How many letters does the top answer for “a burner that mixes air and gas to produce a very hot flame” have?

The most common answer is blowlamp (8 letters).

Crossword clue: a burner that mixes air and gas to produce a very hot flame

2 answers found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

blowlamp 8 letters wn-def

a burner that mixes air and gas to produce a very hot flame

blowtorch 9 letters wn-def

a burner that mixes air and gas to produce a very hot flame