All Niro systems provide pre-heating and heat treatment to kill bacteria, reduce energy consumption and ensure that the correct functional properties are achieved in the feed concentrate.

The low residence time, often down to as low as 6-10 minutes, provides the following benefits:

  • Minimum heat load on product
  • Short start-up and shut-down times
  • Low product losses
  • Reduced cleaning time and costs

MVR Evaporation (Mechanical Vapour Recompression)
For applications where the availability of steam is restricted or expensive, the MVR system is recommended. This system uses high-pressure fans to compress the vapour generated by the evaporation to a higher temperature and return it to the same effect. Excess vapour from this effect is either lead to a condenser or utilized in a finisher.

The MVR evaporator can also be fitted with the wrap-around separator that considerably reduces space requirements while matching or even improving the high efficiency of the traditional tangential separator.


The advantages of the MVR evaporator are:

  • Low energy consumption. This applies to both heating and cooling requirements as the plant produces cold condensate suitable for cooling purposes.
  • Recompression power supplied electrically thus reducing steam requirement .
  • Ease of operation. The fan allows for full and rapid control of evaporation within the entire range of the plant without reconfiguration of the plant.

TVR Evaporation (Thermal Vapour Recompression)
In multiple effect TVR evaporators the evaporative energy in the first effect is supplied from a steam injector that compresses vapour from one of the associated effects to a higher temperature.

The heating medium in any subsequent effect is the vapour generated in the previous effect. Vapour from the final effect is condensed by heating the incoming product and in the condenser. The hot condensate can be reused for boiler water and/or CIP liquid.

The choice between MVR and TVR depends on the local prices of different energy sources, the possibility of using the condensate, the depreciation of the capital cost (including capital cost of the building), and the cost of product losses during cleaning.

Direct Contact Heating
In the early 1980s it was proved that even minimum residence time above 70°C had major impact on product properties. Heating in indirect heaters proved to have too long and uncontrolled residence time for many applications.

Niro's new direct contact heating systems however heat the product 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 the required heating duty and can be designed to give exactly the time/temperature combination required by the product.

Today Direct Contact Heating is the worldwide standard within the dairy industry.

Some of the benefits of Direct Contact Heating systems are:

  • Low viscosity of concentrate, resulting in better SI of the powders
  • Improved quality of instant whole milk powders
  • Improved coffee stability test
  • Low heat powders, applying highest heat treatment temperatures, resulting in better bacteriological properties
  • Tailor making the WPNI of medium heat powders
  • Improved heat stability of high heat, heat stable powders