Convap Scraped Surface Evaporator

Convap® is a single-wall, two-phase scraped-surface evaporator (SSE) with high efficiency for high-viscosity and high-fouling material. It has been specially designed to effectively concentrate products to extremely high solids levels.


  • Convap can process fluids to essentially zero moisture content.
  • Continuous scraping action and high turbulence ensure impressive heat transfer coefficient when concentrating high solids material.
  • Advanced design allows Convap to handle high viscosity and high fouling materials that exceed the limitations of other evaporation solutions.
  • Vacuum conditions preserve valuable colour, flavour and nutritive product components.
  • Vertical design ensures a small footprint when limited space is available.
Convap® evaporators are used for drying food and other products, and are especially suitable for materials that have been pre-concentrated by other means and have become too viscous to handle. In many cases, Convap® can concentrate up to 99% total solids. Continuous scraping prevents build-up of fouling, securing reliable thermal performance with a high temperature differential. In addition to improving efficiency, this also preserves the quality of heat-sensitive products.

Related products

The scraped-surface evaporator principle

As with Contherm® units, product enters the Convap® in the lower end of the cylinder with the assistance of a pump. The heating or cooling media flows in the annular space between the heat transfer wall and the insulated jacket. Mechanical agitation, provided by revolving blades, creates the convection conditions essential for efficient heat transfer.

The scraping blades continuously remove the thin product film from the precision-finished cylinder wall. The centrifugal action of the Convap rotor, driven by a motor on the upper end of the unit, spins heavier liquid droplets toward the cylinder wall. This action assures continuous re-wetting of the heat transfer surface and prevents product burn-on.

More than you thought possible

For continuous processing of demanding products, the complete Contherm® range provides endless possibilities. In fact, today Alfa Laval is the only supplier on the market who can offer robust heat transfer with both double and single-wall scraped surface heat exchanger solutions.

We understand that no two customers’ needs are identical. That’s why Contherm® heat exchangers are always fully tailored to fit the intended application. The end result is more: more capacity, more efficiency and – most importantly – more profitability. When it comes to your business, who doesn’t want more?

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Contherm products

Viscous products

Viscous products

The complete Contherm® range provides solutions for continuous processing of any type of challenging viscous liquid. Whether dealing with low or medium-viscosity products or those with extremely high viscosities, there is a member of the Contherm® family to fit your needs.

Example applications include: ketchup, mayonnaise, hummus, chocolate spreads, fruit pie fillings, gravies and sauces, whipped/aerated products, peanut butter, pizza sauces, puddings, salad dressings, salsa and taco fillings, sandwich spreads, bread dough, mechanically deboned meat (MDM), gelatine, omelettes, baby food, nougat, skin lotions, shampoos, liquorice, and more.

Heat-sensitive products

Scraped-surface heat exchangers are an ideal solution for heat-sensitive products that tend to cause fouling in other types of heat exchangers. With the most complete range available, Alfa Laval can support customers with any challenging heat-sensitive product need.

Example applications include: liquid and scrambled egg products, meat emulsions, fruit preparations and fruit purées, cream cheeses, whey proteins, and more.

Heat-sensitive products

Crystallizing products

Crystallizing products and applications with phase change challenges

Preserving taste, colour and/or texture is a particular challenge for manufacturers of products that can undergo crystallization. We work with your business to find the optimal Contherm® solution to fit your production.

Example applications include: coffee/tea extracts, icings and frostings, sugar concentrates, margarines, shortening, spreads, gelatine broth, lard, fondant, biscuit creams, solvents, fatty acids, petroleum jelly, beer and wine, and more.

Products with particulate matter

Contherm® solutions are always built to the specifications of the target duty. Whether you are processing products with large, small or mixed particles, or switching between non-particulate and particulate products, your Contherm® can be adapted to meet the demands.

Example applications include: meat, chicken pieces, fish meal, pet food, jams and preserves, yoghurt with fruits, a variety of fruit preparations, rice pudding, vegetable pieces, and more.

Products with particulate matter

Sticky products

Sticky products

Many heat exchangers encounter limits when handling process fluids that are sticky. For Contherm®, however, it’s never a problem. The complete Contherm® family can support a full range of mildly to extremely sticky products, from foods to beauty products and more.

Example applications include: caramel, cheese sauces, lecithin, processed cheese, confectionery, yeast extracts, gums, gelatine, mascara, toothpaste, starch, and more.

Contherm Dark Heat Transfer

Contherm®:More than you thought possible

Increased capacity, efficiency and profitability