There are several types of ignitors used for pyro machina.
General Impression: Unreliable and touchy
There are lots of these. Most furnaces, and many propane torches use these, either as piezo electric or electronic sparkers.
For a lot of applications these don't seem to work too well. In theory you only need a small spark to ignite a prefect mixture for fuel and air. In practice it is hard to get the right mixture of fuel and air where you want it when you want it.
Mostly I think these have potential for relighting pilots after they've been blown out.
I fthink if these are to work as primary ignitors then the spark needs to be very high voltage and powerful. A large neon sign transformer or a microwave oven transformer with a ballast would be needed. (The other thought is using a small 110V rat box welder as the power source.
Propane Ignitors use a flame to ignite the fuel. The upside of these designes is that the flame produces a large zone of ignition. The downside is that they continuously consume gas. Rates can be as high as 10-50,000 btu/hr. The other downside (or upside) is that the flame produces light which may or may not be a good thing.
General Impression: Works, tends to blow out.
Propane torches use a high pressure jet of propane to draw in and mix air in a venturi. The problem is that any distrubance will tend to change the ratio of propane to air and can cause the flame to blow out.
General Impression: Works hands down.
These are the simplest, cheapest and most reliable ignitors.
Better than a torch, this design uses a stainless steel wick to hold a propane flame. Unlike a propane torch the wool does a very good job holding the flame during firing. Quote "The flame hides inside the steel wool" What happens is as the big rush of unstable air blows past the ignitor the flame retreats inside the steel wool and continues burning. Afterwards that flame pops back out. These are very hard to put out.
The simplest form is simply a 1/4 inch copper tube with the end caped off and drilled through with a 1/16 drill. Iron bailing wire is then threaded through the hole to keep the cap on and to wrap around the stainless steel wool.
More complicated ones are the Ring Design used on Betsy and the ICP's. In the ring design there is a ring of copper tubing with holes pointing towards the center. The ring is wrapped in stainless steel wool. The advantage of these is when you need a big ass ignitor.
Downside: Continuously consumes propane.
Downside2: Unlike a torch the flame is yellow which may or may not be a problem. Downside3: These are hard to light reliably with an electric ignitor.
Same as a propane torch but fed with alcohol.
Idea, use high pressure brake line. One end of the brake line is coiled with the end terminating inside the coil. End of the brake line is capped off with a small hole. Stainless steel wool is inserted inside the coil as well to form a wick. Torch is fed with pressurised alcohol. Hopefully the flame will vaporize the alcohol in the coils turning it to vapor.
Advantages twofold, the alcohol should burn with a colorless flame. And for liquid fuel devices it removes the need to have a seperate propane tank. (IE single fuel design).
Same as propane wick design but fed with a mixture of air and propane. Advatage might be that the flame would be smaller and hotter and with less nasty black body radiation. AKA more torch like and less flame like.
Hidden advantage, if the flame goes out, relighting it is very safe since as the mixture of propane and air mixes with external air, the mix moves away from the flamibility range. Basically premix systems don't tend to make big poofs when relit (Confined spaces excepting).
May work for some things and not others. Not a lot of experince with these. Disadvantage is that they are hard to put out and thus are a safety issue.
General Impression: May work, may required futzing to make work.
The idea would be to use a premix of fuel and air for a propane torch. The air being supplied by a blower or compressor.
This probably would work better than a propane torch at saying lit since the body of the flame could be protected from being blown out. Migh be possible to use stainless steel wool as a flame holder as well.
Another thought is that because they burn a perfect mixture of fuel and air, these torches could easily be lit using a simple electric BBQ ignitor.
Also no experience with these.
One could use an arc between two carbon rods as an ignitor. High current AC would be applied to two spring loaded carbon rods. The result would be a large hot spark that might do a good job of igniting a flame.