Jim's VM/LM build

[Kimbo]

Hi Jim,
I think what Mac is trying to say is this:

I did my first run today. 30L of 14% VodkaStar turbo. I reckoned that while waiting for my wash to come to a boil, I would work out the cooling lines.Allways have your cooling operating before you fire up I was about halfway finished the lines when I felt a cold mist on my face. I was getting product squirting out of the top of my condensor.This is alarming

I turned off the gas and finished the lines good move. I turned on the reflux condensor, and turned on the gas. I had read about folks only needing a "trickle" of cooling water every still is different, you are better off having way too much cooling water and slowly backin it off if needed, mine needed a bit more than that, it was a pretty steady stream, the condensor gate valve probably 1/2 open. It was using more water than I really wanted, but at least I was getting refluxThis is a good start. I let it equalise for a half hour, and started taking heads from the LM port. The needle valve is very fiddly to get right, and the lack of immediate feedback is frusteratingthis will come with experience. I would twitch the valve, and 30 seconds later I would see the result, usually either a gush of fluid, or fully shut off. Eventually I got it where I wanted it, 2 or 3 drops per second. I filled up my 150ml curry paste jar, and turned off the LM.

I let it equalise for a while, then cracked open the VM gate valve. Nothing happened, so I opened it more. A HUGE gush came out, completely missing my collection vessel and splashing all over the picnic table. It was that delayed reaction thing again. It was actually pretty easy to dial in the proper amount of output though, with that big gate valve.I run my VM with the valve fully open

I still wasnt happy about the amount of cooling water I was using, so I tried reducing the water a little bit. :violence-smack:
The water coming out wasnt that warm,It doesnt need to be warm, as long as its cooler than the vapour it will work I could comfortably hold my hand in it. As I was pondering the lack of heat in my outflow, I felt that familiar cold mist.

Yea, I got the ethanol waterfall again. Streaming down my column, running under my insulation. I quickly cranked the water back up, but it was too late. It ran down the side of the keg, and caught fire. I turned off the gas, but the fire hung out on top of my keg for a few seconds, then shot up under my insulation, melting and burning it. I sprayed it all down, and eventually put it out with the hot side of my cooling hose.

I've quit for the day. Need to reassess the situation, let the adrenaline fade.

Im gonna give my pot still head a go next time. Not so many things to go wrong, only one condensor. I dont really even like neutral spirits, prefer rum.

I need a better reflux condensor for the VM rigThe condenser is fine. This one sucks. What kind of condensor is best for the top of a VM rig? I need one with lots of knockdown.you need less power I think part of the problem was the regulator I was using made it so easy to dump heat into the system. I was probably running about 90kPA of gas at the time. What pressure should I be running my gas at?As an example, my 2.5" VM runs of a single 2400W element

Jim, Please slow down, you will be surprised at how little heat you need to run a still perfectly.
Let this be a lesson to everyone We are glad you didn't get hurt ;-)

[jim]

Thank you for the feedback Kimbo.

I wrote that up straight after the experience, while it was still pretty vivid in my mind. I was still reacting to it, maybe why it comes off as a little glib. I posted it both as a warning and as a way to find out what went wrong. Thanks to Mac for seeing instantly what the problem was.

If I were to do it over again, I would have spent more time in preparation:
1) A printout of Kiwistillers VM operation tuturial at hand. Or at least freshly read.
2) Completed my setup before turning on the heat.

I had no idea of how much heat my regulator/burner combination was capable of producing. A while after I had put everything away, I went to the Homedistiller website to determine how much power I had been dumping into the system. I figured it took about 15 minutes to bring the 30 liter wash to a boil. This worked out to be about 8kW, or about 100kPA on my LPG regulator.

The mistake that started the fire was not turning the heat down after bringing it to a boil, way down to around 2.5kW or maybe 30kPA on my reg. The guide even suggests running it down to a couple of hundred watts (10kPA) for the equilibration.

From what has been explained to me, it looks like my condensor works very well. It was coping with 8kW worth of vapor. The massive amount of condensed liquid dropped back down into my packed collumn, eventually flooding it, and got pushed back up by the rising vapor. This is what sprayed out of my still head and started the fire.

I did have a fire extinguisher right next to me, and if the fire ever looked like it was going to get out of control, I would have used it. However, only about a cup of condensate escaped and ignited, and I was quite easily able to put it out with the hose I had on hand. Water might not be able to directly put out an ethanol fire, but it can dilute the ethanol past the point where it can burn.

I am just starting out in running anything beyond a simple pot still, and I really appreciate how much support and feedback this forum provides.