They look like standard high pressure propane burners. Useful for heating sparge water, but they will caramelize wort instantly. I use one for burning blackberry canes and it will use a 20 lb tank in under an hour.
Remember one unassailable statistic, as explained by the late, great George Carlin: "Just think of how stupid the average person is, and then realize half of them are even stupider!"
"I would like to die on Mars, just not on impact." Elon Musk