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Brazing of Stainless Steel to Aluminium for Pots and Pans Production

The following article provides some answers on general questions regarding the use of NOCOLOK Sil Flux for manufacturing pots and pans. What is the NOCOLOK Sil Flux quantity (per m²) required for sandwich brazing or pressure cookers (stainless steel to aluminium)? The recommended load for NOCOLOK Sil Flux is approximately 15 to 25 g/m². Brazing aluminium to stainless […]

Cladding Alloys

Brazing sheet comprises of a core alloy clad on 1 or 2 sides with a lower melting aluminum-silicon (Al-Si) alloy. This thin layer, usually makes up 5 % to 10 % of the total thickness of the brazing sheet. It melts and flows during the brazing process, to provide upon cooling a metallic bond between […]

Zn Flux – The Alternative Flux for Corrosion Protection

All heat exchanger manufacturers currently using zinc-coated tubes or zinc-coated brazing sheet and extrusions for corrosion protection are invited to consider NOCOLOK® Zn Flux as an alternative. How does NOCOLOK® Zn Flux work? The flux – a fine white powder with the chemical formula KZnF3 – is manufactured by Solvay Fluor similarly to standard NOCOLOK® […]

Controlled Gas Plasma Depostion (CGPD)

A new coating technology for the functionalization of semi-finished aluminium products for heat exchanger (HEX) applications has been developed by Erbslöh Aluminium GmbH with assistance from Solvay Fluor. In contrast to binder-based flux coatings, it is now possible to apply various kinds of NOCOLOK® fluxes free of any adhesives for the Controlled Atmosphere Brazing (CAB) […]

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Magnesium – Effects on Brazeability

For added strength and machineability, certain alloys contain Mg. Most notably are the 6XXX series alloys (up to 1% Mg) that are used for fittings and machined components and the so-called long life brazing sheet alloys (up to 0.3% Mg in the core). There is a limit to the amount of Mg tolerated in NOCOLOK® […]

Benefits of brazed heat exchangers – Refrigerant charge reduction

This increase in efficiency means the same refrigerant capacity can be produced with smaller exchange surfaces at the condenser and evaporator, with an associated reduction in piping volume, i.e. a higher heat exchange efficiency means smaller systems and lower refrigerant charge. Important given that third generation HFC refrigerant blends such as R 410 A are […]

Aluminium Core Alloys

Aluminum alloys are classified according to their alloying elements. The Aluminum Association designations are listed in the table below: Designation System for wrought aluminum alloys Alloys series   Description or major alloying element 1xxx                  99.00% minimum Aluminum 2xxx                 Copper 3xxx       […]

How to evaluate flux load?

How to measure? In the case of heat exchangers, the surface area being fluxed must first be determined. For ease of calculation, the louvers on the fin can be ignored. The radius on the fin can also be ignored. Imagine then the fin pulled out of the heat exchanger and straightened out to form one […]

Benefits of brazed heat exchangers – pressure drop reduction

Brazing also offers the chance to change the design of heat exchangers by substituting round tubes with flat channels (microchannels) which offer improved heat transfer on both refrigerant and air sides for two reasons: better section/surface ratios, which affect the efficiency of heat exchange on the air and the refrigerant side; smaller surfaces in the […]

Brazing Aluminium and Copper

Brazing aluminium to copper is common in the refrigeration industry where copper tubes are brazed to aluminium roll-bond panels or tubes. To join aluminium and copper using brazing technology and standard NOCOLOK® Flux, flame brazing would be applicable (as well as using a low-melting flux with a low-melting filler metal). It is very similar to […]