Key Applications Of Plate Heat Exchangers In Dairy Processing

1. Primary Applications of Plate Heat Exchangers in Dairy Processing

1.1 Rapid Cooling of Fresh Milk

Multi-stage plate heat exchangers (e.g., 6-pass design) utilize tap water and chilled water as cooling media to rapidly reduce the temperature of freshly extracted milk to below 4°C. This process effectively inhibits bacterial growth and extends the shelf life of raw milk.

1.2 Sterilization Processes

• HTST Pasteurization (72-75°C for 15 seconds): Ensures pathogen elimination while preserving active nutritional components.
• UHT Sterilization (135-150°C for 2-5 seconds): Achieves extended shelf life through precise temperature control.

1.3 Cream Separation

• Preheating: Milk is heated to 50-60°C to reduce viscosity before separation.
• Post-separation Cooling: Skimmed milk is immediately cooled to 4°C for storage.
  Typical configurations include combined preheating and cooling sections.

1.4 Fermented Dairy Production

• Preheating ingredients to 40-45°C to activate starter cultures.
• Cooling post-fermentation to halt the process.
• Final cooling to below 10°C for filling.

1.5 Frozen Dairy Processing

In ice cream slurry production:

• Pasteurization: 85°C for 30 seconds.
• Post-homogenization Cooling: Rapid cooling to 4°C.
• Aging Stage: Precise temperature control for optimal texture.

2. Core Performance Parameters

Dairy plate heat exchangers are typically constructed from 316L stainless steel, with titanium available for specific conditions. Plates are precision-stamped with thicknesses of 0.5-1.0 mm, ensuring excellent heat transfer and structural integrity. Design pressure reaches up to 25 bar, with higher-pressure models available upon request. Operating temperatures range from -20°C to 200°C. Sealing materials (EPDM, NBR, or Viton) are selected based on medium characteristics.

3. Key Advantages of Plate Heat Exchangers

1. High Heat Transfer Efficiency: Turbulent flow design achieves heat transfer coefficients of 3000-7000 W/m²·°C.
2. Compact Design: Occupies 1/5 the volume of traditional shell-and-tube heat exchangers for equivalent heat transfer capacity.
3. Hygienic Compliance: Supports CIP/SIP cleaning, meeting 3A sanitary standards.
4. Modular Scalability: Adjustable capacity via plate addition/removal, with heat transfer areas ranging from 1 to 100 m².
5. Long-Term Durability: Industrial-grade gaskets withstand over 5000 assembly/disassembly cycles.

4. Selection Considerations

Equipment selection should account for processing capacity (e.g., 5000 L/h), medium properties (solids content, viscosity), and process requirements (heating/cooling rates). Collaboration with professional suppliers is recommended for tailored solutions.