Minimum boiler charge safety

[fiery creations]

I'm not sure how heating elements work as it pertains to safety and accidental ignition. If they become exposed for a split second, is that all it takes?

If so, I imagine you need to leave x amount of liquid in past having them submerged while it boils since there could be some violent activity in the boiler that could cause them to become exposed?

What kind of buffer is a good idea to leave so your elements stay covered? Say my elements are completely submerged with 5 gallons. If I ran 10 gallons charged at 40%, I should end up with about 6 gallons in the pot at the end. Is that cutting it too close?

[Bolverk]

Yeah, you got to make sure there is enough in the pot to maintain at least 1" over the element after all the alcohol comes over.

A good rule of thumb I've found is that if you're running an 8-10% beer/wash, you'll produce about 20-30% of your initial boiler charge in low wines. So say 10 gals of beer - 3 gals of low wines = 7 gals left in the pot. When doing your spirit run you'll get about 10% of the initial charge in final product. So 3g - (10g × .1) = 2g left in the pot... for me this is not enough I'd need 2 gal exactly to cover my element, I need 3 gals to be safe.

This is also why it's advisable to ferment 3x your boiler volume, so you end up with your spirit run being a near full charge.
30 gal ferment you run 3 10 gal stripping runs and end up with about 9 gals of low wines for for spirit run, and you'll have plenty of liquid to keep your element safe.

[fiery creations]

Yeah, you got to make sure there is enough in the pot to maintain at least 1" over the element after all the alcohol comes over.

That's the part I'm worried about.

I'm doing triple distillation and after 72 gallons of mash I have about 15% of the low wines I need to charge my boiler to about full for a third and final spirit run. I don't want to risk safety, but I also don't want to end up having to run over 500 gallons for one spirit run.

[Bolverk]

If I ran 10 gallons charged at 40%, I should end up with about 6 gallons in the pot at the end. Is that cutting it too close?

This is probably a little close for comfort at least until you've tested it for sure. It's not going to hurt to put a gallon of water in your spirit run just to ensure that level of safety

[fiery creations]

Got my old 15 gal pot still back so I can do this easier and safer.

Still curious though. Is this something where the element is so hot that a brief exposure out of liquid will cause instant ignition? Or is that not how it works?

[NormandieStill]

It's more a prolonged lack of water pulling the heat away that could cause some elements to get red hot. I strongly suspect that by the time you've emptied your boiler to that point, the abv of the vapour is going to be too low to ignite anyway. More than anything it's to protect your element. This hobby will get expensive fast if you treat heating elements as consumables.

[Steve Broady]

Ignition requires fuel and oxygen. Once you start filling the boiler with steam, you’ve pretty quickly pushed all the air out of the headspace. So as I understand it, the danger is not in combustion, but in overheating the element.

[fiery creations]

Ok that's a huge relief. A new element is nothing compared to a possible accident. Thanks guys.

[Steve Broady]

I still wouldn’t recommend making a habit or pushing the limits of safety. But I don’t think the risk of an explosion is that high UNLESS you have other problems, like leaks or some way for oxygen or an oxidizer to get in there while you’re running.

In other words, be safe and be sensible, regardless of what people here say!

[fiery creations]

I still wouldn’t recommend making a habit or pushing the limits of safety. But I don’t think the risk of an explosion is that high UNLESS you have other problems, like leaks or some way for oxygen or an oxidizer to get in there while you’re running.

In other words, be safe and be sensible, regardless of what people here say!

Definitely. Now that I have a 15 gal boiler instead of being forced to use my 26 gal I should end up with a pretty large safety buffer left over in the boiler because I can actually fill it to only 10 gal now.


I did the math on the cost of grain to fill the other with 20 gal and it came out to $972 lol.

[Steve Broady]

I did the math on the cost of grain to fill the other with 20 gal and it came out to $972 lol.

I’m curious about that. For me, my low wines come out about 1/3 the volume of the beer that goes in. 1/6 if I’m running some really poorly converted AG wash. Even at the low end, that’s 120 gallons of wash, and at 2#/gallon, that’s 240# of grain. How much are you paying for yours?

[NZChris]

That would depend on the Watt density you were using.

Also, heat rises making it possible to have it boiling at the surface without heating the charge at the bottom of the pot.

I use a calculator to work out the maximum volume I can safely take off. That said, I put my element so close to the bottom that I can only just get my fingers under it.

[fiery creations]

I did the math on the cost of grain to fill the other with 20 gal and it came out to $972 lol.

I’m curious about that. For me, my low wines come out about 1/3 the volume of the beer that goes in. 1/6 if I’m running some really poorly converted AG wash. Even at the low end, that’s 120 gallons of wash, and at 2#/gallon, that’s 240# of grain. How much are you paying for yours?

I mashed 72 gallons out of 180 pounds of grain, getting about 5% ABV at the end, and got roughly 20 gallons of low wines. I ran that and got about 5 gallons of distillate about evenly split into wide hearts to move on to the third distillation, and feints. The 2.5 gallons of wide hearts is all I have from the 72 gallons to move on to the third distillation. So multiple that by 8 to get 20 gallons to charge the final spirit run.

