Corrofin ® finned tubes are made from copper materials by hellically winding the strip around the tube and soldering them with tin solder at the same time. This achieves a good heat-conducting connection between the tube and the strip. The slightly waved fin foot increases the bond strength between tube and fin and thus improves heat transfer.
Corrofin finned tubes can be used at operating temperatures of up to 150 °C. When using pure tin solder, the permissible operating temperature increases to 180 °C. The ends of the finned area are additionally soldered to the core tube with a soft solder point. If desired, the belt ends can also be secured by a brazing point. To facilitate installation in tubesheets and the possibility of replacement, push-on sleeves can be brazed to one tube end of Corrofin finned tubes, the outer diameter of which is slightly larger than the fin outer diameter.
Corrofin finned tubes are used to cool and heat gases. The following interesting areas of application have emerged:
On request, Corrofin finned tubes can be supplied with hexagonal support rings, which are applied using an injection molding process. The support rings ensure perfect support in the heat exchanger, especially with longer finned tubes. Thanks to the use of silicone rubber, the elasticity of the support rings is retained even under extreme operating conditions. When using hexagonal support rings, a triangular division of the tube arrangement is also specified. In addition, the hexagonal shape of the support rings enables the flow to be guided on the air side in the heat exchanger, which eliminates the need for additional baffles. Alternatively, round support rings made of copper can also be applied.
Schmöle Corrofin finned tubes are made from the materials listed in the table below. The strength properties given in this table apply to the unfinned tube ends at room temperature and are intended to help the designer with the calculation. Deviating values can be found in the finned pipe part due to the soldering process. For pressure vessel systems subject to acceptance, the requirements of AD 2000 leaflet W 6/2 must also be observed for the pipes. Other materials as well as materials according to international and national standards such as ISO, EN, ASTM, ASME, BS, AFNOR etc. on request. When selecting the finned tube and the materials, the operating conditions of the specific individual case must be taken into account. The silicone rubber back-up rings can be used within the permissible operating temperatures for Corrofin finned tubes, i. H. up to 180 °C.
In the case of Corrofin finned tubes, the leak test is carried out by means of an eddy current test on the unfinned base tube. Schmöle supplies Corrofin finned tubes for pressure vessel construction in accordance with AD 2000 leaflet W 6/2. A corresponding special report by the RWTÜV is available for finned tubes with hard-soldered finned strip ends.