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Heat exchangers

Series and customer-specific heat exchangers for every application

LE / LK

HFC | CO2 |  Water | Brine

  • High-quality heat exchangers made in Germany
  • High-performance heat exchangers with maximum power per m²
  • Thermodynamic design with our own design software
  • 100% custom-made with a guaranteed quick delivery time 
  • Individual heat exchanger construction even for a batch size of 1

 

ANFRAGEN                  KALKULIEREN

Customised heat exchangers for your system specific requirements

 

Together with you, we develop customised heat exchangers for your cooling requirements. Either as standard or as a system solution for specific applications.
Regardless of whether it is a question of requirements for refrigerants, energy efficiency, corrosion protection, material combinations, different fin spacings or optimised tube and fin geometries, Roller offers the optimum solution for every performance range and every application in refrigeration technology with its wide range of heat exchangers.
Even under extreme climatic conditions, our heat exchangers prove their performance and reliability every day.

 

Types of heat exchanger

These design types are available to you

Evaporators

can be used in a wide range of cooling and air conditioning scenarios with almost all refrigerants

Condensers

are used wherever heat is to be dissipated into the ambient air using coolants

Air heaters

in various forms are used for heating or ventilation and use either warm water or brine (PWW) 

Air coolers

are frequently used in air conditioning and air dehumidification and use pumped cold water or brine as the circuit medium

Closed-loop recycling system:

Matching supply and exhaust air heat exchangers which can recover up to 80% of the heat

Multi-circuit heat exchangers

are designed so that the circuits are arranged in intermeshing or parallel form in a heat exchanger coil. They are very popular where space is limited or as a redundancy solution

Specially designed heat exchangers

or customer-specific applications (e.g. three-sided, four-sided, round/cylindrical)

Features

All product advantages at a glance

General

  • Capacity range: from the smallest power outputs for electronic switch cabinets under 100 W to industrial heat exchangers over 1 MW
  • Temperature range: -198°C – +150 °C 
  • Heat exchanger coil for an operating pressure of 16 bar / 80 bar with high-pressure refrigerants (CO2/ R744)
  • Core tubes in copper CuDHP with thick walls in Ø 9.5, 10, 12 and 15 mm thicknesses
  • Possible fin spacings: 2.0 / 2.5 / 3 / 4 / 4.5 / 6 / 7 / 8 / 10 / 12 mm (others on request)
  • Core tube with smooth or grooved inner surfaces

 

Connections

  • Distribution outlet header made of copper
  • Coolant distributor made of brass
  • Brazed hexagon nipples, threaded nipples or flange depending on the operating mode (others on request)
  • Ventilation connections
  • Drain connections
  • Special connections on request

Quality and pressure checks

  • Use of high-quality copper tubing primarily from German manufacturers
  • Return bends made from high-quality copper tubing from German manufacturers with a wall thickness of 0.6 – 1.5 mm 
  • Production in accordance with the Pressure Equipment Directive 2014/68/EU
  • Pressure checks on units with water/brine: 18 bar overpressure
  • Pressure checks on units with coolant: 27.5 bar overpressure
  • Pressure checks on units with high-pressure refrigerants: < 27.5 – 115 bar overpressure
  • All units are subject to an exacting outgoing quality check
  • Special checks when flammable coolants are used

 

Inspection and cleaning

  • Smooth fin surfaces prevent soiling and make cleaning easier
  • Thick fans for extra stability during cleaning
  • Robust construction for torsion-free installation 
  • Protective filling (dried air) for heat exchangers using coolants

 

Types of corrosion protection

The heat exchangers can be equipped in a variety of corrosion protection types

Corrosion-resistant aluminium (AlFe1,5Mn)

fins are standard at Roller and can be used for long periods in slightly aggressive ambient air

AlMg3 fins

are highly suitable for use in slightly alkaline atmospheres in industrial applications

Copper fins

offer greater protection against specific environmental conditions, e.g. close to the sea or in construction materials processing

