How to make better soup – with mathematics

Heat transfer Prepared food

How to make better soup – with mathematics

Making a good soup is an art, but it is also a science. Tetra Pak has developed new mathematical models and tools for building tubular heat exchangers that will deliver the target temperature for particulate foods such as soups with a precision not previously possible.

A common practice for designers of heat exchangers is to use the same traditional calculation tools for food with particles as for food without. The problem is that the presence of particles changes the flow and heat dynamics significantly in a heat exchanger. New research by Tetra Pak has investigated exactly how particles affect heat transfer.

The research shows that some conventional formulas can result in deviations by as much as 12°C between the calculated outlet temperature and the actual measured temperature of particulate food leaving a heat exchanger. To avoid this, the heat exchanger is typically over-dimensioned.

On the other hand, if the actual temperature is much higher than expected, the particulate food can be partially destroyed with loss of flavour and colour. In terms of investment costs, the heat exchanger may be over-dimensioned for its purpose, and this is a waste of money and space.

The research, which was carried out over more than two years at Tetra Pak’s Product Development Centre in Lund, Sweden, involved a group of about ten experts, including an external professor and research associates specializing in heat transfer at the University of Lund. Different kinds of particulate foods were tested, such as mango preparations, soup concentrates, chutneys and carrot slurries.

The findings clearly showed how the heat transfer coefficient varies in the presence of particles. As expected, the particles actually improve mixing in the tubes and therefore increase the overall heat transfer coefficient of the liquid phase.

A tool for optimizing process design

The influence of particles has now been quantified, and Tetra Pak has been able to devise a new heat-transfer coefficient formula for particles, and a new calculation tool for particulate food. The new tool is called PartCalc and has been validated by experimental data. It is now being used to help customers optimize their process design for particulate foods.

Tetra Pak’s experiments show that the carrier liquid temperature of a variety of particulate foods leaving a heat exchanger, as calculated by PartCalc, deviates by less than 3°C on average from the actual temperature. This is a considerable improvement on traditional calculations, and gives a good correlation with actual temperatures, thus allowing Tetra Pak to more accurately dimension heat exchanger systems for particulate foods.

The potential benefits to the food processing industry include:

» Improved food quality with assured food safety
» Reduced operating and maintenance costs
» Reduced product losses
» Reduced environmental footprint

“A key factor in process design is to minimize heating without compromising food safety. This demands knowledge about heat transfer in particulate foods,” says Helena Arph, Technology Specialist, Viscous and Particulate Foods at Tetra Pak in Lund, Sweden. She has been closely involved in the research work and presented papers on the findings.

Having trouble watching this video? Watch it here.

Eliminate the guesswork

“The heat transfer coefficient expressing how efficiently the heat is transferred from the wall to the liquid has been known, but the heat transfer coefficient between the liquid and the particle has not been known,” she adds. “People have been making educated guesses about this, or else we have been forced to do individual trials with every particulate product to work out these calculations. But with the research work we have done recently and presented in the white paper, we now have models for how that heat-transfer coefficient changes, depending on the particle size, particle concentration and the viscosity of the liquid.”


Get the inside story here.

Download our white paper, The inside story on heat treatment of particulate foods, January 2016, which contains Tetra Pak’s new findings and more about Tetra Pak’s new formula for calculating the heat transfer coefficient.


Related reading:

