Method for the manufacture of a heat-exchanger having at least one curved tube of flat cross-section
First Claim
1. A method of manufacturing a heat exchanger having a longitudinally curved tube of flat cross-section defining a curved flow path for a first fluid wherein said tube is defined by two broad surfaced curved wall elements joined to each other in spaced apart relationship by at least two curved spacing elements disposed between and soldered to said wall elements, said method comprising in combination the steps of cladding with a soldering composition at least one of each of the mating surfaces between said wall and spacing element and applying soldering heat thereto, characterized by the steps of selecting for said cladding a special solder having a range over which melting occurs, forming a preliminary tube of flat cross-section by assembling broad surfaced wall elements with spacing elements, at least either said wall elements or said spacing elements being pre-clad with said special solder, and effecting preliminary soldering at a first soldering temperature which lies in the lower part of said melting range, shaping said preliminary tube to form the desired longitudinally curved tube, and thereafter effecting a second soldering of said elements at a second soldering temperature above said first temperature.
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Abstract
A method for manufacturing a heat exchanger using a non-eutectic solder which melts over a melting range is disclosed. The soldering is carried out in two successive soldering steps, first at a soldering temperature which is at the lower end of the melting range, and then at a higher soldering temperature within the same range. Flat plates and straight-edge strips are used for the first soldering step. The straight tube of flat cross section produced in this manner is then curved in the desired fashion and soldered in final manner by the second soldering step.
21 Citations
5 Claims
- 1. A method of manufacturing a heat exchanger having a longitudinally curved tube of flat cross-section defining a curved flow path for a first fluid wherein said tube is defined by two broad surfaced curved wall elements joined to each other in spaced apart relationship by at least two curved spacing elements disposed between and soldered to said wall elements, said method comprising in combination the steps of cladding with a soldering composition at least one of each of the mating surfaces between said wall and spacing element and applying soldering heat thereto, characterized by the steps of selecting for said cladding a special solder having a range over which melting occurs, forming a preliminary tube of flat cross-section by assembling broad surfaced wall elements with spacing elements, at least either said wall elements or said spacing elements being pre-clad with said special solder, and effecting preliminary soldering at a first soldering temperature which lies in the lower part of said melting range, shaping said preliminary tube to form the desired longitudinally curved tube, and thereafter effecting a second soldering of said elements at a second soldering temperature above said first temperature.
Specification