Heat Exchangers

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Gasketed Plate Heat Exchangers

The Industrial line’s versatility allows it to be designed and configured for applications ranging from relatively simple duties with low requirements to very demanding duties with the highest requirements on both performance and documentation. The products are used for heating, cooling, heat recovery, condensation, and evaporation.

Equipped with well-designed features, the Industrial line of heat exchangers are easy to maintain and have a long service life. Some of the features available include:

  • ClipGrip™ gasket – a glue free gasket with superior alignment that ensures a perfect seal and trouble-free maintenance.
  • Glued gasket – a two-component, oven-cured epoxy glue keeps the gasket in place during any possible cleaning condition.
  • CurveFlow™ distribution area – ensures full use of the heat transfer area and minimizes fouling.

Additionally, the pressure plate roller, the bearing boxes on the tightening bolts, and the 5 point alignment system with reinforced hangersmake opening and closing the heat exchanger quick and easy without the need for heavy tools or the risk of damaging the plates.

Alfa Laval Industrial line is quick and easy to modify if process parameters change. Our team’s expertise and the availability of parts bring you peace of mind.

Gasketed plate heat exchangers for modern requirements

Our Gasketed plate heat exchangers are optimizing heat transfer by large surfaces of corrugated plates drawing heat from one gas or liquid to the other. The high efficiency and an outstanding reliability in a compact design, offers an investment with the most attractive CTO over the product life time. Not to forget the energy saving capabilities and low environmental footprint.

  • Highest thermal efficiency and close temperature approach

  • Compact units – space saving, easy to service and maintain

  • Maximum uptime – less fouling, stress, wear and corrosion

  • Flexible – easy to adapt to changed duty requirements

Plate types for different needs

Industrial line is available with four different plate configurations:

  • Single plate with a chevron pattern design for parallel flow allows for optimum thermal performance and pressure drop.
  • Single plate with a chevron pattern design for diagonal flow allows for optimum thermal performance through the heat exchanger when it is mounted horizontally and requires complete drainability.
  • Double wall plate is used when extra care is needed to avoid mixing fluids.

    Gemini double wall plate is used when extra care is needed to avoid mixing fluids in hygienic applications.

How it works

The heat transfer area of a gasketed plate-and-frame heat exchanger consists of a series of corrugated plates, assembled between the frame and pressure plates, which retain the design pressure. The sealing between the plates is made of gaskets. For the highest thermal performance and to enable a very close temperature approach, fluids normally run counter-currently through the heat exchanger.

The Industrial line is available with various pressing depths and angles of the chevron pattern and various shapes of the corrugation which are all carefully designed and selected to achieve optimal performance. The CurveFlowTM and the chocolate pattern distribution area are two design features available that ensure fluids are evenly distributed across the entire plate.  The result is that the entire heat transfer surface is fully utilized and stagnant zones that can result in fouling are avoided.

High fllow turbulence between plates results in higher heat transfer; however, the consequence is pressure drop. Our thermal design engineers will help you design and select the model and configuration that is suitable for your application needs while delivering maximum thermal performance and minimizing pressure drop.

The Industrial line can be configured in different ways. The animation shows single pass configuration, but multi-pass with 2 or more passes on each side is also possible.

 Alfa Laval gasketed plate heat exchanger – Flow principle

Flow principle of Alfa Laval gasketed plate-and-frame heat exchanger configured for single pass.

The principles and workings of gasketed plate heat exchangers

The concept behind a heat exchanger is relatively simple – heating or cooling one medium by transferring heat between it and another one.

In a gasketed plate heat exchanger, the plates are fitted with elastomeric gaskets which seal the channels and direct the media into alternate channels. The plate pack is assembled between a frame plate and a pressure plate, and compressed by tightening bolts fitted between these plates. The channel plates and the pressure plate are suspended from an upper carrying bar and fixed in position by a lower guiding bar, both of which are fixed to the support column. The design allows easy cleaning and simple capacity modification (by removing or adding plates).

The heat transfer area of a gasketed plate heat exchanger consists of a series of corrugated plates, assembled between a frame and pressure plates to retain pressure. Gaskets act as seals between the plates. Fluids normally run counter-currently through the heat exchanger. This gives the most efficient thermal performance and enables a very close temperature approach, ie the temperature difference between the exiting process medium and the entering service medium.

For heat sensitive or viscous media, co-current flow can be used to let the coldest fluid meet the hottest when entering the heat exchanger. This minimizes the risk of the media overheating or freezing.

Plates are available with various pressing depths, angles of chevron pattern and various corrugation shapes, all carefully designed and selected to achieve optimal performance. Depending on the application, each product range has its own specific plate features.

The distribution area ensures fluids are evenly distributed across the entire heat transfer surface and help avoid stagnant zones that may cause fouling.

While high flow turbulence between plates results in higher heat transfer, the consequence is pressure drop. Our thermal design engineers can help you design and select the model and configuration that is suitable for your application so that it delivers maximum thermal performance with minimum pressure drop.

Gasketed Plate Heat Exchangers2019-06-09T14:58:32+00:00

Fusion Bonded

Fusion-bonded plate heat exchangers are made of 100% stainless steel and provide efficient heat transfer with a small footprint. They are maintenance free and provide a long service lifetime. They are suited in applications which put high demand on cleanliness, applications where aggressive medias such as ammonia are used or where copper and nickel contamination is not accepted. Can handle very high temperatures or extremely high pressures.

The 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.

