Process Plants

UHT Benefits – in a historical perspective

‘Continuous in-flow sterilization’, better known as UHT (Ultra-High Temperature), was first sought patented during the 1880s, long before the technology became commercially viable with the arrival of the aseptic filling machines in the late 1950s. The UHT technology can be split into direct and indirect sterilization, depending on the specific method of heating and cooling of the product.

The clear advantage of the continuous in-flow sterilization when compared to the ‘in-container autoclave principle’ is that it offers higher capacity, better control of the process and less investment along with improved capacity vs investment.

The other clear rationale of the technology is that it offers a much shorter holding time, as in comparison to the widely used autoclaves. Where the processing temperature in autoclaves is approx. 120°C, the UHT operates at approx. 140°C, which allows for holding times down to 3-5 seconds. This achieves the same bacterial and spore destruction, however with only a third of the destruction of nutrients, meaning that the products appears fresher and tastes better.

This is due to the energy transfer principles where the direct UHT plant has a near-instant heating with the addition of the steam and also a near instant cooling as the condensate is removed by vacuum following the short and well defined holding time.

The indirect system has a far longer heating and cooling time as the energy is transferred from a medium, normally water, through a thin metal wall into the product.

It is important to mention that the direct UHT plant offers the best product quality whereas the indirect UHT plant consumes roughly only half of the steam and cooling resources.

In the early days of the industrial introduction when filling machines were introduced to cold aseptic filling, it was majorly the direct systems, both injection and infusion, that were used. Also, indirect systems developed over the years from being based on plate heat exchangers to tubular heat exchangers, each and all with their own set of advantages and disadvantages.

During the latter part of the 20th century the UHT technology has been further developed, and the direct and indirect technologies have matured with a better understanding of the pros and cons for each technology. This means that, often, they are also applied in a more discreet fashion based on the product and the end-product requirements.

Overview of the UHT Technologies

Today, UHT technology is the go-to solution for quality long-life liquid products and the list below largely depicts the common ranking of the available technologies when it comes to product quality and the total effects of the heat treatment including mechanical damage from cavitation and exposure to superheated steam.

Direct UHT

  • Infusion technology
  • Injection technology

Indirect UHT

  • Tubular heating technology
  • Plate heating Technology

UHT Process Plants

Our new Infusion UHT technology has proven its worth with very discerning clients, and combined with our novel plant design it represents the latest in infusion technology for best final product quality with an unsurpassed improved environmental profile. See more

Our Injection UHT technology represents the best in injection technology for best product quality and supported by our improved environmental profile it presents the most overall economy available for direct steam injection systems. See more

Our tubular based UHT technology is an economical solution to processing. The DST tubular technology is the base of the design that provides best in class quality output of the products with very low consumption of resources, yet long runtimes with stable product quality. See more

Storage and Distribution Systems

The aseptic tank serves as a buffer tank to avoid having to go into recirculation on the UHT plant and to buffer to cover intermediate CIPs without having to stop the filling machines. Our design is based on standard valves, meaning that there are no special parts or tools for the system. This provides easy or no extra training for the personnel and an overall lower stock of spare parts. See more