초록 ▼

A tube having a plurality of hydraulically parallel fluid passages for use in a heat exchanger can be made by forming an elongated, undulating insert and disposing the same within a flattened tube. A noncorrosive brazing flux is adhered to at least one of the interior of the tube and the crests on t

A tube having a plurality of hydraulically parallel fluid passages for use in a heat exchanger can be made by forming an elongated, undulating insert and disposing the same within a flattened tube. A noncorrosive brazing flux is adhered to at least one of the interior of the tube and the crests on the undulating insert. Braze alloy is also located at the interface of the crests of the insert and the interior wall of the tube. Thereafter, the insert is located within the tube without disturbing the flux and the tube deformed along its length to bring the interior of the tube into contact with the crests on the insert. The assembled tube and insert construction is then heated to braze joints between the interior wall of the tube and the crests of the insert along the entire length of the latter.

대표청구항 ▼

A method of making a heat exchanger having a plurality of side-by-side fluid passages each of a hydraulic diameter of about 0.07 inches or less comprising the steps of; (a) providing a flattened tube; (b) forming an elongated, undulating in cross-section, insert of slightly lesser size than the inte

A method of making a heat exchanger having a plurality of side-by-side fluid passages each of a hydraulic diameter of about 0.07 inches or less comprising the steps of; (a) providing a flattened tube; (b) forming an elongated, undulating in cross-section, insert of slightly lesser size than the interior of said tube, said insert having a plurality of crests separated by valleys and sufficiently proximate to each other that, when the insert is placed in the tube, each valley and the adjacent interior wall of the tube will define an elongated passage through the tube having a hydraulic diameter of about 0.07 inches or less, at least one of the interior of said tube and said crests being clad with braze alloy; (c) adhering a noncorrosive brazing flux to at least one of the interior of said tube and said crests; (d) inserting said insert into said tube without disturbing said flux; (e) deforming said tube along its length to bring said interior into contact with said crests; (f) heating the assembled tube and insert to a temperature above the melting point of the braze alloy to braze the crests to said interior; and (g) thereafter cooling the assembled tube and insert.