To get the most from a gas heated boiler I'm wondering how far up the sides the heat can be channelled?
At the moment I have a heat shield that goes up the sides of the boiler to the approx level of the liquid. A lot of useable heat flows out the top of the shield and also radiates through the shield. It's little use insulating the outside of the shield because hotter gas will simply vent out the top and be wasted just the same. What if I did this?
Heat Shield Diag..jpg (4.97 KiB) Viewed 3660 times
Although the heat going up the upper half will be residual and not very fierce, it will be heating the gas in the boiler directly!
Will heating the gas be dangerous?
Is it a waste of time because it will stuff up the column stabilization? (Say the column proper starts just above the exhaust outlet).
Don'T thank Id heat the column , I use presser tanks cut a hole for pot /still , you still need a flame spreader(depending on pot) but it holds in a lot of heat.
I agree with Dndrhead... I'd heat the entire boiler, including the top, but not the column itself because that might throw off the columns ability to reach proper equilibrium... Remember, you want the column to be hotter at the bottom and cooler at the top... If you have the hottest heat hitting part way up the column, that's gonna be the hottest point, potentially negating any length below that point... I'd think it would be like theoretically shortening the column...
heating the boiler above the level of the liquid may be counter productive. Heating the column certainly WILL be counter productive.
What you are doing, is raising the temp of the vapor. If the vapor is coming off from a 90 degree boiling wash, it will be 90 degrees (or close to that), but if you add heat to this, all you are doing is heating the vapor. Say it is now 150 C. In a column still, this may cause more problems due to the heat being MORE than it should be for a given water/ethanol percentage. For a pot still, it will simply mean you have to remove this extra power in the condenser.
All in all, I think this is not a good idea. Yes, putting a heat shield around the boiler will certainly make better use of your gas. However, overdoing it, and heating up the vapor alone is the wrong approach.
H.
Hillbilly Rebel: Unless you are one of the people on this site who are legalling distilling, keep a low profile, don't tell, don't sell.
I'm with Husker on this one. For me it just isn't a good idea. Propane is expensive here- about $25 for a 20lb tank. I can get about 3 to 4 runs off a 20lb tank on my set-up. 5 to 7 gallons at a time in my boiler. How much more effcient do I have to get?
the chimney adapter is the important part. This can be used on an upright oriented drum to take the exhaust gasses out the back to a right angle and riser tube. A suitable hole that fits you boiler cut in the top of the drum (or base, if you use an open top drum, just flip it over for the shroud). Allow enough space to remove the boiler. A keg has top mounted handles and is very suitable for this arrangement when the shroud comes up to just below the top chime or up to the top rib.
i've seen very nice set ups like this used for slaughtering kettles that worked excellent and kept the fumes and smoke above your head while rendering the fat and making "chicharones". The ones i saw used wood fires and had doors on the curved sides to tend the coals and stoke the fire.
Thank you all, that idea is ruled out and back to the drawing board for me!
Glassman your approach using stucco is really appropriate - a mouldable and rigid structure that insulates and is heat proof has everything going for it.
What started me on this is I made a big leibig condenser that should handle stripping runs with a much bigger heat source than I have now. The max output ever from my jacket and coil condenser was 4L/hr with unwanted reflux due to a small outlet pipe. The leibig produced 5L/hr on two stripping runs while just idling and it can go much faster. I want to get more heat into the boiler preferably with greater efficiency rather than a bigger burner.
Now I'm looking at the old steam engine boilers with multiple heat pipes running through the wash, and the stucco idea for insulation and heat channeling.
Ayay wrote:
Now I'm looking at the old steam engine boilers with multiple heat pipes running through the wash, and the stucco idea for insulation and heat channeling.
Steam boilers come in 2 types: Water tube and fire tube boilers. In the most efficient of these the combustion gasses make multiple passes. One pass preheats the water, one pass makes the steam and the first pass "superheats" the steam. In the distiller you would not want to superheat your steam.... and then, how would you clean the boiler after a run?
