How to dig a kiln burning charcoal in rural areas?

There are machine-made kilns and rural earth kilns. I haven't seen the machine-made kiln. It is estimated that it is an improvement of the earth kiln. A rural earthen kiln is to dig a big pit, fill it with wood, and then ram the top cover with earth. After the wood is burnt, the charcoal is taken out and the top cover is intact, and the kiln is successful. There is a horizontal hole filled with wood, the hole is blocked, and there is a charcoal kiln inside. The trick of kiln lies in flue and fire path. The flue draws smoke upward from the bottom of the lowest wood, and the fire channel is the fire channel that ignites the wood in the kiln. The wood in the kiln is carbonized downward from the top, and the wood is placed vertically in the kiln.

Another trick of burning charcoal is to watch the smoke force the fire to seal the kiln. The kiln was closed too early, and the wood in the kiln didn't burn well. It is too late to seal the kiln with barrels and pipes in rural areas, and the charcoal is ashed, and there is less charcoal, so the charcoal can't burn.