Laboratory hood -- prefabricated upper unit contg.The window pulled up and down, fitting or all movable members hung up on the lower part of installation

摘要

A heating boiler comprising a pair of manifolds 4, 5 between which extend finned tubes 14 to 21 through which water to be heated may pass. The fins on the tubes extend axially and, in the case of tubes 14 to 19, are perforated in such a way as to allow hot combustion products from a gas burner assembly 32 to pass through the fins. The finned tubes are arranged across the combustion chamber to form an effective barrier through which the combustion products must pass, thus ensuring efficient transfer of heat to the water within the tubes.