When planning to fill a large enclosed chamber with hydrogen, oxygen and propane, and allow members of the public to voluntarily ignite the contents, we find it’s best to consider ways to decrease the likelihood of blasting out four foot by eight foot sheets of shattered polycarbonate at hundreds of feet per second. If you plan on igniting flammable gases for amazement and amusement (read: art), you really have to consider safety third, and certainly no lower than that.

We’ve taken a number of measures to reduce the risk of life and limb, the most important of which is the hydrogen chamber itself. There’s a lot less chance of someone burning their hand, face, neck, neck, chest or faux fur costume if they are physically separated from the fire by a plastic barrier.

But again we come back to the question: How do we avoid blowing up the chamber? The key is to understand what the maximal flow rate in cubic feet per minute (cfm) is of our bubble blowing devices, and the flash point of hydrogen. Hydrogen becomes flammable in air at concentrations of just 4%. So we built an air blower and duct system that creates positive pressure inside the chamber at roughly 50-100 times our hydrogen usage. In our case, our bubble machines will consume 3-4cfm of hydrogen. Therefore we have installed a blower system that will push around 400cfm of air into the chamber. This reduces the maximum hydrogen concentration in the chamber to less than 2%. In addition, we’ve mounted many nichrome ignitors (see Ben’s last post) to ignite any small pockets of hydrogen, either contained by or not contained by bubbles, before they can collect into a dangerous situation.

How would we know if a dangerous situation occurs before the gigantic explosion? We mount a detector on the wall of our chamber, at a level where we would want to shut down the project if gas somehow pooled from the ceiling down to the detector mount point. If the detector goes off, the project is shut down until the chamber returns to safe levels.

A couple of weeks ago, Erik did some great drawings of the hydrogen chamber in Rhino. Since then, we’ve been working to refine the design (uhh, we forgot a door… can we add one?) and build out the first level.  It was also cool to have Erik show us how he works in Rhino. The software combines the manipulation and viewing power of a 3d modeler like Maya with the accuracy and dimensioning capabilities of a CAD program. Perfect combination for this kind of work.

So far, first the six steel frames are welded, the aluminum for the surrounds is cut and drilled, and yesterday I got about half of the brackets welded on. It’s cool to see our physical work starting to look like the 3d model!

We’ve begun work on the PyroCardium sculpture, making a 6-foot-tall version with 1 Watt red LEDs to appear at False Profit Alchemy on April 26 at Cell Space. On the virtual side, the sculpture truss and helix is all modeled up in 3D using Rhino. On the physical side, the TIG welder is out, as is the metal bender, and the smaller truss is coming together.

Probably the most challenging aspect of building a swirly sculpture (aside from the dancing fire) is bending thick pieces of aluminum on all 3 axes. Dyche has come up with a pretty ingenious method. Our first helix will be comprised of seven semi-circles, of successively smaller diameter. Each piece of aluminum stock is placed in the metal roller at angle, so it gets bent in a semi-circle in one dimension, and pulled upward out of the circle’s plane as well. When these pieces connect together, the decreasing diameter is what gives the sculpture its skewed shape.

False Profit Labs is happy to announce that we will be making appearances around the Bay Area in the coming months. First, on April 12 you can come out to NASA Ames at Moffett Field and enjoy our fire art out on the tarmac in celebration of Yuri’s Night. Check out their website here: www.ynba.org.Then on May 3 & 4 we bring more explosions to Maker Faire at the San Mateo Fairgrounds. More on this at: www.makerfaire.com.We’ll publish more details as we get them, but for now here’s an appetizing 3d model that Brendan Colloran made in Matlab(!) for the PyroCardium scultpure. Now it’s just a matter of building it.

They’re in.  And here they are so you can see not only what we’re up to this year for Burning Man, but also so you can get involved.  There are at least a dozen sub-projects related to The Hydrogen Economy and PyroCardium.  Maybe you want to help with construction of a double-helix sculpture, or you’re good at machining small plastic and metal parts.  Maybe you have no skills at all but are full of enthusiasm.  Perfect.  Post a comment with your contact info and we’ll find a way to plug you into the mix.The 2008 False Profit Labs Burning Man Proposals:

The Hydrogen Economy

PyroCardium