Tunnel Freezer
Tunnel freezer–IQF is a simple structure, highly efficient freezing equipment. There are stainless steel belt tunnel freezer and mesh belt tunnel freezer.
How does a tunnel freezer work?
A tunnel freezer uses cold air or a refrigerant¹ system to freeze food as it moves along a conveyor belt rapidly. The food is exposed to low temperatures for a set period, ensuring uniform freezing and preserving its quality.
Food moves on a belt through three stages:
- Pre-cooling (-10°C)
- Deep freezing (-30°C)
- Stabilization (-18°C)
Fans blow cold air from all directions.
The Freezing Process in 3 Steps :
Using chicken nuggets as an example
| Stage | Temperature | Time | What Happens |
| 1 | -5°C | 2 min | Surface hardens |
| 2 | -35°C | 5 min | Core freezes |
| 3 | -20°C | 3 min | Temperature balances |
Why speed matters?
Slow freezing makes ice crystals puncture cell walls. Quick freezing keeps juices inside – that’s why frozen berries still taste fresh.
What temperature is a tunnel freezer?²
Tunnel freezers typically operate at temperatures ranging from -18°C to -40°C (-0.4°F to -40°F), depending on the type of product being frozen. The specific temperature depends on the freezing requirements of the food being processed.
Temperature Customization
See how different foods require specific settings:
| Food Type | Temperature | Time |
| French fries | -35°C | 12 min |
| Shrimp | -40°C | 8 min |
| Dough | -25°C | 20 min |
Glazing Machine
After tunnel freezer, we can use glazing machine, let products enter 0 degrees ice water, because products less then-18 degrees now, the ice water will be attached to the surface of the products.
Hardening Machine
Join Yurnfreeze and Start Your Journey to Efficient Freezing
Yurnfreeze Tech Co., Ltd is more than just an equipment manufacturer—we’re your trusted partner in food processing. Our dedicated technical team is here to support you every step of the way, from solution design to after-sales service, ensuring your production line runs seamlessly. Visit our website at www.elephantelf.com to learn more about our self-stacking spiral freezers, or reach out to us at info@elephantelf.com to get a customized freezing solution tailored to your needs!
