Brochure Evaporators Condensers in a New Dimension PPI00018EN

Evaporators and condensers in a new dimension

AlfaVap and AlfaCond

Compared to conventional shell-and-tube evaporatorsand condensers, AlfaVap and AlfaCond work magicon your wallet. They not only require less floor area,thus saving expensive space, but also substantiallyreduce investment costs, and minimize maintenance –without sacrificing reliability or safety.

Optimize your performance

4 AlfaVap and AlfaCond

Why use AlfaVap and AlfaCond?

Save moneyThe unique designs of AlfaVap andAlfaCond provide substantially higherthermal efficiency than conventionalshell-and-tube units, which meansmuch less heat transfer area is needed.This makes AlfaVap and AlfaCondextremely economical, especially whenexotic materials such as SMO,titanium, nickel and Hastelloy arerequired.

Save space The compact, versatile design ofAlfaVap and AlfaCond means thattransportation, erection and installationcosts are all drastically reducedcompared to conventional shell-and-tube units.

Easy maintenanceThe plate construction of AlfaVap andAlfaCond means that the heat transfersurfaces are easily accessible forinspection or mechanical cleaning,simply by removing the tightening boltsand rolling back the pressure plate.The special corrugated patterns ensurea high degree of turbulence over thewhole plate. This turbulence not onlyreduces fouling but also makeschemical cleaning very effective. Inaddition, due to the low hold-up

volume of both AlfaVap and AlfaCond,only very small amounts of cleaningchemicals are needed compared toshell-and-tube installations.

Easy to increase capacityAlfaVap and AlfaCond make it easy toadjust capacity to meet changingneeds, simply by adding or removingplates, while retaining the existingframe. This is a major advantage inrelation to shell-and-tube units, wherecapacity is fixed at the level decided onat the time of installation.

Comparison between shell-and-tube and AlfaVap for a three-effect system that evaporates NaOH from 32 to 50%.The savings in installation costs and space are clearly apparent from the layouts shown above.

16 m (52’)

8 m (26’)

AlfaVap and AlfaCond 5

Vapour

Condensate

Cooling water

How it worksAlfaCond is tailored for vacuumcondensation. The vapour inletconnection is very large whereas thetwo condensate outlets are small. Thecooling water connections aremedium-sized and located in thecentre of the plate.

AlfaCond consists of a plate pack withplates welded together in pairs formingso-called cassettes. The cassetteconcept gives rise to two different typeof channels – welded channels usedfor the condensing vapour and gas-keted channels used for the coolingwater.

The plate pattern is specifically de-signed for optimal condensation, withan asymmetric configuration thatfeatures a large gap on the vapour sideand a small gap on the cooling waterside. This makes it possible to maintain

a very low pressure drop on the vapourside while keeping up the velocity andturbulence on the water side. Thismaximizes the heat transfer efficiencyand minimizes fouling.

Why use AlfaCond?● Lower costs because the high heat

transfer efficiency means that much less heat transfer area is needed compared to a conventional shell-and-tube. This makes AlfaCond more cost effective, especially if stainless steel or titanium is required.The compactness of the design also saves space, which reduces trans-port, erection and installation costs.

● Less fouling on the cooling water side compared to shell-and-tube condensers, due to the high turbulence created by the special design of the corrugated plates.

● Easy cleaning of the cooling water side using either mechanical or chemical means.

● Easy to increase capacity by just adding extra cassettes in the existingframe.

● Fully counter-current flow, which makes it possible to sub-cool the non-condensable gases better than in a comparable shell-and-tube in-stallation. This reduces the load on the vacuum pump.

AlfaCondAlfaCond is the world’s first tailor-made plate condenser. It was developed specifically for condensing vapours under lowpressure/vacuum conditions in evaporation and distillation systems. A whole range of AlfaCond condensers is available to suitspecific applications and capacity requirements.

AlfaVap

High heat transfer efficiencyThe special corrugated plate patterninduces a high degree of turbulence,providing substantially better heattransfer coefficients than conventionalshell-and-tube evaporators. AlfaVap isespecially efficient at high concentrationand high viscosities, and can work withtemperature differences down to3–4°C. This is a big advantage whenAlfaVap is used in TVR and MVRsystems.

Cost savingHigh heat transfer efficiency means thatmuch less heat transfer area is neededcompared to shell-and-tubeevaporators. This makes AlfaVapextremely economical, especially whenexotic materials such as SMO,titanium, nickel and Hastelloy arerequired. In addition, the compact andflexible design of AlfaVap drasticallyreduces transport, erection andinstallation costs compared to shell-and-tube units.


The AlfaVap plate evaporator is the result of development work done in collabor-ation with beet sugar manufacturers in the late 1980s. This new type of cost-effective rising film evaporator rapidly became a success in the beet sugar industryand has subsequently spread to many other applications.

There are currently more than 1500 AlfaVap evaporators installed in differentapplications all over the world, and Alfa Laval provides a complete range ofAlfaVap evaporators for a wide selection of applications and capacities.