8x 180 is 1440 pounds of grain. Half of that is malted which is about $1/pound. The other half is unmalted feed, which is substantially cheaper but still adds a couple hundred bucks.

Granted, the building feints should contribute on the subsequent runs. But you get the idea...

I use a calculator to work out the maximum volume I can safely take off. That said, I put my element so close to the bottom that I can only just get my fingers under it.

Now that you said that I think I was doing it wrong. I was just subtracting the alcohol percentage in the boiler charge for what's left over. But I forgot some water is coming through. So shoot....guess I could have ended up at lot lower and closer to the elements than I originally thought.

[OtisT]

I use a calculator to work out the maximum volume I can safely take off. That said, I put my element so close to the bottom that I can only just get my fingers under it.

Now that you said that I think I was doing it wrong. I was just subtracting the alcohol percentage in the boiler charge for what's left over. But I forgot some water is coming through. So shoot....guess I could have ended up at lot lower and closer to the elements than I originally thought.

This Distillate to Water calculator from RAD works good for me when I’m planning a run.

https://homedistiller.org/wiki/htm/calc ... d14701.htm

I use it both for calculate the volume that will remain in the still at the end, as well as planning the volume and number of collection jars I will use.

[Salt Must Flow]

If I were pushing the limit of exposing the element ... I'd install at least a 2" Sight Glass Union in the boiler. If the level starts to get low, just add some water to the boiler.

If were pushing that limit often, I'd attach a water line to my bottom drain. That would make adding water super simple.

[fiery creations]

Man you guys are on top of everything. That sight glass is awesome and I think I'll weld one up to my boiler just so I can peek at it regardless. Didn't know you could put a sight glass directly in the boiler!


Thanks for the calculator. I missed that part of that one.


And holy shit I'm glad you sent it. Looks like I would have ended up with a hair more than 5 gal left and definitely been on the verge of exposing the elements. I was way off.

Screenshot 2024-06-16 175023.png (13.09 KiB) Viewed 2974 times

[Steve Broady]

The 2.5 gallons of wide hearts is all I have from the 72 gallons to move on to the third distillation. So multiple that by 8 to get 20 gallons to charge the final spirit run.

Okay, I see where my confusion came from. I wasn’t thinking of a third distillation on your hearts cut.

Just a thought, and I’ll be the first to admit that I don’t know your recipe, process, equipment, or tastes, so I could be wildly off the mark here. But if you’re concerned about getting the most flavor out of your grain, wouldn’t two distillations be better?

Regardless, I feel like there has to be a LOT of alcohol being lost somewhere. If you look at the whole process from start to finish, going from 5% wash to 60% finished spirit should only require 12x the volume. Call it 20x for very generous cuts, and you’re still only looking at 100 gallons for every 5 gallons of finished product. Again, unless you’re discarding the vast majority of the alcohol that you’re making, and I freely admit that I don’t know your process.

[fiery creations]

The 2.5 gallons of wide hearts is all I have from the 72 gallons to move on to the third distillation. So multiple that by 8 to get 20 gallons to charge the final spirit run.

Okay, I see where my confusion came from. I wasn’t thinking of a third distillation on your hearts cut.

Just a thought, and I’ll be the first to admit that I don’t know your recipe, process, equipment, or tastes, so I could be wildly off the mark here. But if you’re concerned about getting the most flavor out of your grain, wouldn’t two distillations be better?

Regardless, I feel like there has to be a LOT of alcohol being lost somewhere. If you look at the whole process from start to finish, going from 5% wash to 60% finished spirit should only require 12x the volume. Call it 20x for very generous cuts, and you’re still only looking at 100 gallons for every 5 gallons of finished product. Again, unless you’re discarding the vast majority of the alcohol that you’re making, and I freely admit that I don’t know your process.

72x.05=3.6

3.6/.6=6

I ended up with a bit over 5. Considering I did discard foreshots on each strip and can get every drop out of the boiler, it seems pretty close to me

[jonnys_spirit]

I'm not sure how heating elements work as it pertains to safety and accidental ignition. If they become exposed for a split second, is that all it takes?

If so, I imagine you need to leave x amount of liquid in past having them submerged while it boils since there could be some violent activity in the boiler that could cause them to become exposed?

What kind of buffer is a good idea to leave so your elements stay covered? Say my elements are completely submerged with 5 gallons. If I ran 10 gallons charged at 40%, I should end up with about 6 gallons in the pot at the end. Is that cutting it too close?

If you took off at a 100%abv then yes. 10g charge @ 40%abv will yield 4 gallons of pure ethanol and leave behind 6g of 0%abv stillage in the boiler. 100%abv isn't likely in a pot still if that's what you're running...

I would consider trying to move the element lower in the boiler - as low as it can go...

The liquid covering the element does provide protection from dry-firing which could create smoke or something similar as the element heats excessively and fails. They're not designed for dry firing.

Others have commented about the fire triangle requiring FUEL+O2+IGNITION in order to go "boom". This is true.

For the sake of safety I would recommend not actually testing that and to do everything in your power to prevent dry firing - That's the best way to avoid a catastrophe, ruining a batch, and damaging your equipment.

