My little problem

[Andy]

I ran the 500 this morning and all seemed to be running as normal.
Top temp at 79.5 or there abouts and bottom temp about 57
Normally I will get between 3.5 and 4 litre @ 93% and during the last 500ml the top temp will start to climb.
Today however, at the 3 litre mark the top temp dropped so I raised the bottom temp, this started the top temp to jump and I got a massive surge of output.
I couldnt control the temps from there on so I gave up.
The only thing that I changed was to add a small amount of copper mesh to stop the saddles dropping out and to fill the 1 inch gap in the column.
Could the mesh have caused this???

[lyonacre]

Thats really interesting. I have been having similar problems since I got my T500 and have not been able to work out what the problem is.

The latest thought is that my cold water supply follows a fairly torturous route with miles of pipe through the loft so when it's cold there are some gallons of really cold before it stabilises and similar when its hot.

I have been trying to start the still up after running a fair amount of water off first and found that is helping BUT as midday arrives in summer it all goes to pot and as the sun sets in winter the same happens.

So as far as I can tell it is the cold water pipe that is causing most of my problems and I just keep a careful eye and try to choose my time of day carefully.

I tried all sorts of things with the column all to no avail, nothing seemed to change things as much as the sun or lack of it.

Oh, there was one exception! Purely by accident we noticed that the cold input pipe was resting against the still. When we moved it and kept it away the temperature control improved a lot!

None of that probably helps but it may just spur a new thought

[Capt-Cudellez]

Hi Andy, did you hear anything strange before the surge? I've had the same problem on one or two runs, I could hear the copper saddles tinkling or rattling right before it happens, which I guess was the sound of the column flooding, I'm pretty sure its flooding as I've experienced running the T500 as a pot and the output was many many times what you could ever get even when running without any cooling, I got about 400mls in a matter of seconds.

I believe one cause of flooding is having the packing too tightly packed, the vapor traveling up the column prevents the reflux returning down the column and the liquid just pools until it fills the top of the column, then it get interesting very quickly. Try removing a few ceramic saddles, or loosening your copper mesh roll slightly.

I'm pretty confident it is a packing issue, as I killed the power, gave the column a good shake while still attached to the boiler, powered her back up and checked that my shaking didn't cause any leaks. Ran with no issue after that, and no rattling.

[Andy]

Thanks guys, nice to know I'm not alone.
I kind of figured it was the mesh being too tight.