System and method for attaching stainless steel side plates to the copper/brass tubes of a heat exchanger core

Abstract

A system and method for attaching very thin stainless steel plates to a radiator or heat exchanger core using the CuproBraze® brazing technique. The use of thin stainless steel side plates produces the structural strength needed in the radiator or heat exchanger core assembly without adding an excessive amount of weight. Heretofore, the CuproBraze® brazing technique has not been used with stainless steel. The stainless steel radiator or heat exchanger core side plates need only be about half as thick as a copper/brass side plate to provide the strength needed for support of the radiator or heat exchanger core.

1 ) A process for attaching stainless steel side plates to the copper/brass tubes and fins of a radiator or heat exchanger core, said process comprising the steps of:
 i) applying a light even coat of a CuproBraze® paste or its equivalent ribbon or film to one side of said stainless steel side plates and drying at approximately 120° C. for 5 minutes;   ii) applying a light even coat of a CuproBraze paste or its equivalent ribbon or film to both sides of said copper/brass tubes of said radiator or heat exchanger core and drying at approximately 120° C. for 5 minutes;   iii) assembling said copper/brass tubes and fins of said radiator or heat exchanger core in a press placing the coated sides of said stainless steel side plates against the coated sides of said radiator or heat exchanger core and compressing together;   iv) placing headers on the end of said copper/brass tubes   v) applying CuproBraze paste or its equivalent ribbon or film on the joints between said headers and said copper/brass tubes   vi) heating in an oven according to the following cycle:   (1) a purge of about five minutes±one minute;   (2) a rapid warm up to about 1243° F.±10° F.;   (3) an about 60 second±30 second heat soak at about 1243° F.±10° F.;   (4) a cool/down to approximately room temperature to 200° F.   
     
     
         2 ) A radiator or heat exchanger core assembly made according to the steps of  claim 1 .