Since I'm going to be using a highly concentrated methanol solution, I'm installing a 1 gallon fuel cell so that I can externally vent the harmful fumes and also better contain the fluid in the event of a roll-over.
The cell I'm using is a 1 gallon Jaz junior dragster cell, which has a 1/4" barb fitting as a vent. I'd like to connect a hose to this for external venting outside the passenger compartment.
It would be easiest to run the vent line out one of the trunk vents, which would mean that the vent would be below the tank.
Do I need to install a check valve of any sort on that line? I think that installing a check valve is typical on the vent line of a fuel cell, but that seems like it would be problematic. For example, methanol is very subject to volumetric expansion with temperature shifts. So, as it gets warmer, methanol vapor and air will need to escape from the cell through the vent line. On the other hand, as the methanol is used air will need to enter the cell from the vent line to replace the methanol. So, I can't use a check valve, can I?
If I have no valve on the vent line and the vent hose is lower than the tank, do I need to worry about a siphoning effect getting started if the tank splashes the top of the cell and the vent fitting? Or if heat expansion pushes the methanol level up to the top of the cell? I definitely don't need a puddle of methanol under my car in the garage when we get a sudden climate shift!
Would a siphoning effect be prevented because there would be no way for air to enter the cell to replace any methanol that would be drawn out?
Another scenario -- If I flip the car and it ends up on its roof (something that could happen since I track the car), will the methanol pour out of the cell through the vent line? I think it would, though the flow rate would definitely be slowed down due to the fact that the methanol would have to flow out the same line that the air came back in to replace it. This is where a check valve would come in handy, except for the fact that I don't want to pressurize the cell when the meth vapor pressure increases due to an increase in ambient heat. In a worst case scenario like the car burning after a wreck, I could imagine an inadequately vented methanol cell becoming a little bomb in my trunk!
Any help would be appreciated. I can't be the first one on here to deal with these issues.
Thanks!
