I found a simple cost-free method of burning up to 5 pounds of chips over a simple wood fire, using a fine steel mesh with the chips laid out in a layer about 2 feet off the ground, held in place with stacked brick walls. Build your pile of slender pieces of dry wood underneath in a 'log cabin' campfire setup, then sprinkle either paraffin or other wax over the chips, OR frying oil that's been used at least 3 times. Then light it up! The chips burn at an intensely high heat that the plastics practically vaporize into bright flame. The whole thing burns pretty thoroughly in a mere 15-20 minutes (sometimes the chips on the edges of the screen don't, and might need more wax or oil). Crush down the embers so you can slip a thin sheet of scrap steel (easily obtained from a trashed fridge, washing machine, etc) underneath the screen to catch anything that falls through as it cools, the chips burn so completely once you get the nuances of the burn just right, that they will fall apart at the slightest touch.
If you do a lot of chips, you can prop up the steel mesh with a few lengths of rebar to keep the mesh from sagging as it gets orange-yellow hot in the middle. The rebar won't get in the way of the flame.
Paraffin is best, as there's no smoke at all when the fire gets going. Used fry oil will make some smoke, but not too much when you get the fire lay built right. I've gotten wood fires with this setup up to a bit beyond copper's melting point with nothing more than the correct wood arrangement and airflow. You don't want it THAT hot for this purpose, but know that it's achievable!
In my first brick wood-fired kiln decades ago, I managed to melt low-grade steel pipe used for playground equipment back in those days. That rather came as a shock, since I had planned to use it as a tall crucible for melting aluminum. Found a cast-iron pipe and used that instead!