Industrial Air Blast Freezing Room with extremely low temperatures from -35°C to -40°C High-speed forced convection is the fundamental freezing solution in most agricultural, aquatic, and livestock/poultry processing plants for export. Unlike conventional cold storage, blast freezers aim to minimize the time it takes for the product's core temperature to reach -18°C, thus overcoming the "maximum ice crystallization zone" (-1°C to -5°C) and protecting the cellular structure from breakdown. Tan Long Design and construction of industrial blast furnaces optimized for aerodynamics and superior energy efficiency.
🏢 Tan Long General Contractor's Practical Implementation Capabilities
Tan Long has supplied and installed hundreds of industrial blast freezers with capacities ranging from 2 tons to 20 tons per batch:
- Ca Mau Clean Seafood Processing Complex: The system includes a 10-ton/batch blast freezer and a high-speed IQF conveyor belt.
- Durian processing plants in Dak Lak and Tien Giang provinces: Freezing chamber for durian segments and whole durians for export to China.
- KIDO Foods & Saigon Food: The ready-to-eat food freezing system meets HACCP and ISO 22000 standards.
1. Aerodynamic Principles & Forced Freezing in Air blast freezers
Structural Diagram & Principle of Forced Airflow in a Freezer Tunnel
The blast freezer operates on a high-intensity forced convection heat exchange mechanism. Cold air at temperatures of -38°C to -42°C is blown by high-pressure fans through the gaps between product trays placed on a trolley:
- Air velocity reached 3-5 m/s: Breaking down the stagnant boundary gas film surrounding the product increases the convective heat transfer coefficient α by 3–4 times compared to static storage.
- Quick Freezing Time (Quick Freezing): The product's core temperature can be lowered from +25°C to -18°C in just 4-8 hours, depending on the product size.
- Maintain food quality: Free water within the cells freezes instantly into microscopic crystals, without tearing the cell membrane. When thawed, the sweetness, nutrients, and original weight are not lost (drip loss). < 1.5%).
2. Technical Specifications Table for Tan Long Air blast freezer
| Freezing Capacity | Freezing/Batch Time | Suitable Compressor Unit | Specifications for Tunnels & Carports |
|---|---|---|---|
| 2.5 – 3 tons/batch | 4-6 hours | 2-stage screw compressor 50 HP (Bitzer / Hanbell / Mycom) | 4-6 stainless steel 304 cotton carts, 150mm PIR panel |
| 5-6 tons/batch | 5 – 7 hours | 90-100 HP, 2-stage screw compressor, NH3 or R404A/R507A refrigerant. | 8-10 stainless steel 304 cotton carts, with the air blowing vertically. |
| 10-12 tons/batch | 6-8 hours | Twin compressor unit 160-200 HP, circulating pump liquid supply system | 16-20 stainless steel 304 cotton carts with aerodynamic airflow-directed ceilings. |
| 15-20 tons/batch | 6-8 hours | Mycom industrial 2-stage screw-type NH3 central system | Underground parking with two parallel rows of vehicles, stainless steel sliding doors at both ends for easy access. |
3. Energy-Optimized Design & Industrial Durability
- Industrial evaporator with large fin pitch (12 – 14mm): Specially designed to prevent rapid ice formation during the evaporation of moisture from fresh produce, extending the duration of continuous cooling.
- High-pressure axial fans: The sealed, waterproof IP55 motor has a temperature resistance range of -40°C, and the extruded aluminum alloy fan blades create a stable airflow of 40,000 – 80,000 m³/h.
- Smart Air Baffle Ceiling: Prevent the cold air from running across the tunnel roof, forcing the entire flow of cold air to pass through each layer of cargo trays.
- Automatic hot gas defrosting system: Reducing the defrosting time of the evaporator coil to just 15–20 minutes saves 70% of electricity compared to defrosting with electric resistance.
4. Cost Breakdown Estimate for the Air blast freezer Construction Project
| System Components | Proposed Technical Specifications | B2B Estimation Format |
|---|---|---|
| Compressors & Condensers | Bitzer/Mycom two-stage compressor, Evaporative Condenser cooling tower | Breakdown by cooling kW and brand |
| Air blast freezer cooling unit | Aluminum impeller with copper or stainless steel tubing, high static pressure blower fan. | Breakdown based on heat exchange area (m²). |
| Tunnel lining & Anti-slip floor | 150mm PIR panel made of 304 stainless steel, with 2-3mm thick ribbed stainless steel anti-slip floor lining. | Calculated based on shell area and material specifications. |
| Cotton Cart & Storage Tray | Made of 304 stainless steel, the wheels are resistant to extreme temperatures down to -40°C without breaking. | Pricing is based on the number of vehicles and tray size. |
Is your business in need of a survey, upgrade, or new design for your industrial refrigeration system?
With over 18 years of practical experience leading more than 29 major national projects, Tan Long's team of HVAC engineers is committed to providing accurate thermal load calculations, optimizing the COP efficiency coefficient, switching between natural refrigerants NH3/CO2, and saving 20–30% in operating electricity costs.
Engineer Nguyen Toan Thinh (Technical Director)
With over 18 years of practical experience in directing, consulting, designing, and constructing heavy industrial refrigeration systems, ASRS automated warehouses, and IQF freezing systems across more than 29 major national projects.
