms thick streams downward on the cup that are resistant to being grabbed by the vapor headed to the risers (entrainment)

Because the entrance to the risers is generally a square cut 90°, there would be a fair donut shaped boundary layer at the entrance to each riser, having the cup at the top gets the liquid away from the high flow area until it forms a big stream off the bolt head

The liquid would also have to travel a good distance horizontally to get back up the riser

*Sorry, Simpson's reference, I am of course talking about the vapor interaction with the bath

Re: Bitsa the bubbla build

PostPosted: Mon Aug 13, 2018 8:17 am
by woodduck
I've refrained from commenting on this post because I was hoping you guys would go find the answers in the threads.

All this info is in the previous build threads, lengths, angle or square cut, distance from bottom of cup, slots no slots, cap sizes etc etc it's all there you just gotta read as much as you can and all the questions re building a bubbler will be answered. I don't say this to be a prick I say it to help out. I knew nothing about bubblers before I researched them. Reading ALL the bubbler threads taught me so much not just about what size to make things but why. It also taught me how to run one properly so when it was ready to go I felt like I was ready to go too.

That's my words of advice. Good luck :handgestures-thumbupleft:

Re: Bitsa the bubbla build

PostPosted: Mon Aug 13, 2018 1:37 pm
by mattyb
woodduck wrote:I've refrained from commenting on this post because I was hoping you guys would go find the answers in the threads.

All this info is in the previous build threads, lengths, angle or square cut, distance from bottom of cup, slots no slots, cap sizes etc etc it's all there you just gotta read as much as you can and all the questions re building a bubbler will be answered. I don't say this to be a prick I say it to help out. I knew nothing about bubblers before I researched them. Reading ALL the bubbler threads taught me so much not just about what size to make things but why. It also taught me how to run one properly so when it was ready to go I felt like I was ready to go too.

That's my words of advice. Good luck :handgestures-thumbupleft:



I can assure you I have read almost every thread in the plated column area.

However there is only so much I can take in and so much time I have to read also. Unfortunately I run a farm, a small business and look after my 2 kids full time so sometimes its just easier to ask and come back for the answers.

Totally know where you are coming from though but I like to get up to date info also and if everyone only read previous threads and didn't post it would be a pretty quiet place. Appreciate all the effort you more experienced guys put in with advise so don't take this as me being a prick either :-)

Re: Bitsa the bubbla build

PostPosted: Mon Aug 13, 2018 3:49 pm
by woodduck
I was in your same position when I built my bubbler mate, I guess I just became obsessed with bubblers and couldn't get enough of learning about them. I would spend night after night reading.

I guess what I like to see is, "hey guys, I've been reading up on down commers and it seems some go for 100mm and others are just under the plate, is there any particular reason why they are so different? " this shows us you've had a crack at finding the answers.

Here are my down commers and cups, there was a small amount of discussion there that might help,

viewtopic.php?f=36&t=6709&start=60#p117393