Cheers,
jonny

[Salt Must Flow]

Man you guys are on top of everything. That sight glass is awesome and I think I'll weld one up to my boiler just so I can peek at it regardless. Didn't know you could put a sight glass directly in the boiler!

If I were to install one of those sight glasses, I'd place it on the side of the boiler, down relatively low. If you see the level of the boiler through the glass, you know it's time to add some water. Exactly where to place it is obviously up to you. Perhaps high enough above the element so you know the level is safe.

[SaltyStaves]

When I know I'll be running down to the absolute limit of my minimum fill height, I make sure the size and number of my collection jars doesn't exceed the volume I can safely take off.

I've never taken off one jar too many and exposed my element.

[fiery creations]

When I know I'll be running down to the absolute limit of my minimum fill height, I make sure the size and number of my collection jars doesn't exceed the volume I can safely take off.

I've never taken off one jar too many and exposed my element.

Well that's a really simple easy way to be sure... Tried doing a bunch of math instead of just thinking of that duh.

[fiery creations]

If I were pushing the limit of exposing the element ... I'd install at least a 2" Sight Glass Union in the boiler. If the level starts to get low, just add some water to the boiler.

If were pushing that limit often, I'd attach a water line to my bottom drain. That would make adding water super simple.

Hey man, have you installed this on a keg boiler? I’m worried that the curvature may make it difficult to weld the round sight glass on with that tiny lip. Wondering if I need to weld on a ferrule then tri clamp on a window instead.

[Salt Must Flow]

If I were pushing the limit of exposing the element ... I'd install at least a 2" Sight Glass Union in the boiler. If the level starts to get low, just add some water to the boiler.

If were pushing that limit often, I'd attach a water line to my bottom drain. That would make adding water super simple.

Hey man, have you installed this on a keg boiler? I’m worried that the curvature may make it difficult to weld the round sight glass on with that tiny lip. Wondering if I need to weld on a ferrule then tri clamp on a window instead.

I used a grinder to shape it for a tight fit. Some might cut a precise size hole, insert the sight glass into the hole then weld around it. It would leave a small protrusion inside of the keg doing it that way, but it shouldn't really matter. I just took my time to grind it so it would fit nice so it would be flush.

The exact one in that link is very short. If you search around on Amazon for instance, you'll find some that are a little longer. That would give you a little more material to grind curved if you want.

[fiery creations]

If I were pushing the limit of exposing the element ... I'd install at least a 2" Sight Glass Union in the boiler. If the level starts to get low, just add some water to the boiler.

If were pushing that limit often, I'd attach a water line to my bottom drain. That would make adding water super simple.

Hey man, have you installed this on a keg boiler? I’m worried that the curvature may make it difficult to weld the round sight glass on with that tiny lip. Wondering if I need to weld on a ferrule then tri clamp on a window instead.

I used a grinder to shape it for a tight fit. Some might cut a precise size hole, insert the sight glass into the hole then weld around it. It would leave a small protrusion inside of the keg doing it that way, but it shouldn't really matter. I just took my time to grind it so it would fit nice so it would be flush.

Perfect, gonna snag it and weld it up. Thanks!

[Salt Must Flow]

If I were pushing the limit of exposing the element ... I'd install at least a 2" Sight Glass Union in the boiler. If the level starts to get low, just add some water to the boiler.

If were pushing that limit often, I'd attach a water line to my bottom drain. That would make adding water super simple.

Hey man, have you installed this on a keg boiler? I’m worried that the curvature may make it difficult to weld the round sight glass on with that tiny lip. Wondering if I need to weld on a ferrule then tri clamp on a window instead.

I used a grinder to shape it for a tight fit. Some might cut a precise size hole, insert the sight glass into the hole then weld around it. It would leave a small protrusion inside of the keg doing it that way, but it shouldn't really matter. I just took my time to grind it so it would fit nice so it would be flush.

Perfect, gonna snag it and weld it up. Thanks!

The exact one in that link is very short. If you search around on Amazon for instance, you'll find some that are a little longer. That would give you a little more material to grind curved if you want.

[NZChris]

If you are going to go to the trouble of cutting and welding your boiler, the effort might be better spent on lowering your elements so that it doesn't take 5 gallons to cover them and enabling you to run smaller charges.

[bilgriss]

That was also where my mind initially went before the cool talk of adding sight glasses. The lower the element, the less it takes to cover it and maintain some space above.

I worried quite a lot about this issue until I spent the time to measure how much it took to actually cover my element in the boiler, added some for good measure, and then figured out about three times that much for a minimum boiler charge. I have a relatively small pot, so I'd have to do a pretty unreasonably small ferment to ever have to worry.

[fiery creations]

If you are going to go to the trouble of cutting and welding your boiler, the effort might be better spent on lowering your elements so that it doesn't take 5 gallons to cover them and enabling you to run smaller charges.

That’s on my big 26 gal boiler, and they are about as low as they can get.

This one’s going on the smaller 15 gal keg. Haven’t tested it yet but I’m pretty sure it it’s only 2-3 gallons on that one.