I have a question for everyone here with a good eye or experience!
A buddy is getting pushed to buy a falling film for ethanol, and he keeps inquiring what unit is the best on the market…most efficient throughput wise.
I suggested the delta because it seems the most efficient with those plate heat exchangers…
But, there is so many units to pick from…
What is everyones top pick here and why is it the best? Is my question…
If I need to do anything more than 10GPH of solvent removal I’m doing it with a membrane. Hands down. There’s almost no reason to run a FFE unless you’re just using it to evaporate remaining solvent from your membrane.
If I HAD to use a FFE I’d probably just build one from scrap parts. I don’t really have a smart recommendation for off the shelf.
(@Kingofthekush420 also makes excellent membrane products as you tagged him already)
Put a gun to my head and force me to purchase an off the shelf FFE, I’d try to buy a second hand delta unit. If I were to build one, the design would look pretty similar to the delta one.
But I wouldn’t buy or build an FFE without a gun to my head. If I were to purchase an off the shelf solvent recovery system, I’d send a purchase order to @MagisterChemist for whatever meets my needs.
Hey guys. I have a brand new BizzyBee Falling Film Evaporator for sale if anyone is interested. Put together but never used. Includes all hosing and cables but not chilling/heating pumps.
ERU-200 from Mountain Equipment does 200-250 liters / hour. Air driven, auto-dumps clean solvent. Recommended facility: 14 ton water chiller, 60Kw water heater, air compressor, rotary dry vane vacuum pump.
We have a model that looks just like this. We have it hooked up to 2 tankless water heaters (58kW, 140 F max temp) and have the condenser side hooked up to a -10 chiller.
We feed into it with 3 peristilatic pumps (~300 mL/min each). We don’t have amazing vacuum on the system (around -0.088 MPa vac).
We were getting a lot of bumping until we angled the oil discharge port (left side) downwards into a pump.
All in all, it does much better than our rotovaps, but we are limited by both the heat and to a lesser extent the vacuum. Much easier than the rotovap, but I would try to get a heater than can go hotter than 60 C
Bizzy Bee for me. that silver serpent once dialed in will crush 50GPH. certainly cost is a thing but good design is good design and you get what you pay for.
If the converter I found is correct, -.088 MPa is about -660 torr, which to me seems like either an absolutely enormous air leak and/or your chiller can’t keep up and/or not enough surface area for the vapor to condense in.
On my BZB FFE we have a Bizzy branded (but actually made by Digivac, Lab Society also sells a branded version) vacuum pressure controller which switches a solenoid on and off to maintain within a few torr of an adjustable setpoint value. If there’s a big delta above the setpoint value and the actual vacuum level something is wrong (air leak, vac pump or chiller wasn’t turned on, valve left closed etc). If you’re injecting your ethanol mix and the vac valve is on all the time, you’re kissing a considerable amount of solvent goodbye and diluting your vac pump lubricant at the same time (thereby decreasing vac pump life)
I think regulating your vacuum level is an important feature that a lot of the import/DIY/bare steel FFE/RFE units are missing. At full vacuum you are dropping your evaporation temp considerably, it also means your cooling side needs to work harder to recondense everything and keep vapor losses out the vac pump to a minimum.
Delta had a unit with a liquid ring pump in between the hot side and cold side which is a very smart move IMO, that way they could pull a harder vacuum on the hot side to drop evap temps and put positive pressure on the cold side to make your chillers job easier.
Provided your stuff is insulated there’s no real benefit for vacuum. However your temperature relative to the air temperature is bigger. The corresponding heat loss to the environment would also be higher. So vacuum could help.
Our little scroll vacuums just aren’t super strong, using the same kind we are using on a 50L rotovap. We never really top much below -0.09 MPa on those, even with no load. At our pressure ethanol boils ~30 C, but we probably only remove ~1/2-2/3 the ethanol in the oil on a first pass.
to lower the BP of the solvent so less energy is required to get it to boil, large scale this matters
its super hard to dry out your crude without vacuum which is why I dont like the yellowstone
also, if youre recovering solvent with a low BP youre going to get solvent vapors in the air as the radiator cant condense solvents that close in BP to atmospere, the yellowstone didnt like methanol
i had 20% solvent left after running the thing at 160f which i believe was the highest it would go
you can bet the ffe im building will run under vacuum and will have a chiller of some sort
The lower your bP the lower your heat requirements but you’re sort of forgetting about the correspondingly lower temps required for removal of heat energy from the system.
Robust Chillers are generally much more expensive than heaters, in my experience
