Abstract: The object of this invention is to have shorter sealing chambers (preheating chamber and gradual cooling chamber) located before and after the brazing atmospheric chamber, to make higher sealing of the atmosphere, and to prevent the scratch caused by the conventional curtains made of metal or others. In order for that, the structures made of steel or graphite are installed standing perpendicular to the moving direction on the conveyor belt which is circulating through the atmospheric furnace. And the bendable or flexible sealing materials are installed on the ceiling and on the right and left side walls of the sealing chambers (preheating chamber and gradual cooling chamber), which are located before and after the atmospheric furnace, into the above two chambers, and making these bendable or flexible sealing materials have rubbing contact with the above mentioned structures.

Abstract: When aluminium products are preheated in a preheating furnace up to about 500° C. before they are brazed with a flux in a heating furnace, a nitrogen atmosphere in the preheating furnace is made convectional by fans for improving heating efficiencies and also for having the oxygen which is brought into the preheating furnace as a disturbance thereof and scattered about in the nitrogen atmosphere, contacted to furnace inner walls of the preheating furnace which are made from carbonaceous materials, and reacted therewith so as to be changed to CO, resulting in keeping the oxygen concentration of nitrogen atmosphere low, whereby when the aluminium products are brazed by heating them in a continuous atmosphere furnace including said preheating furnace and said heating furnace, heating time thereof is shorten and the brazing is made more economically than before.

Abstract: The object of this invention is to have shorter sealing chambers (preheating chamber and gradual cooling chamber) located before and after the brazing atmospheric chamber, to make higher sealing of the atmosphere, and to prevent the scratch caused by the conventional curtains made of metal or others. In order for that, the structures made of steel or graphite are installed standing perpendicular to the moving direction on the conveyor belt which is circulating through the atmospheric furnace. And the bendable or flexible sealing materials are installed on the ceiling and on the right and left side walls of the sealing chambers (preheating chamber and gradual cooling chamber), which are located before and after the atmospheric furnace, into the above two chambers, and making these bendable or flexible sealing materials have rubbing contact with the above mentioned structures.

Abstract: When aluminium products are preheated in a preheating furnace up to about 500° C. before they are brazed with a flux in a heating furnace, a nitrogen atmosphere in the preheating furnace is made convectional by fans for improving heating efficiencies and also for having the oxygen which is brought into the preheating furnace as a disturbance thereof and scattered about in the nitrogen atmosphere, contacted to furnace inner walls of the preheating furnace which are made from carbonaceous materials, and reacted therewith so as to be changed to CO, resulting in keeping the oxygen concentration of nitrogen atmosphere low, whereby when the aluminium products are brazed by heating them in a continuous atmosphere furnace including said preheating furnace and said heating furnace, heating time thereof is shorten and the brazing is made more economically than before.