Burner for forced draft controlled mixture heating system using a closed combustion chamber

摘要

An improved fuel and air admixture burner for water heating and/or space heating appliances comprises concentrically arranged inner and outer sheet metal tubes closed at their top ends and the inner tube open at its bottom end through which a combustible fuel and air admixture is adapted to be introduced into the burner. The inner and outer tubes are specially configured to supply a balanced distribution of the combustible fuel and air admixture to the outer surface of the burner while allowing the heating apparatus to operate quietly. Perforations varying in size are distributed over a top zone, a middle zone, and a bottom zone of the inner tube, with the top and bottom zones containing larger perforations and the middle zone containing smaller perforations. The bottom zone is axially longer than the middle zone which in turn is axially longer than the top zone. The outer tube is formed of sheet metal resembling a very fine mesh screen having minute holes arranged in a straight pattern and having as many as 500 or more holes per square inch of surface area.