GEA evaporation technologies for optimal production of milk powder

GEA is a world leader in providing evaporation systems for a variety of milk powder applications. With decades of experience, we understand that the right choice of evaporation and heat treatment technology is critical to achieve optimum product quality and retain the required functional and physical properties, whether your finished product is a milk powder, a pre-concentrate, or sweetened/condensed milk.

Direct contact heating

It is well known that even short residence times at temperatures above 70°C have a major impact on product properties. And, as the use of indirect heaters often involves uncontrolled residence times, GEA’s direct contact systems supply heat instantly by condensing steam directly in the product. 

The heating can take place with or without regenerative steps, depending on the energy costs and/or required heating process, and our systems can be designed to meet the exact time and temperature combination requirements of the product. 

Direct contact heating is the worldwide standard within the dairy industry and offers the following benefits:

  • low concentrate viscosity
  • improved quality of instant whole milk powders
  • low heat powders, resulting in better bacteriological properties
  • tailor-made WPNI values for medium heat powders
  • improved heat stability of high heat, heat-stable powders

Choosing the right evaporation technology

All GEA evaporator systems provide pre-heating and heat treatment to control the microbiological product quality, and are designed to reduce energy consumption. 

 The low residence time in the evaporator, often as short as 10–12 minutes, provides advantages, including:

  • minimum heat load on product
  • short start-up and shut-down times
  • low product losses
  • reduced cleaning time and costs 

MVR (mechanical vapor recompression) evaporation

GEA offers its MVR evaporation system as a solution for dairy applications when the availability of steam is restricted or expensive. The MVR system uses fans to compress the vapor generated during evaporation to a higher temperature and then recycle it to a condenser or finisher. The MVR system can also be fitted with a wraparound separator, which considerably reduces the space required, but still achieves the high efficiency of a traditional tangential separator. 

Further benefits of an MVR evaporator include:

  • low energy consumption (both heating and cooling)
  • electrically supplied recompression power (reduced steam requirement)
  • ease of operation

TVR (thermal vapor recompression) evaporation

With GEA’s multiple TVR evaporators, the evaporative energy in the first unit is derived from a steam injector that compresses vapor from one of the associated units to a higher temperature. The heating medium in any subsequent unit is the vapor generated in the previous one. Vapor from the final TVR is condensed by heating the incoming product. The hot condensate can be reused for boiler and/or clean-in-place (CIP) water.