Hydro Aluminium
Brazed aluminium heat exchanger - Ask for the inexpensive features
B.Bc., B.Com. Bjørn Vestergaard & Tomas Husse. HYDRO ALUMINIUM
Brazed aluminium heat exchangers are cost efficient compared to traditional RTPF in mass production.
The manufacturing principle of brazed aluminium heat exchangers will be explained, and with a better understanding of the manufacturing process it is possible to avoid the most expensive mistakes.
New coating technology for brazing of aluminium heat exchangers
B.Bc., B.Com. Bjørn Vestergaard & Tomas Husse. HYDRO ALUMINIUM
Today mass production of brazed automotive heat exchangers (HEX) is mostly done by Controlled Atmosphere Brazing (CAB). This technique requires, that prior to brazing, the assembled HEX´s are sprayed with flux, which is necessary to allow the fillet formation during brazing. This also applies to the brazing of automotive condensers and evaporators. The fluxing process, which is done by the customer in a continuous process right before brazing, requires in addition to the brazing furnace special fluxing equipment, which includes also a drying section, since the flux is mostly applied in form of an aqueous emulsion.
HYDRO has developed a range of special products called HYBRAZ ™/® coated products, which are already coated with the flux necessary for brazing (HYBRAZ ™/® PF). The use of HYBRAZ ™/® coated products simplifies the production process at the customer, makes the fluxing more effective and allows further advantages, among which a highly increased productivity is one of the most interesting. Furthermore, the customer is able to reduce his costs due to reduced investment (no fluxing equipment necessary).
In addition to coatings which include the flux, also coatings containing filler metals in addition to the flux have been developed (HYBRAZ ™/® PB). Those systems offer for some applications the opportunity to braze parts, which cannot be clad with filler materials like e.g. Multiport Extruded Tubes (MPE) and therewith enable the use of unclad fin instead of clad fin. This technology can be applied e.g. to brazed Al condensers built with MPE’s.
Both techniques are meanwhile introduced in automotive HEX manufacturing. These new techniques are thereby especially interesting for people entering the Al brazing business, since the need for investment is significantly reduced (no fluxing station required) and they can start the production on a state-of-the-art level offering all technical and commercial advantages.
