It never ceases to amaze me, the sheer number of variations of engineering that I have seen applied to something as simple as a pipe. Some are elegant and interesting, others crazed, and still more are like this one - way too much thinking applied to a simple purpose, rather like making the wheel with fifteen moving parts and three socket fittings. I can't recall where I got this picture - someone emailed it to me years ago, but I've forgotten who. It is a classic idea of the "Build a Better Mousetrap" thinking (There's no idea so gracefully simple that it cannot be overcomplicated). I've created numerous drain-plug-style pipes like this one, but have never been pleased with the results. They don't seem to realize the hoped-for cooler smoke, and mostly they are just more annoying to try to clean. Still, such designs are fun to look at and think about!