Time to innovate innovation
The brazed plate heat exchanger (BPHE) is a product of modern innovative technology. Production of BPHE started only 25 years back. High-volume production and industrialized use - only the last 15 years. BPHE have becoma a „close to commodity” product.
Only modern, specialized & focused companies have the best quality production technology!
How to create a modern BPHE from its idea to production
To create a BPHE needs modern computer-aided design. Though, it`s not enough to create a drawing of the product and its plates. The industry is using special software for fluid flow simulation and dynamic strength of the mechanical construction.
First prototypes are produced with the help of 3D printer technology. Product performance verification & testing is done in laboratory environment. In identifying the required parameters , the samples are frequently exposed to hydraulic testing, mechanical strength and fatigue.
Once the design is established, the process of tool manufacturing and the making of jigs, fixtures and rigsbegins. Dies are machined from special alloys. Stamping, forming and cutting toolsmust be very robust and rigid, though tensile enough to withstand a million movements in a total lifetime. Precision production of dies and matrices should not exceed 0.01 mm!
Stainless-steel and cupper-foil, coming both from coil, is pressed together in a one-stroke precision fully-automated press-operation. The surface of the embossed plate must be mirror-like and free from any irregularities. The HT-plates are automatically stacked into the plate-pack. The austenitic steel (AISI316L) used for HT-plates can be very sensitive to local stresses. Only a single defect will cause the entire heat exchanger to be rejected.
For quality brazing, specially developed electrical induction vacuum furnaces are used.Only theextreme vacuum prevent the heat exchangers from any prohibited oxidation processes and provideshigh absorbability of molten copper for best brazing results. Different brazing programs are used for different sizes heat exchangers and furnace loads.
The process of brazing is performed in batches lasting 8 to 12 hours each.The batch is gradually evacuated to vacuum, while being heated in a multi-stage process using stabilization phases. Thebrazing temperature ultimately reaches more than 1.100 C. The entire batch-load is closely controlled via various measurining points all over the vessel. The exposure to the highest melting temperature is to be kept as short as possible in order to minimize unwished metallurgic impact on the stainless-steel. Cooling of the batch is simularly sophisticated knowing its influence on metal structure and final product quality. Cooling is provided by a jacket water system as well as injection of nitrogen.
The excess heat is used for space heating of the production and office facility through a heat recovery system.
Leak testing and outgoing goods control
EKO AIR BPHE offer consistent quality. BPHE are „type approved”. They may vary in size, plate count or plate type corrugation, but they are all born from the same construction principle, and always manufactured in a distinct way, in one-and-the-same way. This ensures the best quality for every BPHE we manufacture.
Every and any product undergoes a multi-stage post-productiontesting procedure:
- Visual inspection. Inspection forcorrect configuration and geometric conformity (e.g. dimensions). Coloring, cupper residues, hermetic sealing, a.s.o.
- Mechanical pressure test Side 1 (side 2 open to atmosphere) with pressure test factor of 1.5 to the max operating pressure.
- Mechanical pressure test Side 2 (side 1 open to atmosphere) with pressure test factor of 1.5 to the max operating pressure. Note: every 6 months, a destructive burst pressure test is being performed. Our BPHE can withstand 140 bars and higher until burst.
- Helium microleakage test Side 1 (side 2 open to atmosphere).
- Helium microleakage test Side 2 (side 1 open to atmosphere).
Only after successfull multi-stage testing, the unit will receive its manufacturers label containing a personalized serial number enabling 100% traceability of any specific unit back to its original manufacturing process.
Non-conformity units are being rejected, analyzed for failure reasona and ultimately scraped. Customer do receive quality product only.