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 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, 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 r90ange of duties. Examples include systems using refrigerants such as ammonia, while its resistance to corrosion also makes AlfaNova popular in district heating installations in which corrosive water is used.

The hygienic heat transfer channels and mechanical strength also make AlfaNova units ideal in applications where the prime focus is on hygiene, such as clean water refrigeration chillers and tap water heating systems.

How It Works -Alfa Nova Heat

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 16 bar. 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.

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Brazed Plate Heat Exchanger

Copper brazed plate heat exchangers provide efficient heat transfer with a small footprint. They are maintenance free, provide a long service lifetime and can withstand high temperatures and extremely high design pressures. They are used in a range of duties including cooling, heating, evaporation and condensing.

Brazed plate heat exchangers are widely used in refrigeration plants. They are normally used to transfer heat from the refrigerant – the primary fluid – and from water or brine as the secondary fluid.

Units in the Alfa Laval AC line of copper-brazed heat exchangers are mainly used as:

  • Evaporators for dry expansion and cooling water
  • Condensers for rejecting or recovering heat to water
  • Economizers for cooling liquid refrigerant and super-heating vapour refrigerant.

They can also be used as:

  • Sub-coolers to cool liquid refrigerants using well water
  • Intermediate heat exchangers in the absorption cycle, to preheat the diluted solution or to pre-cool the concentrated solution.

Alfa Laval AC line of brazed plate heat exchangers provide efficient heat transfer with a small footprint. They are specifically developed to work in air conditioning, refrigeration, chillers and heat pump applications.

Efficient heat transfer with an extremely small footprint, making them ideal for demanding installations where space is at a premium, Alfa Laval brazed plate heat exchangers forming a self-contained unit that can handle both high pressures and high temperatures resulting in significant increases in overall efficiency.

HOW IT WORKS

Brazed plate heat exchangers used for HVAC applications normally use a parallel flow to achieve the most efficient heat transfer. In a single-pass design, all the connections are located on one side of the heat exchanger, making installation very easy.

Alternate Channel Pattern

When used as an evaporator, the channels formed between the corrugated plates and corners are arranged so the two media flow through alternate channels, always in opposite directions (counter-current flow). The two-phase refrigerant (vapour + liquid) enters at the bottom left of the unit. The vapour quality depends on operating conditions in the refrigeration plant.

Dry Expansion

Evaporation of the liquid phase takes place inside the channels. Some degree of superheating is always required – hence the process being called “dry expansion”. The dark blue and light blue arrows show the location of the refrigerant connections. The water (brine) to be cooled flows counter-currently in the opposite channel; the dark and light red arrows show where the water (brine) connections are.

AC Line as Condenser

When used as a condenser, the main components are still the same as for the evaporator. The refrigerant enters at the top left as a hot gas and starts to condense on the surface of the channels. Once fully condensed, it is then subcooled slightly, in a process  called “free condensation”. The dark and light blue arrows show the location of the brine connections. The refrigerant flows counter-currently in the opposite channel and is cooled. The dark and light red arrows show where the refrigerant connections are.

The Alfa Laval CB range of brazed plate heat exchangers feature efficient heat transfer with an extremely small footprint, making them ideal for demanding installations where space is at a premium. The CB range is used in HVAC heating/cooling, refrigeration, process heating/cooling, oil cooling, solar heating and many other applications.

About CB

The thin, corrugated stainless steel plates used in the CB design are brazed together with copper. This forms a self-contained unit that can handle both high pressures and high temperatures. And unlike traditional designs, the brazed plate heat exchanger consists solely of surfaces that actively contribute to heat transfer, resulting in significant increases in overall efficiency.

The CB range of brazed plate heat exchangers has numerous advantages over traditional heat exchangers in both industrial, HVAC and refrigeration installations. The exceptional heat transfer efficiency makes all CB units very compact. As a result, they can tackle large-capacity duties even though there is only limited installation space available.

The brazed construction also does away with gaskets, making CB units ideal in applications where temperatures and/or pressures are high. Examples include district heating and a wide range of heating, cooling and tap water solutions.

Alfa Laval is the world’s leading manufacturer of brazed plate heat exchangers. This means solid experience in designing units that withstand high-pressure and

high-temperature conditions, and in coping effectively with the structural stresses that results from these. Units in the CB range are available in many different sizes and capacities, with varying plate patterns and connections for particular duties and performance specifications. CB units can be configured as single-pass, dual-pass or multi-pass installations, according to project requirements.

All CB brazed heat exchanger units comply with the European Pressure Vessel Safety Directive, and can also be delivered according to other relevant standards and national codes, as required.

How it works

In Copper Brazed (CB) heat exchangers, the surfaces used to provide heat transfer from one medium to the other are thin, corrugated stainless steel plates stacked on top of each other. The two media are sealed within the plate pack by a brazed copper seal around the edge of the plates. This results in a heat exchanger that – unlike traditional designs – consists solely of surfaces which actively contribute to heat transfer, resulting in significant increases in overall efficiency.

The channels formed between the plates and corner ports are arranged so that the media flow through alternate channels – always in a counter-current flow pattern in order to achieve the most efficient heat transfer.

The contact points between the plates are also brazed, helping to withstand the effects of high pressures and high temperatures. Pressure peaks and rapid temperature cause substantial physical stresses within the materials, and Alfa Laval research has focused on the details of these phenomena in order to ensure designs that are extremely resilient and provide a long service life.

Brazed Plate Heat Exchanger2019-06-09T14:03:55+00:00