quote:

Originally posted by Tilly:
... The safest thing to do is to permanently remove the wires going to the heater in the reactor and heat the oil in a container that will never have methanol or methanol vapors in it...

Do methanol vapors build up over time with each consecutive batch being processed? Your concern is the heating element igniting vapors in the WH chamber from left over vapors, current vapors etc?

Hello artesp

quote:

Originally posted by artesp:
Do methanol vapors build up over time with each consecutive batch being processed?

the LEL (Lower Explosive Limit) foe methanol is 7% and the UEL (Upper Explosive Limit) for methanol is 36%. After you have made the first batch of biodiesel in an Appleseed Reactor there will ALWAYS be an explosive atmosphere in the reactor which only requires an ignition source (Turning on the water heater element is perfect) to ignite.

quote:

Your concern is the heating element igniting vapors in the WH chamber from left over vapors, current vapors etc?

It happens all the time. There have been dozens of reports of fires/explosions in Appleseeds when the uncovered heater is turned on. These explosions/fires have resulted in fire shooting out of the vent, people/rooms being sprayed with the residual content of the reactor and bits and pieces being blown off the reactor. So far no permanent injury or deaths have been reported.

Oh, and just a heads up, the "Little Blue HF Pump" which is the recommended pump for the Appleseed reactor has no overload or over temperature safety cut off and has a history of catching on fire when used in the Appleseed Reactor.

After your first batch is brewed and then drained, the reactor will be left full of methanol fumes. As the bio drains it draws air into the reactor mixing with the fumes giving you everything you need for an explosion other than an ignition source. Thats where the heater comes into play...
Jon

artesp,

If you take precautions, either using equipment or process to make sure you do not apply electric to the heating element when the tank is empty, then the odds of anything abnormal happening are slim. I've set one of those tank fires off on purpose. It's like a good roller coaster ride, scary, but not really dangerous.

The three the most common causes of processor shed fires. 1) overheating oil, usually in a plastic tank 2)spontaneous combustion of oily rags, and 3)faulty wiring.

Well I remember when I first built it, I had an electrician friend come and check my wiring and such. Because I had wired it 220v directly from the panel, I wanted to be sure it was good to go. At one point he told me to apply voltage to the WH so he could check the voltage reading at the element. I wasn't thinking and it wasn't but a couple of minutes when there was a loud BOOM!. I've never seen a man jump that fast. The lower element had blown and it shot the vent hose off. That was just an empty WH with no fumes of any kind.

So Jon, I know it depends on the size of the batch but given that I make 30 gallons at a time, do the fumes build up over time? Or whatever amount of fumes you have created the first time around will be the volume of each time after that? Make sense?

What if after the first batch you fill with WVO, then use one vent to pump in air and the other vent with a hose to direct any fumes to the outside. This should rid the WH of any dangerous fumes no? Then you could apply the heat without any worry?

artesep,

The methanol fumes can build up over time, but it really does not matter. As soon as you drain it, there is excess methanol to oxygen. Not all of the methanol vapors will burn in the tank. If you want to prevent the possibility of fires, then eliminate the oxygen. There is no way to eliminate the methanol vapors.

artesp, do you mean you had an explosion in your reactor and there was not any methanol fumes in it?
I have read that there have been dozens of reports of fires and explosions in appleseed reactors. Some of these have apparently resulted in equipment damage and people and rooms being sprayed with oil and methanol from the reactor.

RickDaTech, how do you eliminate the oxygen? I think it is easier to just eliminate the ignition source. That is why I heat my oil external to my reactor.

Henryl,

I don't think it was an explosion per say, it was more the element exploding because the reactor was empty but the element turned on. Whatever pressure it created was enough to blow off the vent tube, create a weird odor, and scare the heck out of us.

quote:

Originally posted by Jon Heron:
After your first batch is brewed and then drained, the reactor will be left full of methanol fumes. As the bio drains it draws air into the reactor mixing with the fumes giving you everything you need for an explosion other than an ignition source. Thats where the heater comes into play...
Jon

I know anything may be possible given the ingredients but if their are fumes up top, 30 gallons of WVO below and somewhere at the bottom an element heating up, how could/does it ignite? If the oil is circulating while heating could this pull down fumes to the element? And if so, will fumes touching a hot element submerged in WVO ignite?

quote:

Whatever pressure it created was enough to blow off the vent tube, create a weird odor, and scare the heck out of us.

