Condenser Safety Issues

[Scribbler]

From my reading, I gather that there are several aspects around condensers to be aware of when distilling. one issue is that the condenser can become blocked by solid materials leading to pressure buildup and then explosion. the other issue is that the coolant flow might stop, or for other reasons (speed, or temperature of coolant) lose its effectiveness.


where would you rank these concerns? My hunch is that the coolant issue would be the more important... pressure would like take at least a little time to build to dangerous levels? perhaps something could be done during this time to stop calamaty. If my intuition is correct, an complete stoppage of the coolant would immediately begin sending flammable vapour down to the output which present an immediate danger. (perhaps not immediate, but probably seconds, and not minutes?)

what other dangers rival the pushing of alcahol vapour out the spout? (I am thinking more along the lines of procedural and design issues... not maintenance issues like leaky pipes or pinholes, weak metal etc... I doubt that advice and wisdom would not help me if I insisted on working with equipment that was not taken care of, so lets just assume that maintenance, upkeep, inspections, and care for the still are already part of the equation...)


Any ideas are appreciated...

[SuperDavid]

not sure what or where your water supply is coming from but mine comes out of the tap so i'm in no danger of getting solids in my condenser to make any blockages, BUT if that did happen to me I'm sure my hoses going to the condenser would pop off before there was any major pressure build up there. We should all be attending our stills while they are running, so if you did end up with alcohol steam coming out of your output because of a coolant blockage you should notice fairly quickly and be able to shut it all down, since you will be attending your still most of the time.

[Ayay]

martenskoop I rekon pressure buildup from a blocked vapor path is the one to watch out for. Not likely if your still is designed correctly. A) There are tight tolerances in the condenser and the boiler pukes up stuff that can block the narrow passages, or B) The still is not open to the atmosphere for some reason. I'm sure there will be warning signals like creaking, pinging, hissing and you have time to cut the power...if you are there. These can cause the boiler to blow at the weakest spot and the more solid the still the more violent the burst of highly flammable gas and boiling hot liquids.

If the flow of cooling water stops you will smell and see the uncondensed alcohol escaping as long as you're there. If you're not there then the whole room can fill up with an ideal explosive mix waiting for a spark. Could be worse than above!

[bronzdragon]

I think that you don't have to worry a lot about an obstructed condenser unless you are cooking off a mash in the boiler (on the grain or on the fruit). Then you may have to watch for obstructions. With that said, it would only happen most times if you were running it too hot and it was pushing a lot of stuff up out of the boiler. As far as pressure build up, if your still is designed correctly, there will be another way for the pressure to release...i.e. on my column the bung at the top with the thermometer would just blow off.

If you see vapor escaping the condenser you are either running it too hot or your condenser is not knocking it down because of a few other considerations, maybe it's not a big enough condenser, or maybe the coolant water is not cool enough.

Cheers

~bd~

[trthskr4]

I have marbles in the short column of my pot still, I'm mildly concerned about one of those getting down to the reducer for the 1/2" condenser so I loosely rolled up a bit of copper mesh and pushed it into the entrance of the condenser where it necks down from 1" to 1/2" to avoid any opportunity for the marbles to totally block off the vapor path.

If you have scrubbers, marbles, chipped glass etc. in your column and you don't overfill the boiler or cause it to puke then you don't much have to worry about a plugged condenser. If you are still worried build a pressure relief into the head of your still with a copper reducer and a steel ball bearing or some other contraption as a safety mechanism.

[stuartashers]

I agree totally when doing a run never leave it that's common sense and you would see if your condenser was getting to hot buy the steam exiting the condenser but I would be monitoring the water out put any way to check the temp to make sure it's cool

[FeralPig]

I do not leave my still when running. I periodically reach up and check the Leibig condenser to see if it is warm/hot further down the length than it should be. For my still, a bare trickle of cooling water will do the condensing job on a full stripping run and keep the condenser cool except the first 4 inches. If I feel the condenser getting hot further down the length than 4 inches, I turn up cooling water or turn down the heat. I also have a removable cap on top of the reflux column and pot column...initially it was for a thermometer before I realized how little that helps in a run...now I consider it something of a safety valve...at least for the pot column. The reflux column condenser is open to the air so pressure is almost impossible.

