Process Engineering Beginner's Guide

CHAPTER SEVENLATENT HEAT TRANSFER

Exactly what is the benefit of going to high school … I cannot quite understand. I imagine it’s an opportunity to meet girls? For example, in high school Chemistry Lab, I was instructed to add a Boiling Stone to my flask before setting the flask of water above my Bunsen burner. But why? What would happen if one omitted these magical stones? After all, my mom boiled water in our apartment’s kitchen all the time, without the aid of boiling stones.

However, six years later, I learned to respect the function of boiling stones. I was working as a tech service engineer on a crude distillation unit for American Oil in Whiting, Indiana. I had drawn a sample, in a quart glass bottle, of light naphtha from the crude tower reflux drum, which operated at 15 psig, or about one bar. It was really cold in Whiting that day. And my sample bottle was brand NEW!

I planned to submit the naphtha sample to the refinery lab for distillation analysis, and had left it open on my desk to allow the light-ends to weather-off, to check the percentage loss of the naphtha before sending it on to the lab. After an hour, the bottle had warmed to room temperature, but none of the naphtha had evaporated. I recall taking a glass rod from my desk drawer to stir up the sour naphtha – which then exploded out of the bottle into my mouth, nose, and eyes!

So, I had to go back to the crude unit reflux drum for a new sample. But this time, I dropped a small pebble into the glass bottle ...