Yeah that's hard and fast! Have to keep upgrading my rig until I can get something similar gman. Next step is definately a stucco shroud like yours...then see about heat pipes or a bigger burner if necessary.
The heat pipes are a last resort because they will be a lot of work and cleaning will be a problem as you say nh_yankee. Even 6 x 1" pipes radiating around will be a lot of work for a small benefit. The shroud is the next in line, then a bigger burner if necessary.
Heat pipes will continue to bug me...one day maybe..
Easier to weld/solder some kind of heatsink onto the bottom of your pot?
If you were confident in your cleaning abilities, you could put one on the inside too...
I think that would provide similar heat transfer capabilities...
your going to get big gains with just the jacket/shroud. remember what the other guys said about how high up the boiler you go. mines a bit over the full line. gman
Tubes just increase the surface area that is heated. The shroud does the same thing. Why not weld fins to the side and ripple the bottom plate. Tube to tube sheet welds are the weakest area of a steam boiler. not worth the trouble and expense. If you truly wanted to try tube style distiller I would recommend having the tubes horizontal, the bottom and have the exhaust gasses ducted so they exit into one end of the tubes and out the other like an old steam engine... Sorry I can't draw it for you.
Good stuff. Not putting a shroud past the fill line is a good point.
I'm looking at a 55 gallon drum. Put the open end down. Cut a hole slightly larger than my boiler in the upper end. Trim the barrel for length so the bottom just covers the burner and the top is just over the full line on my keg boiler. Add legs to keep it off the ground and allow air to the burner. Then wrap the barrel with insulation.
That's the plan anyway, but I'm just getting ready to move to a new place and it's going to take awhile to get things in order there. In the meantime I'll keep an eye on this thread to see what develops.
and the bottom half is what i use for my double boiler:
and don't shield the boiler to high.. even with my heat shield i can super heat the steam at the end of the run (I've been as high as 125°C at the top of the tower and i had rag on top of the keg to insulate and they browned from the heat as you can see in the top pic)
Whiskey, the most popular of the cold cures that don't work (Leonard Rossiter)
Thank you all for the great suggestions...no heating but lots of insulation past the fluid level My burner looks tame compared to the above pics and there lies the answer for a fast stripping run.
Now to balance the need for an initial 75 Watt reflux run so well explained by Snuffy, and a blast furnace for strippin.
I want to try both ends but the strippin will have to wait while I get the reflux up a few notches. Me and the boss do like what I get from refuxin so I'll be working on that end for now
i use the same burner for reflux but 3 rings on REAL low i find i works better with the heat spread over a bigger area.. but i have a bigger burner for reflux now.. i use a forced air and natural gas burner the same one that i use in my forge
Whiskey, the most popular of the cold cures that don't work (Leonard Rossiter)
Last week I made a run after reading this thread. Just after I fired things up and was waiting for the still to warm up I noticed a roll of tin I had laying around. I wrapped it around my burner and the bottom of my keg boiler using c-clamps to hold it in place. I left about a 1/2" gap between it and the keg with the top ending just below half way up the keg. The bottom ended a couple inches lower than the burner. Just adding this simple heat shield with no insulation cut about 20 minutes off of my usual one hour warmup time.
ole boys use 5v tin . end peices is notched for burner the other end is notch for plug. have a small hole in side to slide a fireplace match to lite burners. cuts down on light an noise to.
Just go to Lowes and get their foil backed insulation for water heaters and a roll of silver tape. Wrap the insulation around your keg or pot leaving the bottom 3" uncovered for flame overlap and you will be suprised at how good this works.
the insulation would last about 5 mins with my burner and its also not going to be as effective as just holding the heat that is going around the boil for longer (as the air would be hotter than the contents of the boiler so you might even get a worse result with insulation as apposed to just still air.. but this would also depend on the size of your burner)
Whiskey, the most popular of the cold cures that don't work (Leonard Rossiter)
My burner looks tame compared to the above pics and there lies the answer for a fast stripping run.