rocket stove fireplace insert

just came across this, does anyone have such a stove

Mein.The little barrel its from stainless steel( a beer keg).
With vertical chimney i got a lot of smoke back until the chimney got hot so id be carefull with that.
With horizontal chimney works perfectly.

Reminds me of this one Bruce:  Rocket burner

How far up the chimney does the liner pipe go. How long is the pipe?
I’m replacing my rusted sheepherders smoke generating woodstove with a DIY rocket stove. I hope it draws well.