Hydrophilic fins

This coating offers good protection in damp atmospheres (e.g. sprayed heat exchangers) and helps with condensation drainage

Gold lacquer fins (epoxy)

have a vinyl-based epoxy resin coating. They offer increased protection against slightly aggressive substances such as cleaning products, vinegar etc. and make cleaning easier

2-component lacquer

 with an even coating over the entire fin offers excellent protection against aggressive atmospheres

Tin-coated copper tubing

has an additional layer of tin and offers extra protection against corrosion of the copper core tube

Further corrosion protection options

  • Powder coating with an even coating over the entire fin offers excellent protection against aggressive atmospheres  
  • Frame, cover, end and base plates made from aluminium, stainless steel and copper 
  • Frame parts can be coated with 2-component lacquer 

Available accessories

Available accessories

  • Drain / ventilation connection
  • Threaded flat seals
  • Welding neck flange
  • Loose flange in stainless steel
  • Victaulic quick couplings
  • Electric coil defrost heating
  • Stainless steel frame for unit installation
  • Numerous sub-circuits possible
  • Specially designed frame
  • Other special designs on request

References

Drying - LE/LK - Mälzerei/Malthouse

The drying of food requires a great deal of know-how. The same applies to the heat exchanger systems when it comes to the choice of materials, the construction and tube geometry to ensure the optimum transfer of heat. For the expansion and modernization of two new kilns at a large malthouse in Bremen/Germany, Roller supplied 12 heat exchangers (6 per kiln), each with a power output of approx. 1700 kW.  Total output: 20 MW.

ApplicationMalthouse
AddressBremen / Germany
FluidWater
ProductLE - Heat exchanger

Confectionery cooling - LK - Fritsch

In the production of chocolate Easter bunnies and Santa Clauses, it is important to precisely maintain specified process temperatures. For a chocolate producer from Rhineland-Palatinate, an existing heat exchanger for a cooling tunnel was replicated 1:1 and replaced. The required cooling capacity of 77kW with limited space situation of 1.7 sqm inflow surface led to this cubic direct evaporator with 20 (!!!) pipe rows in depth. With a 50x50 aligned pipe system, the pressure loss is kept as low as possible at a volume flow of 13,000m²/h.

Fail-safety is ensured by the split in two interlocked R407C refrigeration circuits, which operate redundantly to each other. Together with installer company Fritsch, the measurements for this replacement were taken at the end customer's location in order to meet the details of this exceptional requirement right from the start.

ApplicationConfectionery cooling
AddressRhineland-Palatinate / Germany
FluidR407C
ProductLK

Cryogenic test chamber - LE/LK - F. Zaugg

In order to guarantee the quality and resistance of materials, tests under extreme conditions are necessary. To maintain a room temperature of -60°C in this cryogenic test chamber, the system builder, F. Zaugg AG Kälte und Klima, used a special two-stage Roller direct evaporator coil for cascade operation. The test chamber is first cooled to -20°C with R449a via the first circuit. When this temperature has been reached, the second circuit with the cryogenic refrigerant R23 is switched on and the first circuit now cools the cascade condenser for the cryogenic circuit. In order to reliably generate the evaporation temperature of -66°C in the second circuit, the requirements regarding the nature of the evaporator coil as well as the thermodynamic requirements are very specific. In close cooperation with the customer, an optimally suitable solution was also found for this project.

ApplicationEnvironmental simulation
AddressSwiss / Thun
FluidR449a / R23
ProductLE / LK

Blast freezing - LK - Advansor

At this meat processing company, the pre-cooled meat is blast frozen by reducing its temperature to below -18 °C in a very short time. High cooling power and a large air quantity with high external pressure play a key role during blast freezing. For this system operated with CO2, the engineers opted for LE/LK heat exchangers from Roller given the company's wealth of experience in designing and building such products.

ApplicationBlast freezing
AddressGRAO / Spain
FluidCO2
ProductLK - Heat exchanger

Snow Paradise - LK - Klafs

One of the most fascinating cooling experiences can be enjoyed by discerning sauna guests all over the world in so called snow paradies: These winter landscapes are formed with rocks and crevasses and offer a room temperature of -10°C for cooling off after a sauna session.