How it worksAlfaVap is tailor-made for evaporation,with two small inlet feed connectionsand a large outlet for the vapour andconcentrate. There is one large inletconnection for the heating steam, andtwo small outlets for the condensate.

AlfaVap uses the cassette concept withthe plates welded in pairs. The heatingsteam is condensed in the weldedchannels while the evaporated productpasses through the gasketed channels.

Why use AlfaVap?


Less fouling and easy maintenanceThe high turbulence over the wholeplate does not just reduce fouling butalso makes chemical cleaning veryeffective. Due to the low hold-upvolume, only very small quantities ofcleaning chemicals are neededcompared to shell-and-tubes. Theflexible design of the AlfaVap meansthe heat transfer surfaces are easilyaccessible for inspection or mechanicalcleaning by simply removing the tight-ening bolts and rolling back thepressure plate.

Easy to increase capacityA popular feature of AlfaVap is that thecapacity can be increased or reducedby just adding or removing cassettes inthe existing frame. This is a majoradvantage in relation to shell-and-tubeevaporators, where capacity is fixed atthe level decided on at the time ofinstallation.

Improved product qualityThe extremely low hold-up volumemeans that very little product is actuallyin the AlfaVap at any given time. Theshort time the product spends in theevaporator is a big advantage for heatsensitive products. It also permits rapidstart-up and shut down, with onlyminimal waste.

Once throughDue to the rising film concept and thehigh turbulence, AlfaVap providesexcellent wetting ability, which meansthat a once-through evaporationprocess can often be used. In a co-current system, this means no pumpsare needed between the effects. In acounter-current system, it means thatrecirculation pumps are not necessary– only transportation pumps areneeded. The once-through mode alsogives extremely low residence time.

ThermosiphonIn the thermosiphon mode, naturalcirculation is used, rendering recircul-ation pumps unnecessary. This modeis used when the outlet vapour fractionis too high for a once-through evap-oration process. The thermosiphonmode is also used for AlfaVap whenused as a reboiler in distillationsystems.

Forced circulation with boilingThis mode is used when the evap-orated product has a tendency to foul.The forced circulation increases thewetting and turbulence and thusminimizes any fouling tendency.

Forced circulation with flashingThis mode is used when theevaporated product could causeconsiderable fouling or whencrystallization takes place during theevaporation process. The evaporatedliquid is recirculated so rapidly thatboiling cannot take place in theevaporator, and the liquid is thus justheated. The actual evaporation thentakes place when the liquid flashes intothe separator vessel. A special type ofAlfaVap with a wider gap is used forthis mode, to minimize the fouling.

AlfaVap working modes

Corporate Brochure 10

A three-effect system that evaporatesNaOH from 32 to 50% at Akzo Nobelin Sweden. The system was built bythe contractor Chematur Ecoplanning,using AlfaVap and AlfaCond. The needfor exotic materials such as nickelmakes the AlfaVap exceptionally eco-nomical in this application.

AlfaVap and AlfaCond in Multi EffectEvaporation (MEE) systems


E1 E2 E3 E4

AlfaVap and AlfaCond used in a two-effect system that evaporatesfructose from 55 to 75 Brix at Sensus in the Netherlands. The shortresidence time in the AlfaVap makes it the perfect evaporator for theheat-sensitive fructose.

Steam

Feed Concentrate


AlfaVaps used in a two-effect TVRsystem in a sugar refinery in Malaysia.An existing parallel falling film shell-and-tube system can only deliver fine syrupto a concentration of 71 Brix. TheAlfaVap system concentrates all theway to 75 Brix without recirculation,achieving a very short processing time.This results in a better product quality,and provides simpler and faster start-up and shut-down procedures.

A four-effect TVR system built by Tetra Pak, using AlfaVap evaporators.The system evaporates apple juicefrom 10 to 72%. The compactness ofthe AlfaVap makes it possible to installthe whole system on one floor, reduc-ing the installation cost substantiallycompared to a conventional shell-and-tube system.

AlfaVap and AlfaCond in ThermalVapour Recompression (TVR) systems

E1 E2

Steam

Feed Concentrate


AlfaVap in Mechanical VapourRecompression (MVR) systems

An MVR system used for evaporating salty waste water at Newalta Corporation in Canada. By evaporating the salty wastewater, Newalta limits waste disposal and generates fresh distilled water that can be reused in the plant. Aqua Pure, aCanadian contractor, built this unique patented MVR system, which provides improved thermal efficiency and reduced foulingcompared to a conventional shell-and-tube solution. Aqua Pure selected AlfaVap for its unique ability to handle two-phaseflow, its reduced footprint and its ease of service and maintenance.

AlfaVap used in an MVR systemevaporating stillage at a fuel ethanolplant.

