BradtheRad the "fans" look like they are there for the mixing of O2 and gas... Like you said very dangerous design probably will explode or at least catch fire in a most spectacular way. Motors in fans tend to generate occasional sparks, so first time it is turned on it will go boom in their face.
This design is not safe and I recognize this even without being involved in these types of designs.
Mx5boy, if you want an example of how to do this safely then look at any propane grill, where you can easily see how everything assembled (unlike some stoves).
One thing they don't need in a grill are fans to mix air and propane. The pressure in the propane tank (or gas line, in your case) pushes the fuel into the air where it's ignited and then keeps supplying the fuel to keep the flame going. The more gas/propane you supply the bigger the flame.