A step into the winter landscape does not only help to cool off the body, but also to quickly regain the normal oxygen level of the lungs. Roller heat exchangers are also used here to produce the finest powder snow, which can be used to rub off the skin and thus contribute to quite an intense experience.

ApplicationWellness
AddressSchwäbisch Hall / Germany
FluidHFC
ProductLK

Apple storage - LK - Chile

Fans and consumers of Chilean apples can breathe a sigh of relief. Industrial evaporators were produced for a major customer from South America, which contribute to the preservation of the apple harvest, so that consumers worldwide can also enjoy the fruit outside of there own apple season. These direct evaporator coils provide a very high capacity during the cool-down phase of fruit storage, and later operate at reduced capacity in partial-load mode during long-term cooling in order to dissipate the transmission heat through the walls, as well as the respiration heat of the refrigerated goods. The customer's know-how consists on the one hand in designing an efficient solution for these fluctuating loads and on the other hand in creating an atmosphere so that the fruit does not become wrinkled and soft through dehumidification, but remains crisp and fresh.

ApplicationFruit-vegetable cooling - LK - Chile
AddressChile
FluidHFC
ProductLK

Product documentation

Technical data

All important technical data

Tube system identification   2/6 3/7 4/8 5/9 10/11
Tube system   Offset Aligned Offset Aligned Aligned
    25 x 21,65 mm 35 x 35 mm 40 x 35 mm 50 x 50 mm 35 x 35 mm
Tube profile   Smooth or internally grooved Smooth or internally grooved Smooth or internally grooved Smooth or internally grooved Smooth or internally grooved
Tube rows   2 - 12 1 - 20 1 - 20 (up to 12 from one piece) 1 - 20 1 - 20
Tube diameter   10 mm 12 mm 15 mm 15 mm 9,5 mm
Tube wall thickness   0,4 mm 0,4 or 0,6 mm 0,4 or 1,0 mm 0,4 or 1,0 mm 0,35 or 0,7 mm
Fin thickness Aluminium 0,2 - 0,25 mm 0,2 - 0,3 mm 0,2 - 0,3 mm 0,2 - 0,3 mm 0,2 - 0,3 mm
  Alu with gold lacquer 0,2 mm 0,2 mm 0,2 mm 0,2 mm 0,2 mm
  Alu with hydrophilic coating 0,2 mm 0,2 mm 0,2 mm 0,2 mm 0,2 mm
  AlMg3 - 0,2 mm 0,2 mm 0,2 mm -
  Copper 0,2 mm 0,2 mm 0,15 - 0,2 mm 0,2 mm 0,2 mm
Fin spacing   2/2,5/3/4/4,5 mm 2/2,5/3/4/4,5/6/7 mm 2/2,5/3/4/4,5/5/7 mm 4/4,5/6/7/8/10 mm *** 2/2,5/3/4/4,5/6/7/10 mm***
Finned length   80 - 3.200 mm 200 - 4.100 mm* 200 - 4.100 mm* 200 - 4.100 mm* 80 - 3.200 mm
Finned height   75 - 1.900 mm 105 - 2.400 mm** 120 - 2.400 mm** 100 - 2.400 mm** 105 - 2.400 mm**
Finned depth   44 - 260 mm 35 - 700 mm 37 - 700 mm 50 - 1000 mm 35 - 700 mm
Temperature range   -198 °C to 150°C -198 °C to 150°C -198 °C to 150°C -198 °C to 150°C -198 °C to 150°C
    * up to 8.000 mm ** up to 2.700 mm *** 12 mm on request    

How can we help you?

We consult you competently and comprehensively!

Make a concrete enquiry now!


ralph.heller@walterroller.de
Tel.: +49 (0) 7156 / 2001-50

 

sven.koethe@walterroller.de
Tel.: +49 (0) 7156 / 2001-32