[Scribbler]

so when you say you don't leave your still, how much attention do you pay to it? are you watching it one hundred percent of the time, or would you take a newspaper/magazine or something with you and inspect it after every page or something?

just curious... I am still building my own and I just want to get a sense of what everyone does so I can do the same!!!

[HookLine]

No, you do not have to be literally watching it 100% of the time, but you do need to be within a few steps of it, and have direct line of sight to it, for 99.9% of the time.

Learn everything about how your still runs. Watch it; smell it; feel the temp on the boiler, column, and the condensers, including the coolant out; listen to the sound the boiler makes as it is heating up and running, the sound of coolant flowing, the sound of the gas flame (if you are using gas), and the sound the liquid output makes as it it hits the collection container, etc. I find sound a particularly useful indicator.

Get to know your still really well, and you will have several ways of monitoring it.

[dropping_planets]

lost electricity mid=run....

my recirculating water pump stopped running...for 15 seconds i freaked out about explosive vapours filling up the casita... than turned the LPG off... no biggie..

fixed the electricity... flame back on.... no problem

i watch movies and browse the web while i run....
pay attention...as long as your aware of whats going on and you can cut the heat in a moments notice i think your safe....

[FeralPig]

so when you say you don't leave your still, how much attention do you pay to it? are you watching it one hundred percent of the time, or would you take a newspaper/magazine or something with you and inspect it after every page or something?

just curious... I am still building my own and I just want to get a sense of what everyone does so I can do the same!!!

I read a book or the web. I just stay close. I also keep a fire extinguisher nearby (2 actually). But I also built both stills as sturdy and of as good a quality as possible. So leaks and over-pressure shouldn't come out of nowhere and overwhelm me. I have had "duh" moments where I thought cooling water was on and it wasn't...saw vapor coming out the end of the Liebig...I am very much glad I was there to stop that.

I come from a long line of hillbilly/redneck sorts that are more prone to causing fires, explosions, and loss of limbs than normal people so I take extra caution.

[absinthe]

i've had the cooling water fail a few times but just cut the power pour some cold water on the still and fix then restart... i keep a timer with me if im watching a movie or on the net it can be easy to lose track of time

[Mr.Spooky]

i stay with my still the whole process. something i do , (i use a 30 gal drum for recirculation) is put my exit coolant tube (from the condensor) about 5 inches or so above the drum of water so i can always here it runnin, no matter what im doing, i can hear the water runnin. i also have a 3/4 to 1/2copper reducer souldered in the top that i loosley fit a cork in. kinda like a weakest link in my rig so if anything is gonna blow, its gonna be that!

[Scribbler]

is there such a thing as too much coolant? I was thinking about the possibilities of hooking up my garden hose to the condenser, and then hooking up the output to my sprinkler... i could condemse alcahol, and water the lawns/garden at the same time....

would it be bad to have the condenser tubes that cold? (I will be running a large shotgun)...

mk

[Mr.Spooky]

hmmmmmmm,,, good thinking martenskoop . im interested in hearing replies. though im not sure if i would water the garden for the whole duration of the distillin process, this would be a good way to kill 2 birds with 1 stone for an hour or two anyway!

[heynonny]

I use as my 'coolant delivery device' of choice, a bilge pump running on (off) a 6 amp battery charger. mfg's spec = 360 gph @ 5 amps. It is not self-priming (designed for through-hull installation below waterline. it stays primed) so I must I do that the old fashioned way, like stealing gasoline(!). Then make sure the return hose is ALWAYS submerged to maintain prime.
When the pump is running w/o water in the system, the battery charger shows (barely any needle deflection) 100-150 ma However when primed it draws just over 2 amps (on the batt ch gauge. This is one of the things I check (over an' over) Actually, when first fired up the burner sounds like a 'shuttle launch' in progress, and, nervous as I can be, I'll pull the ret. hose out of the tank to make sure of flow, , , Anyway, it works for me -hey-

[rad14701]

I'm going out on a limb here and saying that there is such a thing as too much cooling...

