PS1 2 Bunsen burner flame experiment WIS

investigating the Bunsen blue (hot) flame. With CORRUGATED CARDBOARD, popsicle stick and length od wire (straightened paper clip) Demo for teachers only - hazard with fire/flame.
Investigating what's happening/not happening the inner blue triangle the Bunsen flame close to the top of the chimney.
Care with flame/fire. Do experiment close to a sink. Use goggles. Hold items in tongs. ONLY USE CORRUGATED CARDBOARD
Soak all heated/burnt items in water before disposal - to extinguish all burning/charring.
Why departs not burn?