thecroweater wrote:Ok I'm not sure i have read about Odin doing this do you have a link. I have read a few fails concerning SPP in a 4" but not as a reflux module over a plated column and thought that the right sized SPP might work ok for this if not a pricey way to go about it. Scoria/ lava stone works just fine along with some other products (for instance I am a big fan of ppl using structured copper mesh if using a stainless steel flute)bearriver wrote:Over 2"? Lava rock. Proven to work well by respected members.CH3CH2OH wrote:I am more looking at a packed section above a plated column
According to posts I have read by Odin, SPP does not perform well above plates.
Odin wrote in the thread "SPP Machine Begins" by Big Swede: viewtopic.php?f=50&t=49704&start=30" onclick="window.open(this.href);return false;" rel="nofollow
" Why run SPP over bubble plates? Or why not? SPP works best in semi-flooded conditions. Lots of reflux reduce HETP to around 0.5 centimeters. Less reflux and HETP goes up. If you use plates to strip lots of water out of the gasses you are sending up your column, you will loose one of the places in the column where SPP works best (at the bottom). Just imagine that SPP will give around two distillations just in the first 1 to 1.5 centimeters of the packed column section. If the abv is low enough. If you want to make optimal use of SPP, you run it without any other help."
"There's another reason not to put plates under an SPP packed column section. Ethanol blockage. SPP is so effective, it takes a wash or low wines boiler charge to Azeo very quickly. If you feed your column with too high ABV, for instance via plates, the SPP may cause ethanol blockage: Azeo is reached so close to the entrance of the column, that no temp gradient can develop in the higher parts of the column. Ethanol hold-up, column flooding. That causes one to power down, thus creating less reflux and decreasing efficiency."
I am sure he has mentioned this elsewhere also but am not sure where. Hope it helps.