What's happening here?

[grehund]

Hi All,

I've found that plate-3 (from the bottom) on my 4-plate still doesn't bubble & fills quite a bit, but only on my final neutral run. My stripping runs never seem to have this problem.

What's happening?
Am I doing something wrong?

[blond.chap]

From the sounds of it your vapour is bypassing through the downcomer. Is that plate any different from the others?

[bt1]

Howdy,

Do me a fave and increase/decrease heat input and see what happens...it might just be equilibrium is achieved just on just above that plate for given heat input.

Mines plate 2 at lower heat plate 3 on a normal run and can push up going hard.

bt1

[MacStill]

Just flick the heat off for a few seconds until the downcomer fills, then flick the switch back on.... it's just blowing vapour through the downcomer ;-)

[grehund]

Thanks for the replies.

It tends to cycle through; so it will fill, then start to deplete to almost nothing, then slowly fills back up.

I have varied the heat input, which does fix it temporarily, but then it slowly starts to build again.

When there's just the normal amount of liquid on the plate, it does appear the bubblers are working correctly. I understand that the vapour is following the path of least resistance, I just don't understand why it's happening in such specific circumstances.

More to the point, not sure if it's normal or something I should try to fix.

[bt1]

Yeh reckon mac's nailed it...

what's different about this plate? cup size different, angle, downcomer cut out depth?

bt1

[Gas on]

G'day grehund :handgestures-thumbupleft:
Im guessing your risers & downcomers & caps are screwed together locking onto the plate...
just check that their not loose on the plate :handgestures-thumbupleft: :handgestures-thumbupleft: maybe