Sunday, July 1, 2012

return to abnormalcy

With repairs completed, and the cleanup mostly completed, today we make the next step on our return to the routine of bunkering and resuming the 'any time anywhere' style of work. We'll be casting off shortly for Norfolk, VA, there to load some light oil to flush out our tanks so that we can again load black fuel oils.

        Since we've been carrying crude oil these past months, and crude oil contains everything including gasolines and other aromatic compounds with low flash points (the temperature at which they ignite), crude oil residue is NOT welcome in black oil, which is made by boiling off all the easy to burn stuff. If a slug of gasoline or whatever were to contaminate the black oil, it would burn, say, while preheating (black oil must be warmed so that it will flow, so most of the time there's a heating element in the tank to keep it toasty), or passing through a pipeline, rather than when it actually gets misted and hits the fire, and not when it's in a combustion chamber.
            Black oil won't burn easily. It needs to be atomized, broken into small particles, like a fine mist, before it will burn (surface to volume ratio must be increased), and even then, it needs to get up above 400 degrees or so, if not actually passed through a fire. At the end of the day, the safest course of action is to find an intermediate cargo like diesel oil or some such to flush out the light aromatic hydrocarbons and ensure that nothing is going to be in the tanks that will light off at an inopportune moment when mixed into the next cargo.
         So that's where we're at. We'll be carrying a load of intermediate-grade oil back up north with us, and after that, barring anything unforseen, we'll be in New York this time next week.

1 comment:

HT said...

Time for some VGO Paul,works best to clean tanks...have fun!