Why induction heating is the most innovative option for food processing industry
Induction Drying Processing
Drying consists of providing heat to accelerate evaporation of volatile organic compounds present in an item. For example the ones present in water, solvents in paints, etc.
Drying is a process used in the manufacture of a wide range of products. The fields where we can apply induction are those that require direct or indirect heating through a metallic element.
Examples:
- Direct: automotive disc brakes
- Indirect: drying of paper
There are several methods to achieve the drying process, such as microwave, infrared and electrical resistance. However induction offers a number of advantages over these methods.
Induction heating is an innovative and non-contact electromagnetic heating technology that has several advantages such as high energy efficiency, controlled heating, high safety, and pollution-free. The objective of this article is to build up these and other advantages based on different scientific data about the performance of induction heating in the food industry. We believe that the companies that will apply induction heating in their procedures will have more versatility in sustainable food methods and will be able to face future challenges.
About Induction heating
The induction heating system (generator + coil) will generate a magnetic field that induces a current in the conductive material (reactor vessel), which will rise in temperature.ย Induction heating works only with conductive and ferrous materials. Depending on theย materialโs magneticย permeability and ferromagnetic properties, various metallic materials, such as steel, cast iron, among others, could be heated by induction.ย Non-magnetic conductive materials can also be heated with a lower efficiency.ย Induction heating is seen as anย ideal technologyย for pasteurizing liquid foods,ย but theย versatilityย of induction electric heaters makes it possible to use inย various fieldsย of food and beverage industry as is shown in the next image: 
Induction heating has its advantages over the conventional heating systems (resistance, hot water, gas, steam, etc.) Since it isย non-contactย it is veryย efficient, and the heat is generated inside the work-piece (sample) this meansย direct heatingย of metal surface without thermal inertia andย no conduction loss.ย And since induction requires no warm-up or cool-down cycle,ย make it highly compatible with energy-efficient automated systems. Read the complete article to find out theย 5 most important factsย about Induction Heating in the food industry.
1.ย ย ย Induction heating improves the quality of the foodย
Heat exchangers powered by induction haveย constantย and direct heating to the flowing fluid, with a maximumย uncertainty ofย ยฑย 0.5ย ยฐย Cย ย this avoids local high temperatures and is essential forย controlling the reaction kineticsย in the food industry.
The experimental result of R. Martel, Y. Pouliotย in the University Laval-Canada, comparing milk pasteurized by conventional heating and by induction heating, showed that when working, in a UHT pasteurization process, with induction heating we canย avoid or regulateย the Maillard reactionย (Formation of flavours and browning compounds)ย thisย improves the sensory characteristicsย in the milk and dairy products. (For more data about dairy industry read Appendix A)
It was reported in another scientific paper in Brazilย ย that using ferritic stainless steel (common use in Induction heating systems) in sugar manufacture plants, has several advantages because this metal is chemically and biologically inert, doesย not affectย taste or colourย of the sugar and lower the risk of micro-organism colony growth.
2.ย ย ย Induction heating have good energy and exergy efficiency
Baลaranโs experimental results show that the pasteurization system with induction heater needsย less energy and exergy inputย than DPHE.(Exergy also called second law efficiency is the maximum useful work during a process)
Basaran et al.ย ย and a group of engineers at the University of Celal Bayar-Turkey, compared in a pilot-scale, an induction heater pasteurization system with a DPHE (Double Pipe Heat Exchanger) pasteurization system, with electric boilers, to evaluate energy and exergy, they considered the same temperature increase in both systems from 65 to 110 ยฐ C. After calculations, for both applications, it was found effectiveness or first law efficiency of heat transfer with the inductive heating system isย 95.00% energy efficiencyย andย 46.56% exergy efficiencyย while the conventional heating system with the electric boilerย isย 75.43% energy efficiency and 16.63% exergy efficiency. (Appendix B give more data about energy and exergy).
Thanks to these results, the engineers concluded that apply the inductive method in tomato pasteurization9, strawberry jam, milk, and honey pasteurizationย is more efficient than the DPHE heating system. (To clarify this information, most factories run on fossil fuels, and fossil fuels are much less efficient, 40-65% effectiveness, than the commercial electrical method in this study.).
3.ย ย ย Induction heating system offers reduce the clogging in the system
Cloggingย due to the unwanted material accumulated on the tube surfaces of the heat exchangers is one of theย main problemsย in the food industry, the gunk in the interior of these tubes severely decreases the mass flow rate through the tube bundle. According to experimental results, this effect can beย minimizedย using electromagnetic induction. R. Martel, Y. Pouliot5ย discovered that working with induction the amount ofย proteinย on the heating surface is less. This improvesย cleaning efficiency, increasing production run length with a reduction in the cost of production capacityย ย and aย reduction of the waste-water from the process.
4.ย ย ย Induction installation are sustainable and have small carbon footprit
Nowadays the termย โsustainabilityโย is used to talk about everything, but it hasnโt really been defined very well. Rosen, Marc & Dincer, Ibrahim made a research about exergy efficiency and sustainability, in terms of several measures (order destruction and chaos creation, or resource degradation, or waste exergy emissions).ย They conclude that the process can beโย sustainableโย if isย energy and exergy efficient.ย In these terms we can said that work with inductionย decrease the associated environmental impact,ย because gives rise to better energetic and exergetic performance.
Knowing this, the food and beverage manufacturers that will works with induction have a significant opportunity to haveย โadded valueย โย and sustainable products, working with aย clean technologyย which will help in protecting the environment andย ย decrease the carbon footprintย of the food industry.
5.ย ย ย Induction installationsย improves working conditions for the employees
An induction system improves working conditions for the employees byย eliminating smoke, waste heat, noxious emissions, andย loud noiseย in the facilities (Induction only heats the material and not the workshop). Heating isย safeย and efficient withย no open flameย to endanger the operator; non-conductive materials are not affected and can be located close to the heating zone without damage.
There areย no high pressureย andย no hot steamย systems and so on can avoid any hazard withย explosionsย like in 2016 in a dairy company in steam generator. (In the ARIA databaseย ย you will find more than 300 high temperature-related events that have occurred in France.)
Conclusion
Induction heating is a clean technological innovation designed to save energy, leading to high productivity and efficiency. Induction heating offers repeatable quality and rapid, high intensity, contact less heat generation directly, and accurate on the surface of the work-piece.
Inside the design of induction heating in a process, there is a specialized integration of workers including mechanical, electrical, and chemical engineers that will ensure a customized solution with a unique and innovative procedure with a high level of reliability and durability.
Consumers in all the world are prepared for the food business to be significantly more sustainable so we encore you to think in apply Induction heating for your company to fulfil the challenge to move towards a decrease in the footprint of the food industry,ย focus on the 2030 Agenda for Sustainable Development.ย