First, if your condenser makes the reflux too cool then your column would be working harder than need be for the heat input... The vapors just need to condense and drop, not be made so cool that there is a potential for shock cooling and column flooding... Unlikely, but possible...

Second, if the condenser gets cooler than it needs to be for the amount of vapor, and drops below the ambient dew point, then the condenser will start to collect water vapor from the ambient air (sweat), adding more water into the vapor which will then need to be removed...

[FeralPig]

I'm going out on a limb here and saying that there is such a thing as too much cooling...

First, if your condenser makes the reflux too cool then your column would be working harder than need be for the heat input... The vapors just need to condense and drop, not be made so cool that there is a potential for shock cooling and column flooding... Unlikely, but possible...

I would think the vapor condenses and that is the end of story for that droplet...in other words...it doesn't hang around long enough to get too cool. Get it? Hang around...

Anyway, other than wasting water, I am not sure that too much coolant causes issues except in that old CM still. But I wouldn't be surprised if I were wrong..I frequently am..

[rad14701]

I tested my coolant lines by running maximum coolant through them and the thing was sweating like a pig... Dew point is going to vary with temperature and surrounding humidity, and my kitchen is prone to times of ideal conditions... I have also run the same test and not had any issues with running maximum coolant aside from wasting water so even my own conditions are not always constant...

[Scribbler]

[edited for redundancy]


hiya my spooky... how long is the avergae still run? (i know it is based on the amount of wash)... what is the average sized still?

right now, my limitation is a 6 liter stock pot... I hope to get something bigger at some point, but I figure for a bunch of initial testing I need to work with what I have got... my next step up will probably be in the 20 litre range (that's like 4 gallons right? I know we buy our milk in 4 litre jugs, and my father in law keeps referring to them as gallons, so I assume that there are four litres to the gallon...?)

would an average run -say a stripping run- be longer than 8 hours? I think I could find enough grass and garden to make us of 8 hours worth of water... espcially in summer: I could use the output to fill my kid's mini wading pool... (its ten feet across and 2 or so feet deep!!)

hmmm for that matter, I could set it up beside my care and give it a good cleaning... or wash the walls of my house...


as absurd as this may seem (My examples are admittedly bizarre and ludricrous) I am still interested in whether or not the coolant pipes can be 'too cold' or not... obviously at some point there would be a stage that is 'cooler than necessary' -ie: with the water temperature at 10 degrees C, everything condenses... therefore 5 degree's C would be pointless...

mk

[Scribbler]

First, if your condenser makes the reflux too cool then your column would be working harder than need be for the heat input... The vapors just need to condense and drop, not be made so cool that there is a potential for shock cooling and column flooding... Unlikely, but possible...

Second, if the condenser gets cooler than it needs to be for the amount of vapor, and drops below the ambient dew point, then the condenser will start to collect water vapor from the ambient air (sweat), adding more water into the vapor which will then need to be removed...

i don't think I am too worried about these factors. I think that reflux stills are 'neat' from a functional perspective, but I doubt I will ever build one unless it is for the challenge: I absolutely hate vodka!!! I just don't dig the idea of drinking flavourless alcahol... making super pure alcaholl for my lawnmower might be a neat idea, but not really worth pursuing for me... since my goal is brandy and whiskey type drinks, I am doing the pot still all the way... so no cooled reflux shock syndrom for me...

also, I live in Saskatchewan Canada (on the prairies...) it is so stinking dry here, I don't expect too much condensation from the air: MAYBE in the summer time, but certainly not the winter: my house is so dry that in the winter with the doors closed, my wife and I can bath the kids, then EACH have a hot shower, and the mirrors will be BONE dry!!! -the same thing in the summer would see the TINYEST amount of condensation on the mirrors, but not like in eastern canada where you would have to spend five munutes on the mirror with your towel before seeing your reflection...


say Rad: something I have been meaning to ask you -your avatar... is that actually you in the picture, and are you seriously sitting on the can in your driveway drinking beer? like no offense man, but that is one disturbing image... not the potty humour... i am as filthy as the next guy... a shot of you on the can would not disturb me at all.... but there is something about the outdoorsyness of that photo that REALLY creeps me out!!! I can't put my finger on it... -although I am not so sure I would want my fingers anywhere NEAR that!!!


