Insight on Evaporators Used in Food Industry
Evaporators play a crucial role in the food processing industry, especially in the production of concentrated food products like jam, condensed milk, whey, and cheese powders. These devices are widely adopted by food manufacturing consultants and food technology experts to improve processing efficiency and product shelf life. This article provides insights into the working principle, types, and maintenance of evaporators in the food industry.
Why Evaporation is Essential in Food Processing
In food production, raw materials typically contain excess water that must be removed to achieve the desired product consistency and shelf stability. Evaporation technology is used to:
- Concentrate food products
- Reduce bulk weight and volume
- Lower transportation and storage costs
- Improve microbiological and chemical stability
- Enable downstream processes like spray drying or freeze-drying
Working Principle
Evaporation involves simultaneous heat and mass transfer, where a liquid food product is heated to remove water as vapor. The process results in a concentrated liquid that is still pumpable. Key influencing factors include:
- Temperature and pressure conditions
- Heat propagation rate
- Surface area and vacuum control
Reason for Installation of Evaporators
There are several reasons for concentrating food liquids:
- To reduces costs for storage and transportation.
- To induce crystallization.
- It may be used as an economical preparatory step for subsequent dehydration as in the cases of spray drying, vacuum drying, freeze-dried, crystallization and mixing.
- To reduce water activity to increase microbiological and chemical stability.
- Recover valuable substances and by-products from waste streams.
Components of Evaporator System
Heat Source: Generally steam-based heat exchangers
Evaporation Vessel: Where water is evaporated
Vapour Separator: Separates concentrated product from vapors
Vacuum System: Enhances efficiency by reducing the boiling point
Evaporators may operate singly, or several may operate in series. Each one is referred to as an effect and in multiple-effect systems, the product output from one effect is the feed for the following effect. Similarly, higher-temperature vapour driven out of the product in one effect is used to heat a lower-temperature product in another. Efficiency is gained by using multiple-effect systems.
Types of Evaporators Used
1. Vertical Tube or Calandra Evaporators
- Steam circulates vertically through tubes at the bottom of the evaporator
- Product recirculates for efficient concentration
2. Horizontal Tube Evaporators
- Suitable for low vertical space layouts
- Requires flooded operation for full tube coverage
3. Plate Evaporators
- Compact and modular design
- Allows for easy capacity adjustments
4. Forced Circulation Evaporators
- Ideal for viscous products
- Requires pumps for circulation efficiency
5. Falling Film Evaporators
- Used extensively in dairy plants
- Ensures gentle, controlled evaporation for heat-sensitive materials
Maintenance Tips to Improve Energy Efficiency
To keep evaporators running optimally and reduce energy consumption:
- Prevent air leaks to maintain vacuum pressure
- Clean heat transfer surfaces regularly
- Inspect and replace damaged insulation
- Clean vapour separation vessels frequently
- Avoid water leaks that dilute products
Conclusion
Evaporators are indispensable components in the food processing and manufacturing industry, enabling the efficient concentration of food products while preserving quality and reducing operational costs. From dairy powders to fruit concentrates, their applications span across a wide range of ready-to-eat and shelf-stable products. By selecting the right type of evaporator and maintaining it effectively, food consultants, food processing consultants, and engineering experts can significantly enhance process efficiency, product quality, and energy savings. For any new or expanding food factory design, integrating a well-optimized evaporation system is a key step toward building a world-class food manufacturing facility.
References
- Thermopedia – Evaporator Overview
- Tetra Pak – Dairy Processing Handbook
- L&H Evaporators
- PG&E – Food Processing Systems
Back 
PMG stands for Projects Management Group. We provide state-of-the-art Engineering Services to build world-class food processing factories. 
Engineering is the difference between Chaos and Excellence. If you are going to do it, do it right. 
Explore the diverse range of Products in the Food Processing Industry. 
Explore the technologies at the heart of the the Food Processing Industry. 
Filter
