Plates and Downcomers on a bubler

[ErnieV]

Hi people.

I have been reading with interest all your bubler builds.

please could someone explain the downcomers and the construction of them?

[Brendan]

They are a tube that passes liquid from the plate down to the plate below.

They are set at a height above the plate, at which you want to set your liquid bath depth on the plate...once the liquid reaches this height, any more will overflow into the pipe and fall down to the next plate.

They have to be vapour locked, meaning that they do not allow the rising vapour to go up them...want to force all rising vapour through the plates and allow liquids to make their way down the downcomers...the vapour lock can be achieved by having the bottom of the downcomer at a height so it is submerged below the liquid bath depth...or if above the plate, they need some sort of an overflow cup that allows the liquid in them to overflow out onto the plate below, while stopping vapour from travelling straight up them...

Oh and you also generally alternate sides with their placement through the column to force the heavier liquids to work their way across each plate as they make their way down the bubbler...helps with better separation of the compounds...

How's that?

[kelbygreen]

downcomers are set at a height above the plate. when the plate loads up (fills up) it will go down the downcomer on onto the plate below.

there is many constructions and prob will depend on what plates you use. But just having the next size up stop end soldered on with holes drilled in the inside pipe so the liquid can get threw. There are many types but the idea of them is the bottom has to be submerged so the vapour doesnt drive its self up the downcomer instead is forced threw the plate.

[ErnieV]

Brilliant Brendan.

Thanks for the info. That's really cleared it up in my head. So the downcomer is slightly raised on the plate above to allow the liquid to find a level.

Then as the liquid level rises it gets to the point where it drops down the downcomer pipe, and the downcomer pipe has a liquid trap at the bottom similar to a WC (toilet) u bend. I suppose this could be a large end cap soldered onto the end of a much smaller pipe at one side.

Great, I have it all clear in my head now. Looks like the scrap yard for me on Saturday morning ;-) Watch this space.

[Brendan]

Yep :handgestures-thumbupleft:

[ErnieV]

downcomers are set at a height above the plate. when the plate loads up (fills up) it will go down the downcomer on onto the plate below.

there is many constructions and prob will depend on what plates you use. But just having the next size up stop end soldered on with holes drilled in the inside pipe so the liquid can get threw. There are many types but the idea of them is the bottom has to be submerged so the vapour doesnt drive its self up the downcomer instead is forced threw the plate.

Thanks mate, you typed your reply as I was typing mine to Brendan.