E1

Feed Concentrate


AlfaVap is ideal as a booster to increase capacity in an existing evaporationsystem, where there is seldom enough space to install an extra shell-and-tubeunit. Because of its compactness, an AlfaVap booster provides a practical anda very economical alternative. It can utilize the existing control system anddemisters and only requires a minimum of pipework. The cost of installing anAlfaVap booster is therefore often only a fraction of what it would cost to installa new extra shell-and-tube evaporator.

AlfaVap boosts capacity in existing plant

AlfaVap replaces shell-and-tube in existing plantThe calcium chloride plant at KemiraAB in Sweden had to replace one of itsexisting large shell-and-tube evapor-ators due to corrosion. To replace thisunit, Kemira chose an AlfaVap evapor-ator made of titanium Pd. The AlfaVapwent into operation in 1997 and hasbeen working around the clock eversince, with very little downtime.Chemical cleaning is carried out once ayear by circulating a weak hydrochloricacid.

AlfaVap used for calcium chlorideevaporation at Kemira AB in Sweden.

AlfaVap as booster to Robert evaporator

12 m(40’)

4 m(13’)

2.5 m(8’)

Concentrate

Feed

Steam

Size comparison – AlfaVap versus replaced shell-and-tube

Two AlfaVaps installed as boosters to the second and third effect in abeet sugar factory.

AlfaVap and AlfaCond as reboiler andcondenser in distillation systems


Ethanol condenser at The AbsolutCompany in Sweden. All the columnsat The Absolut Company’s Åhusdistillery use Alfa Laval reboilers andcondensers. The Alfa Laval units werechosen because of their compactnesscompared to corresponding shell-and-tube solutions.

AlfaVap thermosiphon reboiler atCarboneco in Spain. The AlfaVap isused to boil 30% MEA at the bottom ofthe stripping column. The absorption-stripping system at Carboneco is usedto recover carbon dioxide from a co-generation plant. The system was builtby the Danish contractor UnionEngineering.

Dis

tilla

tion

colu

mn

Condenser

Reboiler


Nonstop PerformanceExamples of installed applications

There are more than 1500 AlfaVap and/or AlfaCond installations in different applications all over the world. Alfa Laval canprovide a complete range of AlfaVap and AlfaCond units for a large range of applications and capacities. Some of theapplications where AlfaVap and/or AlfaCond units are installed include:

Alumina liquor

Ammonium lactate

Ammonium nitrate

Beet sugar

Calcium chloride

Cane sugar

Copper electrolyte

Corn steep liquor

Dextrose

Effluent streams

Electrolytes

Ethanol reboilers

Ethylene glycol

Ferric chloride

Fish and meat extract

Fish and meat stick water

Fish silage

Fructose

Fruit juice

Gelatine

Gluconic acid

Glucose

Glycerine

Hydrolysate

Kaolin

Lactic acid

Lysine

Maltodextrine

Maltose

MEA reboilers

Polyols

Soap

Sodium chloride

Sodium hydroxide

Sodium sulphate

Sorbitol

Stillage

Waste waters

Vinasses

AlfaVap and AlfaCond used in a two-effect evaporation system installed in the fishmeal plant Conresa in Spain. The AlfaVapsystem concentrates stick water from 12% up to 40%. “We needed an evaporation system that fitted into our existingbuilding,” says Mr Cobas, Managing Director. ”With the unique compactness of the AlfaVap system, this became a naturalchoice. A conventional falling film shell-and-tube system would have required a whole new building.”

Nonstop PerformanceA lifetime commitment

For us at Alfa Laval, our obligation toyou as a customer does not stopshort at delivery. Our Parts & Serviceorganization is there to ensure thatyour process always runs at peakperformance. This is a commitmentthat extends throughout the lifetimeof the system. We call it NonstopPerformance.

Nonstop Performance is based on ourglobal network of experts, who arealways on standby to provide you withgenuine spare parts on site, in morethan 50 countries, 365 days a year,right around the clock.

In terms of service, we speak yourlanguage. Alfa Laval service is basedon a profound insight into the needsof the process industry. We see everyproduct as part of a process andunderstand the role it plays withinthat process. We can therefore workin close collaboration with you to tailoran individual service package thatmatches your requirements perfectly.

Service must result in bottom-linebenefits. We therefore help you tocalculate the savings that will resultfrom any proposed service package,and the real-term benefits it willprovide.

Challenge us to show you!


Alfa Laval in briefAlfa Laval is a leading global providerof specialized products andengineering solutions.

Our equipment, systems andservices are dedicated to helpingcustomers to optimize the perform-ance of their processes. Time andtime again.

We help our customers to heat,cool, separate and transport prod-ucts such as oil, water, chemicals,beverages, foodstuffs, starch and pharmaceuticals.

Our worldwide organization worksclosely with customers in almost 100countries to help them stay ahead.

How to contact Alfa LavalContact details for all countries arecontinually updated on our website.Please visit www.alfalaval.com toaccess the information.

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Brochure Evaporators Condensers in a New Dimension PPI00018EN