Alfa Laval AlfaNova is the first plate heat exchanger in the world to be made completely of stainless steel – made possible by the unique active diffusion bonding technology patented by Alfa Laval.
Alfa Laval AlfaNova plate heat exchangers are made of 100% stainless steel, with the components fused together using a breakthrough technology that Alfa Laval has patented. This provides levels of hygiene and corrosion resistance unmatched by any other brazed heat exchanger. It also makes it practical to use stainless steel plate heat exchangers in installations normally reserved for conventional semi-welded and welded units.
With the Alfa Laval AlfaNova, it becomes feasible to use a high-efficiency plate heat exchanger under the kinds of extreme temperature and pressure fatigue conditions that would probably destroy a conventional brazed heat exchanger. As a result, AlfaNova units have become a breakthrough gasket-free alternative for a wide range of industrial applications that use aggressive liquids and in which there is a need for high-efficiency, hermetically sealed plate heat exchangers that ensure low life cycle costs even under high-temperature conditions. The 100% stainless steel construction makes it possible to withstand temperatures of up to 550°C (1,020°F).
To guarantee maximum safety, reliability and durability, Alfa Laval AlfaNova units have been subjected to exhaustive testing focusing on pressure fatigue, thermal fatigue and corrosion resistance. Such dependability, along with the other multiple benefits of this innovative design, make AlfaNova a cost-effective heat transfer solution in a wide range of duties. Examples include systems using refrigerants such as ammonia, while its resistance to corrosion also makes Alfa Laval AlfaNova popular in district heating installations in which corrosive water is used.
The hygienic heat transfer channels and mechanical strength also make Alfa Laval AlfaNova units ideal in applications where the prime focus is on hygiene, such as clean water refrigeration chillers and tap water heating systems.
Alfa Laval AlfaNova fusion-bonded heat exchanger consists of corrugated stainless steel plates, a frame plate and a pressure plate. The heat transfer plates in the plate pack are bonded together using AlfaFusion technology, a unique method of bonding stainless steel components that is an Alfa Laval patent.
The brazed design holds the plate pack together internally with contact points, doing away with any need for external plate frames at design pressures of up to 70 bar / 1015 psi. Distributing the load across many separate contact points provides excellent resistance to pressure fatigue. And because all the key parts are made of the same material, this design is thermally efficient as well as being shock-proof and having a mechanical strength fully equivalent to any welded counterpart.
The heat exchanger works on the basis of two media at different temperatures flowing on either side of thin corrugated stainless steel plates stacked on top of each other. The design of the channels between the plates, along with entry and exit ports placed in the corners, means that the two media flow through alternate channels, always in counter-current flow. The media are kept within the plate pack by a fusion-bonded seal around the edge of the plates. The points at which the plates are in contact with each other are also bonded using the same technology, reinforcing the pack against the pressure of the media inside.
The counter-current flow makes it possible to extract heat efficiently even when there are only extremely small differences between the temperatures of the hot and cold media. This results in notable savings on energy costs.