JBT trials coil heat exchanger on apple puree

As well as the University of Parma, JBT works with F&B processors to improve the quality and shelf life of ambient shelf-stable products for metal, glass and plastic containers. 

Stork food & dairy systems

Speaking at Cibus Tec 2016 (October 25-28) Antonio Aldini, R&D manager, JBT, said the company has been present with a factory in Parma since 1962. 

Last year JBT acquired Stork food & dairy systems​, which is known for its sterilization of filling technology and sterilizing milk, with its coil system, he said.  

“We decided to challenge this coil heat exchanger, which we know works well in milk to see what happens if we use it with fruit and vegetables​. 

“JBT has pilot industrial plants at our factories in Parma and Amsterdam, so we decided to go to Amsterdam with Stork to trial apple puree and tomato sauces where we carried out tests, checking the quality of the product after sterilization to see how the heat exchanger performed with this product​.” 

Aldini added, historically JBT sterilizes concentrate puree with a system called ‘4 tubes’ technology, which sterilizes viscous products like tomato sauces, apple puree and concentrate mango puree. 

“Coil is different and its what Stork uses for milk, it has a round shape for milk and juices not puree, which it has different configurations​,” he said.

Hygienic design

He said the advantages of using a coil heat exchanger are; using an ‘endless coil’, curved and uninterrupted; no risk of contamination; using a single pipe that’s very long; hygienic design; easy to clean, and there is no way fibers can get stuck in the pipe, and not having to worry about seal replacement. 

“Because of the tube shape we got the ‘Dean effect’ an extra tube effect with improved heat transfer, better product quality at equal sterility because of a more homogeneous treatment, short and more compact sterilizers​,” added Aldini. 

“We can develop a more compact system developed in height. Our research was dedicated to viscous products and verified at our Amsterdam pilot plant, now we want to see if it is exportable to medium viscous products​.”

The 'Dean effect' is when a product enters a coiled path and centrifugal forces act upon it and velocity differences in the tube cross-section cause the centrifugal forces to vary.

The set up of the pilot included connecting the device to a feed tank, then mono pump, piston pump, where the liquid is heated and cooled with coils before filling. 

Test conditions saw the raw product heated at 30°C and 110°C using two heaters - one with over heated water and the second with steam. 

The results for the apple puree saw no difference in the visual appearance of the product; tests at 530 l/h flow rate (190 seconds holding time); Delta E general change in color 0.98 and little change in viscosity, which has no impact on product quality – overall the pilot tests proved a success.