Core Structural Components
Conventional quick-freezing equipment primarily consists of four core components: the refrigeration system, the conveying/propulsion system, the electrical control system, and the enclosed freezing chamber. Specific structural optimizations are made based on these foundations depending on the equipment type.
Main Refrigeration Methods
Mechanical Refrigeration Cycle
This method utilizes a closed-loop system comprising a compressor, condenser, and evaporator to circulate refrigerant and absorb heat. Fans then blow the cooled air at high speed onto the product surface to facilitate heat exchange. It is the standard refrigeration solution for mainstream models such as tunnel and spiral freezers, typically maintaining an internal temperature of -30°C to -40°C.
Low-Temperature Phase-Change Refrigeration
Using liquid nitrogen (-196°C) or liquid carbon dioxide as the medium, this method achieves ultra-fast freezing through direct spraying or immersion, leveraging the medium's ability to absorb significant latent heat during vaporization. Some models can complete the freezing process in 10–15 minutes, with product weight loss (dehydration) kept under 1%.
Contact Conduction Refrigeration
Pre-cooled metal plates make direct contact with packaged products, rapidly extracting internal heat via thermal conduction; this method is best suited for regularly shaped, block-like food items.
Operational Workflows of Typical Models
Tunnel Freezer: Products move at a constant speed on a conveyor belt through an enclosed, low-temperature tunnel. High-speed circulating cold air makes full contact with the products from various angles. The process is fully continuous and automated, making it ideal for high-volume, assembly-line food production.
Spiral Freezer: Products move slowly up or down along a spiral conveyor belt. An annular air duct directs low-temperature airflow to evenly envelop the products along the spiral path, significantly reducing cold energy loss. For the same production capacity, it occupies only one-third to one-half the floor space of a tunnel freezer.
Push-Type Freezer: Trays containing products are manually pushed onto tracks. As the products move in a step-wise fashion, they undergo heat exchange with a vertical, annular low-temperature airflow generated by fans and air deflectors. Featuring a simple, easy-to-maintain structure, this type is suitable for small-to-medium-scale processing operations. Liquid Nitrogen Flash Freezer: Atomized liquid nitrogen is sprayed directly into the freezing chamber, instantly removing heat from the product's surface. The liquid nitrogen displaces oxygen within the chamber, inhibiting food oxidation and extending shelf life to more than three times that of traditional freezing methods.
