A stenter machine is (and don't worry, I didn't know either) a 150'-long machine
which takes rolls of textile fabric (6' - 10' wide), unrolls it, passes it through a chemical bath (if required),
then passes it through a number of heated chambers to stretch/cure the fabric.
The chambers (in my case) have air pumped in from below through radiators
(heated by heat-exchange oil, piped in from a distant boiler) before being pumped out
(overheat ducting leading to a blower in the base of a tin chimney) to exhaust.

The heat-exchange oil does not come in contact with the airflow/fabric, which does give of fluff (and in the case of polyester, apparently an oily residue), so I have a material-first-ignited.
Operating T's are generally below 210C/410F, so I'm looking for a plausible ignition source.

Jurisdiction & Inspections - this is Africa...