hi all :)
untill now i've been running one of these :
originally as supplied by mac, it was a 3 plater, but i added another section and made a 4th plate. i'm not sure if i have taken a step forward, or if i'm loosing the plot and after my boiler builds just gone build bonkers 8-} . i took this lot (originality a few lengths from the scrappy) :
threw them together, and ended up with this:
the easy flanges were soldered together as usual, and i tig brazed the view port side arms with 15% sticks (was the only thing other than 45% i could get in 1.6mm). this thread was originallygoing to be a bit of a comparison of small caps vs large caps, but i thought some of you might find my first run .... amusing.
i had changed my usual cooling set up (3/4 gate valve, feeding the rc from the top, then out through the bottom and into the bottom of the pc). i thought a needle valve might give me some more fine control, so i hooked it up and the flow was so restricted, i decided to reverse the flow through the rc to make sure it would always be full.
i threw in a tpw, one of two, got water flowing and fired up the boiler (ok, so i turned on the switch :)) ). took some time, but as it started to heat up first the bottom plate portal started to fog up, and slowly, slowly, the same thing creeping up the column. when the whole column finally got going, the top plate started to fill... it was like a friggin fountain blowing out the top of the downcommer :scared-eek: .
i turned off the element for a few seconds, then on again. that was enough to get some fluid into the downcommer to block off the vapour. then the next problem... vapour pouring out of the vent hole in the parrot where it connect to the pc. there wasn't enough cooling in the rc to throw it into full reflux. i think the 400mm copper mesh packed column between the column and the rc helped give a little reflux. the pc was running a lot hotter than usual.. the valve, even fully open, was just too restricting ~x( . i clipped some curved copper plate in front of the vent so the vapour was hitting it, condensing and dripping into a pan. luckily there was no ignition sources nearby.. once the temp started to go up i shut it down. i know there was still alcohol to be had, but i didn't feel comfortable continuing, and it was a cleaning run any way... but i did want to know what abv i'd get out of the small plates.
considering it was running more or less in pot still mode and i was loosing product it could have been worse. 91.3% temp adjusted. someone commented that you loose flavour with small caps, so i figured that would equate to higher abv. running 4 large bubble cap plates on the old column plus the 400mm packed section had me getting 93.5%. i have put the cooling system back the way it was.. except i changed to the 3/4 gate to a 1/2 gate. i tested the flow, and it's *much* better, and the smaller gate gives me better control over the flow than the 3/4. tomorrow i'll have another crack with a mix of tpw, fermented juice from bottled fruit (various fruits) and some spirits i had run in the past that i just don't care for. we'll see what abv i get. :pray: