Mar 23 2001
Background
The CuproBraze process is a technique for manufacturing heat exchangers, particularly automotive radiators. Developed by the International Copper Association, CuproBraze radiators have already proved themselves in US road tests, and the process is showing promise in a range of other heat exchanger products as it offers significant advantages over existing systems, according to the developers.
Recognising the potential of the CuproBraze process, Seco/Warwick has marked its one hundredth anniversary by building a specialist furnace at its Development Centre in Titusville, Pennsylvania, USA, to conduct brazing trials and prototyping work on heat exchangers.
CuproBraze technology enables the manufacture of light, strong, efficient and compact heat exchangers, including oil coolers, heater cores, charge air coolers and condensers, from high strength and high conductivity copper and copper alloys. These alternative materials and technology offer several benefits over existing systems, including a 10% cost saving over conventional aluminium heat exchangers while offering better energy efficiency. Scrap levels from the CuproBraze process are low as rejects can be easily re-brazed, and less energy is required in the brazing process itself. Brazing is carried out at 300°C lower than the melting point of the materials, and the system is much less sensitive than aluminium to rapid heating and cooling cycles.
In comparison to copper/brass systems, CuproBraze has stronger brazed joints, is 35-40% lighter and is easier to recycle. In addition, the braze filler is a non toxic alloy with good wetting and adhesion with no further use for toxic lead solder in the process.
The new braze filler is an alloy of copper, tin, nickel and phosphorous with a metallic content of between 75-90% depending on the joint position and application technique. Different types of binders and braze alloys can be used for the tube to fin joints and tube to header joints, and application can be either by spraying, brushing or rolling.
由Seco/Warwick开发的新炉子突出了Cuprobraze工艺的其他一些优势。炉子是紧凑的前载设计，仅需要8x7m的底面积。但是，提供1200x1200x400mm的免费工作负载空间，较大的替代室尺寸为1500x1500x600mm。加热系统由高压，高速循环风扇通过90kW的电元素，通过工作量通过90kW的电元素，以提供氮气气氛的最佳流动，以获得最佳的最佳悬挂性所需的紧密温度均匀性。在低于750°C的工作温度下，这种加热方法是将热量转移到工作量的最快方法。
The whole process is rapid, with purging, heating and one complete cycle of cooling being achieved in 20 minutes for a single layer of radiators (16kg) or 30 minutes for a double lay (32kg). In Seco/Warwick's new furnace, the speed and accuracy of the process is ensured with a PL system responsible for temperature control sequencing and logic. Such control will achieve optimum conditions for the CuproBraze process, for which Seco/Warwick expects to see growing demand.