Client Location: Chicago
Equipment Supplier: Square Technology Group Co., Ltd.
IQF: Ambient spiral cooler& spiral freezer
Refrigeration System: Bitzer Compressor Unit& Evaporative condenser
Project Overview
Square Technology Group supplied a customized spiral cooling and freezing system for a dumpling processing facility in Chicago.
The upstream steaming machine was provided by another supplier. After steaming, dumplings exit the cooker at approximately 80°C and must undergo staged cooling before final freezing to ensure product quality and surface integrity.
To achieve optimal results, Square designed a two-stage spiral system:
- Ambient Spiral Cooler (Plastic Belt)
- Spiral Freezer (Stainless Steel Belt)
In addition to the freezing equipment, Square also supplied the complete refrigeration package using Bitzer compressor units.
Process Flow
Steamer (by others)
→ Ambient Spiral Cooler (80°C → 40°C)
→ Spiral Freezer (40°C → Core temperature -18°C)
Stage 1: Ambient Spiral Cooling
Freshly steamed dumplings at approximately 80°C enter the first spiral system equipped with a plastic modular belt.
The purpose of this stage is to naturally cool the dumplings down to approximately 40°C before entering the freezer.
Why Plastic Belt Was Used in the Ambient Cooler
Two important engineering considerations determined the belt selection:
1️ Prevention of Black Wear Debris
Under ambient temperature conditions, friction between:
- Ремень из нержавеющей стали
- Polymer guide rails
can generate black wear particles. These particles may contaminate food products.
Plastic modular belts significantly reduce friction-related debris generation in room-temperature environments.
2️ Protection of Product Surface
At high temperatures (~80°C), dumplings are soft and delicate.
When placed directly on stainless steel mesh belts, the uneven mesh structure may leave imprint marks on the dumpling surface.
Plastic modular belts provide:
- A flatter contact surface
- More uniform support
- Reduced risk of surface marking
This ensures excellent product appearance and premium quality.
Stage 2: Spiral Freezing
After cooling to approximately 40°C, the dumplings enter the spiral freezer.
For the freezing stage, Square selected a standard stainless steel belt.
Why Stainless Steel Belt Is Suitable in Freezing Conditions
1.Reduced Friction in Low Temperature
In freezing environments, friction between the stainless steel belt and polymer guide rails is significantly lower.
No black debris is generated under low-temperature operation.
2.No Surface Imprint Risk
Since the dumplings are already cooled to around 40°C before entering the freezer, their structure is firmer and more stable.
Even when using a stainless steel belt, no imprint marks occur.
Freezing Performance
The spiral freezer successfully reduces the dumpling core temperature to:
-18°C
Final product results:
- Excellent shape retention
- Smooth surface
- No belt marks
- No contamination
- Uniform freezing
- Stable product quality
Refrigeration System Design
Square Technology also supplied the refrigeration package using Bitzer compressor units.
Special Climate Consideration – Chicago Winter
Due to the cold winter climate in Chicago, special attention was given to the evaporative condenser system.
To ensure stable operation during low ambient winter temperatures:
- An additional heater set was installed in the evaporative condenser
This enhancement prevents freezing risks and ensures reliable winter operation.
Project Outcome
The entire system has been operating reliably and efficiently.
The customer reports:
- Stable production performance
- Excellent product quality
- Reliable winter operation
- High satisfaction with overall system design
Key Project Highlights
Two-stage thermal control strategy
Different belt materials optimized by temperature zone
Product surface protection engineering
Contamination risk prevention
Climate-adapted refrigeration design
Core temperature achieved: -18°C
