I know an elderly mechanic who heated his shop using a simple used oil burner.
His design was quite simple a a long 6" steel pipe running at a slight angle suspended from the cieling (roughly 1ft drop in 20ft run) a smaller 1" angle iron was held up in the center of the large pipe. this was the oil path He only used about 12ft of angle iron at the low end.
an oil tank was suspended and oil was piped by gravity and adjusted with a small valve to drip into the channel iron ( the oil feed pipe was welded through the large pipe)
He would start the oil dripping and light this buy simply putting a piece of paper at the low end . once lit it only took a minute or so for the draft to have the pipe roaring like a jet engine other than at the first there was no sign of smoke from the chiminy . It was simple and effective within a few minuted the entire 30+ft of large pipe was glowing providing radiant heat a cieling fan blew the hot air down as well .
He'd been using this method since the 1930s according to him with no problems.