Abstract: A method of fabricating a condenser tube having a pre-determined tube length and multiple channels including the steps of forming an aperture in a flat strip of metal; moving the flat strip through a plurality of forming operations to fold into an enclosed tube containing channels, which channels include the aperture in their sides and bottoms; and severing the enclosed tube across the aperture to separate the enclosed tube into one condenser tube. The aperture eliminates the need for the channel sides to be severed, hence only the portion of the condenser tube enclosing the channels requires severing. Each pair of apertures is spaced from the next pair of apertures by the pre-determined tube length so that each sever produces one condensing tube of the pre-determined tube length with the apertures being divided into open notches. The invention also includes a heat exchanger utilizing the condenser tube with channel sides containing portions of the apertures.

Abstract: A method of fabricating a condenser tube having a pre-determined tube length and multiple channels including the steps of forming an aperture in a flat strip of metal; moving the flat strip through a plurality of forming operations to fold into an enclosed tube containing channels, which channels include the aperture in their sides and bottoms; and severing the enclosed tube across the aperture to separate the enclosed tube into one condenser tube. The aperture eliminates the need for the channel sides to be severed, hence only the portion of the condenser tube enclosing the channels requires severing. Each pair of apertures is spaced from the next pair of apertures by the pre-determined tube length so that each sever produces one condensing tube of the pre-determined tube length with the apertures being divided into open notches. The invention also includes a heat exchanger utilizing the condenser tube with channel sides containing portions of the apertures.

Abstract: A folded heat exchanger tube (10) of the type that is rigidified with a pair of abutted 90 degree walls (16) extending along the interior length thereof, so as to join the lower (12) and upper (14) walls thereof, has a separate inner web member (20) anchored and fixed inside between a pair of curved, out turned feet (18) on the abutted walls (16) and the inner surface of the lower wall (12). A widened and flattened central channel (24) in the web (20) is engaged by the under surfaces of the curved feet (18), and is approximately as wide as the total width of the tow feet (18).

Abstract: An improved method for producing a basic B tube configuration for a folded heat exchanger tube (26). A braze clad metal strip (10) having inner (1) and outer (0) surfaces and a opposed edges (12) is progressively formed over and in by a series of progressive roller stations (14A, 16A-14J, 16J) until the lower edges (12) on a pair of central abutting flanges 18 centrally engage the strip inner surface (1). Between two of the roller stations (G and H), a powered dispense valve (20) with nozzle (22) continuously dispenses a bead (24) of material containing flux or, alternatively, flux and braze material. Bead (24), rather than being a thin stripe, is a thick semi cylindrical shape, with substantial viscosity. As the flanges (18) move into abutment and the downstream roller stations, the flange edges (12) are forced down into the bead (24), some of which is pumped up between the outer surfaces (0) of the abutted flanges (18), yielding a good, solid braze joint between the two.

Abstract: An improved method for producing a basic B tube configuration for a folded heat exchanger tube (26). A braze clad metal strip (10) having inner (I) and outer (O) surfaces and a opposed edges (12) is progressively formed over and in by a series of progressive roller stations (14A, 16A-14J, 16J) until the lower edges (12) on a pair of central abutting flanges 18 centrally engage the strip inner surface (I). Between two of the roller stations (G and H), a powered dispense valve (20) with nozzle (22) continuously dispenses a bead (24) of material containing flux or, alternatively, flux and braze material. Bead (24), rather than being a thin stripe, is a thick semi cylindrical shape, with substantial viscosity. As the flanges (18) move into abutment and the downstream roller stations, the flange edges (12) are forced down into the bead (24), some of which is pumped up between the outer surfaces (O) of the abutted flanges (18), yielding a good, solid braze joint between the two.