The heat and expanding gasses generated from the electrical short creates a significant pressure wave. I have seen a 13,800V switchgear single phase and short out, it vapourized 3" off of the 3 bussbars that were 3" X 1/4" solid copper, the missing copper completely copper clad the inside of the switch. It also folded the 5/8" solid square steel latch on the top and bottom of the door over like they where playdoh, blew the safety glass out of the door and cracked the safety glass on all the doors for 5 cubicles down... There was a plumber haging a large valve about 10' from it when it blew... he had to go home for the rest of the day never mind the mess in his pants!
The weird odour is the smell of ozone...
Things like that give you a healthy respect for electricity...
Jon

quote:

Originally posted by artesp:

quote:

Originally posted by Jon Heron:
After your first batch is brewed and then drained, the reactor will be left full of methanol fumes. As the bio drains it draws air into the reactor mixing with the fumes giving you everything you need for an explosion other than an ignition source. Thats where the heater comes into play...
Jon

I know anything may be possible given the ingredients but if their are fumes up top, 30 gallons of WVO below and somewhere at the bottom an element heating up, how could/does it ignite? If the oil is circulating while heating could this pull down fumes to the element? And if so, will fumes touching a hot element submerged in WVO ignite?

There is no problem if the element is covered in oil, thats why it is so important to have a safety built in to prevent the possibility of the heater ever coming on when not covered in oil, a pipe could leak, your pump could fail, etc. that could expose your element to the fumes if no safety is in place...
Jon

RickDaTech, This information is good to know. Where did you find it? Is there a website that has all of these statistics about making biodiesel at home.

quote:

Originally posted by RickDaTech:
The three the most common causes of processor shed fires. 1) overheating oil, usually in a plastic tank 2)spontaneous combustion of oily rags, and 3)faulty wiring.

You have that backwards. While the reactor is full of oil and methanol there will be little oxygen available because the initial adding of the methoxide to the oil will displace most of the air in the reactor leaving an atmosphere that is probably above the Upper Explosive Limit for Methanol vapor. When you drain the reactor the oil and liquid methanol are replaced by air and there is now plenty of air available for an explosion to occur with the remaining methanol vapor if there is an ignition source available.
The dozens of explosions that have apparently been reported verify this.
I never have an ignition source anywhere near my reactor.

quote:

Originally posted by RickDaTech:
artesep,
The methanol fumes can build up over time, but it really does not matter. As soon as you drain it, there is excess methanol to oxygen. Not all of the methanol vapors will burn in the tank. If you want to prevent the possibility of fires, then eliminate the oxygen. There is no way to eliminate the methanol vapors.

Tilly,

If you want information from me, ask me straight like a man.

quote:

Originally posted by henryl:


RickDaTech, how do you eliminate the oxygen? I think it is easier to just eliminate the ignition source.

Fill it with WVO.

Do you mean that to prevent reactor fires and explosions you recommend refilling the reactor with oil as soon as it is emptied and leave it sit full of oil?

quote:

Originally posted by RickDaTech:
Fill it with WVO.

quote:

Do you mean that to prevent reactor fires and explosions you recommend refilling the reactor with oil as soon as it is emptied and leave it sit full of oil?

That sounds like a good idea if you are doing continuous processing, which some people do. I have a batch of pretreated oil that has been sitting in my processor for about a week now. I don't have the heating element enabled, so that isn't a problem.

If the potential ignition source is disabled at the time you are draining the BD and it remains disabled until the element is covered once again with oil, there should be no problems.

The problem remains that often we have several things going on at the same time and might forget to turn off the heating element. There are safety features discussed on this forum to help you minimize that potential, but the safest way to do it would be to heat the oil externally and then transfer it to the processor for mixing with the methoxide. This requires additional space and adds an additional step to the process, so for some it is not practical.

quote:

Fill it with WVO.

The only time it doesn't work well for me in in the winter; I would be using a lot of energy to keep the WVO liquid all week until I got a chance to brew it.

Of course, THIS winter I plan to have the shed heated 24/7...so wouldn't be an issue anymore!

Guys,

I accidentally left off the [tongue in cheek] tags on my last post. After what yuse guys said, I'll have to think about it as a possible viable option.

What about venting while it settles after the reaction? I transfer to an open top cone bottom tank. Should this be sealed while settling and/or vented to the outside? How different are the fumes on the reacted fuel as compared to straight methanol? What are the dangers of any fumes given off by the glycerol while draining?