jmk

[rad14701]

say Rad: something I have been meaning to ask you -your avatar... is that actually you in the picture, and are you seriously sitting on the can in your driveway drinking beer? like no offense man, but that is one disturbing image... not the potty humour... i am as filthy as the next guy... a shot of you on the can would not disturb me at all.... but there is something about the outdoorsyness of that photo that REALLY creeps me out!!! I can't put my finger on it... -although I am not so sure I would want my fingers anywhere NEAR that!!!

Do a Google search for rednecks... I seem to recall explaining how I stumbled across the image in another thread somewhere here... No, it's not me or my trailer...

[HookLine]

I'm going out on a limb here and saying that there is such a thing as too much cooling...

An old debate: Can you overcool the reflux condensate?

According to the two Mikes in The Compleat Distiller, you can't, provided the coolant flow rate (and, I presume, the coolant in temperature) are fairly constant. The column will very quickly stabilise around those values, and very cold coolant has little adverse effect, if any.

[Ayay]

is there such a thing as too much coolant? mk

Can't have too much coolant unless water supply is a problem. If the coolant flow is ideal then the temp may be high enough to kill the weeds and anything between them?

[FeralPig]

"sweating like a pig.." humph!


Whats wrong with a toilet on the front porch? Saves a walk inside. I have always said the perfect retirement property would be one where I can pee off the back porch and walk naked around the front yard with no one seeing... Believe me, no one wants to see the naked Pig in daylight...



I would think all the hardcores here would want to build a pot and a reflux column for no other reason than these things are a hoot to build and test. I sure wish I could make a living building these.

[rad14701]

Believe me, no one wants to see the naked Pig in daylight...

Might help keep people looking the other way...

Yeah, I had so much coolant running once that even the clear water lines were dripping due to condensation drawn out of the humid air... I climbed up and looked down at the condenser and upper half of the coil was drawing condensation into the reflux... Ended up slowing the coolant until the condensation disappeared... But, like I said, this only happened when there was a lot of excess moisture in the air that lowered the dew point...

Perhaps a column larger than my 1.25" would never experience such problems but I've got more condenser than I need for the boiler and column... I can run in stripping mode with only marginally more coolant than I use in reflux mode and never lose vapor out the top unless I push to a rolling boil, then all bets are off as I'll flood the condenser section...

[LWTCS]

Dern Rad,
Every one is disturbed by your avitar weather it is there, or if it is not there Theres got be a anthropolodgical term for that kind of phenomena?

On my pot still, I luv when my 2" jacket sweats like a pig. Hooch comes out chilled.

[rad14701]

Dern Rad,
Every one is disturbed by your avitar weather it is there, or if it is not there Theres got be a anthropolodgical term for that kind of phenomena?

That would be "apathy"... Or not...

[ct1870]

hey rad i like the pic. i've seen it before and think it is hallarious. you know around these parts we use to eat inside and crap outside. now, everyone craps inside and eats outside. i have a 3/4 in with a 1 1/2 outside, i fill the cooler with cool water and let it go. the condenser is 36 in long and i monitor the water temp it can get warm before i let it out and fill it back up with cool water again. i have tested with water with frozen 2 liter jugs and cold water and addjusted the flame that heats the pot. it seems there is a safe point to run the temp of the flame and not over-do-it. even with the warmest of water. i have never check the temp of my water before i have changed it out. but looks like a wide range of temp to run on. if i do a stripping run it heats up a hellova lot faster than doing a slow run. i guess what i am saying is that depending on the condenser size depends on how much energy you can run the still not the temp of the water that is cooling it. as long as you have a good flow and the water temp is less than the vapor temp does this make since. been a long day.

[Ethanol Al]

I could use the output to fill my kid's mini wading pool... (its ten feet across and 2 or so feet deep!!)

Just a thought, throw a small pump in the pool and use pool water to cool the still, Its a win/win, you get your still cooled and the kids get a little heat in the pool!