Separators and sustainability: how the right equipment can reduce the dairy industry’s climate impact
The science of separation
A brief history of separation
Separate wheys: the role of separators in today’s consumer trends
Why cold milk separation is hot again
Watch Your Speed – Tetra Pak® Homogenizer 250
It’s not you, it’s me – Tetra Pak® Homogenizer 250
4 things to look for in a homogenizer
Devils and details – the technologies you need for great spreadable cheese
Spreading knowledge: everything you need to know about mayonnaise production
How to control the cost of mayonnaise and cold emulsion production
The great mayonnaise controversy
3 global food trends and the challenges they pose for mayonnaise producers
4 tips to help you choose the right high shear mixer
High shear mixing reduces the cost of mayonnaise production
How to achieve high-quality mayonnaise
New mixer paves way for geographical and portfolio expansion
How a regional beauty producer saved $70,500 on energy costs
A short history of mixing – from mortar and pestle to microns
The heat exchanger budget dilemma: why project and operational managers disagree
Product-to-product tubular heat exchangers: surprisingly versatile
New heat exchanger welding technique meets 3-A Standard
Quantum leap: the secret to optimum heat exchanger configuration
Buying and owning a Tetra Pak® Tubular Heat Exchanger is child’s play
The digital future of dairies: automation and its effects
Four health trends and how your homogenizer can help you capitalize on them
Common quality issues homogenizers solve
A day in the life of a super-efficient dairy separator
What on Earth do separators have to do with space travel?
Infographic: faster, greener skin care cream manufacturing
How airtight separators help solve the coconut challenge
Why standard steel won’t suffice for dairy separators
Do you need help to navigate the mayonnaise maze?
Why two-stage homogenization is best for tomato products
Fine-tune your homogenizer to boost quality of tomato products
The magic inside our tubular heat exchangers
Cook and grind: from rock-hard beans to paste in 15 minutes
How to choose the right mixing and blending process
Simulation and its role in improving your product quality
How to streamline production for formulated UHT dairy products
2 common powder mixing challenges – and how to solve them
Mixing: where ingredients become products
Reduce total cost of ownership for recombined milk processing by 30%
Yoghurt is booming – here is the best way to mix it
4 steps to perfect blending – with optimal yield and minimal losses
5 questions that hold the secret to the perfect product
How to scale up sauce production
Finished syrup production: success is sweet
How to dissolve sugar safely, economically and reliably
Continuous benefits: 4 reasons to consider in-line blending
Cunning innovation makes a stir in the soft-drink world
Beverages with bite: how to process drinks with particles
How to design the optimal heat exchanger setup for your needs
Minimize your food safety risks with floating protection system
Viscous products and heat transfer: 5 things to think about
Corrosion: how to prevent an everyday risk becoming a problem
Infographic – A brief history of heating food
5 troubleshooting tips for tubular heat exchangers
How to make better soup – with mathematics
Infographic – Food heat transfer basics
Lower your operating costs with preventive maintenance
How to choose the right heat exchanger
Case closed: the magic inside airtight separators
Reduce your pressure – reduce your energy costs
How to ensure separation enhances value in whey production
How a Bactofuge unit restored one dairy’s market share
Clarification: 5 things you need to know
Bacto basics: how to achieve top-quality dairy products
3 tips for keeping your separator clean
Film: the basics of separation in 1 minute
4 important questions about NIZO
Condition monitoring: everything’s under control
The importance of centrifugal separation for product quality
Why an airtight separator is best for product quality
How to achieve high-quality tea through separation
The basic workings of milk homogenization
Homogenizing lactic acid drinks: 4 things to know
The joy of soy: homogenization challenges and solutions
Wanted: a quick lab method for assessing RNGS shelf-life stability
Homogenization: the secret to longer life
Homogenization: what you need to know
9 ways homogenization improves beverage quality
The ketchup effect
How a dairy solved the problem of excessive creaming
Five tips for avoiding common homogenization mistakes
Why a tiny gap makes a big difference for homogenization
How to choose the right piston for your application
How a dairy giant cut CIP energy costs by up to 10%
3 things you need to know about the compressed air for your separator
Video: Best value homogenization in the long run
Discover the benefits of cold milk separation
Homogenizer guide: what to consider for minimum TCO
Good quality water improves separator lifetime and performance: 5 important facts
The secret to large homogenizer cost savings
The cream of the crop: how the separator sparked a dairy revolution
Five reasons to choose an airtight separator
7 things to know about separators
Homogenizer total cost of ownership: what you need to know
How to produce more – without increasing your input
Low noise separators – hearing is believing
Homogenizer buying guide – 6 things to know
Why Tetra Pak Homogenizers give you best value in the long run
Get ten years’ peace of mind with unique warranty
How a dairy saved €19,500 in annual energy costs